BACKGROUND AND AIM: Serum alanine aminotransferase (ALT) is not only a surrogate marker of chronic liver disease but also predictive of future development of cardiovascular disease (CVD) in adults; however, pediatric reference data are rare, and "healthy-range ALT limits" have not been assessed to predict cardiovascular risk in children and adolescents.
METHODS: Data from 2242 examinees (1171 boys and 1071 girls; 10-18 years of age) in the Korea National Health and Nutrition Examination Survey IV (2007-2009) were analyzed. The reference values of ALT levels were determined according to age and sex. Multiple logistic regressions were used to assess the association between healthy-range ALT limits (ALT level >30 IU/L for boys and >19 IU/L for girls) and each cardiovascular risk factor.
RESULTS: The 50th, 90th, and 95th percentiles of ALT levels were respectively 14, 27, and 35 IU/L in boys and 11, 19, and 24 IU/L in girls. Subjects with ALT levels higher than healthy-range ALT limits not only exhibited higher odds ratios for metabolic syndrome but also showed higher each cardiovascular risk related to obesity, hypertension, and dyslipidemia compared with subjects whose ALT levels were within the healthy range (P < 0.001).
CONCLUSIONS: The present study shows normal ALT reference data of Korean children and adolescents. The present study also showed the effectiveness of healthy-range ALT limits in predicting each cardiovascular risk factor in a national representative population.