title: Testosterone, aging, and body composition in men from Harare, Zimbabwe.
abstract: To examine age-related changes in body composition and testosterone (T) among men in an urban sub-Saharan African population, measures of body composition and salivary T were obtained from 109 males ages 20-78 in Harare, Zimbabwe. Measures included height, weight, suprailiac and triceps skinfold, and percent body fat by bioelectric impedance (BIA). Saliva samples were assayed for T using radioimmunoassay. Average BMI of the overall sample (23.16 (SD = 18.12) kg/m(2) was close to Western populations, while salivary T levels (AM = 196 +/- 96 pmol/l; pm = 172 +/- 98 pmol/l) were much lower. Both morning (beta = -0.535; P < 0.001) and afternoon salivary T declined with age (beta = -0.385; P < 0.001). Multiple regression models indicate that pm salivary T (beta = 0.24; P = 0.025), was a predictor of fat-free mass, but neither am nor pm salivary T was related to fat mass or other measures of body composition. In addition, height was significantly related to pm salivary T levels in men under the age of 60. Multivariate regression indicates that pm salivary T is a predictor of fat-free mass when controlled for height and adiposity. These findings suggest that T is related to both lean mass and overall body size among men from a non-Western nonsubsistence population. As such they are consistent with the hypothesis that bioavailable T plays a role in energetic allocation among human males.
authors.affiliation: Department of Anthropology, Boston University, Boston, Massachusetts 02215, USA.
authors.forename: William D
authors.initials: WD
authors.lastname: Lukas
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Campbell
authors.forename: Peter T
authors.initials: PT
authors.lastname: Ellison
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D000728:Androgens / Q000032:analysis / Q000378:metabolism; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D017097:Electric Impedance; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011863:Radioimmunoassay; D012044:Regression Analysis; D012463:Saliva / Q000378:metabolism; D013739:Testosterone / Q000032:analysis / Q000378:metabolism*; D014505:Urban Population; D015030:Zimbabwe
chemical_list: D000728:Androgens; D013739:Testosterone