Cardiometabolic risk in youths: Fatness outweighs fitnes

Both fatness and fitness are associated with cardiometabolic risk factors in American youths, but fatness associations are stronger. Although maintaining high levels of fitness and preventing obesity may affect cardiometabolic risk factors positively, obesity prevention may have greater benefit.

Jago and associates collected data on 4955 sixth-grade students from 42 US middle schools as part of HEALTHY, a National Institute of Diabetes and Digestive and Kidney Diseases study. Height, weight, and waist circumference were measured. Body mass index (BMI) was calculated and interpreted as an indicator of fatness. Fitness was assessed using the 20-m shuttle test. Fasting blood samples were obtained. Total cholesterol, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, triglyceride, glucose, and insulin concentrations were measured.

Means for each risk factor (except HDL cholesterol, which was the reverse) increased across the obesity groups; values were highest for the obese group and lowest for the normal weight group. Waist circumference, LDL cholesterol, triglycerides, diastolic blood pressure, and insulin were inversely associated with fitness. When both BMI group and fitness were included in the model together, the BMI group was a significant predictor of almost all cardiometabolic risk factors.

The authors noted that several associations between fitness and cardiometabolic risk factors were attenuated after adjustment for fatness.