Body elemental composition: comparison between black and white adults.

Abstract

The age-related changes in body chemical composition were measured in a normal black population ranging in age from 30 to 80 yr. The levels of total-body calcium, phosphorus, sodium, and chlorine were measured by in vivo neutron activation. In addition, the lean body mass (total-body potassium) was measured by whole-body counting of 40K. These data were compared with the same data obtained on a normal white population in a previous study. Although there were no significant differences in the height of the two groups, black men and women had significantly higher total-body calcium, phosphorus, sodium, chlorine, and potassium than the sex-and age-matched white population. The increased levels of total-body calcium and potassium when normalized for the weight and height of the subjects were reduced but still remained significantly higher than those of the white population. Clearly specific reference standards for skeletal and muscle mass as well as for sodium and chlorine need to be established for black populations.

Frequent Sequence Variation in the Human Myostatin (GDF8) Gene as a Marker for Analysis of Muscle-Related Phenotypes

“…African Americans have greater handgrip and hip flexion strength than Caucasians (Rantanen et al, 1998). This racial difference may be due to the greater muscle mass (Aloia et al, 1997;Cohn et al, 1977;and Gasperino et al, 1995) and the higher density of the lean body mass component of body composition (Schutte et al, 1984) found in African Americans. These differences are observed despite lower levels of physical activity among African Americans (Tuten et al, 1995).…”

How Useful Is Body Mass Index for Comparison of Body Fatness across Age, Sex, and Ethnic Groups?

“…Bias can be introduced into adipose tissue/fat measurements if a method makes assumptions related to body composition proportions and characteristics that are inaccurate across 229 different populations. Among these methodological concerns are the following observations: hydration of fat free body mass changes with age and differs across ethnic groups (13)(14)(15); the density of fat free body mass changes with age and differs between men and women (16,17); and total body potassium decreases with age (15) and fatness (18) and differs between blacks and whites (19,20). These between-group differences influence the absolute accuracy of methods for estimating fatness such as the two-compartment total body water, underwater weighing, and total body potassium methods (21).…”

Creatinine levels among Mexican Americans, Puerto Ricans, and Cuban Americans in the Hispanic Health and Nutrition Examination Survey

“…African Americans are known to have higher serum creatinine levels than whites with comparable glomerular filtration rates [18]. This observation is probably explained by a higher muscle mass in African Americans [19][20][21]. While differences in genetic admixture among groups with different national origins is one possible explanation for differences in serum creatinine levels, our results suggest that this is at best an incomplete explanation for observed differences in serum creatinine levels across these groups.…”