Fitness is a stronger predictor of fasting insulin levels than fatness in overweight male middle-school children

J Pediatr. 2007 Apr;150(4):383-7. doi: 10.1016/j.jpeds.2006.12.051.


Objective: We studied the relationship between % body fat (%BF), cardiovascular fitness (CVF), and insulin resistance (IR) in overweight middle-school children.

Study design: Middle school children (n = 106, body mass index [BMI] > 95th percentile for age) underwent evaluation of body composition, maximal volume of oxygen utilization (VO2) uptake/kg lean body mass (VO2max/kgLBM), and fasting glucose and insulin (FI) concentrations and derived homeostasis model assessment index (HOMA(IR)).

Results: Both %BF (r = .33, P < .001) and VO2max/kgLBM (r = -0.42, P < .0001) were significantly correlated with FI. Bivariate regression analysis revealed %BF (P = .008 vs FI, P = .035 vs HOMA(IR)) and VO2max/kgLBM (P < .001 vs FI, P = .009 vs HOMA(IR)) to be independent predictors of insulin sensitivity. In males, VO2max/kgLBM was a better predictor of FI and HOMA(IR) than %BF.

Conclusions: In obese middle-school children, both %BF and VO2max/kgLBM are independent predictors of FI levels. The relationship between CVF and FI levels was significant in both sexes but was particularly profound and stronger than %BF in males. Efforts to reduce risk of type 2 diabetes mellitus in an increasingly obese child population should include exercise intervention sustained enough to improve CVF.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adiposity*
  • Blood Glucose / metabolism
  • Body Mass Index
  • Child
  • Fasting
  • Female
  • Humans
  • Insulin / blood*
  • Insulin Resistance
  • Logistic Models
  • Male
  • Multivariate Analysis
  • Obesity / diagnosis
  • Obesity / metabolism*
  • Oxygen Consumption
  • Physical Fitness*
  • Sex Factors


  • Blood Glucose
  • Insulin