Obesity, insulin resistance, and the risk of an elevated alanine aminotransferase activity in the Korean adolescent population

Abstract

It is unclear to what extent insulin resistance (IR) modulates the association linking obesity to alanine aminotransferase (ALT) activity elevation. We measured the homeostatic model assessment for IR (HOMA-IR) in 1591 participants aged 12-18 years from the 2008 to 2009 Korea National Health and Nutrition Examination Survey. Overweight adolescents had an odds ratio of 7.23 [95% confidence interval (95% CI), 4.33-12.10] for an elevated ALT activity compared with normal-weight adolescents, and the corresponding risk was 23.62 (95% CI, 12.98-42.98) in obese adolescents. Adjustments for other participant factors did not substantially affect the results. The addition of the HOMA-IR data decreased the estimate for overweight adolescents by 27% and for obese adolescents, the decrease was 47%. Both obesity and IR markers remained independent predictors of outcome. The greater the obesity level, the more that IR contributes to the association between obesity and an elevated ALT activity.