Serum Alanine Aminotransferase and Its Association with Metabolic Syndrome in Children: The Bogalusa Heart Study

Background: The aim of this study was to examine the distribution of alanine aminotrasferase (ALT) and its association with metabolic syndrome variables and their clustering in apparently healthy children. Methods: A cross-sectional study of 1,524 preadolescents (age, 4-11 years, 62% white, 51% male) and 1,060 adolescents (age, 12-18 years, 58% white, 51% male) enrolled in the Bogalusa Heart Study was performed. Results: ALT levels showed a significant race (whites>blacks) difference in preadolescents and a gender (males>females) difference in adolescents. Both preadolescents and adolescents in the age, race, and gender-specific top versus bottom quartiles of ALT had significant increases in the prevalence of adverse levels (>75(th) percentile specific for age, race, and gender) of body mass index (BMI), systolic blood pressure, total cholesterol to high-density lipoprotein cholesterol (HDL-C) ratio (adolescents only), insulin resistance index (HOMA-IR), and clustering of all four of these metabolic syndrome variables. In multivariate analyses, BMI was the major independent predictor of ALT in both preadolescents and adolescents; other independent predictors were total cholesterol to HDL-C ratio, HOMA-IR, white race in preadolescents and male gender in adolescents. With respect to the ability of ALT to identify children with clustering of the metabolic syndrome variables, area under the receiver operating characteristic curve analysis (c-statistics) adjusted for age, race, and gender yielded a value of 0.67 for preadolescents and 0.82 for adolescents. Conclusion: An elevation in serum ALT within the reference range relate adversely to all of the major components of metabolic syndrome and their clustering in children and, thus, may be useful as a biomarker of the presence of metabolic syndrome and related risk in pediatric population, especially adolescents.