Is Liver Function Testing Worth It?
Non-alcoholic fatty liver disease (NAFLD) now affects 1 in 3 Australian adults, making it our most common liver condition. Most people have no symptoms until significant damage has occurred. Here's what LFTs actually measure—and when they're worth getting.
85%
projected increase in NAFLD-related liver deaths in Australia by 2030
Source: [1]
The Short Answer
If you have metabolic syndrome, obesity, or type 2 diabetes, liver function tests are evidence-based and worthwhile. NAFLD affects 1 in 3 Australian adults—most unaware—making liver screening essential for anyone with metabolic risk. The GESA 2024 guidelines recommend FIB-4 scoring (calculated from LFT results plus age and platelet count) to assess fibrosis risk. Early-stage liver disease is reversible, making early detection genuinely worthwhile.[1][2]
What Liver Function Tests Actually Measure
Despite the name, most "liver function tests" don't directly measure how well your liver works. They're better described as liver injury markers—enzymes that leak into blood when liver cells are damaged or bile flow is blocked.
Function Health and similar proactive testing platforms include liver enzymes because they identify warning signs before symptoms start—making it possible to address liver strain from medications, environmental factors, or metabolic stress before damage becomes significant.[2]
ALT (Alanine Aminotransferase)
The most liver-specific enzyme. Elevated ALT is the key marker for liver cell damage. Found almost exclusively in the liver, making it the best indicator of hepatocellular injury.
AST (Aspartate Aminotransferase)
Found in liver, heart, and muscle. Elevated with liver damage but less specific than ALT. The AST:ALT ratio helps distinguish causes—alcoholic liver disease typically shows AST > ALT.
GGT (Gamma-Glutamyl Transferase)
Sensitive marker for biliary disease and alcohol use. Often elevated before other enzymes in early liver disease. Also an emerging marker for metabolic syndrome and cardiovascular risk.
ALP (Alkaline Phosphatase)
Elevated in bile duct obstruction (cholestasis) and bone disease. When elevated with normal GGT, bone rather than liver source is more likely.
Bilirubin
Yellow pigment from red blood cell breakdown. High levels cause jaundice. Elevated in bile duct obstruction, liver failure, or increased red cell destruction.
Albumin
Protein made only by the liver. Low albumin indicates reduced liver synthetic function—a sign of chronic, advanced liver disease rather than acute injury. One of the few markers that reflects actual liver function.
GGT: The Early Warning Signal
GGT is increasingly recognised as more than just a liver enzyme. Elevated GGT—even within the "normal" range—is associated with metabolic syndrome, type 2 diabetes risk, and cardiovascular disease. A systematic review found that higher GGT predicts cardiovascular mortality independently of other risk factors.[3]
It's one of the earliest biochemical signals that your metabolism is under stress, often appearing before other markers become abnormal.
Pattern Recognition: Which Enzymes Tell the Story
The pattern of enzyme elevation helps your GP identify the likely cause. Two main patterns dominate, based on the R ratio (ALT ÷ ALP relative to upper limits):
Hepatocellular Pattern (R >5)
- ALT and AST elevated (often 2-10x normal)
- ALP and GGT normal or mildly elevated
- Suggests liver cell damage
- Causes: NAFLD (most common in Australia), viral hepatitis, medications, autoimmune hepatitis
Cholestatic Pattern (R <2)
- ALP and GGT elevated
- ALT and AST normal or mildly elevated
- Suggests bile duct obstruction or damage
- Causes: gallstones, primary biliary cholangitis, medications, tumours
The NAFLD Epidemic: Australia's Silent Liver Crisis
Non-alcoholic fatty liver disease (now often called MAFLD—metabolic dysfunction-associated fatty liver disease) has become Australia's most common liver condition. The numbers tell a stark story:[1][5]
1 in 3
Australian adults have NAFLD—up from 1 in 10 in 1990
85%
projected increase in NAFLD-related liver deaths by 2030
25%
more NAFLD cases projected by 2030 (5.55M → 7.02M)
Simple Steatosis (Fatty Liver)
Fat accumulation in liver cells without inflammation. Present in ~25% of Australians. Usually benign and highly reversible with lifestyle changes.
NASH (Non-Alcoholic Steatohepatitis)
Fatty liver WITH inflammation and liver cell damage. Present in 5-7% of Australians. Reversible with intervention before significant fibrosis develops.
Early Fibrosis (F1-F2)
Scarring beginning to develop from ongoing damage. Still potentially reversible with aggressive lifestyle intervention—this is the critical window.
Advanced Fibrosis/Cirrhosis (F3-F4)
Significant or irreversible scarring. Liver function progressively declines. Risk of liver failure and liver cancer increases substantially.
The Silent Progression
NAFLD typically causes no symptoms until advanced stages. You can have significant liver fat—even early fibrosis—and feel completely well. Up to 30% of patients with confirmed cirrhosis can have normal LFT results.[6]
This is why the GESA 2024 guidelines now recommend screening for anyone with metabolic risk factors—not waiting for symptoms or elevated enzymes.
The FIB-4 Score: Beyond Basic LFTs
Australian guidelines now recommend calculating a FIB-4 score for anyone with suspected NAFLD. This simple formula uses your age, AST, ALT, and platelet count to estimate fibrosis risk—without needing expensive imaging or liver biopsy.[1]
Low probability of advanced fibrosis (>95% negative predictive value). Repeat screening in 2-3 years if risk factors persist.
Requires further assessment—your GP may order additional testing like ELF score, Hepascore, or FibroScan.
High probability of advanced fibrosis. Referral to hepatologist or gastroenterologist recommended.
FIB-4 Accuracy Note
FIB-4 is most accurate for ages 35-65. In younger patients, false positives are common; in older patients, false negatives may occur. Your GP will interpret results in context.[1]
Who Should Test? GESA 2024 Screening Recommendations
The Gastroenterological Society of Australia (GESA) 2024 consensus statement recommends active screening for NAFLD in people with:[1]
Metabolic Risk Factors
- Type 2 diabetes (strongest risk factor)
- Obesity (BMI >30)
- Two or more metabolic features:
- • Waist ≥102cm (men) or ≥88cm (women)
- • BP ≥130/85 mmHg
- • Triglycerides ≥1.7 mmol/L
- • HDL <1.0 (men) or <1.3 (women) mmol/L
Lifestyle Factors
- Regular alcohol consumption (>2 standard drinks/day)
- Rapid weight loss or weight cycling
- Very low protein diets
- Certain medications (amiodarone, methotrexate, tamoxifen, corticosteroids)
Other Risk Factors
- Family history of liver disease or cirrhosis
- History of viral hepatitis (B or C)
- Autoimmune conditions
- Polycystic ovary syndrome (PCOS)
- Obstructive sleep apnoea
What Your GP Will Do With Abnormal Results
Mildly abnormal LFTs are common—approximately 1 in 10 routine blood tests show mildly elevated liver enzymes. Your GP will interpret results in context and may recommend further investigation.[6]
Mildly Elevated (1-2x normal)
Often repeated at 1-2 months to confirm persistence. Common causes: NAFLD, medications, recent viral illness, alcohol
Significantly Elevated (>3x normal)
Usually prompts immediate investigation—hepatitis serology, liver ultrasound, autoimmune markers
Suspected NAFLD
FIB-4 score calculated, liver ultrasound (85% sensitivity for steatosis), lifestyle counselling
High FIB-4 (>2.67)
Referral to gastroenterologist or hepatologist for further assessment
The Good News About NAFLD Reversibility
Unlike many chronic diseases, early-stage NAFLD is genuinely reversible. The evidence shows:[7]
- 5-10% weight loss significantly reduces liver fat and can reverse early fibrosis
- Mediterranean diet consistently reduces liver fat and inflammation
- Physical activity benefits liver health independently of weight loss
- Coffee consumption (3-4 cups/day) is associated with reduced fibrosis progression
This is one condition where lifestyle intervention genuinely works—if caught before irreversible scarring.
Is It Worth the Cost?
✗ Probably Skip If...
- You're at low metabolic risk with normal weight and no risk factors
- You had normal LFTs and FIB-4 in the last 2-3 years with no change in risk factors
- You don't consume alcohol and have no metabolic syndrome features
✓ Worth Considering If...
- You have type 2 diabetes (strongest NAFLD risk factor)[1]
- You're overweight (BMI >25) or have central obesity
- You have metabolic syndrome (2+ features)
- You consume alcohol regularly (>2 standard drinks daily)
- You're starting or taking medication that can affect the liver
- You have fatigue, right upper abdominal discomfort, or unexplained weight loss
The Bottom Line
LFTs combined with FIB-4 scoring are now the recommended first-line assessment for Australia's most common liver condition.
With NAFLD projected to cause an 85% increase in liver deaths by 2030, and most people unaware they're affected, liver function testing makes sense for anyone with metabolic risk factors. The GESA 2024 guidelines provide a clear pathway: LFTs → FIB-4 → ultrasound → specialist referral if needed.
Most importantly, early-stage liver disease is reversible. Unlike conditions where "early detection" still leads to watching and waiting, catching NAFLD early means lifestyle changes can genuinely halt or reverse progression—a rare opportunity in medicine where screening directly improves outcomes.
Frequently Asked Questions
Disclaimer:This information is educational only and not medical advice. Results should be interpreted by your health practitioner in the context of your symptoms and health history. Treatment decisions should be made with your doctor or specialist.