Blood pressures of South African black schoolchildren aged 10--12 years.

In South Africa, in urban but not rural areas, hypertension in Black adults is commoner than in local White adults. To throw light on this situation, blood pressures have been determined in series of South African Blacks, initially on children aged 10--12 years, in rural and urban areas. Mean data are among the lowest recorded. They are lower (p less than 0.01) in the main than those of Black children in U.S.A. Neither levels of salt nor sugar intakes appeared influential. Evidently, noxious factors promotive of hypertension in urban Black adults are not yet in operation in children.