Influence of aerobic power and percent body fat on cardiovascular disease risk in youth.

PURPOSE: To describe how the relationships between aerobic power or percent body fat and cardiovascular disease (CVD) risk differ by age.
METHODS: A sample of 1,824 young persons was divided into age groups (8-10, 11-13, and 14-16 years). Aerobic power (VO(2)max) was predicted using a submaximal cycle ergometer test, whereas percent body fat was assessed using the sum of skinfolds. Six CVD risk factors were measured: high-density lipoprotein cholesterol, total cholesterol, triglycerides, systolic and diastolic blood pressures, and fasting insulin. These risk factors were classified into risk categories (none, borderline, or at risk) and summed to determine a total CVD risk score.
RESULTS: The percentages of participants with elevated risk scores was low, despite the high mean percent body fat and low mean aerobic power. Correlations among the six risk variables and either body fat or aerobic power were strongest in the youngest participants. In the multiple regression models adjusted for gender and SES, percent body fat was a stronger predictor of CVD risk score than aerobic power. The variance in risk score attributed to fatness was greatest in the youngest participants and declined in older age groups.
CONCLUSIONS: Percent body fat had a greater influence on CVD risk than aerobic power. The relationship between body fat and total risk score was strongest in the youngest participants. Thus, interventions to improve CVD risk in youth should target body fat reduction beginning at an early age.