Comparison of blood lipids, lipoproteins, anthropometric measures, and resting and exercise cardiovascular responses in children, 6–7 years old

The purpose of this investigation was to determine sex differences and interrelationships in anthropometric, blood lipids and lipoproteins, steady rate and maximal bicycle ergometric measures in boys ( N = 38) and girls ( N = 28) ages 6 to 7 years. After adjusting for a significantly ( P < 0.05) higher sum of skinfold measure for the girls, significant ( P < 0.05) sex differences were obtained for high-density lipoprotein cholesterol (HDL-C), resting heart rate, and steady-rate heart rate. Lower HDL-C values (43.3 vs 49.6 mg/dl) for the girls accounted for their lower cholesterol since no sex differences were found for low-density lipoprotein cholesterol (LDL-C). Following 4 min of steady-rate bicycling at 90 kgm, girls had higher heart rates (131 vs 119 beats·min −1 whereas no differences ( P > 0.05) existed in preexercise and maximal heart rates. Multiple regression analyses resulted in weak but significant ( P < 0.05) prediction equations for cholesterol and cumulative work performed on the bicycle. A significant ( P < 0.05) negative correlation between HDL-C vs triglycerides ( r = 0.46) was obtained for the girls. These data indicate that sex differences exist for selected ergometric, anthropometric, and blood lipid and lipoprotein measures as early as 6 years. Also, the association among blood lipid and lipoprotein measures may differ between boys and girls.