The Prevalence of Diabetes Among Overweight and Obese Individuals is Higher in Poorer than in Richer Neighbourhoods

OBJECTIVEDiabetes is increasing in prevalence worldwide. This study investigated whether the elevated prevalence of diabetes in lower-income neighbourhoods could be explained by higher rates of overweight and obesity.METHODSA total of 7434 patients who attended respiratory clinics in 2 Ontario cities were linked to administrative databases to ascertain diagnoses of diabetes, chronic obstructive pulmonary disease and asthma. Body mass index (BMI) was obtained from clinic databases and median neighbourhood income from the Canadian census. Prevalence ratios were estimated by log-linear multiple binary regression.RESULTSBMI and neighbourhood income were independently associated with the prevalence of diabetes. At any level of BMI, subjects living in richer neighbourhoods were less likely to have been diagnosed with diabetes than subjects in poorer neighbourhoods.CONCLUSIONIn addition to body weight, neighbourhood income-related factors are associated with the risk of diabetes. These may include diet, physical activity and pollution exposures. Additional etiologic research is required to explain the income-related differential. From a resource perspective, the health care system will need to invest resources in low-income neighbourhoods to provide counselling and treatment for those individuals at risk for diabetes or for those already diagnosed.