Modifiable risk factors for Type 2 diabetes mellitus in a peri-urban community in South Africa

Aims To investigate the prevalence of Type 2 diabetes mellitus (DM) and its risk factors in a working class peri-urban community in South Africa. Methods Pr cross-sectional descriptive study was conducted in 1996, where a ll persons aged 15 years and older, who were resident in randomly selected houses in Mamre, 55 km from the centre of Cape Town, were sampled. Subjects underwent a 75-g oral glucose tolerance test. Socio-demographic and anthro pometric data were obtained and physical activity was assessed using a 7-da y activity recall questionnaire. The 1985 WHO criterial were used to define diabetes. Results The response rate was 64.5% (n=974). The participants comprised 56% women, 44% men, mean age 37.6 (range 15-86) years. The crude prevalence of Type 2 DM was 7.1% and impaired glucose tolerance (IGT) 8.0%. The age-adju sted prevalence of Type 2 DM was 10.8% (95% confidence interval (CI) 8.2-13 .5%) and IGT 10.2% (95% CI 7.7-12.8%). Regression analysis indicated that a ge (risk ratio (RR) 7.40, 95% CI 3.45-15.86), waist circumference (RR 4.53, 95% CI 2.04-10.05), low total energy expenditure (RR 1.75, 95% CI 1.07-2.5 6) and family history of diabetes (RR 2.31, 95% CI 1.42-3.77) were independ ent risk factors for Type 2 DM, while sex, obesity and regular alcohol cons umption were not. Conclusions This previously unstudied community has an intermediate prevale nce on the international scale of Type 2 DM, which is linked to potentially modifiable risk factors.