Fitness as a stronger predictor of fasting insulin levels than fatness in overweight male children

Childhood represents a choice window of opportunity for lifetime acquisition of physically active behaviour. To study the relationship between % body fat (%BF), cardiovascular fitness (CVF), and insulin resistance (IR), 106 overweight (BMI>95th percentile for age) middle school children underwent evaluation of body composition, maximal volume of oxygen utilization uptake/kg lean body mass (VO2max/kgLBM), fasting glucose and insulin (FI) concentrations and derived homeostasis model assessment index (HOMA (IR)). Bivariate regression analysis revealed that both %BF and VO2max/kgLBM were independent predictors of FI levels (P=0.008 and P<0.001 vs FI, respectively) and insulin sensitivity (P=0.035 and P=0.009 vs HOMA(IR), respectively). In males, VO2max/kgLBM was better than %BF in predicting FI and HOMA(IR). Similar to what is known in adults, cardiovascular fitness predicts insulin sensitivity as well as fatness in children, if not even better. The authors conclude that efforts to reduce risk of type 2 diabetes in obese children should include exercise intervention sustained enough to improve CVF.

Abstract

Keywords:
BMI – Exercise – HOMA – Insulin resistance – Insulin sensitivity – Obesity – Overweight