Relationship between Serum Aminotransferase Levels and Metabolic Disorders in Northern China

BACKGROUND Increasing evidence suggests an association between elevated serum aminotransferase levels and metabolic disorders (metabolic syndrome, hyperlipemia and diabetes mellitus). However, the significance of relatively low levels of aminotransferases in relation to metabolic disorders has not been fully investigated in the general population. We investigated the association between serum amiontransferase levels and metabolic disorders using data from a survey in Jilin province, China. METHODS In 2007, a survey was conducted throughout Jilin, China, covering both urban and rural areas. A total of 3835 people, 18 to 79 years old including 1761 men and 2074 women, underwent real-time ultrasonography, blood tests including aspartate aminotransferase and alanine aminotransferase, and had interviews with a structured questionnaire. RESULTS Serum aminotransferase levels within the normal range were associated with metabolic syndrome independent of age, occupation, cultural and educational level, income, body mass index, waist circumference, smoking, and alcohol intake. Compared with the lowest level (<20 IU/L), the adjusted odds ratios for ALT levels of 20-29, 30-39, 40-49 and >50 IU/L were 1.92, 2.50, 2.97, and 3.52 in men, and 1.38, 1.54, 3.06, and 2.62 in women, respectively. Near-normal serum aminotransferase levels associated with hyperlipemia, NAFLD, DM were also found in the study. CONCLUSIONS Normal to near-normal serum aminotransferase levels are associated with metabolic disorders. Serum ALT levels of 21-25 IU/L for men, and 17-22 IU/L for women are suggested as cutoff levels that detect metabolic disorders affecting the liver.