Determinants of persistent obesity and hyperinsulinemia in a biracial cohort: a 15-year prospective study of schoolgirls.

Abstract

To identify childhood-adolescent determinants of persistent hyperinsulinemia and obesity. We conducted a 15-year prospective study of 296 African-American and 260 Caucasian girls. Childhood insulin level (partial R2=40.4%) and 14-year change in body mass index (BMI; partial R2=20.2%) were major predictors for average insulin Z score during the 15-year follow-up. Waist circumference at age 19 years, 10-year mean percentage of calories from carbohydrates, 15-year change in insulin Z score, the interaction of race with 8-year change in waist, and 14-year change in glucose level were major predictors of a 14-year change in BMI, explaining 66.7% of variability. In girls with all 9 insulin measurements in 15 years persistently in the top 25% versus girls with all measures in the bottom 75%, variables predicting the persistent insulin category included waist circumference at age 11 years (odds ratio [OR], 1.25; 95% CI, 1.11-1.40; P=.0003), 14-year change in BMI (OR, 1.26; 95% CI, 1.01-1.57; P=.037), and 8-year change in waist circumference (OR, 1.16; 95% CI, 1.01-1.32; P=.038). Childhood interventions to reduce occurrence of hyperinsulinemia and obesity in early adulthood should focus on childhood-adolescent hyperinsulinemia, obesity, central adiposity, and adolescent increases in these factors.