The relationship between insulin sensitivity and surrogates for adiposity in youth.

Abstract

The purpose of this report is to identify which surrogate of adiposity best identifies the risk of insulin resistance (HOMA-IR) in youth; could be used for all ages, both sexes, and both Caucasians and African Americans. The participants were 1,511 youth; 8-17 yrs old, 37.5% African American and 55.4% Caucasians. Cross sectional analyses (ROC and regression) of HOMA-IR and several obesity surrogates were performed. Measurements included fasting insulin and glucose, body mass, height, waist circumference, and triceps and subscapular skinfolds. These were used to determine BMI, BMI percentile (and z-score), waist percentiles, waist to height ratio (WHtR) and the HOMA-IR. The WHtR cut-point derived from the ROC was the same for both sexes; whereas all other surrogates had sex-specific cut-points. Logistic regression to determine the odds ratios for insulin resistance found that the cut-points for all adiposity surrogates were highly associated with HOMA-IR; OR > 6.5. BMI percentiles had the highest OR for the girls, while waist circumference had the highest OR for the boys. WHtR and sum of skinfolds were most consistent for both sexes. The results indicate that all the surrogates for adiposity are useful for assessing the risk of insulin resistance. Although sum of skinfolds may be least influenced by age, sex and race of all the adiposity surrogates, waist-height ratio provides a good alternative for both sexes. (PsycINFO Database Record (c) 2016 APA, all rights reserved)