American Journal of Clinical Nutrition, Vol 9, 461-472, Copyright © 1961 by The American Society for Clinical Nutrition, Inc.

Fibrinolytic Activity of Whole Blood from South African Bantu and White Subjects

¹ From the Human Biochemistry Research Unit, South African Institute for Medical Research, and Council for Scientific and Industrial Research, Johannesburg, South Africa

Fibrinolytic activity in whole blood has been determined in groups of rural Bantu, urban Bantu and white subjects. It has been found that: (1) Mean activity in rural Bantu males is significantly greater than in urban Bantu males; both groups are significantly superior in activity to the white males studied. (2) Rural and urban Bantu females have significantly lower activities than the white females studied. (3) Fibrinolytic activity determined in groups of Bantu and white subjects at noon, followed by a fat-free or a fatty meal (31 to 34 gm. butter fat), shows no significant change when determined three hours later; in Bantu males and females there is a tendency toward acceleration of activity following ingestion of the fatty meal, whereas white females tend to show a slight inhibition of activity following both fat-free and fatty meals. (4) A group of rural Bantu pursuing active occupations did not have greater mean fibrinolytic activity compared with another group doing no active work during the experimental period, nor was a correlation apparent in the numerous individual Bantu and white subjects investigated.

It is imperative to take account not only of the limitations of current methods of determining fibrinolysin activity, but also of our ignorance over the applicability of the results obtained to in vivo conditions. Nevertheless, the experimental in vitro observations reported herein, indicating superiority in fibrinolytic activity of Bantu males over white males, but not of Bantu females over white females, demonstrate that higher fibrinolytic activity is not characteristic of the Bantu population. Caution must therefore be exercised against assigning undue importance to fibrinolytic activity (as assessed by the test used) in retarding the occurrence of acute thrombotic episodes in the coronary vessels of these people.