Racial differences in the sums of skinfolds and percentage of body fat estimated from impedance in black and white girls, 9 to 19 years of age: The National Heart, Lung, and Blood Institute Growth and Health Study

Objectives: This National Heart, Lung, and Blood Institute Growth and Health Study report assesses racial differences in fat patterning in black and white girls ages 9 to 19 years, comparing the sum of triceps and subscapular skinfolds (SSFs) and percentage of body fat (%BF) from impedance as two indices of adiposity. It is hypothesized that racial differences in fat patterning manifest during puberty.

Research Methods and Procedures: SSF and %BF were measured annually. Racial differences in SSF and %BF were evaluated by age. Associations between %BF and SSF were evaluated using the Pearson's correlations coefficient. Classification agreement was evaluated using the kappa-statistic. Effects of pubertal stage and race on classification agreement were examined using multivariate models.

Results: White girls had a greater mean %BF at 9 to 12 years of age; black girls had a greater %BF thereafter. Black girls had a greater mean SSF at every age. The correlation coefficient between SSF and %BF was 0.79, and there was good agreement between %BF and SSF in separating high (> 85th percentile) from not high (kappa = 0.60 for whites and 0.66 for blacks). SSF associated more with %BF in prepuberty and early puberty than in late puberty.

Discussion: Despite good correlations between %BF and SSF, the two methods indicate different fat patterns in black and white girls.