Metabolic features of Johannesburg Bantu with myocardial infarction

The metabolic features of 4 groups of Johannesburg Bantu were studied: obese and non obese patients with myocardial infarction, and obese and non obese control subjects. Individuals in the first 3 groups were westernized or semi westernized, whereas the non obese controls were largely unsophisticated. By comparison with the latter, the first 3 groups all exhibited a similar pattern of abnormalities consisting of basal and glucose stimulated hyperinsulinemia, impaired glucose tolerance, and raised fasting serum lipid levels. Serum growth hormone responses to glucose loading in both groups of infarcted patients were similar to those of control subjects. Obese infarcted sufferers and obese control subjects had depressed growth hormone responses by comparison with the corresponding non obese groups. Serum uric acid levels were similar in all 4 groups. The findings are discussed in relation to the hypothesis that hyperinsulinism and occlusive atherosclerosis are causally related. For various reasons, including the fact that obesity is very common in Johannesburg Bantu while myocardial infarction is rare, the hypothesis is considered to be an oversimplification.