Risk factors for serum alanine aminotransferase elevation: A cross-sectional study of healthy adult males in Tokyo, Japan

Background: Liver-protective effects of light-to-moderate alcohol consumption have been suggested.

Aims: To determine predictors of ALT elevation in asymptomatic subjects with and without ultrasonographical evidence of fatty liver.

Methods: Cross-sectional survey of 9703 healthy males. Exclusion criteria were HBV or HCV infection, any use of hepatotoxic medication, history of alcohol abuse, chronic renal or hepatic failure, or treatment for metabolic disorders. Presence of fatty liver was evaluated by ultrasonography; visceral adipose tissue (VAT) was measured by computed tomography (CT).

Results: 7148 males (mean age, 50.3±7.8 years) were included; 2406 (33.7%) had fatty liver at ultrasonography. ALT was elevated in 163 (3.4%) and 554 subjects (23.0%) of fatty liver-negative and fatty liver-positive subgroups, respectively. Light (40-140g/week) alcohol consumption was significantly and independently associated with reduced prevalence of ALT elevation in the fatty liver-negative subgroup (OR=0.568, 95% CI=0.342-0.943, P=0.029). ALT elevation was significantly related to age, VAT, high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG) in the fatty liver-negative subgroup.

Conclusion: Light alcohol consumption is not associated with serum ALT elevation in the Japanese male population. Metabolic syndrome factors are significantly associated with prevalence of ALT elevation, irrespective of the presence of fatty liver.