Modi®able risk factors for Type 2 diabetes mellitus in a peri-urban community in South Africa N. S. Levitt*, K. Steyn§, E. V. Lambert³, G, Reagon², C. J. Lombard¶, J. M. Fourie§, K. Rossouw§, M. Hoffman² Abstract 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 A cross-sectional descriptive study was conducted in 1996, where all 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 anthropometric data were obtained and physical activity was assessed using a 7-day activity recall questionnaire. The 1985 WHO criteria were used to de®ne 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-adjusted prevalence of Type 2 DM was 10.8% (95% con®dence interval (CI) 8.2±13.5%) and IGT 10.2% (95% CI 7.7±12.8%). Regression analysis indicated that age (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±2.56) and family history of diabetes (RR 2.31, 95% CI 1.42±3.77) were independent risk factors for Type 2 DM, while sex, obesity and regular alcohol consumption were not. Conclusions This previously unstudied community has an intermediate prevalence on the international scale of Type 2 DM, which is linked to potentially modi®able risk factors. Diabet. Med. 16, 946±950 (1999) Keywords peri-urban, physical activity, prevalence, South Africa, Type 2 diabetes mellitus Abbreviations DM, diabetes mellitus; IGT, impaired glucose tolerance Introduction The rising prevalence of diabetes makes it an ever- increasing contributor to morbidity, premature mortality and healthcare costs. This is particularly a problem for developing countries [1±6]. The growing global burden of diabetes has directed more attention toward primary prevention. Cross-sectional and longitudinal studies have identi®ed a number of risk factors, some of which are potentially modi®able. The risk factors include increasing age, acculturation, urbanization, obesity, upper segment fat distribution and physical inactivity [1±3,5,7±13]. Departments of *Medicine and ²Community Health, and ³MRC/UCT Bioenergetics of Exercise Research Unit, University of Cape Town, Cape Town, South Africa §Chronic Diseases of Lifestyle Programme and ¶Centre for Epidemiological Research in Southern Africa, Medical Research Council, Tygerberg, South Africa Received 8 December 1998; revised 15 August 1999; accepted 21 August 1999 Correspondence to: Professor Naomi S. Levitt, Department of Medicine, University of Cape Town Medical School, Observatory 7925, Cape, South Africa. E-mail: dinky@uctgsh1.uct.ac.za 946 ã 1999 British Diabetic Association. Diabetic Medicine, 16, 946±950