E p i d e m i o I o g y / H e a ! t h Se r v i c e s / P s y c h o s o c i a I Research N A L A R T I C L E Effect of Socioeconomic Risk Factors on the Difference in Prevalence of Diabetes Between Rural and Urban Populations in Bangladesh M. ABU SAYEED, MD LlAQUAT ALI, PHD M. ZAFIRUL HUSSAIN, MSC M.A. KARIM RUMI, MSC AKHTAR BANU, MSC A.K. AZAD KHAN, PHD OBJECTIVE — To compare the prevalence of diabetes between the poor and rich of rural and urban populations in Bangladesh. RESEARCH DESIGN AND METHODS— A total of 1,052 subjects from urban and 1,319 from rural communities (age 2:20 years) of different socioeconomic classes were inves- tigated. Capillary blood glucose levels, fasting and 2 h after a 75-g glucose drink (2-h blood glu- cose [BG]), were measured. Height, weight, waist, hips, and blood pressure were also measured. RESULTS — Age-adjusted (30-64 years) prevalence of NIDDM was higher in urban (7.97% with 95% CI 6.17-9.77) than in rural subjects (3.84%, CI 2.61-5.07), whereas impaired glu- cose tolerance (1GT) prevalence was higher in rural subjects. In either urban or rural areas, the highest prevalence of NIDDM was observed among the rich, and the lowest prevalence was observed among the poor socioeconomic classes. The rural rich had much higher prevalence of IGT than their urban counterpart (16.5 vs. 4.4%, CI 6.8-17.4). Increased age was an impor- tant risk factor for IGT and NIDDM in both rural and urban subjects, whereas the risk related to higher BMI and waist-to-hip ratio (WHR) was less significant in rural than urban subjects. Using logistic regression and adjusting for age, sex, and social class, the urban subjects had no excess risk for NIDDM. In contrast, an excess risk for glucose intolerance (2-h BG 5:7.8 mmol/1) was observed in the rural subjects. CONCLUSIONS — Adjusting for age, sex, and social class, the prevalence of NIDDM among urban subjects did not differ significantly from that among rural subjects. Increased age, higher socioeconomic class, and higher WHR were proven to be independent risk factors for glucose intolerance in either area. S tudies comparing rural and urban dia- betes prevalence among Asians have shown that urban populations have a higher prevalence of diabetes than their rural counterparts (1-6). Urbanization with its changed lifestyle in the developing com- munities has been attributed as a risk factor for an increasing trend of diabetes preva- lence (1). This trend in the developing countries has been substantiated by the World Health Organization (WHO) Dia- betes Reporting Group (2). Several small surveys in Bangladesh have also shown an increasing trend (7-10). Although the rural population consti- tutes >85% of the country's total popula- From the Department of Epidemiology and Biostatistics (M.A.S., L.A., M.Z.H., M.A.K.R., A.K.A.K.), Research Division, Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disor- ders (BIRDEM); and the Institute of Nutrition and Food Science (A.B.), University of Dhaka, Dhaka, Bangladesh. Address correspondence and reprint requests to M. Abu Sayeed, MD, Research Division, BIRDEM, 122 Kazi, Nazrul Islam Ave., Dhaka, Bangladesh. Received for publication 21 February 1996 and accepted in revised form 11 November 1996. BG, blood glucose; dBR diastolic blood pressure; IGT, impaired glucose tolerance; NGT, normal glucose tolerance; OR, odds ratio; sBP, systolic blood pressure; SD, standard deviation; WHO, World Health Organ- ization; WHR, waist-to-hip ratio. tion, almost 65% of the registered diabetic subjects of the Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders (BIR- DEM) were from urban areas (11,12). This study was undertaken to estimate the prevalence of impaired glucose tolerance (IGT) and NIDDM simultaneously in the rural and urban populations living at dif- ferent socioeconomic levels and to deter- mine the excess risk for diabetes, if any, in an urban population. RESEARCH DESIGN AND METHODS — All men and women ^ 2 0 years of age were considered eligible for the study, except pregnant women and subjects on medication. For rural subjects, 600 village households out of 3,620 were randomly selected in Kharua union, which has a total population of 19,910. The rural poor were classified as landless farmers sub- sisting on active agrarian labor and the rural rich as landholders, usually maintaining a sedentary habit. The rural middle class was a heterogeneous population other than the two classified groups (rural poor, rural rich). In the city of Dhaka, 4 out of 12 slums were selected randomly for the urban poor (n = 315) and 5 out of 15 housing estates for government employees were chosen for the urban rich (n = 985). Each eligible subject was examined for height, weight, and girth of waist and hip. The measurements were taken while the subject was barefoot and wearing light cloth- ing. Fasting capillary blood glucose (BG) was estimated using Hemoglucotest strip and Reflolux (Boehringer, Mannheim), and a drink of 75 g glucose was given (13). Each subject was allowed a 15-min rest before taking blood pressure. Finally, blood glucose estimation was repeated 2 h after the drink. Statistical analysis Age-adjusted prevalence was given for the truncated age range of 30-64 years, based on the population census of 1991 (2,14). The groups based on geographical location, socioeconomic class, and glycemic status DIABETES CARE, VOLUME 20, NUMBER 4, APRIL 1997 551