Influence of light alcohol consumption on lifestyle-related diseases: a predictor of fatty liver with liver enzyme elevation in Japanese females with metabolic syndrome

BACKGROUND: Although heavy drinking is known to lead to liver injury, some recent studies have reported that light alcohol consumption (LAC) may play a protective role against fatty liver in the general population, and may even play a protective role against non-alcoholic fatty liver disease (NAFLD) in males with metabolic syndrome (MS). However, the association between LAC and fatty liver with liver enzyme elevation in females with MS is unclear. METHODS: Participants of this study were 20,853 females who underwent a regular health check-up between April 2008 and March 2012 at our hospital. Enrolled subjects were 1141 females with MS, who underwent all necessary tests and drank less than 20 g/day of alcohol. We investigated the presence of fatty liver with liver enzyme elevation, defined in this study as alanine aminotransferase (ALT) levels ≧31 IU/I, and the association between LAC and fatty liver with ALT elevation. RESULTS: There was no significant difference in the prevalence of fatty liver and ALT between light drinkers and non-drinkers. The prevalence of individuals receiving a treatment for dyslipidemia and impaired glucose tolerance (IGT) was significantly lower in light drinkers than in non-drinkers. Body mass index (BMI), waist circumference (WC), diastolic blood pressure (DBP), triglyceride (TG), uric acid (UA), IGT, and visceral fat type MS (V-type MS) were significant predictors of the prevalence of fatty liver with ALT elevation in logistic regression analysis. The odds ratio [OR] (95 % confidence interval [CI], p value) for fatty liver with ALT elevation were as follows: BMI, 2.181 (1.445–3.293, p <0.001); WC, 1.853 (1.280–2.684, p <0.01); DBP, 1.604 (1.120–2.298, p <0.05); TG, 2.202 (1.562–3.105, p <0.001); UA, 2.959 (1.537–5.698, p <0.01); IGT, 1.692 (1.143–2.506, p <0.01); and V-type MS, 3.708 (2.529–5.437, p <0.001). CONCLUSIONS: There was no significant difference in the prevalence of fatty liver with ALT elevation in females with MS between light drinkers and non-drinkers, suggesting that other factors such as BMI, WC, V-type MS, and lifestyle-related disease may be more important than LAC for the prevalence of fatty liver with ALT elevation.