Body mass index and liver enzyme activity in serum

The association between body mass index (BMI) and serum liver enzyme activity [gamma-glutamyltransferase (GGT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST)] was studied in 3167 subjects, 2373 men and 794 women. The subjects were managers and employees, ages 18-64 years, who were examined during a program of preventive medicine. Analysis of covariance was used to compare the serum liver enzyme activities (expressed as natural logarithms) of the subjects, who were subdivided according to BMI, while also considering age, alcohol and cigarette consumption, and physical activity. In men, the percentage increase in the geometric mean of liver enzyme activity of the obese subjects (BMI greater than 30 kg/m2) compared with that of the normal subjects (BMI less than or equal to 25 kg/m2) was 47.7% (P less than 0.001) for GGT, 55.3% (P less than 0.001) for ALT, and 19.7% (P less than 0.001) for AST; in women, the increase was 63.2% (P less than 0.01) for GGT, 58.4% (P less than 0.001) for ALT, and 7.3% (P greater than 0.05) for AST. Thus, our observations demonstrate a relation between BMI and serum liver enzyme activity.