Metabolic syndrome and ALT: a community study in adult Koreans.

OBJECTIVE: To investigate an association between the metabolic syndrome (MS) and alanine aminotransferase (ALT) of normal ranges. DESIGN: A population-based cross-sectional survey in three rural communities, South Korea. SUBJECTS: A total of 1248 men and 2157 women aged 30y and older. MEASUREMENTS: Body mass index (BMI), waist circumference, fasting blood lipid and glucose, resting blood pressure, and ALT. RESULTS: ALT and BMI increased with an addition of the MS components. A consistent association between ALT more than 15 IU/I and the MS was found in both sexes, independently of age, education, BMI, smoking, alcohol drinking, and sedentary life style. The odds ratios for the MS in the highest quintiles of ALT were 7.1-fold higher than the reference quintile in men and 2.1-fold higher in women. The likelihood ratio tests for trend were also significant with ALT increments (P<0.001 for trend). CONCLUSION: The MS is significantly associated with the higher quintiles of normal ALT in both genders. ALT could be a sensitive marker of hepatic dysfunction associated with the MS, even in the range below the current limit.