Abstract
M.A.
Because of the high incidence of hypertension amongst South African blacks, many hypothesis
have been forwarded to account for the relative higher index of hypertension amongst South
African blacks when compared to whites. Because of the virtue lack of endemic proportions
of hypertension in South African blacks at the beginning of this century, the often - quoted
genetic hypothesis that hypertension is genetically determined would seem not to hold for
South African situation. However, this was not yet tested as one of the risk factors or
precursors to hypertension, namely the higher indices of cardiovascular reactivity had not been
compared in the South African group between white and black subjects.
This study investigated the hypothesis that the offspring of black hypertensive parents would
show greater cardiovascular reactivity than those of black non-hypertensive parents, and also
show greater cardiovascular reactivity than the children of white hypertensive parents as well
as the children of white non-hypertensive parents.
These hypotheses were partially supported. As expected the children of black hypertensives
did show greater indices of cardiovascular reactivity when compared to both children of white
hypertensives and the children of black non-hypertensives. An interesting finding however,
was that the children of white hypertensives had shown greater indices of the psychological
construct of state anxiety than the children of black hypertensive and black non-hypertensive
subjects. Whereas this study supported the hypothesis that an inherited cardiovascular
reactivity would and could account for the greater index of hypertension amongst South
African blacks, it is also possible that the non-psychological expression of tension or
cardiovascular reactivity in the form of state anxiety could partially account for the results
herein obtained.