Kt. Thomas et al., ETHNIC AND AGE TRENDS FOR BODY-COMPOSITION IN WOMEN RESIDING IN THE US SOUTHWEST .2. TOTAL FAT, Medicine and science in sports and exercise, 29(1), 1997, pp. 90-98
This study assessed body density (ED) in an ethnically diverse sample
of women (African American, Caucasian, Mexican American and Native Ame
rican) (N = 139) who were between 20 and 30 or 40 and 50 yr of age and
of normal weight for their height. ED was assessed using three method
s: hydrostatically determined density (UWW), total body potassium (TBK
) and the Jackson ct al. (1980) sum of seven SF with gluteal circumfer
ence (SF). Ethnic differences in ED were detected by TBK and UWW. ED f
rom SF did not detect ethnic differences, and the SEE was unacceptable
Based on multiple regression, the prediction equation was: ED = 1.119
7794 - 0.000224382 (X(3)) + 0.006999 (e2) - 0.000320177 (X(2)) - 0.001
892 (el) + 0.001750 (e3) - 0.000537005 (x(1)) (where x(1) = gluteal C,
x(2) = age in years, x(3) = sum of 7 SF and e1, e2, and e3 describe e
thnicity). This formula had a reduced SEE, a higher correlation with h
ydrostatically determined BD, and was sensitive to ethnic differences
detected with other measures of ED. A 24-mmol decrease in potassium wa
s found when comparing the older Caucasian women with the younger Cauc
asian women, while the difference for the African, Mexican, and Native
American groups was 200-300 mmol.