Liver enzyme activity and body mass index.

Obesity has been identified as a risk factor for liver disease in a number of cross-sectional studies. We investigated the association of biochemical livers tests (BLTs) among male employees of The Dow Chemical Company who had participated in two consecutive health surveillance examinations. The activity of three liver enzymes-alanine aminotransferase, aspartate aminotransferase, and gamma glutamyl transferase were used as measures of liver injury. Body mass index was strongly associated with increased enzyme activity in both examinations. Alcohol consumption was similarly associated with higher BLT results. Body mass index remained significantly associated with each BLT after controlling for alcohol consumption, race, and age. When changes in BLTs were investigated over time, the employees who gained weight showed a significant increase in alanine aminotransferase activity compared with those who did not gain weight.