Body fat distribution, relative weight, and liver enzyme levels: a population-based study

Regional body fat distribution may represent an independent risk factor for several conditions, especially metabolic and cardiovascular diseases; recent findings have shown that abdominal fat accumulation can be an independent predictor of hepatic steatosis. Very few studies, mostly using selected clinical samples, have focused on the relationship between indices of abdominal visceral fat accumulation and the most commonly used biochemical liver tests, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase (GGT). The aim of the present study was to evaluate the relation between central fat accumulation, as assessed by abdominal height, relative weight, as determined by body mass index (BMI), and liver function tests (ALT, AST, and GGT) in a random sample of 2,704 residents of Erie and Niagara Counties in New York State, 35-80 years of age and free from known hepatic disease. Multiple linear regression models were used, with liver enzymes as dependent variables with abdominal height and BMI as independent variables, and the inclusion of several covariates (age, race, education, smoking status, pack-years of smoking, drinking status, and total ounces of ethanol in the past 30 days). Abdominal height was consistently a better correlate of ALT and GGT levels than BMI in both sexes. In addition, abdominal height was the most powerful independent predictor of ALT in both sexes as well as of GGT among women. In conclusion, these findings support a role for central adiposity independent from BMI in predicting increased levels of hepatic enzymes, likely as a result of unrecognized fatty liver.