Fitness versus Fatness and Insulin Resistance in U.S. Adolescents

[摘要] Background. The present study examined the relationship between insulin resistance and bothwaist circumference and cardiorespiratory fitness in U.S. adolescents.Methods. NHANES assessed a nationally representative sample of U.S. adolescents (12–18 yrs)between 1999–2002. Abdominal adiposity was estimated by waist circumference, overalladiposity by BMI, and cardiorespiratory fitness (maximal oxygen uptake (VO2max) from atreadmill exercise test). Insulin resistance was estimated from fasting insulin and glucose usingthe homeostatic model assessment method (i.e., HOMA) and was log-transformed.Results. 1078 adolescents were included in the study. Positive correlations existed betweenlnHOMA and waist circumference (r=0.59;r=0.54) for boys and girls, respectively.lnHOMA andVO2max were inversely related in boys (r=−0.29) but not girls (r=−0.06). Gender-specific analyses by BMI category showed that the significant inverse relationship in lnHOMA andVO2max was primarily present in obese boys.Conclusion. Among adolescents, important gender and BMI differences exist in the relationshipbetween insulin resistance and fitness. While waist circumference and BMI are importantpredictors in all children, fitness appears especially important in obese boys. These findings mayhave important implications for gender-specific interventions to prevent adult obesity anddiabetes mellitus.

[学科分类] 内分泌与代谢学