Sex differences in the association between level of childhood interleukin-6 and insulin resistance in adolescence

Abstract

The purpose of this study was to determine whether levels of interleukin-6 (IL-6) in childhood are related to insulin resistance in adolescence. Further, to explore how fatness and cardiorespiratory fitness ( V O 2 p e a k ) moderate this relationship. Methods. 292 nine-year-old children ( 𝑛 = 2 9 2 ) were followed for 4 years. Anthropometrics and V O 2 p e a k were measured. Fasting blood samples were analyzed for IL-6, insulin, and glucose. Homeostasis model assessment (HOMA-IR) was used as a measure of insulin resistance. Results. For girls but not boys, levels of IL-6 at age 9 yrs correlated with HOMA-IR at age 13 yrs: 𝑟 = 0 . 2 2 3 , 𝑃 = 0 . 0 0 8 . Girls with IL-6 levels within the highest quartile at age 9 yrs had an odds ratio of 3.68 (CI = 1.58–8.57) being in the highest quartile of HOMA-IR four years later. Conclusion. In this cohort, IL-6 levels in childhood were related to insulin resistance in adolescence, but only for girls.