BACKGROUND: BMI is one factor that is used to determine a child's eligibility for lipid screening and treatment. BMI, which is an indirect measure of body fat, may inadequately represent the biological effect of body fat percentage on lipid concentrations. OBJECTIVE: We examined the relation between directly measured body fat percentage and lipid concentrations in a representative sample of US youths. DESIGN: Data from 7821 participants aged 8-19 y from the 1999-2004 NHANES were analyzed. Body fat percentage was measured by dual-energy X-ray absorptiometry. Total and HDL-cholesterol concentrations were measured in serum. Serum triglyceride and LDL-cholesterol concentrations were measured in a subsample of 2661 fasting NHANES participants aged 12-19 y. Prevalences of adverse total cholesterol (>200 mg/dL), LDL cholesterol (>130 mg/dL), triglycerides (>150 mg/dL), and HDL cholesterol (<35 mg/dL) were measured. RESULTS: Approximately 10.0% [±0.7% (SE)] of participants had high total cholesterol, 7.0 ± 0.4% of participants had low HDL cholesterol, 9.7 ± 1.0% of participants had high triglycerides, and 7.6 ± 0.7% of participants had high LDL cholesterol. Prevalence of adverse total cholesterol, HDL cholesterol, triglycerides, and LDL cholesterol in US youths with high adiposity (greater than or equal to the age- and sex-specific 75th percentile of body fat percentage) was significantly greater (P < 0.01) than for participants without high adiposity. In multiple linear regressions adjusted for age, survey period, and race-ethnicity, the variance in lipid concentrations explained by body fat percentage was 2-20% (P < 0.001). CONCLUSION: Adverse lipid concentrations and high adiposity are significantly associated in youths.
BACKGROUND: BMI is one factor that is used to determine a child's eligibility for lipid screening and treatment. BMI, which is an indirect measure of body fat, may inadequately represent the biological effect of body fat percentage on lipid concentrations. OBJECTIVE: We examined the relation between directly measured body fat percentage and lipid concentrations in a representative sample of US youths. DESIGN: Data from 7821 participants aged 8-19 y from the 1999-2004 NHANES were analyzed. Body fat percentage was measured by dual-energy X-ray absorptiometry. Total and HDL-cholesterol concentrations were measured in serum. Serum triglyceride and LDL-cholesterol concentrations were measured in a subsample of 2661 fasting NHANES participants aged 12-19 y. Prevalences of adverse total cholesterol (>200 mg/dL), LDL cholesterol (>130 mg/dL), triglycerides (>150 mg/dL), and HDL cholesterol (<35 mg/dL) were measured. RESULTS: Approximately 10.0% [±0.7% (SE)] of participants had high total cholesterol, 7.0 ± 0.4% of participants had low HDL cholesterol, 9.7 ± 1.0% of participants had high triglycerides, and 7.6 ± 0.7% of participants had high LDL cholesterol. Prevalence of adverse total cholesterol, HDL cholesterol, triglycerides, and LDL cholesterol in US youths with high adiposity (greater than or equal to the age- and sex-specific 75th percentile of body fat percentage) was significantly greater (P < 0.01) than for participants without high adiposity. In multiple linear regressions adjusted for age, survey period, and race-ethnicity, the variance in lipid concentrations explained by body fat percentage was 2-20% (P < 0.001). CONCLUSION: Adverse lipid concentrations and high adiposity are significantly associated in youths.