Glucose and insulin response to a glucose load in Salisbury blacks: Part II. the contrast with whites

Rhodesian Whites have a higher prevalence than Blacks of diabetes mellitus, a disease with a recognized genetic factor. The glucose tolerance test results of Black and White men standarized for age and occupation were compared, and then the interaction between serum glucose, insulin and a selection of other factors was contrasted statistically by race. Serum glucose concentrations, but no insulin values, differed by race in subjects with similar occupations. The interaction of glucose but not insulin with age, body mass index, and maximum volume of oxygen per kilogram body mass also differed by race. Serum insulin values vaired with cigarette smoking in Blacks. As serum insulin but not glucose also varied cross-sectionally in Blacks with increasing standards of living, there is further mathematical evidence that serum glucose concentrations are more directly under genetic control than are insulin concentrations. Differences in the serum insulin concentrations between Blacks and Whites in Rhodesia are probably caused by environmental factors.