SEX-HORMONE LEVELS AND BODY HAIR-GROWTH IN KUNG-SAN AND KAVANGO MEN FROM NAMIBIA

The relation between hair growth and levels of sex hormones in serum a nd saliva was investigated in 256 !Kung San and Kavango men (ages 18 t o 39 years) from Namibia/Southern Africa. Serum concentrations of tota l testosterone (Tser), 5alpha-dihydrotestosterone (DHT), and estradiol (E2) as well as the level of bioavailable non-SHBG-bound testosterone in the saliva (Tsal) were determined by radioimmunoassay. The distrib ution and density of scalp and facial hair as well as the development of terminal hair on the chest, abdomen, pubic area, arms, fingers, and legs were categorized using objective criteria. Covariance analyses r evealed marked differences in the distribution of body hair in the San and the Negro sample. This is partly explained by a significant influ ence of androgen and estrogen levels on the growth of terminal hair. D HT and the ratio DHT/Tser are significantly positively related to midp halangeal hair growth and negatively to pubic hair development. Tsal, the bioavailable fraction of total testosterone, exerts a weak positiv e influence on the degree of arm and leg hair growth; the most signifi cant positive effect on the growth of abdominal, arm, and leg hair in our samples is caused by E2. The ratio Tser/E2 correlates significantl y negatively with the arm and leg hair development and the ratio DHT/E 2 with the degree of abdominal, pubic, arm, and leg hair, whereas lowe r DHT concentrations occur in men with stronger hair development. (C) 1993 Wiley-Liss, Inc.