Associations between total body fat and serum lipid concentrations in obese human adolescents.

To investigate the relationships between obesity and serum lipid concentrations, we measured eight anthropometric parameters, body mass index (BMI), total body fat (TBF), and serum lipid profiles in 790 apparently healthy adolescents. TBF was assessed using a body fat analyzer. Serum concentrations of triglyceride, total cholesterol, and low- or high-density lipoprotein-cholesterol (LDL-C or HDL-C) were determined by standard enzymatic procedures. There were no significant differences in serum lipid concentrations between obese adolescents (BMI > or = 95th percentile) and lean adolescents (BMI < 5th percentile), nor between overweights (BMI > 25 kg/m2) and underweights (BMI < 19 kg/m2). However, serum lipid concentrations were significantly higher in males with TBF > 37% (TBF > 95th percentile) than in males with TBF < 6% (TBF < 5th percentile; p < 0.01). Serum lipid concentrations were more strongly correlated with TBF than with BMI. Correlation coefficients between serum lipid concentrations and TBF were higher in males than in females for cholesterol (r = 0.37 vs 0.23), triglycerides (r = 0.29 vs 0.27), HDL-C (r = -0.34 vs 0.12), and LDL-C (r = 0.24 vs 0.15). In short, compared to BMI, TBF reflects serum lipid concentrations more closely. During adolescence, the association between TBF and serum lipid concentrations is stronger in males than in females.