Anthropometric-hormonal correlation patterns in San and Kavango males from Namibia

Correlations between sex hormone levels and body dimensions--so far investigated only in Caucasian populations--were analysed using data from 114 !Kung San hunter-gatherers and 137 urban and rural Kavango men from Namibia. The androgens testosterone (Tser) and 5 alpha-dihydrotestosterone (DHT) in the serum and free testosterone in the saliva (Tsal) as well as oestradiol (E2) in the serum were determined by the radioimmunoassay method. The body dimensions were described by 50 anthropometric features which were additionally subjected to factor analysis yielding seven factors. Most of the individual measurements as well as the resulting factor scores correlated significantly with the sex hormone variables and the hormone ratios Tser/DHT, Tsal/Tser, and Tser/E2 in the !Kung San and the two Kavango samples. For an extended comparison pertinent data from a German sample were included in the analysis. This made it possible to test the stability of metric hormonal correlations in different populations living under various ecological and economical conditions. While the breadth measurements in all samples show relatively consistent correlations to both absolute hormones and hormone ratios, the correlations to the other body measurements and individual factor scores turn out to be less stable. Here, the effect of sex hormones on physical growth, which is experimentally well documented, is obviously differentially covered by genetic and environmental factors specific for the groups in question.