What to do if a CT scan shows fatty liver and elevated liver enzymes?

Management of Fatty Liver with Elevated Liver Enzymes

When CT shows fatty liver with elevated liver enzymes, immediately assess alcohol intake, obtain AST:ALT ratio to distinguish alcoholic from non-alcoholic fatty liver disease, screen for metabolic syndrome components (diabetes, obesity, dyslipidemia), and initiate lifestyle modification with 7-10% weight loss as first-line therapy. 1, 2

Initial Diagnostic Workup

Determine the Etiology of Fatty Liver

• Calculate the AST:ALT ratio to differentiate between alcoholic and non-alcoholic causes: an AST:ALT ratio >2 suggests alcohol-induced liver disease, while a ratio <1 indicates metabolic disease-related NAFLD 1
• Quantify alcohol consumption through detailed clinical evaluation including family member interviews when necessary, as excessive alcohol intake (>20-30 g/day) defines alcoholic liver disease 1
• Exclude other common causes of elevated liver enzymes including viral hepatitis (hepatitis B and C), drug-induced liver injury, hereditary hemochromatosis, autoimmune hepatitis, alpha1-antitrypsin deficiency, and Wilson disease 1

Screen for Metabolic Syndrome Components

• Assess for diabetes and insulin resistance as 44% of fatty liver patients have diabetes mellitus, 29% have impaired glucose tolerance, and 17% are hyperinsulinemic 3
• Measure fasting lipids since hypertriglyceridemia and/or low HDL-cholesterol occur in 86% of fatty liver patients 3
• Document body mass index and waist circumference as NAFLD prevalence increases to 70% with obesity and 90% with diabetes mellitus 1
• Check blood pressure as part of comprehensive metabolic syndrome evaluation 4

Risk Stratification for Disease Severity

Assess Fibrosis Risk

• Calculate FIB-4 or NAFLD Fibrosis Score for non-invasive fibrosis risk stratification, as enzyme levels alone do not predict fibrosis stage 2, 4
• Consider liver biopsy in patients over age 40 or with diabetes at any age, as these are risk factors for nonalcoholic steatohepatitis (NASH) and cirrhosis 5
• Recognize that 25-30% of NAFLD cases progress to NASH with hepatocyte injury and inflammation, which can lead to fibrosis, cirrhosis, and hepatocellular carcinoma 1, 2

Understand Prognostic Implications

• NASH patients have reduced survival compared to simple steatosis, with increased cardiovascular mortality and liver-related deaths 6
• 5.4% of NAFLD patients develop end-stage liver disease including hepatocellular carcinoma during long-term follow-up 6
• Progression of liver fibrosis occurs in 41% of patients and is associated with weight gain exceeding 5 kg, increased insulin resistance, and more pronounced hepatic fatty infiltration 6

Treatment Strategy

First-Line Lifestyle Modification

• Prescribe weight loss of 7-10% body weight through caloric restriction and exercise as the primary treatment for NAFLD 4
• Restrict saturated fat to <7% of total calories as part of dietary intervention 4
• Expect improvement in 96% of patients with dietary intervention and weight loss, with liver enzymes normalizing in more than half of patients during follow-up 3

Medical Management

• Statins are not contraindicated and may be beneficial for cardiovascular risk reduction in NAFLD patients 4
• Consider metformin in insulin-resistant patients, as it significantly improves fatty liver prevalence, severity, and fasting insulin compared to placebo 7
• Treat underlying metabolic conditions including diabetes and dyslipidemia with appropriate medications as needed 3

Monitoring and Follow-Up

Short-Term Monitoring

• Repeat liver enzymes in 2-3 months to establish trend, as 84% of abnormal liver tests remain abnormal at 1 month and 75% at 2 years 4
• Do not assume spontaneous resolution given the high persistence rate of abnormal liver enzymes 4

Indications for Hepatology Referral

• Refer immediately if ALT >8× upper limit of normal (ULN) or >5× baseline 4
• Refer if ALT >3× ULN with total bilirubin >2× ULN 4
• Refer if evidence of synthetic dysfunction such as elevated INR or low albumin 4

Common Pitfalls to Avoid

• Do not rely on CT as the primary diagnostic modality for mild fatty infiltration, as CT fails to detect early steatosis and lacks accuracy for mild disease; ultrasound is the appropriate first-line imaging tool 1
• Do not overlook the high prevalence of glucose intolerance, as 69 of 88 NAFLD patients develop diabetes or impaired glucose tolerance during long-term follow-up 6
• Do not underestimate cardiovascular risk, as hepatic steatosis is an independent risk factor for metabolic syndrome, type 2 diabetes, and cardiovascular mortality 8
• Do not assume benign disease in young patients, as NAFLD with steatosis and inflammation can occur in patients aged 20-40 years with obesity as the only risk factor 5