The prevalence of diabetes mellitus in a large group of South African Indians.

The prevalences of diabetes mellitus and impaired glucose tolerance (IGT) among 866 Indians living in the Chatsworth area of Durban were determined. The study group was selected by cluster sampling and the participants underwent a modified glucose tolerance test (GTT) (determination of fasting and 2-hour plasma glucose levels after a 75 g glucose load). On the basis of the revised World Health Organization criteria the overall prevalence of diabetes mellitus was 11% and of IGT 5,8%. Of the 368 men, 7,6% were found to have diabetes mellitus and 7,1% IGT; the prevalence of diabetes mellitus was much greater among women (13,5%), while there was less IGT (4,8%). Subjects with diabetes mellitus were significantly older (mean 50,7 years) than those with a normal GTT (mean 30,9 years), but of similar age distribution compared with the IGT group (mean 46 years). Subjects with a normal GTT had a significantly lower mean body mass index (22,1 +/- 2,8) compared with diabetic subjects (26,1 +/- 5,2) or the IGT group (25,8 +/- 6,6). Obesity was commonly associated with both diabetes mellitus and IGT, particularly among women.