MetALD
MetALD is steatotic liver disease with cardiometabolic risk factors plus increased alcohol intake in the overlap range between MASLD and ALD thresholds.
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References
[1] Lecture slides: GC 240. MASLD and Alcoholic Liver Disease.pdf [2] Lecture slides: Teaching Clinic - Non-viral chronic liver diseases (Prof. Yuen Man Fung) 2.pdf [3] Senior notes: Block A - Gastroenterology Interactive Tutorial.pdf (Case 2) [4] Senior notes: MBBS Final MB (Medicine) (Felix PY Lai).pdf (alcohol-related liver disease and cirrhosis sections)
MetALD (Metabolic Dysfunction-Associated and Alcohol-Related Liver Disease)
MetALD is a relatively new nomenclature introduced in the 2023 multi-society Delphi consensus (endorsed by AASLD, EASL, and ALEH) to describe patients who have features of both metabolic dysfunction-associated steatotic liver disease (MASLD) and significant alcohol consumption — essentially an overlap category sitting between "pure" MASLD and "pure" alcohol-related liver disease (ALD) on a continuous spectrum [1][2].
The name itself tells you the condition:
- Met = Metabolic (≥1 cardiometabolic risk factor present)
- ALD = Alcohol-related Liver Disease
- Combined → MetALD: steatotic liver disease in a patient who has both metabolic risk factors AND drinks more than the MASLD threshold but less than the ALD threshold.
Specifically:
- MASLD: steatotic liver disease + ≥1 cardiometabolic risk factor, with alcohol intake < 140 g/week (women) or < 210 g/week (men) [1]
- MetALD: steatotic liver disease + ≥1 cardiometabolic risk factor, with alcohol intake 140–350 g/week (women) or 210–420 g/week (men) [1][2]
- ALD: steatotic liver disease with alcohol intake > 350 g/week (women) or > 420 g/week (men) [1]
Why a New Term?
Previously, the field used mutually exclusive labels (NAFLD vs. ALD). In reality, many patients drink moderately AND have metabolic syndrome. The old system forced clinicians to pick one category and ignore the other driver. MetALD explicitly acknowledges the dual-hit pathophysiology, which is extremely common in clinical practice — the concept of concomitant liver disease [3]. In Hong Kong, many patients with HBV-related liver disease also have MASLD superimposed, and some drink alcohol on top of that, making MetALD clinically very relevant [3][4].
1.1 Nomenclature Evolution (Important for Exams)
| Old Term | New Term (2023 Delphi) | Key Change |
|---|---|---|
| NAFLD | MASLD | Defined by presence of metabolic risk factors, not absence of alcohol |
| NASH | MASH (Metabolic dysfunction-Associated Steatohepatitis) | Dropped "non-alcoholic" |
| Overlap NAFLD + ALD | MetALD | New formal category |
| Alcoholic liver disease | ALD (no change) | Threshold now explicitly defined |
| Fatty liver disease (umbrella) | Steatotic Liver Disease (SLD) | Overarching umbrella term |
GC 240 slide [1]: The new nomenclature uses "Steatotic Liver Disease (SLD)" as the overarching term, with MASLD, MetALD, ALD, and cryptogenic SLD as subcategories.
2. Epidemiology
- SLD (all forms) affects approximately 25–38% of the global adult population
- MASLD alone accounts for ~25–30% of adults worldwide
- MetALD prevalence is estimated at 3–5% of the general adult population in Western studies, though precise figures vary because the category is newly defined
- The overlap is extremely common in clinical hepatology practice — up to 20–30% of patients initially labelled "NAFLD" in older cohorts would now reclassify as MetALD under the new criteria
- In Hong Kong, HBV remains the most common cause of cirrhosis (~64–75% by WHO pooled estimates) [3], but MASLD is rapidly rising
- The concept of concomitant liver disease is emphasized: many HBV carriers also have MASLD/MetALD [3][4]
- Hong Kong has a rising prevalence of metabolic syndrome (obesity ~30–40% of adults, diabetes ~10%) combined with a cultural context where moderate alcohol use (especially beer and wine) is increasingly common
- Dual liver disease (e.g., HBV cirrhosis + MAFLD) is common in HK [4]
- High fructose foods → fatty liver; Coffee → beneficial for fatty liver [4]
2.3 Risk Factors
The risk factors for MetALD are essentially the union of MASLD risk factors and ALD risk factors:
| Cardiometabolic Criterion | Threshold |
|---|---|
| BMI ≥ 25 kg/m² (or ≥ 23 in Asian populations) OR waist circumference ≥ 94 cm (men) / 80 cm (women) in Asians | Overweight / central obesity |
| Fasting glucose ≥ 5.6 mmol/L or HbA1c ≥ 5.7% or T2DM | Dysglycaemia |
| Blood pressure ≥ 130/85 mmHg or on antihypertensives | Hypertension |
| Triglycerides ≥ 1.7 mmol/L or on lipid-lowering therapy | Hypertriglyceridaemia |
| HDL-C < 1.0 mmol/L (men) / < 1.3 mmol/L (women) or on lipid-lowering therapy | Low HDL |
- MetALD specifically requires moderate-to-increased alcohol intake: 140–350 g/week (women) or 210–420 g/week (men) [1][2]
- For reference: 1 standard drink ≈ 10 g pure alcohol (varies by country; in HK, a 330 mL can of 5% beer ≈ 13 g)
- So MetALD range ≈ roughly 2–5 drinks/day for men, 1.5–3.5 drinks/day for women
- Genetic susceptibility: PNPLA3 I148M variant (strongest genetic risk factor for SLD, particularly relevant in Asian populations), TM6SF2, MBOAT7, HSD17B13
- Dietary factors: High fructose intake, ultra-processed foods, soft drinks [4]
- Sedentary lifestyle / physical inactivity: reduced AMPK activation → reduced glucose uptake + reduced FFA metabolism [8]
- Gut microbiome dysbiosis: alcohol and metabolic syndrome both independently alter gut flora, increasing gut permeability and endotoxin (LPS) translocation
- Age: older age increases risk
- Sex: Women are more susceptible to alcohol-related liver injury at lower intake levels (less gastric alcohol dehydrogenase, higher body fat percentage, oestrogen effects on oxidative stress)
- Concurrent viral hepatitis: especially HBV in Hong Kong context [3][4]
High Yield — Hong Kong Exam Point
When asked about causes of chronic liver disease or cirrhosis in Hong Kong, remember:
- HBV (most common, ~64–75%)
- MASLD/MetALD (rising rapidly, often concomitant with HBV)
- HCV (~5–10%)
- ALD ( > 5%)
- Others (autoimmune hepatitis, PBC, PSC, Wilson's, haemochromatosis)
The concept of dual/concomitant liver disease (e.g., HBV + MASLD, or HBV + MetALD) is extremely important and commonly tested [3][4].
3. Anatomy and Function (The Liver in MetALD)
The liver is the body's largest solid organ (~1.5 kg), situated in the right upper quadrant. Understanding MetALD requires appreciating the hepatic lobule — the functional unit of the liver:
- Hepatic lobule: hexagonal arrangement with a central vein, portal triads at the periphery (hepatic artery, portal vein, bile duct)
- Hepatic acinus (of Rappaport): the functional microcirculatory unit, divided into three zones based on oxygen gradient:
- Zone 1 (periportal): highest O₂, first to receive blood from portal triad; site of gluconeogenesis, fatty acid oxidation, cholesterol synthesis
- Zone 2 (intermediate): transitional
- Zone 3 (pericentral/centrilobular): lowest O₂, last to receive blood; site of lipogenesis, CYP450 metabolism (including alcohol metabolism via CYP2E1), glycolysis
Why does this matter for MetALD?
- Alcoholic steatosis/steatohepatitis classically affects Zone 3 (centrilobular) — this is where CYP2E1 is concentrated for ethanol metabolism, generating reactive oxygen species (ROS)
- MASLD/MASH steatosis can be panlobular but often starts in Zone 3 as well (due to lipogenesis occurring there)
- In MetALD, the dual insult means Zone 3 bears the brunt from both directions, accelerating injury
- Lipid metabolism: synthesis, packaging (VLDL), and oxidation of fatty acids
- Glucose metabolism: glycogen storage, gluconeogenesis, insulin clearance
- Detoxification: Phase I (CYP450, especially CYP2E1 for ethanol) and Phase II (conjugation)
- Protein synthesis: albumin, clotting factors (especially Factor VII with shortest half-life of ~6 hours), complement
- Bile synthesis and excretion: cholesterol excretion, fat-soluble vitamin absorption
- Immune function: Kupffer cells (resident macrophages) are critical in MetALD pathogenesis
4. Etiology (Focus on Hong Kong)
MetALD, by definition, requires two concurrent etiological drivers:
This is essentially the pathophysiology of metabolic syndrome / insulin resistance:
- Metabolic syndrome: cluster of metabolic disorders due to insulin resistance [8]
- Cause: likely central obesity [8]
In Hong Kong specifically:
- Rising rates of obesity (30–40% overweight/obese by Asian BMI criteria)
- High prevalence of T2DM (~10% of adults)
- High fructose foods → fatty liver [4] — relevant given the dietary shift toward processed/sweetened foods
- Sedentary urban lifestyle
- Social/cultural alcohol consumption patterns in Hong Kong have increased
- Beer, wine, and spirits consumption among working-age adults
- Women may be under-recognized as moderate drinkers
- Alcohol thresholds for MetALD: 140–350 g/week (women), 210–420 g/week (men) [1]
While MetALD per se is defined by metabolic + alcohol drivers, in Hong Kong practice:
- Many patients have TRIPLE pathology: HBV + metabolic steatosis + moderate alcohol [3][4]
- This accelerates fibrosis progression and increases HCC risk synergistically
- HBV can cause HCC without cirrhosis (DNA integration and direct carcinogenesis), unlike MASLD where cirrhosis is usually required for HCC development [4]
5. Pathophysiology
The pathophysiology of MetALD is best understood as a synergistic dual-hit (or multi-hit) model where metabolic and alcohol-related mechanisms converge to cause hepatic steatosis → steatohepatitis → fibrosis → cirrhosis → hepatocellular carcinoma.
Step by step:
- Insulin resistance (driven by visceral adiposity, genetic susceptibility, sedentary lifestyle) → peripheral adipose tissue becomes resistant to insulin's anti-lipolytic effect → increased free fatty acid (FFA) release into portal circulation
- Hyperinsulinaemia (compensatory) activates SREBP-1c (sterol regulatory element-binding protein 1c) in hepatocytes → de novo lipogenesis (DNL) ↑ → more triglyceride synthesis
- Simultaneously, insulin resistance impairs fatty acid β-oxidation in hepatocyte mitochondria
- Net result: triglyceride accumulation in hepatocytes → steatosis (fatty liver)
- Accumulated lipids generate toxic lipid intermediates (diacylglycerols, ceramides, free cholesterol, lysophosphatidylcholines) → lipotoxicity → endoplasmic reticulum (ER) stress, mitochondrial dysfunction, oxidative stress
- Injured hepatocytes release damage-associated molecular patterns (DAMPs) → activate Kupffer cells (resident macrophages) and recruit neutrophils → inflammation = steatohepatitis (MASH)
Step by step:
- Ethanol metabolism occurs primarily in Zone 3 hepatocytes via:
- ADH pathway (cytosol): ethanol → acetaldehyde → acetate (by ALDH2)
- MEOS/CYP2E1 pathway (smooth ER): induced by chronic alcohol use; generates reactive oxygen species (ROS) as a byproduct
- Catalase pathway (peroxisomes): minor role
- Both ADH and CYP2E1 pathways increase the NADH/NAD⁺ ratio, which:
- Inhibits fatty acid β-oxidation (needs NAD⁺)
- Promotes lipogenesis
- Inhibits gluconeogenesis
- Result: steatosis
- Acetaldehyde is directly toxic: forms protein adducts → triggers immune response, mitochondrial damage, collagen synthesis by stellate cells
- CYP2E1-generated ROS → oxidative stress → lipid peroxidation → hepatocyte necrosis
- Alcohol increases gut permeability ("leaky gut") → bacterial endotoxin (LPS) reaches liver via portal vein → activates Kupffer cells via TLR4 → release of pro-inflammatory cytokines (TNF-α, IL-6, IL-1β) → steatohepatitis
This is the crux of MetALD pathophysiology:
| Mechanism | Metabolic Arm | Alcohol Arm | Synergy in MetALD |
|---|---|---|---|
| Steatosis | ↑ DNL, ↑ FFA flux, ↓ β-oxidation | ↑ NADH/NAD⁺, ↓ β-oxidation | Double suppression of β-oxidation + double promotion of lipogenesis → more severe steatosis |
| Oxidative stress | Lipotoxicity, mitochondrial dysfunction | CYP2E1-generated ROS | Compounded ROS generation — alcohol induces CYP2E1, which also metabolizes dietary lipids into toxic aldehydes |
| Inflammation | DAMPs → Kupffer cell activation | LPS → TLR4 → Kupffer cell activation | Two independent inflammatory triggers activating the same effector cells |
| Gut dysbiosis | Metabolic syndrome alters microbiome | Alcohol disrupts tight junctions + alters microbiome | Synergistic gut barrier breakdown → massively increased endotoxin translocation |
| Fibrosis | Hepatic stellate cell (HSC) activation by inflammatory mediators | Acetaldehyde directly activates HSCs + TGF-β release | Accelerated fibrogenesis — both pathways converge on stellate cell activation |
| Immune dysregulation | Adipokine imbalance (↓ adiponectin, ↑ leptin) | Acetaldehyde-protein adducts trigger autoimmune-like response | Amplified adaptive immune injury |
Key Concept — Why MetALD Progresses Faster
The metabolic and alcohol pathways converge on the same downstream effectors (Kupffer cells, hepatic stellate cells, mitochondria) but via different upstream triggers. This means the liver is hit from multiple directions simultaneously, leading to:
- More severe steatohepatitis
- Faster fibrosis progression
- Higher risk of cirrhosis and HCC compared to either MASLD or ALD alone
The common final pathway (regardless of whether the initial driver is metabolic, alcoholic, or both):
- Hepatocyte injury (necrosis/apoptosis) → release of DAMPs and cytokines
- Kupffer cell activation → TGF-β, PDGF, CTGF release
- Hepatic stellate cell (HSC) activation: quiescent HSCs (storing vitamin A) → activated myofibroblast-like cells → produce type I and III collagen
- Extracellular matrix (ECM) deposition in the space of Disse → capillarisation of sinusoids (loss of fenestrations) → impaired nutrient exchange
- Progressive fibrosis (F1 → F2 → F3 → F4/cirrhosis)
- Cirrhosis: diffuse distortion of liver architecture + formation of regenerative nodules, surrounded by fibrous bands [3]
- Cirrhosis leads to → portal hypertension (increased intrahepatic resistance) → decompensation (ascites, variceal bleeding, hepatic encephalopathy, jaundice)
- In MetALD (as with MASLD), HCC generally requires cirrhosis as an intermediate step [4]
- This is in contrast to HBV, where HCC can occur without cirrhosis due to direct HBV DNA integration into host genome [4][5]
- Mechanisms of hepatocarcinogenesis in MetALD:
- Chronic inflammation → repeated hepatocyte turnover → increased DNA replication errors
- Oxidative DNA damage from ROS
- Telomere shortening
- Epigenetic alterations (DNA methylation, histone modification)
- Activation of oncogenic signalling (NF-κB, STAT3, Wnt/β-catenin)
6. Classification
| Stage | Histology | Clinical Correlate |
|---|---|---|
| Simple steatosis | ≥5% hepatocytes with fat droplets; no significant inflammation or ballooning | Usually asymptomatic, benign course |
| Steatohepatitis (MetALD-related steatohepatitis) | Steatosis + lobular inflammation + hepatocyte ballooning ± Mallory-Denk bodies ± neutrophilic infiltration | Elevated ALT/AST, may be symptomatic |
| Fibrosis | F0 (none) → F1 (perisinusoidal/periportal) → F2 (perisinusoidal + periportal) → F3 (bridging) → F4 (cirrhosis) | Progressive liver dysfunction |
| Cirrhosis | F4: regenerative nodules + fibrous septa + architectural distortion | Decompensation features |
| HCC | Malignant hepatocyte transformation | Usually on background of cirrhosis |
Note: The histological pattern in MetALD can show features of both MASH (zone 3 predominant steatosis, ballooning, lobular inflammation) and ASH (Mallory-Denk bodies, neutrophilic satellitosis, perivenular/pericellular fibrosis). This overlap can make histological distinction difficult, which is partly why the clinical MetALD category is useful.
Liver elastography (e.g., FibroScan / transient elastography) is the non-invasive clinical tool for fibrosis staging [4]:
| Liver Stiffness (kPa) | Interpretation |
|---|---|
| < 7 | F0–F1 (minimal/no fibrosis) |
| 7–10 | F2 (significant fibrosis) |
| 10–12 | F3 (advanced fibrosis) |
| > 12 | Suggestive of cirrhosis (F4) [4] |
CAP score (Controlled Attenuation Parameter) quantifies steatosis [4]:
Child-Pugh Score is used to subclassify cirrhosis [3]:
| Parameter | 1 point | 2 points | 3 points |
|---|---|---|---|
| Bilirubin (μmol/L) | < 34 | 34–50 | > 50 |
| Albumin (g/L) | > 35 | 28–35 | < 28 |
| INR | < 1.7 | 1.7–2.3 | > 2.3 |
| Ascites | None | Mild / controlled | Moderate-severe / refractory |
| Encephalopathy | None | Grade 1–2 | Grade 3–4 |
- Child A (5–6): Compensated cirrhosis [3]
- Child B (7–9): Decompensated cirrhosis [3]
- Child C (10–15): Decompensated cirrhosis (severe) [3]
7. Clinical Features
7.1 Symptoms
MetALD is often clinically silent in its early stages. Symptoms emerge as disease progresses along the spectrum:
- Asymptomatic — most common presentation
- Why? Liver parenchyma has no nociceptive nerve fibres. Only the Glisson's capsule (liver capsule) is innervated. Mild steatosis causes no capsular distension → no pain [6]
- Fatigue / malaise (non-specific)
- Why? Proposed mechanisms: cytokine-mediated (TNF-α, IL-6 from Kupffer cell activation) → central fatigue; also deranged serotonin metabolism in liver disease
- The patient is often identified incidentally through persistently elevated liver enzymes on routine blood testing [4]
- Right upper quadrant discomfort / dull ache
- Why? Hepatomegaly from steatosis ± inflammation → distension of the liver capsule (Glisson's capsule) → dull aching pain. Liver parenchyma has no nerve fibres → only when you have inflammation and swelling of the liver, you will get dull aching. Generally not pain → biliary tract causes pain, but liver pathology classically does not [6]
- Nausea, loss of appetite
- Why? Inflammatory mediators (TNF-α) have direct appetite-suppressive effects. Also, hepatic congestion can impair gastric emptying.
- History of moderate-to-increased alcohol intake (by definition in MetALD range)
- May have features of alcohol dependence or misuse (though MetALD patients are not necessarily "heavy drinkers" — they sit in the moderate range)
- Social / occupational / interpersonal issues related to alcohol use
When MetALD has progressed to cirrhosis and decompensation:
- Jaundice (yellowing of skin and sclera)
- Why? Impaired hepatocyte conjugation and excretion of bilirubin → usually direct (conjugated) bilirubin is elevated [6]. In advanced disease, both direct and indirect bilirubin rise.
- Ascites — abdominal distension, shifting dullness
- Why? Portal hypertension → splanchnic vasodilation → activation of RAAS → sodium and water retention; also ↓ albumin (↓ oncotic pressure) + ↑ hydrostatic pressure in portal system
- Peripheral oedema
- Why? Hypoalbuminaemia (↓ oncotic pressure) + sodium/water retention
- Easy bruising / bleeding tendency
- Why? Impaired synthesis of clotting factors (II, VII, IX, X, protein C, protein S) + thrombocytopaenia (splenic sequestration from splenomegaly due to portal hypertension)
- Haematemesis / melaena (from variceal bleeding)
- Why? Portal hypertension → portosystemic collateral formation → oesophageal/gastric varices → rupture
- Hepatic encephalopathy — confusion, asterixis, personality change, somnolence
- Why? Porto-systemic shunting + impaired hepatic ammonia clearance → ↑ ammonia → crosses BBB → astrocyte swelling (via glutamine synthesis) → cerebral oedema + altered neurotransmission
- Pruritus
- Why? Bile salt deposition in skin (cholestatic phase); also LPA (lysophosphatidic acid) via autotaxin pathway
7.2 Signs
- Obesity / central adiposity — reflects the metabolic component
- BMI ≥ 25 (or ≥ 23 in Asians) commonly found [1]
- Acanthosis nigricans — velvety, darkened skin in body folds (neck, axillae, groin)
- Why? Hyperinsulinaemia → stimulates IGF-1 receptors on keratinocytes → epidermal hyperplasia and hyperpigmentation. A cutaneous marker of insulin resistance.
- Spider naevi (spider angiomas) — central arteriole with radiating vessels, blanch on pressure, found in distribution of SVC (face, neck, upper chest, arms)
- Why? Hyperoestrogenaemia due to impaired hepatic oestrogen metabolism → arteriolar vasodilation and neovascularisation. > 5 spider naevi is pathological.
- Palmar erythema — redness of thenar and hypothenar eminences
- Why? Same mechanism: hyperoestrogenaemia → peripheral vasodilation
- Gynaecomastia (males)
- Why? Impaired hepatic metabolism of oestrogen → relative hyperoestrogenaemia
- Testicular atrophy (males)
- Why? ↑ SHBG (produced by liver in response to oestrogen excess) → ↓ free testosterone; also direct toxic effect of alcohol on Leydig cells
- Dupuytren's contracture — thickening and contracture of palmar fascia
- Why? Classically associated with alcohol use; mechanism unclear, possibly related to oxidative stress and fibroblast activation
- Parotid enlargement — bilateral, non-tender
- Why? Associated with alcohol use; mechanism involves fatty infiltration of parotid gland and possibly malnutrition-related hypertrophy
- Hepatomegaly (early stages) → may become shrunken in end-stage cirrhosis
- Why? Fatty infiltration → enlarged, smooth, non-tender liver. In cirrhosis, fibrotic contraction → shrunken, hard, nodular liver.
- Splenomegaly
- Why? Portal hypertension → congestion of spleen
- Caput medusae — dilated periumbilical veins radiating outward
- Why? Recanalised paraumbilical vein due to portal hypertension → collateral flow through abdominal wall veins
- Dupuytren's contracture, parotid enlargement (mentioned above)
- Peripheral neuropathy (glove-and-stocking sensory loss, absent ankle jerks)
- Why? Direct neurotoxic effect of alcohol + thiamine (vitamin B1) deficiency → Wernicke-Korsakoff pathology
- Proximal myopathy
- Why? Direct alcohol myotoxicity + malnutrition
- Cerebellar signs (wide-based gait, intention tremor, dysarthria) — if chronic alcohol cerebellar degeneration
- Why? Selective vulnerability of cerebellar Purkinje cells to alcohol toxicity
- Jaundice — scleral icterus (detectable when bilirubin > ~35 μmol/L)
- Ascites — shifting dullness, fluid thrill
- Peripheral oedema — pitting, gravity-dependent
- Asterixis / liver flap — involuntary, irregular flapping tremor of dorsiflexed hands
- Why? Metabolic encephalopathy → impaired neural inhibitory pathways → myoclonic lapses in sustained posture
- Fetor hepaticus — sweet, musty breath odour
- Why? Dimethyl sulfide (from mercaptans) bypassing hepatic clearance via portosystemic shunts
- Leukonychia (white nails)
- Why? Hypoalbuminaemia → changes in nail bed vascularity
- Terry's nails — proximal white nail, distal pink/red band
- Why? Same mechanism; associated with cirrhosis
- Elevated ALT and AST — reflection of hepatocyte damage [6]
- In MetALD, the AST:ALT ratio can be variable:
- Pure MASLD/MASH: ALT > AST (typically)
- Pure ALD: AST > AST (classically AST:ALT ≥ 2:1, because alcohol impairs pyridoxal-5-phosphate [B6], needed for ALT synthesis; also mitochondrial AST release from alcohol-damaged mitochondria)
- MetALD: often intermediate AST:ALT ratio (1:1 to 2:1) — this ambiguity is actually a clinical clue
- Elevated GGT — particularly sensitive to alcohol use (GGT induction by alcohol) and also raised in cholestatic liver disease
- In case 2 of the Interactive Tutorial: ALT 115, AST 68, GGT 102 with fatty liver on ultrasound [4]
- In MetALD, the AST:ALT ratio can be variable:
- For monitoring progress and prognosis in liver disease: INR (reflection of Factor VII synthesis) [6]
Clinical Pearl — AST:ALT Ratio in MetALD
In pure ALD, the classic teaching is AST:ALT ≥ 2:1 (because alcohol depletes pyridoxal phosphate needed for ALT synthesis, and damaged mitochondria release mitochondrial AST). In pure MASLD, ALT > AST. In MetALD, the ratio is often between 1:1 and 2:1 — this intermediate pattern should raise clinical suspicion for dual pathology. However, once cirrhosis develops (from any cause), AST tends to become greater than ALT because progressive fibrosis reduces ALT release more than AST.
When a patient presents with features suggestive of steatotic liver disease, the clinical approach involves:
- Confirm hepatic steatosis — usually via imaging (ultrasound showing echogenic liver, or FibroScan CAP score > 248 dB/m)
- Quantify alcohol intake — use standardised tools (AUDIT-C, detailed alcohol history in grams/week)
- Assess for cardiometabolic risk factors — BMI, waist circumference, fasting glucose/HbA1c, lipid panel, BP
- Apply the SLD classification [1][2]:
- ≥1 metabolic risk factor + alcohol < 140/210 g/wk → MASLD
- ≥1 metabolic risk factor + alcohol 140–350/210–420 g/wk → MetALD
- Alcohol > 350/420 g/wk → ALD
- Exclude other causes — viral hepatitis (HBV, HCV), autoimmune hepatitis, PBC/PSC, Wilson's disease, haemochromatosis, drug-induced, alpha-1 antitrypsin deficiency
- Stage the disease — non-invasive fibrosis assessment (FibroScan, FIB-4, NFS) ± liver biopsy
- Screen for complications — HCC surveillance if cirrhosis (6-monthly USS ± AFP)
HCC surveillance indications for MASLD/MetALD: cirrhosis is generally required (unlike HBV where age-based criteria suffice) [4] For HBV: Male ≥ 40, Female ≥ 50, or underlying cirrhosis, or family history of HCC [4]
Important Exam Point — Weight Loss Targets
Resolution of fatty liver does not require BMI returning to 25. Weight loss of 5–7% is already sufficient in non-fibrosis patients. 10% weight loss is needed in fibrosis patients — which is why GLP-1 receptor agonists work, as they achieve > 10% weight reduction [4].
High Yield Summary
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MetALD = Metabolic dysfunction-associated steatotic liver disease + moderate alcohol use (140–350 g/wk women, 210–420 g/wk men) — a NEW 2023 category on the SLD spectrum between MASLD and ALD.
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Pathophysiology = synergistic dual-hit: insulin resistance (↑ FFA, ↑ DNL, ↓ β-oxidation) + alcohol metabolism (CYP2E1 → ROS, ↑ NADH/NAD⁺, acetaldehyde toxicity, gut-derived LPS). Both converge on Kupffer cell activation, stellate cell fibrogenesis, and oxidative stress in Zone 3.
-
Risk factors = metabolic syndrome (obesity, T2DM, dyslipidaemia, HTN) + moderate alcohol + genetic susceptibility (PNPLA3) + high fructose diet + sedentary lifestyle. In HK, concomitant HBV is extremely common.
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Clinical features: Often asymptomatic early. Key signs = hepatomegaly, features of metabolic syndrome (acanthosis nigricans, central obesity), chronic liver disease signs (spider naevi, palmar erythema, gynaecomastia), and eventually decompensation signs (jaundice, ascites, encephalopathy).
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AST:ALT ratio in MetALD is often intermediate (1:1 to 2:1), with elevated GGT. This contrasts with pure MASLD (ALT > AST) and pure ALD (AST:ALT ≥ 2:1).
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Non-invasive assessment: FibroScan (liver stiffness > 12 kPa suggests cirrhosis; CAP > 280 dB/m suggests severe steatosis). Child-Pugh score subclassifies cirrhosis (A = compensated, B/C = decompensated).
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HCC surveillance: In MetALD/MASLD, cirrhosis is generally required before commencing 6-monthly USS ± AFP. In HBV, age-based criteria apply.
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Weight loss: 5–7% for non-fibrotic SLD, ≥10% for fibrotic SLD. GLP-1 receptor agonists are emerging evidence-based treatments.
Active Recall — MetALD
[1] Lecture slides: GC 240. MASLD and Alcoholic Liver Disease.pdf [2] Lecture slides: Teaching Clinic - Non-viral chronic liver diseases (Prof. Yuen Man Fung) 2.pdf [3] Senior notes: Block A - Abdominal distension_ ascites and cirrhosis.pdf [4] Senior notes: Block A - Gastroenterology Interactive Tutorial.pdf (Case 2) [5] Senior notes: Maksim Surgery Notes.pdf (HCC section) [6] Senior notes: Block A - Jaundice after raw oysters_ acute hepatitis.pdf [7] Senior notes: Block A - Patients with non-viral chronic liver diseases.pdf [8] Senior notes: Ryan Ho Endocrine.pdf (Type 2 DM and metabolic syndrome section)
Differential Diagnosis of MetALD
When a patient presents with suspected steatotic liver disease — elevated liver enzymes, hepatic steatosis on imaging, features of metabolic syndrome, and/or a history of alcohol use — the key clinical challenge is to correctly classify the type of SLD and exclude other causes of chronic liver disease that can mimic or coexist with MetALD.
The differential diagnosis operates on two levels:
- Within the SLD spectrum: Is this MASLD, MetALD, or ALD? (These sit on a continuum.)
- Beyond SLD: Are there other causes of chronic liver disease that could explain or contribute to the picture?
"Be systematic in problem solving: What is the probability diagnosis? What serious disorders cannot be missed (red flags)? What conditions are often missed (pitfalls)? Could this patient have a 'masquerade'?" [9]
This safe diagnostic model from Murtagh's (referenced in CFB lectures) applies perfectly here. When you see elevated liver enzymes + steatosis, don't just slap on a "fatty liver" label. Think systematically.
The first step is to place the patient on the SLD continuum based on alcohol intake and metabolic risk factors [1][2]:
| Condition | Alcohol Intake | Metabolic Risk Factors | Key Distinguishing Points |
|---|---|---|---|
| MASLD | < 140 g/wk (F), < 210 g/wk (M) | ≥1 present | Purely metabolic driver. ALT often > AST. GGT may be mildly elevated. |
| MetALD | 140–350 g/wk (F), 210–420 g/wk (M) | ≥1 present | Dual driver. AST:ALT ratio intermediate (1:1 to 2:1). GGT often disproportionately elevated (alcohol induction). [1][2] |
| ALD | > 350 g/wk (F), > 420 g/wk (M) | May or may not be present | Alcohol is dominant driver. Classic AST:ALT ≥ 2:1. May see macrocytosis (MCV > 100 fL) from B12/folate deficiency or direct alcohol toxicity on erythropoiesis. |
| Cryptogenic SLD | Below MASLD threshold | None present | Diagnosis of exclusion — steatosis without identifiable cause. May represent "burnt-out" MASH where fat has disappeared but fibrosis remains. |
Why Is Classification Within SLD Important?
It isn't just academic labelling. The classification determines:
- Prognosis: MetALD progresses faster than either MASLD or ALD alone due to synergistic pathophysiology (as discussed in the pathophysiology section)
- Management priorities: MetALD patients need BOTH metabolic optimisation AND alcohol reduction/cessation
- HCC surveillance strategy: Differs by underlying aetiology [4]
- Candidacy for liver transplantation: Alcohol intake thresholds and abstinence requirements differ
Practical Challenges in Distinguishing MASLD vs MetALD vs ALD
- Patients frequently under-report alcohol intake — use validated tools like AUDIT-C (Alcohol Use Disorders Identification Test – Consumption) to get more accurate estimates
- The thresholds are based on self-reported weekly intake, which is inherently imprecise
- Biomarkers of alcohol use can supplement history:
- Elevated GGT — an inducible enzyme, meaning it can be induced by exogenous substances (alcohol, drugs) independent of liver cell damage* [10]. So an isolated GGT rise with normal ALP suggests alcohol or drug induction rather than cholestasis
- Carbohydrate-deficient transferrin (CDT) — elevated with sustained heavy alcohol intake (> 60 g/day for ≥2 weeks); more specific than GGT for heavy drinking
- Phosphatidylethanol (PEth) — a direct metabolite of ethanol incorporated into RBC membranes; detectable for ~28 days after last drink; most specific biomarker for recent alcohol consumption
- MCV — macrocytosis common in chronic alcohol use (direct toxicity on erythroid precursors + folate deficiency), but non-specific
- AST:ALT ratio: as discussed, pure ALD classically ≥ 2:1 (alcohol depletes pyridoxal-5-phosphate needed for ALT synthesis + mitochondrial AST released from damaged mitochondria); MetALD shows an intermediate ratio
2. Differential Diagnosis Beyond SLD (Other Causes of Chronic Liver Disease)
This is critical because:
- Other conditions can mimic MetALD (elevated liver enzymes + steatosis on imaging)
- Other conditions can coexist with MetALD — the concept of concomitant/dual liver disease is common, especially in Hong Kong [3][4]
- Missing a treatable alternative diagnosis (e.g., Wilson's disease, autoimmune hepatitis) has serious consequences
When you encounter persistently elevated liver enzymes, the structured approach is to exclude all other causes before attributing findings to MetALD:
| Condition | Key Features Distinguishing from MetALD | Investigations | Hong Kong Relevance |
|---|---|---|---|
| Chronic HBV | Most common cause of cirrhosis in HK (~64–75%) [3]. Can present with elevated ALT/AST and may have concurrent steatosis. HBV can cause HCC without cirrhosis [4][5]. | HBsAg, anti-HBs, HBeAg, anti-HBe, HBV DNA | Extremely common; dual liver disease (HBV + MASLD/MetALD) is frequently seen in HK [3][4] |
| Chronic HCV | May cause steatosis directly (particularly genotype 3). AST often > ALT. Associated with cryoglobulinaemia, membranoproliferative GN. | Anti-HCV IgG, HCV RNA | ~5–10% of liver disease in HK [3] |
From the GI Interactive Tutorial Case 2: A patient with HBsAg positive AND CAP score 330 dB/m (severe steatosis) illustrates dual liver disease — HBV + MAFLD/MetALD. This is common in Hong Kong. [4]
Why dual pathology matters: Each insult independently drives fibrogenesis. A patient with HBV + MetALD has accelerated fibrosis progression compared to either alone. Both pathologies must be actively managed.
| Condition | Key Features | Investigations | Why It Can Be Confused with MetALD |
|---|---|---|---|
| Autoimmune Hepatitis (AIH) | Young-to-middle-aged women; fluctuating ALT/AST (can be very high); may present with acute hepatitis or insidious chronic disease; associated with other autoimmune conditions (thyroiditis, vitiligo, coeliac disease). HCC is rare in autoimmune hepatitis [7]. | ANA, SMA (anti-smooth muscle antibody), anti-LKM1, elevated IgG, liver biopsy (interface hepatitis, plasma cell infiltration) | Both can present with chronically elevated transaminases. AIH may coexist with steatosis (patients may also be overweight). |
| PBC (Primary Biliary Cholangitis) | Middle-aged women; pruritus, fatigue; cholestatic LFT pattern (elevated ALP, GGT). M2 isoform of antimitochondrial antibody is highly specific for PBC [7]. | AMA (M2 isoform), elevated IgM, liver biopsy (florid duct lesion) [7][10] | Can present with elevated GGT, which is also seen in MetALD. But the LFT pattern is predominantly cholestatic rather than hepatitic. |
| PSC (Primary Sclerosing Cholangitis) | Male predominance; associated with IBD (especially UC); cholestatic LFT; beading/stricturing of bile ducts on MRCP. | pANCA, MRCP (characteristic beading), liver biopsy ("onion-skin" periductal fibrosis) | Cholestatic pattern differentiates from MetALD's hepatitic pattern. |
Clinical Pearl — Isolated GGT Elevation
An isolated rise in GGT with normal ALP suggests drug-induced elevation (phenytoin, carbamazepine, barbiturates), alcohol, or fatty liver — NOT cholestasis. This is because GGT is an inducible enzyme, induced by exogenous substances independent of liver pathology [10]. This is a common exam pitfall — don't reflexively investigate for biliary obstruction if only GGT is elevated.
| Condition | Key Features | Investigations | Why Consider |
|---|---|---|---|
| Haemochromatosis | Iron overload → bronze skin, diabetes ("bronze diabetes"), arthropathy, cardiomyopathy, hepatomegaly, hypogonadism. Middle-aged men (women protected by menstruation until menopause). | Serum ferritin, transferrin saturation ( > 45% suggestive), HFE gene testing (C282Y, H63D), liver biopsy with Perls' stain, MRI liver (iron quantification) | Both cause hepatomegaly and elevated transaminases. Ferritin is also elevated in metabolic syndrome (as an acute phase reactant) — must distinguish true iron overload from inflammatory hyperferritinaemia. |
| Wilson's Disease | Young patients ( < 40 years); can mimic Parkinson's (extrapyramidal copper deposition) [7]. Kayser-Fleischer rings (copper in Descemet's membrane), neuropsychiatric symptoms. Fulminant hepatic failure due to Wilson's: young patient, no other cause, Coombs-negative haemolytic anaemia [7]. | Serum ceruloplasmin (low), 24-hour urine copper (elevated), slit-lamp for KF rings, genetic test (does not have to be positive — hereditary pathway is very heterogeneous, not just ATP7B) [7], liver biopsy (hepatic copper content) | Can present with steatosis and elevated transaminases. Must be excluded in any young patient with unexplained liver disease. |
| Alpha-1 Antitrypsin Deficiency | Lower lobe emphysema (young non-smoker) + liver disease. PiZZ phenotype (homozygous). | Serum alpha-1 antitrypsin level, phenotyping/genotyping, liver biopsy (PAS-positive, diastase-resistant globules) | Can cause steatohepatitis and cirrhosis. Rare in Asian populations but should not be forgotten. |
This is a critical "masquerade" that mimics MetALD:
- Common culprits: methotrexate, amiodarone, tamoxifen, corticosteroids, valproate, tetracycline — all can cause hepatic steatosis
- Herbal and traditional Chinese medicines — extremely relevant in Hong Kong; patients may not volunteer this information unless specifically asked
- Supplements, drugs should be specifically enquired about [4]
- Mechanism: direct hepatotoxicity, mitochondrial dysfunction, inhibition of β-oxidation, or promotion of lipogenesis — mimicking the metabolic arm of MetALD
- Key differentiator: temporal relationship between drug exposure and liver enzyme elevation; improvement after drug withdrawal
Exam Pitfall — Always Ask About Over-the-Counter and Herbal Medications
In Hong Kong, many patients take traditional Chinese medicines, supplements, or health foods that can cause hepatotoxicity. These are easily missed if you only ask about prescribed medications. Supplements, drugs — always ask [4]. A patient labelled as "MetALD" may actually have drug-induced steatohepatitis that would resolve with drug cessation.
| Condition | Why It Mimics MetALD | How to Differentiate |
|---|---|---|
| Hypothyroidism | Causes weight gain, dyslipidaemia, elevated transaminases, and hepatic steatosis (impaired lipid metabolism) | TSH, free T4. Liver abnormalities improve with thyroid hormone replacement. |
| Cushing's syndrome | Central obesity, insulin resistance, dyslipidaemia, hypertension, hepatic steatosis — essentially iatrogenic metabolic syndrome | Clinical features (striae, moon facies, proximal myopathy), morning cortisol, suppression tests [11] |
| Polycystic ovary syndrome (PCOS) | Insulin resistance, obesity, dyslipidaemia — all promote MASLD/MetALD | Clinical (hirsutism, oligomenorrhoea), hormonal profile, pelvic USS |
| Growth hormone deficiency | GH is lipolytic; deficiency → hepatic fat accumulation | IGF-1, GH stimulation tests |
| Condition | Key Features | Why Consider |
|---|---|---|
| Coeliac disease | Can cause elevated transaminases (up to 10% of unexplained elevated ALT); mechanism: increased gut permeability → hepatic inflammation | Anti-tTG IgA, duodenal biopsy. Liver enzymes normalise with gluten-free diet. |
| Heart failure (congestive hepatopathy) | Right heart failure → hepatic venous congestion → elevated transaminases, hepatomegaly, "nutmeg liver" | Clinical features of RHF (JVP, peripheral oedema, hepatojugular reflux), echocardiography. Why does RHF cause liver dysfunction? Hydrostatic back-pressure in hepatic veins → centrilobular necrosis. |
| Budd-Chiari syndrome | Hepatic vein thrombosis → acute or chronic hepatomegaly, ascites, elevated transaminases | Doppler USS of hepatic veins, CT/MRI with contrast. Consider in young patients with thrombophilia. |
| Glycogen storage diseases | Rare; hepatomegaly, hypoglycaemia, elevated transaminases | Liver biopsy, genetic testing. More relevant in paediatric populations. |
3. Differential Diagnosis of Specific Presentations
Different presentations of MetALD trigger different differential diagnoses:
From the GI Interactive Tutorial Case 2: "A 53-year-old gentleman with persistently elevated liver enzymes upon routine health check — ALT 115, AST 68, GGT 102 — is completely asymptomatic. He is a non-drinker [in that case]." [4]
The approach:
- Pattern recognition on LFT [10]:
- Hepatitic pattern (ALT/AST predominant): MetALD, MASLD, ALD, viral hepatitis, AIH, Wilson's, haemochromatosis, DILI
- Cholestatic pattern (ALP/GGT predominant): PBC, PSC, biliary obstruction, infiltrative disease, DILI (cholestatic subtype)
- Mixed pattern: overlap — does not exclude any of the above
- Quantify alcohol, assess metabolic risk factors → classify within SLD spectrum
- Screen for viral, autoimmune, metabolic causes as above
- Stage fibrosis non-invasively
When MetALD has already progressed to cirrhosis and the patient presents with decompensation (jaundice, ascites, encephalopathy):
- The differential for the cause of cirrhosis is wide (see table below)
- In Hong Kong, HBV is the most common cause of cirrhosis (~64–75%) [3]
- Must identify the aetiology because it determines specific management (e.g., antiviral therapy for HBV/HCV, immunosuppression for AIH, copper chelation for Wilson's)
| Cause | Approximate % in HK | Key Distinguishing Feature |
|---|---|---|
| HBV | 64–75% [3] | HBsAg+, HBV DNA detectable |
| MASLD/MetALD | Rising (probably 10–15%) | Metabolic risk factors, alcohol history, exclusion of others |
| HCV | 5–10% [3] | Anti-HCV+, HCV RNA+ |
| ALD | > 5% [3] | Heavy alcohol history, AST:ALT ≥ 2:1 |
| AIH | ~2–5% | ANA/SMA+, elevated IgG, interface hepatitis on biopsy |
| PBC | ~1–3% | AMA+, cholestatic pattern |
| Wilson's | Rare | Young patient, low ceruloplasmin, KF rings |
| Haemochromatosis | Rare in Chinese | Elevated transferrin saturation, HFE genotyping |
Key concept: confusion in cirrhosis does NOT mean hepatic encephalopathy (HE). HE is actually a less common cause of confusion in cirrhosis. The most common causes are head injury and drug-related confusion [12].
Differential for confusion in cirrhosis:
- Head injury (falls are common in cirrhotic patients — coagulopathy, sarcopaenia, postural hypotension) → order CT brain [12]
- Drug-related (sedatives, opioids, benzodiazepines — impaired hepatic clearance) → urine toxicology [12]
- Infection / sepsis (SBP, UTI, pneumonia — cirrhotic patients are immunocompromised)
- Metabolic disturbance (hyponatraemia, hypoglycaemia, uraemia) → electrolyte panel [12]
- Alcohol withdrawal / delirium tremens (relevant in MetALD/ALD patients)
- Wernicke's encephalopathy (thiamine deficiency — consider in any patient with alcohol history)
- Hepatic encephalopathy — a diagnosis by exclusion; no single diagnostic test [12]
High Yield — HE is a Diagnosis of Exclusion
A very common exam mistake is to assume that any confused cirrhotic patient has hepatic encephalopathy. HE is essentially a diagnosis by exclusion — no one test is diagnostic. You MUST rule out head injury (CT brain), drug effects (drug history/toxicology), infection, metabolic disturbance, and withdrawal states before attributing confusion to HE [12]. This is a favourite exam question.
| Category | Differentials | Key Investigation(s) |
|---|---|---|
| Within SLD spectrum | MASLD, ALD, Cryptogenic SLD | Alcohol quantification (AUDIT-C, PEth, CDT), metabolic risk factor assessment |
| Viral | Chronic HBV, Chronic HCV | HBsAg, HBV DNA; Anti-HCV, HCV RNA |
| Autoimmune | AIH, PBC, PSC | ANA, SMA, IgG; AMA (M2), IgM; pANCA, MRCP |
| Metabolic/Genetic | Haemochromatosis, Wilson's disease, A1AT deficiency | Ferritin, transferrin sat, HFE; ceruloplasmin, 24h urine Cu; A1AT level |
| Drug-induced | DILI (including herbal/TCM) | Temporal drug history, improvement on withdrawal |
| Endocrine | Hypothyroidism, Cushing's, PCOS | TFT, cortisol, hormonal profile |
| Cardiac | Congestive hepatopathy | Echocardiography, JVP assessment |
| Vascular | Budd-Chiari syndrome | Doppler USS hepatic veins |
| Other | Coeliac disease, glycogen storage diseases | Anti-tTG IgA; liver biopsy |
High Yield Summary — Differential Diagnosis of MetALD
-
Within SLD: Differentiate MetALD from MASLD and ALD based on alcohol intake thresholds (MetALD = 140–350 g/wk women, 210–420 g/wk men + ≥1 metabolic risk factor). AST:ALT ratio and GGT help but are not definitive.
-
Must exclude: Chronic HBV (most common cause of liver disease in HK), HCV, autoimmune hepatitis, PBC/PSC, Wilson's disease, haemochromatosis, DILI (including herbal medicines), hypothyroidism.
-
Concomitant disease is the rule, not the exception: In HK, dual/triple pathology (HBV + MetALD ± others) is extremely common. Finding one diagnosis does not exclude another.
-
Confusion in cirrhosis ≠ HE: Must exclude head injury, drugs, infection, metabolic disturbance, and withdrawal states. HE is a diagnosis of exclusion.
-
Isolated GGT elevation (with normal ALP): Think alcohol, drugs (enzyme induction), or fatty liver — NOT cholestasis.
-
Drug history: Always ask about supplements, herbal medicines, and TCM in Hong Kong patients.
Active Recall — Differential Diagnosis of MetALD
References
[1] Lecture slides: GC 240. MASLD and Alcoholic Liver Disease.pdf [2] Lecture slides: Teaching Clinic - Non-viral chronic liver diseases (Prof. Yuen Man Fung) 2.pdf [3] Senior notes: Block A - Abdominal distension_ ascites and cirrhosis.pdf [4] Senior notes: Block A - Gastroenterology Interactive Tutorial.pdf (Case 2) [5] Senior notes: Maksim Surgery Notes.pdf (HCC section) [7] Senior notes: Block A - Patients with non-viral chronic liver diseases.pdf [9] Lecture slides: CFB (FM02) Introduction to common problems - Differentiating the normal from the abnormal.pdf [10] Senior notes: Block A - Introduction to GI_Hepatology investigations (LFT, Endoscopy).pdf [11] Senior notes: Block A - Endocrine Data Interpretation.pdf [12] Senior notes: Block A - A jaundiced and incoherent patient_ liver failure.pdf
Diagnostic Criteria, Algorithm, and Investigations for MetALD
1. Diagnostic Criteria for MetALD
MetALD does not have a single "diagnostic criterion" in the way that, say, infective endocarditis has Duke's criteria. Instead, the diagnosis is established by satisfying three pillars simultaneously, as defined by the 2023 multi-society Delphi consensus [1][2]:
Steatosis must be documented by at least one of the following:
- Imaging: ultrasound (echogenic liver), CT (low hepatic attenuation), MRI-PDFF (proton density fat fraction ≥ 5%)
- Liver elastography CAP score: steatosis grading [4]
- Histology: ≥ 5% of hepatocytes containing lipid droplets on liver biopsy (gold standard but invasive)
- Biomarkers: e.g., Fatty Liver Index (FLI) > 60 as a validated surrogate when imaging is unavailable
At least one of the following must be present [1]:
| CMR Factor | Threshold |
|---|---|
| Overweight / obesity | BMI ≥ 25 kg/m² (or ≥ 23 in Asian populations) OR waist circumference ≥ 94 cm (M) / ≥ 80 cm (F) in Asians |
| Dysglycaemia | Fasting glucose ≥ 5.6 mmol/L, or HbA1c ≥ 5.7%, or T2DM |
| Hypertension | BP ≥ 130/85 mmHg or on antihypertensives |
| Hypertriglyceridaemia | TG ≥ 1.7 mmol/L or on lipid-lowering therapy |
| Low HDL-C | < 1.0 mmol/L (M) / < 1.3 mmol/L (F) or on lipid-lowering therapy |
| Sex | MetALD Alcohol Range | For Comparison: MASLD | For Comparison: ALD |
|---|---|---|---|
| Women | 140–350 g/week | < 140 g/week | > 350 g/week |
| Men | 210–420 g/week | < 210 g/week | > 420 g/week |
Practical conversion: 1 standard drink ≈ 10 g alcohol. So MetALD in men ≈ 21–42 standard drinks/week ≈ 3–6 drinks/day.
The diagnosis requires that other causes of steatotic liver disease have been reasonably excluded (viral hepatitis, autoimmune liver disease, Wilson's disease, haemochromatosis, drug-induced causes, etc.) — or if present, they are acknowledged as concomitant pathology [2][7].
Key Exam Point — MetALD Is a Positive Diagnosis, Not Just Exclusion
Unlike the old NAFLD (which was defined by the ABSENCE of alcohol — a negative definition), MetALD is defined by the PRESENCE of three positive criteria: steatosis + metabolic risk factors + moderate alcohol. This is a fundamental philosophical shift in the 2023 nomenclature. You confirm what IS there, rather than excluding what ISN'T.
The following algorithm outlines the systematic clinical approach to diagnosing MetALD, from initial suspicion through to staging and complication screening:
3. Investigation Modalities — Detailed Breakdown
The investigations for MetALD can be organised into five tiers, from basic to specialised:
Tier 1: Baseline Blood Tests (Confirm Liver Injury + Assess Function)
LFTs assess three distinct aspects of hepatic function [13][10]:
- Cellular integrity (hepatocyte damage markers): ALT, AST
- Synthetic function (true "liver function"): Albumin, Prothrombin Time / INR
- Excretory function: Bilirubin, ALP, GGT
| Test | What It Measures | Expected in MetALD | Interpretation / Why |
|---|---|---|---|
| ALT | Cytoplasmic enzyme released from damaged hepatocytes. More liver-specific than AST. | Mild-to-moderately elevated (typically < 300 U/L) | Reflects ongoing hepatocyte injury from steatohepatitis. In most primary liver diseases, ALT > AST [10]. |
| AST | Present in hepatocyte cytoplasm AND mitochondria. Also found in heart, muscle, kidney. | Elevated, but pattern depends on relative metabolic vs alcohol contribution | Four conditions cause AST > ALT: alcoholic hepatitis, HCC, congestive heart failure, ischaemic hepatitis [10]. In MetALD, ratio is intermediate. |
| AST:ALT ratio | Ratio of the two transaminases | 1:1 to 2:1 in MetALD (intermediate between MASLD < 1 and ALD ≥ 2:1) | In alcoholic hepatitis: AST > ALT, ratio > 2:1, and AST almost never > 500 U/L [10]. The B6 depletion and mitochondrial AST release mechanism explains this. |
| GGT | Microsomal enzyme. An inducible enzyme [10]. | Disproportionately elevated — often the highest of all liver enzymes | Isolated GGT elevation (with normal ALP) → alcohol, drugs (phenytoin, carbamazepine, barbiturates), or fatty liver [10]. In MetALD, the alcohol component induces GGT independently of liver damage. |
| ALP | Excretory marker. Present in liver (canalicular membrane), bone, placenta, intestine. | Usually normal or mildly elevated | If ALP is markedly elevated, think cholestatic causes (PBC, PSC, biliary obstruction) rather than pure MetALD. ALP and GGT both elevated in ~90% of cholestasis [10]. |
| Albumin | Synthesised exclusively by the liver. Half-life ~21 days. | Normal in early disease; low in advanced cirrhosis | Reflects synthetic function. Low albumin = poor prognostic marker in cirrhosis. |
| PT / INR | Reflects synthesis of clotting factors (especially Factor VII, half-life ~6 hours). | Normal in early disease; prolonged in cirrhosis | INR is the best prognostic marker for monitoring liver disease progress. If AST/ALT falling + INR improving → recovery. If AST/ALT falling + INR worsening → concern for fulminant hepatitis [6]. |
| Bilirubin | Both direct (conjugated) and indirect (unconjugated). | Normal early; elevated in advanced disease | Usually direct bilirubin elevated in hepatitis [6]. In cirrhosis, both fractions rise. |
High Yield — Three Aspects of LFT Interpretation
| Finding | Significance in MetALD | Mechanism |
|---|---|---|
| Macrocytosis (↑ MCV) | Suggests significant alcohol component | Alcohol permeates RBC membranes and alters lipid structures [10]; also folate/B12 deficiency from malnutrition |
| Thrombocytopaenia | Suggests portal hypertension / hypersplenism / advanced disease | Splenic sequestration from splenomegaly; also direct alcohol marrow toxicity and decreased thrombopoietin production by diseased liver |
| Anaemia | Multifactorial | Chronic disease, GI bleeding, folate/B12 deficiency, alcohol marrow suppression |
| Leukocytosis with neutrophilia | Suggests alcoholic hepatitis flare or infection | Alcohol stimulates neutrophil release; also consider SBP if ascites present |
| Test | Purpose | Expected Findings |
|---|---|---|
| Fasting glucose / HbA1c | Screen for T2DM (CMR factor) and assess glycaemic control | May be elevated; T2DM is both a risk factor and consequence of MetALD |
| Lipid profile (TC, LDL, HDL, TG) | Assess CMR factors; dyslipidaemia screening | ↑ TG, ↓ HDL-C are typical; LDL-C may be normal or elevated |
| Renal function (Cr, urea, eGFR) | Baseline renal function; screen for hepatorenal syndrome in cirrhosis | May be normal early; elevated in advanced disease |
| Electrolytes (Na, K) | Metabolic derangements in cirrhosis | Hyponatraemia (dilutional, from RAAS activation in cirrhosis); hypokalaemia (if on diuretics) |
| Uric acid | Associated with metabolic syndrome and gout | Often elevated |
This is the "liver screen" — a panel of tests to exclude other causes and identify dual pathology [4][7][13]:
| Test | Condition Screened | Key Interpretive Points |
|---|---|---|
| HBsAg, Anti-HBs, Anti-HBc | Chronic HBV | HBsAg +ve, Anti-HBs -ve, Anti-HBc +ve → acute OR chronic infection [14]. Add HBeAg, Anti-HBe, HBV DNA to stage. Most common cause of cirrhosis in HK [3]. |
| Anti-HCV | Chronic HCV | If positive → confirm with HCV RNA. Hard to catch acute phase unless needlestick injury [13]. |
| ANA, SMA, Anti-LKM1, IgG | Autoimmune hepatitis | Autoimmune hepatitis is difficult to diagnose, sometimes a diagnosis of exclusion. Autoantibodies are not specific — require diagnostic criteria [13]. |
| AMA (M2 isoform), IgM | PBC | M2 isoform of AMA is highly specific for PBC [7][10]. |
| pANCA | PSC | If positive, proceed to MRCP for bile duct imaging. |
| Ferritin, Transferrin saturation | Haemochromatosis | TSAT > 45% is suggestive [15]. BUT ferritin is an acute phase reactant — elevated in metabolic syndrome, infection, malignancy. Must interpret in context. |
| Ceruloplasmin, 24h urine copper | Wilson's disease | Low ceruloplasmin + high urine copper + KF rings on slit-lamp. Genetic test does not have to be positive — hereditary pathway is very heterogeneous [7]. |
| Alpha-1 antitrypsin level | A1AT deficiency | Low level → phenotyping/genotyping. Rare in Asians. |
| TFT (TSH, fT4) | Hypothyroidism | Can cause steatosis and elevated transaminases. Easily treated and reversible. |
| Coeliac screen (anti-tTG IgA) | Coeliac disease | Can cause unexplained elevated ALT (up to 10% of cases). |
Exam Point — Don't Forget Drug History
Supplements, drugs — always ask [4]. In Hong Kong, traditional Chinese medicines and health supplements are extremely common causes of drug-induced liver injury that can mimic MetALD. A thorough drug history (including over-the-counter, herbal, and TCM preparations) is an essential "investigation" that costs nothing.
Alcohol Biomarkers (Objective Assessment)
Since MetALD diagnosis hinges on alcohol intake quantification, objective biomarkers supplement self-report:
| Biomarker | What It Measures | Utility |
|---|---|---|
| GGT | Inducible by alcohol; elevated with regular consumption | Sensitive but non-specific. Also elevated in liver disease, drugs, obesity. |
| CDT (Carbohydrate-Deficient Transferrin) | Elevated with sustained heavy drinking ( > 60 g/day for ≥ 2 weeks) | More specific than GGT for heavy alcohol use; normalises within 2–4 weeks of abstinence |
| PEth (Phosphatidylethanol) | Direct ethanol metabolite incorporated into RBC membranes | Most specific biomarker; detectable for ~28 days; quantitative (correlates with intake level) |
| MCV | Macrocytosis from direct membrane toxicity + folate deficiency | Non-specific but supportive; takes months to normalise |
| AST:ALT ratio | Indirect marker; ratio ≥ 2:1 strongly suggests alcohol dominance | Useful for pattern recognition; cannot quantify intake |
| Modality | How It Works | Key Findings / Thresholds | Pros | Cons |
|---|---|---|---|---|
| Ultrasound (USS) | Hyperechoic liver compared to kidney cortex | Echogenic/bright liver = steatosis. Cannot quantify precisely. | Cheap, widely available, no radiation, can assess portal hypertension signs (splenomegaly, ascites, portal vein diameter) | Operator-dependent; insensitive for < 20% steatosis; limited in obesity |
| FibroScan CAP (Controlled Attenuation Parameter) | Measures ultrasound attenuation by fat during transient elastography | < 248 dB/m = normal; 248–280 = mild-moderate steatosis; > 280 = severe steatosis [4] | Quantitative, reproducible, simultaneous fibrosis assessment | Less reliable if BMI > 30 (use XL probe); ascites can interfere |
| MRI-PDFF (Proton Density Fat Fraction) | Quantifies hepatic fat fraction using magnetic resonance | ≥ 5% = steatosis. Most accurate non-invasive method. | Gold standard for non-invasive steatosis quantification; excellent for clinical trials | Expensive, limited availability, time-consuming |
| CT | Low hepatic attenuation (liver darker than spleen) | Liver:spleen attenuation ratio < 1 suggests steatosis | Can be incidental finding on CT done for other reasons | Radiation exposure; insensitive for mild steatosis; not used primarily for steatosis assessment |
| Liver biopsy | Histological assessment of fat droplets in hepatocytes | ≥ 5% steatosis on histology = diagnostic gold standard | Can simultaneously assess inflammation, ballooning, fibrosis | Invasive, sampling error, complications (bleeding, pain), inter-observer variability |
Fibrosis stage is the strongest predictor of liver-related outcomes in any form of SLD — more important than the degree of steatosis or inflammation. The question is: how far has the disease progressed?
Non-Invasive Fibrosis Assessment
A. Serum-Based Scores
| Score | Components | Calculation | Interpretation |
|---|---|---|---|
| FIB-4 | Age, AST, ALT, platelet count | Age × AST / (Platelet count × √ALT) | < 1.3 = low risk (F0–F1); 1.3–2.67 = indeterminate; > 2.67 = high risk (F3–F4) |
| NFS (NAFLD Fibrosis Score) | Age, BMI, impaired fasting glucose/DM, AST/ALT ratio, platelet count, albumin | Complex formula (online calculator) | < -1.455 = low risk; -1.455 to 0.676 = indeterminate; > 0.676 = high risk |
| APRI | AST, platelet count | (AST / upper limit of normal) / platelet count × 100 | < 0.5 = unlikely significant fibrosis; > 1.5 = likely cirrhosis |
Why use these? They are free, widely available, and can be calculated from routine blood tests. They serve as excellent first-line triage tools to identify patients who need further assessment. The key limitation is the "indeterminate" zone — many patients fall here and need a second test.
B. Imaging-Based Fibrosis Assessment
| Modality | How It Works | Key Thresholds | Notes |
|---|---|---|---|
| Transient Elastography (FibroScan) — Liver Stiffness Measurement | Shear wave propagation through liver; stiffer liver = faster wave = higher kPa | < 7 kPa = F0–F1; 7–10 = F2; 10–12 = F3; > 12 kPa = suggestive of cirrhosis (F4) [4] | Most widely used. Simultaneous CAP measurement. Unreliable if BMI > 30 (use XL probe), acute hepatitis flare, cholestasis, congestion. |
| Shear Wave Elastography (SWE) | Point or 2D shear wave measurement during USS | Similar principles; thresholds vary by manufacturer | Can be combined with conventional USS assessment |
| MR Elastography (MRE) | Magnetic resonance-based stiffness measurement | ≥ 2.88–3.54 kPa (MRE values are different from FibroScan) | Most accurate non-invasive method; expensive, limited availability |
From the GI Interactive Tutorial Case 2: "Liver elastography: liver stiffness 15 kPa (> 12 kPa suggestive of liver cirrhosis); CAP score 330 dB/m (> 280 dB/m suggestive of severe steatosis)" [4] — this patient has both cirrhosis-level fibrosis AND severe steatosis, consistent with advanced MetALD or concomitant disease.
C. Liver Biopsy
Remains the gold standard for fibrosis staging but is reserved for specific indications:
- Discordant non-invasive test results
- Suspicion of concomitant liver disease requiring histological confirmation (e.g., autoimmune hepatitis)
- Clinical trial enrolment
- Pre-transplant assessment
- When steatohepatitis vs simple steatosis distinction will change management
Histological scoring systems:
- NAS (NAFLD Activity Score): steatosis (0–3) + lobular inflammation (0–3) + hepatocyte ballooning (0–2) = 0–8. NAS ≥ 4 is generally considered diagnostic of steatohepatitis. However, NAS was designed for clinical trials, not as a standalone diagnostic tool.
- SAF Score (Steatosis, Activity, Fibrosis): more modern, used in European centres
- Fibrosis stage (Kleiner): F0–F4 as previously described
- Alcoholic hepatitis scoring: Maddrey's Discriminant Function, ABIC score, Lille score — used if there is a flare of alcoholic hepatitis within MetALD
Tier 5: Complication Screening and Severity Assessment
Once MetALD is diagnosed and staged, investigations focus on complications:
Gold standard: Hepatic Venous Pressure Gradient (HVPG) ≥ 10 mmHg = clinically significant portal hypertension [3]:
- Method: catheter via internal jugular or femoral vein → hepatic vein → measure FHVP (free hepatic venous pressure) → inflate balloon → measure WHVP (wedged hepatic venous pressure, surrogate for portal pressure) → HVPG = WHVP – FHVP [3]
- Not commonly used in clinical practice — too invasive, does not change management, mainly for research [3]
- In HK, not routinely done [3]
Practical alternatives [3]:
- Ultrasound (not sensitive but may show): splenomegaly, nodular small liver, increased portal vein diameter, decreased portal vein flow, varices [3]
- Upper GI endoscopy (OGD): screen for oesophageal/gastric varices — indicated in all patients with cirrhosis
- Platelet count < 150 × 10⁹/L + liver stiffness > 20 kPa: Baveno VII criteria suggest these patients can be spared screening endoscopy if LS < 20 AND platelets > 150 (low risk of varices)
| Modality | Frequency | Indication |
|---|---|---|
| USS liver ± serum AFP | Every 6 months | In MetALD/MASLD: cirrhosis is generally required for HCC surveillance [4]. Unlike HBV, where age-based criteria apply. |
HBV-specific HCC surveillance indications (different from MetALD): Male ≥ 40, Female ≥ 50, OR underlying cirrhosis, OR family history of HCC [4]. Since HBV can cause HCC without cirrhosis, more stringent criteria are applied [4].
| Score | Components | Use |
|---|---|---|
| Child-Pugh Score | Bilirubin, albumin, INR, ascites, encephalopathy | Compensated (A, 5–6) vs. Decompensated (B 7–9, C 10–15) [3]. Clinical classification and prognosis. |
| MELD Score (Model for End-Stage Liver Disease) | Bilirubin, INR, creatinine (± sodium in MELD-Na) | Transplant listing prioritisation. Higher MELD = higher 90-day mortality without transplant. |
| Investigation | Purpose |
|---|---|
| Ascitic fluid analysis (if ascites present) | Diagnostic paracentesis: cell count, albumin (SAAG calculation), culture. SAAG ≥ 11 g/L = portal hypertensive ascites. Rule out SBP (polymorphonuclear count ≥ 250/mm³). |
| Ammonia (arterial) | Not diagnostic of HE — not always raised, may not correlate with severity [12]. Suggestive only. |
| Bone densitometry (DEXA) | Hepatic osteodystrophy screening in cirrhosis |
| Echocardiography | Screen for cirrhotic cardiomyopathy; pre-transplant evaluation |
To illustrate how these investigations are interpreted in practice, consider the GI Interactive Tutorial Case 2 [4]:
| Investigation | Result | Interpretation |
|---|---|---|
| ALT | 115 U/L | Elevated — hepatocyte damage |
| AST | 68 U/L | Elevated — ALT > AST (ratio ~0.6), suggesting metabolic-predominant liver disease |
| GGT | 102 U/L | Disproportionately elevated — inducible enzyme; consider alcohol, drugs, fatty liver [10] |
| Albumin | Normal | Synthetic function preserved — not yet advanced disease |
| Bilirubin | Normal | Excretory function preserved |
| ALP | Normal | No cholestatic component |
| BMI | 33.2 kg/m² | Obese — metabolic risk factor present |
| HBsAg | Positive | Chronic HBV infection — dual liver disease [4] |
| HBeAg | Negative | E-antigen negative chronic HBV (likely immune-control or HBeAg-negative hepatitis) |
| Anti-HCV | Negative | HCV excluded |
| AFP | 15 ng/mL (normal < 12) | Mildly elevated — warrants monitoring; consider HCC surveillance |
| HBV DNA | 1.34 × 10⁶ IU/mL | High HBV DNA → increased risk of cirrhosis and cancer [4] |
| Liver stiffness | 15 kPa | > 12 kPa → suggestive of cirrhosis [4] |
| CAP score | 330 dB/m | > 280 dB/m → severe steatosis [4] |
Diagnosis: Dual liver disease — HBV-related cirrhosis AND MAFLD (or MetALD if alcohol intake is in the 210–420 g/week range) [4].
5. Special Considerations for Investigation Interpretation
Ferritin is often elevated in MetALD patients, but this does NOT necessarily mean iron overload:
- Ferritin is an acute phase reactant — elevated in inflammation, metabolic syndrome, obesity, infection, malignancy
- In MetALD, hepatic inflammation drives ferritin elevation
- To differentiate true haemochromatosis from reactive hyperferritinaemia: check TSAT ( > 45% suggests true overload) [15]
- If TSAT is normal/low and ferritin is elevated → likely reactive (metabolic syndrome-related)
Exam Pitfall — Elevated Ferritin ≠ Haemochromatosis
A very common mistake is to diagnose haemochromatosis based on elevated ferritin alone in a patient with MetALD. Ferritin is an acute phase reactant and is commonly elevated in metabolic syndrome. Always check TSAT. True haemochromatosis has TSAT > 45% + elevated ferritin + compatible genetics or liver iron content.
Four conditions where AST > ALT (must know) [10]:
- Alcoholic hepatitis — AST:ALT > 2:1, AST almost never > 500 U/L
- Hepatocellular carcinoma — check AFP, imaging
- Congestive heart failure — check clinical context, USS liver shows engorged hepatic veins
- Ischaemic hepatitis — profound shock, disproportionate LDH elevation
In MetALD: ratio is intermediate (1:1 to 2:1) because both metabolic (ALT-predominant) and alcohol (AST-predominant) drivers are present. Once cirrhosis develops from ANY cause, AST tends to exceed ALT (reduced hepatocyte ALT content in cirrhotic liver).
Prof emphasises: only when there is a physical entity causing the pathology is imaging helpful. In other cases, a diagnosis can be made using solely clinical and laboratory investigations. Don't expose patients to unnecessary radiation and don't clog up the wait times [10].
In MetALD:
- USS/FibroScan → very helpful (confirm steatosis, stage fibrosis, screen for portal hypertension/HCC)
- CT/MRI → reserve for specific indications (HCC characterisation, equivocal USS, pre-operative planning)
- MRCP/ERCP → only if cholestatic picture suggesting biliary pathology [10]
High Yield Summary — Diagnostic Criteria, Algorithm & Investigations for MetALD
-
Three pillars for MetALD diagnosis: (a) Hepatic steatosis on imaging/biopsy, (b) ≥1 cardiometabolic risk factor, (c) Alcohol 140–350 g/wk (F) or 210–420 g/wk (M). Plus exclusion or acknowledgment of other aetiologies.
-
Algorithm: Confirm steatosis → Quantify alcohol + assess CMR → Classify on SLD spectrum → Aetiological screen (viral, autoimmune, metabolic, drug) → Stage fibrosis → Screen for complications if cirrhosis.
-
LFT interpretation: ALT/AST = damage markers; albumin/INR = synthetic function; ALP/GGT/bilirubin = excretory function. AST:ALT ratio is intermediate in MetALD. GGT is disproportionately elevated due to alcohol induction.
-
Non-invasive fibrosis staging: FIB-4 and NFS as first-line triage; FibroScan (LS > 12 kPa = cirrhosis; CAP > 280 = severe steatosis) as second-line. Biopsy reserved for discordant results or when histology changes management.
-
Aetiological screen must be performed in every patient: HBV/HCV serology, autoimmune markers, iron/copper studies, A1AT, TFT, drug history. Dual liver disease is the rule in Hong Kong.
-
HCC surveillance: 6-monthly USS ± AFP for MetALD patients with cirrhosis. Different criteria for HBV (age-based).
-
Portal hypertension: HVPG (gold standard but not routinely done); USS and OGD for practical assessment.
Active Recall — Diagnostic Criteria, Algorithm & Investigations for MetALD
References
[1] Lecture slides: GC 240. MASLD and Alcoholic Liver Disease.pdf [2] Lecture slides: Teaching Clinic - Non-viral chronic liver diseases (Prof. Yuen Man Fung) 2.pdf [3] Senior notes: Block A - Abdominal distension_ ascites and cirrhosis.pdf [4] Senior notes: Block A - Gastroenterology Interactive Tutorial.pdf (Case 2) [6] Senior notes: Block A - Jaundice after raw oysters_ acute hepatitis.pdf [7] Senior notes: Block A - Patients with non-viral chronic liver diseases.pdf [10] Senior notes: Block A - Introduction to GI_Hepatology investigations (LFT, Endoscopy).pdf [12] Senior notes: Block A - A jaundiced and incoherent patient_ liver failure.pdf [13] Senior notes: Learning_Points_All_Lectures.txt (GI/Hepatology section) [14] Senior notes: Block A - I am a hepatitis B carrier.pdf [15] Senior notes: Maksim Medicine Notes.pdf (Haemochromatosis section)
Management of MetALD
The management of MetALD is fundamentally about addressing two drivers simultaneously — the metabolic component and the alcohol component — while also managing the consequences of liver disease at whatever stage the patient presents. Unlike many conditions where there is a single pharmacological "magic bullet," MetALD management is primarily lifestyle-driven, with pharmacotherapy playing a supporting and rapidly evolving role.
2. Tier 1: Lifestyle Modification (Core — ALL Patients)
This is the cornerstone of MetALD management. No drug can substitute for effective lifestyle change. Every single MetALD patient, regardless of disease stage, receives this.
This is the single most impactful intervention for the metabolic component of MetALD.
Resolution of fatty liver does not require BMI returning to 25. Weight loss of 5–7% is already sufficient in non-fibrosis patients. 10% weight loss is needed in fibrosis patients — which is why GLP-1 drugs work, as they achieve > 10% weight reduction. [4]
| Weight Loss Target | Disease Stage | Expected Benefit |
|---|---|---|
| 5–7% of body weight | Simple steatosis, early steatohepatitis (F0–F1) | Reduces hepatic steatosis, improves insulin sensitivity, may resolve steatohepatitis |
| ≥ 10% of body weight | Steatohepatitis with fibrosis (F2–F3) | Can reverse fibrosis (not just steatosis), significant histological improvement |
| > 10% | Cirrhosis (F4) | May slow progression; cannot reverse established cirrhosis but can reduce portal pressure and improve metabolic parameters |
Why does weight loss work?
- Reduces visceral adipose tissue → ↓ FFA flux to liver → ↓ steatosis
- Improves insulin sensitivity → ↓ hyperinsulinaemia → ↓ de novo lipogenesis (SREBP-1c pathway)
- Reduces inflammation (↓ TNF-α, ↓ IL-6 from adipocytes) → ↓ steatohepatitis
- Reduces gut-derived endotoxin translocation (improved gut barrier function)
This is the cornerstone for the alcohol component of MetALD. By definition, MetALD patients drink in the moderate-to-increased range (140–350 g/wk women, 210–420 g/wk men) [1].
Alcohol abstinence is the cornerstone of treatment of alcoholic liver disease. It can improve survival and potentially reverse histological injury. [16]
| Recommendation | Rationale |
|---|---|
| Complete abstinence is ideal, especially if advanced fibrosis or cirrhosis | Even moderate alcohol accelerates fibrogenesis in a metabolically stressed liver. In cirrhosis, any alcohol increases decompensation risk and HCC risk. |
| At minimum, reduce to below MASLD threshold ( < 140 g/wk women, < 210 g/wk men) | If complete abstinence is not achievable, reclassifying to MASLD-range intake still reduces the synergistic dual-hit |
| No alcohol for 6 months for acute hepatitis; no alcohol for life for chronic hepatitis [6] | Applies to any concurrent hepatitis flare in MetALD patients |
Alcohol cessation support:
- Brief intervention and motivational interviewing (first line for moderate drinkers)
- AUDIT-C screening tool for monitoring
- Pharmacotherapy for alcohol dependence (if applicable — though MetALD patients are typically moderate drinkers, not dependent):
- Naltrexone — opioid antagonist; reduces craving and rewarding effects of alcohol. Contraindicated in acute hepatitis or hepatic failure (hepatotoxic at high doses)
- Acamprosate ("acamprosate" = "a-camp-ros-ate" → think "anti-craving") — modulates GABA/glutamate balance; reduces withdrawal symptoms and craving. Renally excreted, safe in liver disease.
- Disulfiram — aldehyde dehydrogenase (ALDH) inhibitor; causes accumulation of acetaldehyde after alcohol ingestion → unpleasant flushing, nausea, tachycardia ("disulfiram reaction"). Contraindicated in severe liver disease because it inhibits the very enzyme needed to clear acetaldehyde.
- Baclofen — GABA-B agonist; evidence for reducing alcohol consumption in cirrhotic patients (one of the few drugs studied in this population)
Why Not Just Tell Patients to Stop Drinking?
MetALD patients are typically moderate drinkers who may not perceive themselves as having an "alcohol problem." Telling them to stop completely may meet resistance. The clinical approach must be nuanced: explain that their liver is being hit from two directions (metabolism + alcohol), and that reducing either driver — but especially alcohol — will slow disease progression. Frame it as harm reduction, not moral judgment.
| Dietary Strategy | Rationale | Mechanism |
|---|---|---|
| Mediterranean diet | Best evidence-based diet for SLD; rich in monounsaturated fats, omega-3, fibre, polyphenols | Anti-inflammatory, improves insulin sensitivity, reduces hepatic de novo lipogenesis |
| Avoid high fructose foods | High fructose foods → fatty liver [4] | Fructose bypasses phosphofructokinase regulation → uncontrolled hepatic lipogenesis via SREBP-1c + ChREBP; also generates uric acid (pro-inflammatory) |
| Coffee is beneficial | Coffee → beneficial for fatty liver [4] | Coffee polyphenols (chlorogenic acid, kahweol) have anti-inflammatory, anti-fibrotic, antioxidant effects. Meta-analyses show dose-dependent reduction in liver fibrosis and HCC risk. 3–4 cups/day appears optimal. |
| Reduce ultra-processed foods, refined carbohydrates, sugary drinks | Drive hyperinsulinaemia and hepatic lipogenesis | Rapid glycaemic load → insulin spike → SREBP-1c activation → de novo lipogenesis |
| Adequate protein intake (1.2–1.5 g/kg/day in cirrhosis) | Prevent sarcopaenia (muscle wasting is common and prognostic in cirrhosis) | Ammonia is also cleared by muscle (glutamine synthesis); less muscle = worse HE risk |
| Sodium restriction ( < 2 g/day) in patients with ascites | Reduce fluid retention | Less sodium → less water retention → less ascites accumulation (works synergistically with diuretics) |
| Recommendation | Evidence |
|---|---|
| 150–300 minutes/week of moderate-intensity aerobic exercise (e.g., brisk walking, cycling, swimming) | Reduces hepatic steatosis independent of weight loss; improves insulin sensitivity via ↑AMPK activation → ↑glucose uptake + ↑FFA oxidation |
| Resistance training 2–3 times/week | Preserves/builds muscle mass (critical in cirrhosis for sarcopaenia prevention); improves metabolic parameters |
| Reduce sedentary time | Even without formal exercise, breaking up sedentary periods reduces metabolic risk |
Why does exercise work even without weight loss? Because exercise independently activates AMPK (AMP-activated protein kinase) in hepatocytes and skeletal muscle → promotes fatty acid β-oxidation and glucose uptake, reduces de novo lipogenesis, and improves mitochondrial function. This is a metabolic benefit separate from calorie balance.
Since MetALD by definition requires ≥1 cardiometabolic risk factor, these must be actively managed:
| Risk Factor | Target | Preferred Agent(s) | Notes |
|---|---|---|---|
| T2DM | HbA1c < 7% (individualised) | GLP-1 RA and/or SGLT2i preferred (dual benefit for liver + cardiorenal protection) [4][17] | Metformin remains traditional first line but newer agents have liver-specific benefits |
| Hypertension | < 130/80 mmHg | ACEI/ARB (especially if proteinuria or CKD); CCB, thiazide | ACEi/ARB have additional anti-fibrotic properties in liver. Avoid in decompensated cirrhosis with hypotension. |
| Dyslipidaemia | LDL-C targets per CV risk stratification | Statins (safe in compensated cirrhosis; NOT contraindicated) | Common misconception: statins are often avoided in liver disease. In fact, statins are safe and beneficial in compensated chronic liver disease (including cirrhosis). Avoid only in decompensated cirrhosis or acute liver failure. |
| Obesity | Weight loss as above | Lifestyle ± pharmacotherapy ± bariatric surgery | See below for obesity pharmacotherapy and surgery |
High Yield — Statins Are Safe in Compensated Liver Disease
A very common mistake is to withhold statins from patients with chronic liver disease because of "liver toxicity concerns." In reality, statins are safe and beneficial in compensated MASLD/MetALD/cirrhosis. They reduce cardiovascular events (the #1 cause of death in early SLD) and may even have anti-fibrotic and anti-HCC properties. Only avoid in decompensated cirrhosis or active acute hepatitis with markedly elevated transaminases ( > 5–10× ULN).
3. Tier 2: Pharmacotherapy for MetALD
The pharmacological landscape for SLD is rapidly evolving. As of 2025–2026, the key agents are:
| Feature | Details |
|---|---|
| Drug class | Thyroid hormone receptor-beta (THR-β) selective agonist |
| Name breakdown | "Res-meti-rom" → think "restorative metabolism" via thyroid receptor modulation |
| Mechanism | Selectively activates THR-β in hepatocytes → ↑ fatty acid β-oxidation, ↓ hepatic lipogenesis, ↓ cholesterol, anti-fibrotic effects. Does NOT activate THR-α (avoids cardiac/bone side effects of systemic thyroid hormone). |
| Indication | Non-cirrhotic MASH with moderate-to-advanced fibrosis (F2–F3), in conjunction with lifestyle modification |
| Evidence | MAESTRO-NASH trial: significant histological improvement in MASH resolution and fibrosis improvement vs placebo at 52 weeks |
| Contraindications | Decompensated cirrhosis; severe hepatic impairment (Child-Pugh B/C); caution with concomitant strong CYP2C8 inhibitors |
| Side effects | Diarrhoea, nausea; requires monitoring of LFTs (paradoxical ALT elevations can occur early then resolve) |
| Relevance to MetALD | Although approved for MASH, it is reasonable to consider for MetALD patients with significant metabolic-driven steatohepatitis and fibrosis, provided the alcohol component is also being addressed |
| Feature | Details |
|---|---|
| Drug class | GLP-1 receptor agonists (GLP-1 RA); tirzepatide is a dual GIP/GLP-1 RA |
| Name breakdown | GLP-1 = "Glucagon-Like Peptide 1" — an incretin hormone from gut L-cells that promotes insulin secretion, suppresses glucagon, slows gastric emptying, and promotes satiety |
| Mechanism for liver | (1) Promotes weight loss ( > 10% with semaglutide/tirzepatide) → reduces hepatic steatosis; (2) direct hepatoprotective effects — reduces hepatic inflammation and de novo lipogenesis; (3) improves insulin sensitivity |
| Relevance | GLP-1 RA for MAFLD → emerging evidence, on top of DM and obesity [4]. They achieve > 10% weight reduction, which is why they work in fibrosis patients [4]. |
| Indications in MetALD | T2DM with MetALD (strongest indication); obesity with MetALD (even without diabetes — emerging indication); MASH with fibrosis |
| Contraindications | Personal or family history of medullary thyroid carcinoma (MTC) or MEN2 syndrome (preclinical thyroid C-cell tumour risk); acute pancreatitis; severe GI disease |
| Side effects | Nausea, vomiting, diarrhoea (dose-dependent; usually transient); pancreatitis (rare); gallstones (from rapid weight loss); gastroparesis |
| Key drug | Semaglutide (Ozempic/Wegovy) — LEAN trial (liraglutide) and ongoing ESSENCE trial (semaglutide) showing MASH resolution [17] |
From the Nephrology Interactive Tutorial: "Ozempic / GLP-1 RA → semaglutide" is listed among the management options for diabetic nephropathy and vasculopathy [17], reflecting the broad cardiorenal-hepatic benefit of this drug class.
| Feature | Details |
|---|---|
| Drug class | Sodium-Glucose Co-Transporter 2 Inhibitors |
| Name breakdown | "SGLT2" = "Sodium-Glucose Linked Transporter 2" in the proximal tubule; "-gliflozin" suffix = SGLT2i |
| Mechanism for liver | (1) Glycosuria → caloric loss → modest weight reduction; (2) reduces insulin levels (less glucose reabsorption → less compensatory hyperinsulinaemia) → ↓ hepatic de novo lipogenesis; (3) anti-inflammatory effects; (4) possible direct hepatoprotective effects (improved autophagy) |
| Indications in MetALD | T2DM with MetALD; heart failure (regardless of DM status); CKD with eGFR > 20 |
| Contraindications | eGFR < 20 (for glycaemic efficacy; cardiorenal benefit may persist); recurrent UTIs or genital mycosis; T1DM (DKA risk) |
| Side effects | Genital mycotic infections (candidiasis), UTIs, euglycaemic DKA (rare), Fournier's gangrene (very rare), volume depletion |
| Evidence for liver | SGLT2i → massive reduction in risk of renal failure [17]; emerging data showing reduction in hepatic steatosis and ALT in MetALD/MASLD patients |
| Feature | Details |
|---|---|
| Drug class | PPARγ agonist (thiazolidinedione) |
| Mechanism | Activates PPARγ → promotes adipocyte differentiation → redistributes fat from liver/viscera to subcutaneous adipose tissue (a "safer" depot); improves insulin sensitivity; anti-inflammatory in liver |
| Evidence | PIVENS trial: pioglitazone improved MASH histology (resolution of steatohepatitis) in patients with or without diabetes |
| Indications | MASH with or without T2DM; can be considered in MetALD for the metabolic component |
| Contraindications | Heart failure (NYHA III–IV) — TZDs cause fluid retention [18]; pioglitazone and saxagliptin shown to have increased risk of heart failure [18]; bladder cancer (pioglitazone — controversial); osteoporosis (↑ fracture risk, especially in postmenopausal women) |
| Side effects | Weight gain (paradoxical — redistributes fat, doesn't reduce it), peripheral oedema, bone fractures, bladder cancer risk |
| Feature | Details |
|---|---|
| Mechanism | Antioxidant → scavenges ROS → reduces oxidative stress-mediated hepatocyte injury and inflammation |
| Evidence | PIVENS trial: 800 IU/day vitamin E improved MASH histology in non-diabetic patients |
| Indication | Non-diabetic adults with biopsy-proven MASH (without cirrhosis) |
| Contraindications/Cautions | Prostate cancer risk (SELECT trial — ↑ risk at high doses); all-cause mortality concern at doses > 400 IU/day (meta-analysis); haemorrhagic stroke risk at very high doses |
| Limitation | Not effective in T2DM-associated MASH (PIVENS showed benefit only in non-diabetics); limited data in MetALD specifically (alcohol component generates different ROS species via CYP2E1) |
For MetALD patients with BMI ≥ 27 with comorbidities or ≥ 30 who have not responded to lifestyle modification [19]:
| Agent | Mechanism | Typical Weight Loss | Key Considerations |
|---|---|---|---|
| Semaglutide 2.4 mg SC weekly (Wegovy) | GLP-1 RA | ~15–17% | Dual benefit for liver and cardiometabolic profile; first choice for MetALD if available |
| Tirzepatide (Mounjaro/Zepbound) | Dual GIP/GLP-1 RA | ~20–22% | Greatest weight loss of any current agent; emerging liver data |
| Orlistat | Pancreatic lipase inhibitor → ↓ fat absorption | ~5–8% | GI side effects (steatorrhoea, faecal urgency); fat-soluble vitamin malabsorption |
| Naltrexone/Bupropion (Contrave) | Opioid antagonist + noradrenaline-dopamine reuptake inhibitor → appetite suppression | ~5–8% | Contraindicated in uncontrolled HTN, seizure disorders; caution in liver disease |
| Phentermine/Topiramate | Sympathomimetic + carbonic anhydrase inhibitor | ~8–10% | Contraindicated in CVD; not widely available outside US |
For patients who meet surgical criteria:
Surgery is considered eligible if BMI ≥ 40 without comorbidity, or BMI ≥ 35 with comorbidity (e.g., diabetes, respiratory insufficiency). Lower threshold if comorbidity present (now suggesting BMI ≥ 30). [19]
| Procedure | Mechanism | Weight Loss | Liver Benefit |
|---|---|---|---|
| Roux-en-Y Gastric Bypass (RYGB) | Restrictive + malabsorptive | ~25–30% | Most data for MASH resolution; reverses fibrosis in many patients |
| Sleeve Gastrectomy | Restrictive (removes ~80% stomach) | ~20–25% | Effective for MASH; simpler procedure |
| Adjustable Gastric Banding | Restrictive (adjustable band) | ~15–20% | Less effective than RYGB/sleeve; declining use |
Contraindications for bariatric surgery in MetALD context:
- Decompensated cirrhosis (high surgical mortality — portal hypertension increases bleeding risk)
- Active alcohol dependence (relative contraindication; most bariatric programs require documented abstinence period)
- Severe coagulopathy
Key Concept — The Treatment Gap
The principle is to keep developing drugs that narrow the treatment gap between lifestyle modification alone (modest weight loss) and bariatric surgery (dramatic weight loss). GLP-1 RAs and dual agonists are closing this gap. [19]
4. Tier 3: Disease-Specific Management
In Hong Kong, dual liver disease (e.g., HBV + MetALD) is common [3][4]. Each co-existing condition requires its own specific treatment:
| Concomitant Disease | Management |
|---|---|
| Chronic HBV | Antiviral therapy (entecavir or tenofovir) if indicated by guidelines — active viral replication + active disease (elevated ALT + HBV DNA > 2000 IU/mL + moderate fibrosis) [14]. Aim: suppress HBV DNA to undetectable → prevent cirrhosis and HCC [14]. |
| Chronic HCV | Direct-acting antivirals (DAAs) — e.g., sofosbuvir/velpatasvir for 12 weeks → SVR12 = essentially a cure [13] |
| Autoimmune hepatitis | Immunosuppression (prednisolone ± azathioprine). Check TPMT and NUDT15 before starting azathioprine [20]. |
A MetALD patient may present with an acute alcoholic hepatitis flare superimposed on chronic liver disease. This is a medical emergency with high short-term mortality.
| Assessment | Details |
|---|---|
| Maddrey Discriminant Function (DF) | DF = [4.6 × (Patient PT – Control PT in seconds)] + Bilirubin (mg/dL). DF ≥ 32 → severe alcoholic hepatitis → consider corticosteroids [10][16]. |
| MELD score | MELD > 20 → less favourable assessment for steroid benefit [16] |
Management of severe alcoholic hepatitis (DF ≥ 32):
| Intervention | Details | Rationale |
|---|---|---|
| Corticosteroids (Prednisolone 40 mg/day × 28 days) | Indicated if DF ≥ 32 [16] | Reduces hepatic inflammation and short-term (28-day) mortality by ~30% |
| Contraindications to steroids | Sepsis, active GI bleeding, renal failure, pancreatitis [16] | Steroids increase infection risk in already malnourished, immunocompromised patients |
| Lille score at Day 7 | If bilirubin does not decrease 7 days after starting steroids → stop steroids (unlikely to reduce mortality) [16] | Non-responders gain no benefit and only risk from continued immunosuppression |
| Nutritional support | Good nutrition is critical; enteral feeding via nasogastric tube may be needed in severely ill patients [16] | These patients are severely malnourished; caloric intake ≥ 35 kcal/kg/day + protein ≥ 1.2 g/kg/day |
| Pentoxifylline | Anti-TNF; reduces inpatient mortality from hepatorenal failure [16]. However, monoclonal anti-TNF antibodies (infliximab) should NOT be used — increased death from infection/renal failure [16]. | Pentoxifylline is a phosphodiesterase inhibitor with modest anti-TNF properties; safer than biological anti-TNFs |
Exam Point — Don't Give Steroids to Every Alcoholic Hepatitis Patient
Steroids for alcoholic hepatitis require objective assessment — use Maddrey DF ≥ 32 or MELD > 20. Do NOT give steroids without proper scoring. These patients are malnourished and will die from infections, not the hepatitis itself [10][16]. Always check for contraindications (sepsis, bleeding, renal failure, pancreatitis) and reassess with Lille score at Day 7.
5. Tier 4: Management of Cirrhotic Complications
When MetALD has progressed to cirrhosis and decompensation, management shifts to complication-driven care. This section provides a brief overview (complications will be covered in detail in the next section):
| Line | Treatment | Mechanism |
|---|---|---|
| 1st | Sodium restriction ( < 2 g/day) + spironolactone (100–400 mg/day) ± furosemide (40–160 mg/day) | Spironolactone blocks aldosterone → natriuresis. Furosemide adds loop-level natriuresis. Typical ratio: 100:40 mg to maintain normokalemia. |
| 2nd | Therapeutic large-volume paracentesis (LVP) + albumin replacement (6–8 g/L of ascitic fluid removed) | Mechanical removal of ascitic fluid; albumin prevents post-paracentesis circulatory dysfunction |
| 3rd (Refractory ascites) | TIPS (Transjugular Intrahepatic Portosystemic Shunt) | Shunts portal blood directly to hepatic vein → reduces portal pressure. Contraindicated in patients with hepatic encephalopathy [13] since it shunts ammonia-laden blood directly to systemic circulation. |
| Setting | Management |
|---|---|
| Primary prophylaxis (varices found on screening OGD) | Non-selective beta-blockers (propranolol, carvedilol) or endoscopic variceal ligation (EVL) |
| Acute variceal bleeding | Resuscitation → octreotide/terlipressin (splanchnic vasoconstriction) → urgent OGD with EVL → IV antibiotics (ceftriaxone) → if uncontrolled → balloon tamponade → TIPS |
| Secondary prophylaxis | NSBBs + EVL (combination is superior to either alone) |
Treatment for hepatic encephalopathy → since its effects are due to increased ammonia: [13]
- Decreased production → getting rid of the bacteria that produce ammonia (rifaximin)
- Increased removal → laxatives (lactulose), "shit it all out" [13]
| Agent | Mechanism | Notes |
|---|---|---|
| Lactulose | Osmotic laxative → acidifies colonic pH → converts NH₃ to NH₄⁺ (non-absorbable) → increased faecal excretion. Also reduces ammonia-producing bacterial growth. | Titrate to 2–3 soft stools/day. First-line for both acute and maintenance. |
| Rifaximin | Non-absorbable antibiotic → reduces ammonia-producing gut bacteria (especially urease-producing species) | Add-on to lactulose for prevention of recurrent HE. Not first-line alone. |
| BCAA supplements | BCAA also used as treatment in hepatic encephalopathy, to increase ammonia removal [10] | Branched-chain amino acids promote glutamine synthesis in skeletal muscle (alternative ammonia detoxification pathway) |
| Protein restriction | Protein reduction — but not that useful since protein is crucial [13] | Old teaching was to restrict protein in HE; current evidence shows this worsens sarcopaenia and outcomes. Maintain adequate protein (1.2–1.5 g/kg/day). |
| Indication | Considerations |
|---|---|
| Decompensated cirrhosis (MELD ≥ 15) | Standard indication. MetALD patients may face additional scrutiny regarding alcohol intake. |
| HCC within Milan criteria | Single tumour ≤ 5 cm or up to 3 tumours each ≤ 3 cm, no vascular invasion, no extrahepatic spread |
| Liver transplantation is accepted for selected patients with alcoholic cirrhosis [16] | Most centres require documented period of abstinence (traditionally 6 months, increasingly flexible with emerging evidence) |
| NOT performed for acute alcoholic hepatitis | Due to increased surgical mortality and high rates of recidivism [16] — though this is evolving with recent trials showing benefit in selected non-responders to steroids |
| Treatment | Key Contraindications in MetALD Context |
|---|---|
| Resmetirom | Decompensated cirrhosis (Child-Pugh B/C); severe hepatic impairment |
| GLP-1 RA | Personal/family history of MTC or MEN2; acute pancreatitis; severe GI disease |
| SGLT2i | eGFR < 20 (for glycaemic control); T1DM (DKA risk); recurrent genital infections |
| Pioglitazone | Heart failure NYHA III–IV [18]; osteoporosis; bladder cancer history |
| Vitamin E (high dose) | Prostate cancer risk; haemorrhagic stroke; all-cause mortality concern > 400 IU/day |
| Statins | Decompensated cirrhosis; acute liver failure; grossly elevated transaminases ( > 5–10× ULN) |
| Corticosteroids (for AH) | Sepsis, active GI bleeding, renal failure, pancreatitis [16] |
| TIPS | Hepatic encephalopathy [13]; right heart failure; hepatic vein thrombosis |
| Bariatric surgery | Decompensated cirrhosis; active alcohol dependence; severe coagulopathy |
| Naltrexone | Acute hepatitis; hepatic failure; concurrent opioid use |
| Disulfiram | Severe liver disease; ischaemic heart disease; psychosis |
| Parameter | Frequency | Purpose |
|---|---|---|
| LFTs (ALT, AST, GGT) | Every 3–6 months | Monitor hepatocyte injury and alcohol biomarker |
| HbA1c, fasting glucose | Every 3–6 months | Glycaemic control |
| Lipid profile | Annually (or per CV risk) | Dyslipidaemia management |
| FibroScan (liver stiffness + CAP) | Annually if F0–F2; 6-monthly if F3 | Fibrosis progression monitoring |
| USS liver ± AFP | 6-monthly if cirrhosis | HCC surveillance |
| OGD | At diagnosis of cirrhosis; repeat per variceal status | Variceal surveillance |
| Body weight, BMI, waist circumference | Every visit | Weight loss monitoring |
| Alcohol intake (AUDIT-C) | Every visit | Alcohol reduction monitoring |
| Bone densitometry (DEXA) | Baseline if cirrhosis; repeat as indicated | Hepatic osteodystrophy |
| Mental health screening | Periodically | Depression, anxiety (common in MetALD); alcohol use disorder screening |
High Yield Summary — Management of MetALD
-
Lifestyle modification is the cornerstone for ALL patients: weight loss (5–7% for non-fibrotic, ≥10% for fibrotic), alcohol reduction/cessation, Mediterranean diet, exercise, coffee.
-
Pharmacotherapy is rapidly evolving: Resmetirom (first approved drug for MASH, 2024); GLP-1 RAs (semaglutide, tirzepatide) are emerging as game-changers with > 10% weight loss; SGLT2i for cardiorenal-hepatic benefit; pioglitazone and vitamin E for specific MASH subgroups.
-
Metabolic risk factors (DM, HTN, dyslipidaemia) must be actively managed. Statins are safe in compensated liver disease.
-
Concomitant liver disease (especially HBV in HK) requires its own specific treatment (antivirals for HBV, DAAs for HCV).
-
Acute alcoholic hepatitis flare: Maddrey DF ≥ 32 → prednisolone 40mg/day; reassess with Lille score at Day 7; contraindicated if sepsis, bleeding, renal failure, pancreatitis.
-
Cirrhotic complications: Ascites (spironolactone ± furosemide → LVP → TIPS); varices (NSBBs ± EVL); HE (lactulose + rifaximin); HCC (6-monthly USS ± AFP).
-
Liver transplantation: Accepted for decompensated cirrhosis; requires abstinence period for alcohol component; NOT for acute alcoholic hepatitis.
Active Recall — Management of MetALD
References
[1] Lecture slides: GC 240. MASLD and Alcoholic Liver Disease.pdf [3] Senior notes: Block A - Abdominal distension_ ascites and cirrhosis.pdf [4] Senior notes: Block A - Gastroenterology Interactive Tutorial.pdf (Case 2) [6] Senior notes: Block A - Jaundice after raw oysters_ acute hepatitis.pdf [10] Senior notes: Block A - Introduction to GI_Hepatology investigations (LFT, Endoscopy).pdf [13] Senior notes: Block A - Gastrointestinal Data Interpretation.pdf [14] Senior notes: Block A - I am a hepatitis B carrier.pdf [16] Senior notes: MBBS Final MB (Medicine) (Felix PY Lai).pdf (Alcoholic liver disease section) [17] Senior notes: Block A - Nephrology Interactive Tutorial.pdf [18] Senior notes: Block A - Deterioration of eyesight in a diabetic patient_ diabetic complications.pdf [19] Senior notes: Block A - I am overweight, doctor_ obesity; Hyperlipidaemia.pdf [20] Senior notes: Block A - Chronic diarrhoea_ irritable bowel syndrome and inflammatory bowel disease.pdf (Azathioprine section)
Complications of MetALD
MetALD complications arise from the progressive liver injury spectrum (steatosis → steatohepatitis → fibrosis → cirrhosis) and from the metabolic syndrome that defines the condition. Because MetALD involves a synergistic dual-hit, complications tend to develop earlier and more aggressively than in either MASLD or ALD alone. Additionally, the metabolic component drives significant extrahepatic morbidity — particularly cardiovascular disease, which is actually the leading cause of death in early-stage SLD, not liver disease itself.
The complications can be organised into three categories:
- Hepatic complications (from progressive liver disease)
- Extrahepatic complications (from metabolic syndrome and systemic inflammation)
- Complications specific to alcohol (neurological, psychiatric, nutritional)
1. Hepatic Complications
These complications follow the natural progression of MetALD toward cirrhosis and decompensation.
- MetALD has a higher rate of fibrosis progression than either MASLD or ALD alone, because:
- Both metabolic and alcohol pathways converge on hepatic stellate cell activation (via TGF-β from Kupffer cells + direct acetaldehyde-mediated activation)
- Double suppression of β-oxidation → more severe steatohepatitis → more hepatocyte necrosis → more fibrogenesis
- Cirrhosis is defined histologically as diffuse distortion of liver architecture with formation of regenerative nodules, surrounded by fibrous bands (F4) [3]
- Once cirrhosis develops, further complications fall into two broad categories: portal hypertension and hepatocellular dysfunction
Six associated complications of liver failure: Infections, Variceal bleeding, Ascites / SBP, Hepatorenal syndrome, Hepatic encephalopathy, Coagulopathy (+HCC) [21]
1.2 Portal Hypertension and Its Consequences
Why does portal hypertension develop?
- In cirrhosis, fibrotic bands and regenerative nodules compress hepatic sinusoids → increased intrahepatic vascular resistance (mechanical component)
- Additionally, activated stellate cells (which have contractile properties like smooth muscle) cause dynamic sinusoidal constriction → further increases resistance
- Simultaneously, splanchnic vasodilation (from ↑ NO production in response to portal hypertension) leads to decreased effective arterial blood volume → activates RAAS and sympathetic nervous system → sodium and water retention
- Clinically significant portal hypertension is defined as HVPG ≥ 10 mmHg [3]
The most common complication of cirrhosis (~60% of patients develop ascites within 10 years of compensated cirrhosis).
Pathophysiology (understand from first principles):
The "peripheral arterial vasodilation hypothesis" explains ascites formation:
- Portal hypertension → splanchnic arteriolar vasodilation (mediated by ↑ NO) → ↓ effective arterial blood volume (EABV)
- ↓ EABV → baroreceptor activation → RAAS activation + sympathetic activation + ADH release (non-osmotic)
- Result: sodium and water retention by kidneys
- Combined with: ↑ hydrostatic pressure in portal venous system (pushes fluid out of splanchnic capillaries into peritoneum) + ↓ oncotic pressure (from hypoalbuminaemia — liver can't synthesise adequate albumin)
- Net result: transudation of fluid into peritoneal cavity → ascites
Diagnosis:
- Clinical: abdominal distension, shifting dullness, fluid thrill
- Diagnostic paracentesis: SAAG (Serum-Ascites Albumin Gradient)
- SAAG ≥ 11 g/L → portal hypertensive ascites (cirrhosis, heart failure, Budd-Chiari)
- SAAG < 11 g/L → non-portal hypertensive (peritoneal carcinomatosis, TB peritonitis, nephrotic syndrome, pancreatitis)
Complications of ascites:
- Spontaneous Bacterial Peritonitis (SBP) — see below
- Refractory ascites — fails to respond to maximal diuretic therapy
- Hepatic hydrothorax — ascitic fluid translocates through diaphragmatic defects (usually right-sided pleural effusion)
A dreaded complication — infection of ascitic fluid without an identifiable intra-abdominal surgical source.
Pathophysiology:
- In cirrhosis, the gut barrier is compromised (alcohol and metabolic dysfunction both ↑ intestinal permeability → "leaky gut")
- Bacteria translocate from the gut lumen → mesenteric lymph nodes → bloodstream → ascitic fluid
- Impaired hepatic clearance (↓ Kupffer cell function, ↓ complement/opsonin production) → bacteraemia is not cleared → seeds ascitic fluid
- Liver failure causes reticuloendothelial dysfunction and reduced opsonization → impaired ability to clear toxins and reduced production of immune factors [21]
- Low ascitic fluid protein ( < 15 g/L) = low opsonic activity = high risk for SBP
Diagnosis:
- Ascitic fluid PMN (polymorphonuclear) count ≥ 250 cells/mm³ = diagnostic of SBP (even before culture returns)
- Culture: most commonly E. coli, Klebsiella, Streptococcus pneumoniae (monomicrobial, gram-negative predominant)
Why is SBP important? Hospital mortality is ~20%; 1-year recurrence rate is ~70% without prophylaxis. It is an indication for liver transplant assessment.
Pathophysiology:
- Portal hypertension → blood seeks alternative routes to bypass the high-resistance liver → portosystemic collaterals form
- Most clinically significant collaterals: oesophageal varices (via left gastric/coronary vein → oesophageal venous plexus → azygos system) and gastric varices
- As varices enlarge, the vessel wall tension increases (LaPlace's law: wall tension ∝ transmural pressure × radius) → eventually ruptures → massive upper GI haemorrhage
- Mortality per bleeding episode: ~15–20% (improving with modern therapy)
Key points from lectures:
- Screening OGD is indicated in all patients with cirrhosis to detect varices
- Primary prophylaxis: non-selective beta-blockers (carvedilol, propranolol) or endoscopic variceal ligation (EVL)
Pathophysiology (understand the cascade):
- Advanced cirrhosis → severe splanchnic vasodilation → profound ↓ EABV
- Maximal RAAS/SNS/ADH activation → intense renal vasoconstriction (kidneys sacrifice their own perfusion to maintain systemic BP)
- Result: functional renal failure — kidneys are structurally normal but functionally impaired due to extreme haemodynamic compromise
- The kidneys would work perfectly if transplanted into a healthy body — the problem is upstream (the cirrhotic liver)
Classification:
- HRS-AKI (previously Type 1): rapidly progressive renal failure (creatinine doubles within 2 weeks); often triggered by SBP, GI bleeding, or large-volume paracentesis without albumin replacement. Carries very high mortality.
- HRS-CKD (previously Type 2): slowly progressive renal impairment; associated with refractory ascites. Better short-term prognosis but still indicative of advanced disease.
Management:
- Albumin (volume expansion to improve EABV) + vasoconstrictors (terlipressin or noradrenaline — to counteract splanchnic vasodilation)
- Definitive treatment: liver transplantation (only cure, since the kidney itself is normal)
- TIPS can improve renal function in selected cases by reducing portal pressure and improving effective circulating volume [13]
1.3 Hepatocellular Dysfunction and Its Consequences
Confusion in cirrhosis does NOT mean hepatic encephalopathy. In fact, confusion in cirrhosis is still most commonly caused by head injury and drug-related causes. HE is a less common cause of confusion in cirrhosis. [12]
Pathophysiology:
- In cirrhosis, the liver fails to metabolise ammonia (NH₃) to urea (via the urea cycle)
- Additionally, portosystemic shunts divert ammonia-laden portal blood directly to systemic circulation, bypassing the liver
- ↑ Arterial ammonia → crosses BBB → taken up by astrocytes → glutamine synthetase converts NH₃ + glutamate → glutamine (osmolyte) → astrocyte swelling → cerebral oedema → altered neurotransmission
- Also: ↑ GABAergic tone (from endogenous benzodiazepine-like substances), ↑ manganese deposition in basal ganglia, neuroinflammation
Grading (West Haven Criteria):
| Grade | Clinical Features |
|---|---|
| Covert (Minimal/Grade 1) | Psychometric test abnormalities only (subclinical); trivial lack of awareness, shortened attention span |
| Grade 2 | Bedside, usually when patients realise symptoms and present [13]; lethargy, disorientation to time, personality change, asterixis |
| Grade 3 | Somnolent but rousable; confused, bizarre behaviour; marked asterixis [13] |
| Grade 4 | Coma; unrousable; may require intubation in ICU [13] |
Diagnosis:
- A diagnosis by exclusion — no single test is diagnostic [12]
- Arterial ammonia: not always raised, may not correlate with severity. Not all nitrogenous compounds are ammonia. [12]
- EEG abnormalities: for difficult cases or ICU patients [12]
- Psychometric tests: constructional apraxia (drawing a 5-point star), Reitan's number connection test [12]
- Must exclude: head injury (CT brain), drug effects (drug history, urine toxicology), infection (septic screen), metabolic disturbances (electrolytes, glucose), alcohol withdrawal [12]
Precipitating factors (very commonly examined):
- Infection (most common precipitant — SBP, UTI, pneumonia)
- GI bleeding (blood in gut → ↑ ammonia production by gut bacteria)
- Constipation (↑ time for bacterial ammonia production in colon)
- Dehydration / electrolyte imbalance (especially hypokalaemia → metabolic alkalosis → more NH₃ crosses BBB)
- Drugs (sedatives, opioids, benzodiazepines — impaired hepatic clearance)
- High protein load (dietary or from GI bleeding)
- TIPS (portosystemic shunt → more ammonia bypasses liver)
- Acute kidney injury (↓ renal ammonia excretion)
- Non-compliance with lactulose/rifaximin
High Yield — HE Precipitants
In any exam question about a cirrhotic patient presenting with confusion, you MUST systematically search for and identify the precipitant. The management of HE is not just lactulose — it is identifying and treating the trigger. A favourite exam scenario is a cirrhotic patient with SBP precipitating HE.
Pathophysiology: The liver synthesises virtually all clotting factors (except Factor VIII, which is also made by endothelial cells and is actually elevated in cirrhosis) and natural anticoagulants (Protein C, Protein S, Antithrombin).
In cirrhosis:
- ↓ Pro-coagulant factors (II, V, VII, IX, X, XI, fibrinogen) → bleeding tendency
- ↓ Anti-coagulant factors (Protein C, S, Antithrombin) → paradoxically, thrombotic tendency
- ↓ Thrombopoietin production → ↓ platelet count (compounded by splenic sequestration from splenomegaly)
- Dysfibrinogenaemia (abnormal fibrinogen with altered sialic acid content)
- Result: a "rebalanced haemostasis" — the cirrhotic patient is in a precarious equilibrium that can tip toward either bleeding OR thrombosis depending on the clinical context
Clinical relevance:
- INR is the best marker for monitoring liver synthetic function [6], but does NOT reliably predict bleeding risk in cirrhosis (because standard PT/INR only measures pro-coagulant factors, not the counterbalancing loss of anticoagulants)
- Factor VII has the shortest half-life (~6 hours) [6] — first to drop, making PT/INR an early marker of failing synthetic function
Infections in liver failure are very common [21].
Why are cirrhotic patients immunocompromised?
- Reticuloendothelial dysfunction and reduced opsonization [21]
- Kupffer cells (liver-resident macrophages) are dysfunctional → impaired clearance of bacteria from portal blood
- ↓ Production of complement components (C3, C4) → ↓ opsonisation
- ↓ Production of pattern-recognition receptors
- Portal hypertension → portosystemic shunts → bacteria bypass hepatic filtration
- Gut barrier dysfunction ("leaky gut") → increased bacterial translocation
- Malnutrition → impaired cellular immunity
Common infections:
- Especially from the respiratory and urinary tract [21]
- Organisms: Staph, Strep, gram-negative rods [21]
- Bacteraemia in up to 25% of fulminant hepatic failure patients [21]
- Fungal infection: especially Candida [21]
- SBP (see above)
Key implication: In MetALD patients with cirrhosis, any acute deterioration (confusion, fever, worsening jaundice, worsening ascites) → always screen for infection (blood cultures, urine culture, CXR, diagnostic paracentesis if ascites present).
- HCC surveillance is indicated for MetALD/MASLD patients with cirrhosis (6-monthly USS ± AFP) [4]
- For other causes of HCC such as MAFLD, cirrhosis is one of the requirements [4]
- This is in contrast to HBV, where HCC can occur without cirrhosis (via direct HBV DNA integration), so age-based surveillance criteria apply: Male ≥ 40, Female ≥ 50, or underlying cirrhosis, or family history of HCC [4]
- MetALD-related HCC has some unique features:
- May present at larger size (compared to viral hepatitis HCC) because surveillance is less established/less systematic for SLD
- Often occurs in patients without recognised cirrhosis (up to 20–30% of MASLD/MetALD-HCC arises in non-cirrhotic livers, though cirrhosis is the major risk factor)
- Metabolic comorbidities (obesity, DM) may complicate surgical candidacy
Mechanisms of hepatocarcinogenesis in MetALD:
- Chronic inflammation → repeated hepatocyte necrosis and regeneration → ↑ DNA replication errors → oncogenic mutations accumulate
- Oxidative DNA damage from CYP2E1-generated ROS and lipid peroxidation products
- Insulin resistance → ↑ IGF-1 signalling → promotes hepatocyte proliferation
- Altered gut microbiome → secondary bile acid production → FXR pathway deregulation
- Acetaldehyde-DNA adducts → mutagenesis
A distinct syndrome where a patient with chronic liver disease (e.g., MetALD-cirrhosis) experiences an acute deterioration with multi-organ failure.
Precipitants: infection (most common), GI bleeding, active alcoholism (binge on top of MetALD), DILI, variceal bleeding, surgery
Prognostic factors for ACLF depend on 6 organ-specific factors [21]:
- Cerebral: HE
- Respiration: SaO₂/FiO₂
- Circulation: Need for vasopressors
- Liver: Bilirubin level
- Coagulation: INR level
- Kidney: Creatinine level
All 3 components of the MELD score (bilirubin, INR, creatinine) are present in the ACLF assessment → MELD score is still useful in prognosticating ACLF as well, not just for acute liver failure and transplant prioritisation [21]
2. Extrahepatic Complications (Metabolic / Cardiovascular)
These complications are driven by the metabolic syndrome component of MetALD and are critically important because cardiovascular disease is the #1 cause of death in early-stage SLD — not liver disease.
- MetALD patients have all the cardiovascular risk factors clustered together: T2DM, hypertension, dyslipidaemia, obesity, insulin resistance
- Additionally, liver disease itself contributes to CVD:
- Hepatic inflammation → systemic inflammation (↑ CRP, ↑ IL-6, ↑ TNF-α) → accelerated atherosclerosis
- Dyslipidaemia pattern: ↑ TG, ↓ HDL-C, ↑ small dense LDL particles (most atherogenic subtype)
- ↑ Coagulation factor production (fibrinogen, Factor VIII) → pro-thrombotic state
- ↑ PAI-1 (plasminogen activator inhibitor-1) from steatotic liver → impaired fibrinolysis
Manifestations: ischaemic heart disease, stroke, peripheral arterial disease, heart failure
This is why statin therapy and aggressive CVD risk factor management are essential even in patients with liver disease — the liver concern should not prevent cardioprotective treatment.
- MetALD and T2DM have a bidirectional relationship:
- Insulin resistance → hepatic steatosis (MetALD driver)
- Hepatic steatosis → worsens insulin resistance (↑ hepatic glucose output, impaired insulin clearance) → accelerates T2DM
- Progression: hyperinsulinaemic euglycaemia → impaired glucose tolerance → early T2DM (relative insulin deficiency) → late T2DM (absolute insulin deficiency from progressive β-cell loss due to glucotoxicity and lipotoxicity) [8]
- In cirrhosis: "hepatogenous diabetes" can develop even without pre-existing metabolic syndrome, because the cirrhotic liver cannot clear insulin properly (↑ portal-systemic shunting) and has impaired glycogen storage
- MetALD is an independent risk factor for CKD, through:
- Shared risk factors (DM, HTN)
- Systemic inflammation and oxidative stress
- RAAS activation in cirrhosis → renal vasoconstriction
- Hepatorenal syndrome (see above) in advanced disease
- Strongly associated with obesity/metabolic syndrome
- Intermittent nocturnal hypoxia → oxidative stress → worsens hepatic inflammation and fibrosis
- Creates a vicious cycle: OSA → worse liver disease → worse metabolic derangement → worse OSA
3. Complications Specific to the Alcohol Component
While MetALD patients are by definition moderate (not heavy) drinkers, the alcohol intake is sufficient to contribute to specific complications, especially when combined with metabolic dysfunction:
- Relevant if the MetALD patient is admitted and abruptly stops alcohol
- Spectrum (in order of timing):
- 6–12 hours: tremor, anxiety, diaphoresis, tachycardia, insomnia (autonomic hyperactivity from CNS excitation — loss of GABA inhibition + glutamate excitation unmasked)
- 12–24 hours: alcoholic hallucinosis (visual/auditory hallucinations with intact sensorium)
- 24–48 hours: withdrawal seizures (generalised tonic-clonic)
- 48–96 hours: delirium tremens (DT) — confusion, agitation, hallucinations, autonomic instability, fever. Mortality 5–15% if untreated.
AOS Psychiatry: "1 MCQ on medical situation — what is delirium vs delirium tremens. 1 MCQ on alcohol withdrawal — how to manage (complications: seizure etc)" [22]
Management of alcohol withdrawal:
- Benzodiazepines (chlordiazepoxide, diazepam, or lorazepam) — GABA-A agonists to replace the lost inhibitory tone
- In cirrhosis: prefer lorazepam or oxazepam (metabolised by glucuronidation, NOT hepatic CYP450 → safer in liver disease)
- Avoid long-acting benzodiazepines (diazepam) in severe liver disease — risk of accumulation
- Thiamine (vitamin B1) supplementation — MUST give before glucose to prevent Wernicke's encephalopathy
- Monitoring: CIWA-Ar score (Clinical Institute Withdrawal Assessment for Alcohol, revised) — guides benzodiazepine dosing
- Wernicke's encephalopathy: acute neurological emergency from thiamine deficiency
- Triad: confusion, ophthalmoplegia (CN VI palsy), ataxia (classic triad present in < 30% of cases)
- Pathology: haemorrhagic necrosis of mammillary bodies and periventricular grey matter
- Treatment: IV thiamine (Pabrinex) BEFORE glucose — giving glucose without thiamine can precipitate or worsen Wernicke's (glucose metabolism consumes thiamine via the pentose phosphate pathway and TCA cycle)
- Korsakoff's syndrome: chronic, irreversible sequela if Wernicke's is not treated
- Anterograde amnesia (cannot form new memories), confabulation (fabricates memories to fill gaps)
- Pathology: persistent mammillary body atrophy
- Chronic alcohol consumption is directly toxic to cardiomyocytes → dilated cardiomyopathy → heart failure
- Mechanism: acetaldehyde damages myocyte mitochondria, disrupts calcium handling, causes myocyte apoptosis
- Reversible if alcohol is ceased early enough; otherwise progressive
- In MetALD, this compounds the already elevated cardiovascular risk from metabolic syndrome
- Alcohol is directly neurotoxic + chronic alcohol use → thiamine deficiency → impaired nerve metabolism
- Distal symmetrical sensorimotor polyneuropathy (glove-and-stocking distribution)
- Often overlaps with diabetic neuropathy in MetALD patients → difficult to disentangle clinically
- Alcohol is the major cause of both acute and chronic pancreatitis
- In MetALD patients, gallstones (from obesity/metabolic syndrome) are also a major cause of acute pancreatitis — so the dual aetiology applies to the pancreas as well as the liver
- Chronic pancreatitis → pancreatic exocrine insufficiency (steatorrhoea, malabsorption) and endocrine insufficiency (pancreatogenic diabetes — even harder to manage because both β-cells AND α-cells are destroyed) [23]
| Deficiency | Mechanism | Clinical Consequence |
|---|---|---|
| Thiamine (B1) | ↓ Dietary intake + impaired intestinal absorption by alcohol | Wernicke-Korsakoff, peripheral neuropathy, high-output cardiac failure (wet beriberi) |
| Folate | ↓ Dietary intake + impaired absorption + alcohol inhibits dihydrofolate reductase | Macrocytic anaemia |
| Vitamin B12 | Less commonly deficient than folate; but chronic gastritis from alcohol → impaired IF production | Macrocytic anaemia, neuropathy |
| Vitamin D | Impaired hepatic 25-hydroxylation in liver disease + ↓ dietary intake + ↓ sunlight exposure | Hepatic osteodystrophy, osteoporosis → fractures |
| Zinc | ↓ Dietary intake + ↑ urinary losses from alcohol | Impaired immune function, delayed wound healing, dysgeusia |
| Magnesium | ↑ Renal losses from alcohol + ↓ dietary intake | Muscle cramps, arrhythmias, seizure threshold lowering |
| Category | Complication | Key Pathophysiological Mechanism | Clinical Relevance |
|---|---|---|---|
| Hepatic — Portal HTN | Ascites | Splanchnic vasodilation → ↓ EABV → RAAS → Na/H₂O retention + ↓ oncotic pressure + ↑ hydrostatic pressure | Most common complication of cirrhosis |
| SBP | Gut bacterial translocation + impaired hepatic clearance → infection of ascitic fluid | PMN ≥ 250; mortality ~20% | |
| Variceal bleeding | Portosystemic collaterals under high pressure → rupture | Mortality ~15–20% per episode | |
| Hepatorenal syndrome | Extreme renal vasoconstriction from maximal neurohumoral activation in advanced cirrhosis | Functional renal failure; only cure is transplant | |
| Hepatic — Dysfunction | Hepatic encephalopathy | ↑ Ammonia (impaired clearance + shunting) → astrocyte swelling → cerebral oedema | Diagnosis of exclusion; always find precipitant |
| Coagulopathy | ↓ Clotting factors + ↓ anticoagulants + ↓ platelets = "rebalanced haemostasis" | Can bleed OR clot; INR monitors synthetic function | |
| Infections | Reticuloendothelial dysfunction + ↓ opsonins + leaky gut | Trigger for ACLF; always screen | |
| HCC | Chronic inflammation + oxidative damage + regeneration → oncogenic mutations | 6-monthly USS ± AFP if cirrhosis | |
| ACLF | Acute insult on chronic liver disease → multi-organ failure | Prognosticate with MELD / CLIF-ACLF | |
| Extrahepatic | CVD (IHD, stroke) | Metabolic syndrome + systemic inflammation + pro-thrombotic state | #1 cause of death in early SLD |
| T2DM progression | Bidirectional: IR → steatosis → worsens IR → accelerates DM | "Hepatogenous diabetes" in cirrhosis | |
| CKD | Shared risk factors + RAAS activation + systemic inflammation | HRS is the extreme end | |
| Alcohol-specific | Withdrawal syndromes | CNS excitatory rebound (↓ GABA, ↑ glutamate) after chronic alcohol cessation | DT mortality 5–15% if untreated |
| Wernicke-Korsakoff | Thiamine deficiency → haemorrhagic necrosis of mammillary bodies | Give thiamine BEFORE glucose | |
| Alcoholic cardiomyopathy | Direct myocyte toxicity by acetaldehyde | Compounds metabolic CVD risk | |
| Pancreatitis | Alcohol + gallstones from metabolic syndrome → dual aetiology | Chronic → exocrine + endocrine insufficiency | |
| Nutritional deficiencies | ↓ Intake + impaired absorption + ↑ losses | Thiamine, folate, vitamin D, zinc, magnesium |
High Yield Summary — Complications of MetALD
-
Cardiovascular disease is the #1 killer in early-stage MetALD — not liver disease. Aggressive CVD risk management is paramount.
-
Six complications of liver failure: Infections, variceal bleeding, ascites/SBP, hepatorenal syndrome, hepatic encephalopathy, coagulopathy (+HCC).
-
Hepatic encephalopathy is a diagnosis of exclusion. Confusion in cirrhosis is most commonly from head injury or drugs, NOT HE. Always search for precipitants (infection, GI bleeding, constipation, drugs, electrolyte imbalance, AKI).
-
SBP: ascitic PMN ≥ 250 = diagnostic. Mechanism: gut bacterial translocation + impaired hepatic clearance + low ascitic opsonic activity.
-
HRS: functional renal failure from extreme renal vasoconstriction. Treatment: albumin + terlipressin. Definitive cure: liver transplant.
-
Coagulopathy in cirrhosis is "rebalanced" — both pro-coagulant AND anti-coagulant factors are reduced. INR does NOT reliably predict bleeding risk.
-
HCC surveillance in MetALD: 6-monthly USS ± AFP if cirrhosis. In HBV: age-based criteria apply regardless of cirrhosis status.
-
Alcohol withdrawal: spectrum from tremor to delirium tremens. Use lorazepam/oxazepam in liver disease. Always give thiamine BEFORE glucose.
-
ACLF: prognosticate with 6 organ-specific factors (cerebral, respiratory, circulatory, liver, coagulation, kidney) — all 3 MELD components are included.
Active Recall — Complications of MetALD
References
[3] Senior notes: Block A - Abdominal distension_ ascites and cirrhosis.pdf [4] Senior notes: Block A - Gastroenterology Interactive Tutorial.pdf (Case 2) [6] Senior notes: Block A - Jaundice after raw oysters_ acute hepatitis.pdf [8] Senior notes: Ryan Ho Endocrine.pdf (Type 2 DM section) [12] Senior notes: Block A - A jaundiced and incoherent patient_ liver failure.pdf [13] Senior notes: Block A - Gastrointestinal Data Interpretation.pdf [21] Senior notes: Block A - A jaundiced and incoherent patient_ liver failure.pdf (Complications section) [22] AOS material: AOS - Psych.md [23] Senior notes: Block A - Upper abdominal pain_ peptic ulcer; pancreatitis and gallstone.pdf (Chronic pancreatitis section)
High Yield Summary
-
MetALD = Metabolic dysfunction-associated steatotic liver disease + moderate alcohol use (140–350 g/wk women, 210–420 g/wk men) — a NEW 2023 category on the SLD spectrum between MASLD and ALD.
-
Pathophysiology = synergistic dual-hit: insulin resistance (↑ FFA, ↑ DNL, ↓ β-oxidation) + alcohol metabolism (CYP2E1 → ROS, ↑ NADH/NAD⁺, acetaldehyde toxicity, gut-derived LPS). Both converge on Kupffer cell activation, stellate cell fibrogenesis, and oxidative stress in Zone 3.
-
Risk factors = metabolic syndrome (obesity, T2DM, dyslipidaemia, HTN) + moderate alcohol + genetic susceptibility (PNPLA3) + high fructose diet + sedentary lifestyle. In HK, concomitant HBV is extremely common.
-
Clinical features: Often asymptomatic early. Key signs = hepatomegaly, features of metabolic syndrome (acanthosis nigricans, central obesity), chronic liver disease signs (spider naevi, palmar erythema, gynaecomastia), and eventually decompensation signs (jaundice, ascites, encephalopathy).
-
AST:ALT ratio in MetALD is often intermediate (1:1 to 2:1), with elevated GGT. This contrasts with pure MASLD (ALT > AST) and pure ALD (AST:ALT ≥ 2:1).
-
Non-invasive assessment: FibroScan (liver stiffness > 12 kPa suggests cirrhosis; CAP > 280 dB/m suggests severe steatosis). Child-Pugh score subclassifies cirrhosis (A = compensated, B/C = decompensated).
-
HCC surveillance: In MetALD/MASLD, cirrhosis is generally required before commencing 6-monthly USS ± AFP. In HBV, age-based criteria apply.
-
Weight loss: 5–7% for non-fibrotic SLD, ≥10% for fibrotic SLD. GLP-1 receptor agonists are emerging evidence-based treatments.
High Yield Summary — Differential Diagnosis of MetALD
-
Within SLD: Differentiate MetALD from MASLD and ALD based on alcohol intake thresholds (MetALD = 140–350 g/wk women, 210–420 g/wk men + ≥1 metabolic risk factor). AST:ALT ratio and GGT help but are not definitive.
-
Must exclude: Chronic HBV (most common cause of liver disease in HK), HCV, autoimmune hepatitis, PBC/PSC, Wilson's disease, haemochromatosis, DILI (including herbal medicines), hypothyroidism.
-
Concomitant disease is the rule, not the exception: In HK, dual/triple pathology (HBV + MetALD ± others) is extremely common. Finding one diagnosis does not exclude another.
-
Confusion in cirrhosis ≠ HE: Must exclude head injury, drugs, infection, metabolic disturbance, and withdrawal states. HE is a diagnosis of exclusion.
-
Isolated GGT elevation (with normal ALP): Think alcohol, drugs (enzyme induction), or fatty liver — NOT cholestasis.
-
Drug history: Always ask about supplements, herbal medicines, and TCM in Hong Kong patients.
High Yield Summary — Diagnostic Criteria, Algorithm & Investigations for MetALD
-
Three pillars for MetALD diagnosis: (a) Hepatic steatosis on imaging/biopsy, (b) ≥1 cardiometabolic risk factor, (c) Alcohol 140–350 g/wk (F) or 210–420 g/wk (M). Plus exclusion or acknowledgment of other aetiologies.
-
Algorithm: Confirm steatosis → Quantify alcohol + assess CMR → Classify on SLD spectrum → Aetiological screen (viral, autoimmune, metabolic, drug) → Stage fibrosis → Screen for complications if cirrhosis.
-
LFT interpretation: ALT/AST = damage markers; albumin/INR = synthetic function; ALP/GGT/bilirubin = excretory function. AST:ALT ratio is intermediate in MetALD. GGT is disproportionately elevated due to alcohol induction.
-
Non-invasive fibrosis staging: FIB-4 and NFS as first-line triage; FibroScan (LS > 12 kPa = cirrhosis; CAP > 280 = severe steatosis) as second-line. Biopsy reserved for discordant results or when histology changes management.
-
Aetiological screen must be performed in every patient: HBV/HCV serology, autoimmune markers, iron/copper studies, A1AT, TFT, drug history. Dual liver disease is the rule in Hong Kong.
-
HCC surveillance: 6-monthly USS ± AFP for MetALD patients with cirrhosis. Different criteria for HBV (age-based).
-
Portal hypertension: HVPG (gold standard but not routinely done); USS and OGD for practical assessment.
High Yield Summary — Management of MetALD
-
Lifestyle modification is the cornerstone for ALL patients: weight loss (5–7% for non-fibrotic, ≥10% for fibrotic), alcohol reduction/cessation, Mediterranean diet, exercise, coffee.
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Pharmacotherapy is rapidly evolving: Resmetirom (first approved drug for MASH, 2024); GLP-1 RAs (semaglutide, tirzepatide) are emerging as game-changers with > 10% weight loss; SGLT2i for cardiorenal-hepatic benefit; pioglitazone and vitamin E for specific MASH subgroups.
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Metabolic risk factors (DM, HTN, dyslipidaemia) must be actively managed. Statins are safe in compensated liver disease.
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Concomitant liver disease (especially HBV in HK) requires its own specific treatment (antivirals for HBV, DAAs for HCV).
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Acute alcoholic hepatitis flare: Maddrey DF ≥ 32 → prednisolone 40mg/day; reassess with Lille score at Day 7; contraindicated if sepsis, bleeding, renal failure, pancreatitis.
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Cirrhotic complications: Ascites (spironolactone ± furosemide → LVP → TIPS); varices (NSBBs ± EVL); HE (lactulose + rifaximin); HCC (6-monthly USS ± AFP).
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Liver transplantation: Accepted for decompensated cirrhosis; requires abstinence period for alcohol component; NOT for acute alcoholic hepatitis.
High Yield Summary — Complications of MetALD
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Cardiovascular disease is the #1 killer in early-stage MetALD — not liver disease. Aggressive CVD risk management is paramount.
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Six complications of liver failure: Infections, variceal bleeding, ascites/SBP, hepatorenal syndrome, hepatic encephalopathy, coagulopathy (+HCC).
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Hepatic encephalopathy is a diagnosis of exclusion. Confusion in cirrhosis is most commonly from head injury or drugs, NOT HE. Always search for precipitants (infection, GI bleeding, constipation, drugs, electrolyte imbalance, AKI).
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SBP: ascitic PMN ≥ 250 = diagnostic. Mechanism: gut bacterial translocation + impaired hepatic clearance + low ascitic opsonic activity.
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HRS: functional renal failure from extreme renal vasoconstriction. Treatment: albumin + terlipressin. Definitive cure: liver transplant.
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Coagulopathy in cirrhosis is "rebalanced" — both pro-coagulant AND anti-coagulant factors are reduced. INR does NOT reliably predict bleeding risk.
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HCC surveillance in MetALD: 6-monthly USS ± AFP if cirrhosis. In HBV: age-based criteria apply regardless of cirrhosis status.
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Alcohol withdrawal: spectrum from tremor to delirium tremens. Use lorazepam/oxazepam in liver disease. Always give thiamine BEFORE glucose.
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ACLF: prognosticate with 6 organ-specific factors (cerebral, respiratory, circulatory, liver, coagulation, kidney) — all 3 MELD components are included.
MASLD & MASH
Metabolic dysfunction-associated steatotic liver disease (MASLD) is hepatic steatosis associated with cardiometabolic risk factors, which can progress to its inflammatory subtype, metabolic dysfunction-associated steatohepatitis (MASH), characterized by lobular inflammation, hepatocyte ballooning, and risk of fibrosis.
Alcoholic Liver Disease
Alcoholic liver disease is a spectrum of hepatic injury caused by chronic excessive alcohol consumption, ranging from fatty liver (steatosis) to alcoholic hepatitis and ultimately cirrhosis.