The association of elevated alanine aminotransferase activity with obesity in health screenig subjects

Lee, Jong Hyup; Kang, Kyoung Hee; Kim, Sae Hwan; Park, Ji Hyun; Cho, Chang Min; Kwon, Young Oh; Kim, Sung Kuk; Choi, Yong Hwan

Abstract

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) has recently been recognized to be one of the leading causes of chronic liver disease. Obesity and type 2 diabetes are associated strongly with NAFLD. Although often used to detect liver disease, sometimes the cause of elevated Alanine Transaminase (ALT) activity was unclear. In the absence of other causes, the author examined whether BMI and metabolic markers of NAFLD can explain the cause of abnormal ALT in Korean.
METHODS
From April 2002 to November 2003, 9997 persons visited health promotion center of Kyungpook National University Hospital and took health screening. After excluding persons with excessive alcohol consumption, abnormal gamma-GTP, hepatitis B, hepatitis C, 8379 persons were included in this study. All patients underwent anthropometric measures, blood chemistry analysis and abdominal ultrasonographic exam.
RESULTS
Elevated ALT levels were found in 10% (835 persons) of the all subjects. In univariate analysis, factors associated with elevated ALT levels (p<0.05) included male sex, younger age (20-40 years), higher Body Mass Index (BMI), higher blood pressure, higher fasting blood glucose, higher triglyceride, lower HDL and more fatty change in ultrasonography. The proportion of elevated ALT with fatty change in ultrasonography was 57% and with higher BMI (>or=23 kg/m2) was 79% in abnormal ALT group. In multivariate logistic regression study, total cholesterol and blood pressure were eleminated but sex, BMI, triglyceride level, ultrasonographic fatty change were strongly associated with elevated ALT level (p<0.01).
CONCLUSION
In this study, unexplained ALT elevation was strongly associated with obesity, adiposity and other features of metabolic syndrome, and thus may represent nonalcoholic fatty liver disease. However, more research is needed for the definite clinical determinants of nonalcoholic fatty liver disease in Korean.