Background: Adult obese subjects are susceptible to an excess of cardiovascular events due to insulin resistance through the metabolic syndrome or hyperinsulinism itself. These deleterious factors go on and amplify from childhood into adulthood. To the best of our knowledge no comparison of insulin resistance indices has been performed between obese and normal children.
Objectives: The main objective of this study is to compare the insulin sensitivity index (HOMA-IR) of two cohorts of obese vs non-obese children. The secondary goals consist in checking the Gaussian distribution of the HOMA-IR index in non-obese and in obese children, in one hand, and comparing components of the metabolic syndrome in obese children with normal or with increased HOMA-IR values, in the other hand.
Methods: We analysed 463 non-obese children (cohort FLVS) from 256 families who were compared with 850 obese children from 602 families (cohort OBE). Gaussianity (normality) distribution of HOMA-IR was checked by Quantile-Quantile plot (Q-Q plot). Assuming normality we considered as extreme children whose log HOMA-IR values deviate plus or minus two standard deviations from the mean.
Results: When adjusted for sex, age and BMI, we found that the 3rd and 97th centiles of HOMA-IR were 0.61 and 0.69 respectively in FLVS cohort. Using these thresholds, we classified children in OBE cohort as hypersensitive to insulin (IH) (one out of 850 children (0.1%)); sensitive to insulin (IS) (224 out of 850 children (26.3%)); and resistant to insulin (IR) (625 out of 850 children (73.5%)). Normality of HOMA-IR was observed in both FLVS and OBE cohorts, with few outliers. Components of the metabolic syndrome are more present in the IR class than in both IH and IS classes.
Conclusions: For the first time an insulin resistance has been compared between obese and normal children. Given the variability of the definition of the metabolic syndrome, the classification of obese children with respect to their HOMA-IR values provides a useful tool especially with relevance to future potential complications.
01 Oct 2015 - 03 Oct 2015