Association of raised liver transaminases with physical inactivity, increased waist-hip ratio, and other metabolic morbidities in severely obese children.

OBJECTIVE: To identify factors associated with raised alanine transaminase, aspartate transaminase, and gamma-glutaryl transferase in severely obese children PATIENTS AND METHODS: In all, 201 children with early-onset obesity and greater than 140% ideal weight for height were recruited. Anthropometric and body fat measurements, fasting blood tests, and oral glucose tolerance tests were performed.
RESULTS: The mean and standard deviation (SD) for age was 11.1 (3.0) years, for weight for height 170.5% (22.7%), and for percentage body fat was 40.7% (5.2%). Elevated liver transaminases were present in 53 subjects (26.4%), who were therefore at risk for nonalcoholic fatty liver disease, and was associated with male sex (odds ratio [OR] 2.144, 95% confidence interval [CI] 1.033-4.448), Chinese ethnicity (OR 2.062, 95% CI 1.038-4.096), reduced physical activity (OR 2.389, 95% CI 1.163-4.909), insulin resistance (P < 0.05), elevated triglyceride levels (P = 0.029), and increased waist-hip ratio (P = 0.005). Stepwise logistic regression analysis of the main factors as covariates revealed Chinese ethnicity, waist-hip ratio, reduced physical activity, and homeostasis model assessment index were significant predictors. Alanine transaminase/aspartate transaminase were not well correlated with percentage body fat and weight for height. Subjects with type 2 diabetes mellitus and impaired glucose tolerance were more likely to have raised hepatic transaminases (OR 6.176, 95% CI 1.326-28.754). The severity of metabolic syndrome correlated with increasing aspartate transaminase, alanine transaminase, and gamma-glutaryl transferase (P < 0.01).
CONCLUSIONS: Insulin resistance, truncal adiposity, and physical inactivity are major determinants potentially modifiable to reduce risk of nonalcoholic fatty liver disease. Increasing physical activity levels were associated with decreasing insulin resistance and transaminases, despite lack of correlation with waist-hip ratio, which supports the direct benefit of regular physical activity in preventing nonalcoholic fatty liver disease.