High prevalence of type 2 diabetes in all ethnic groups, including Europeans, in a British inner city: relative poverty, history, inactivity, or 21st century Europe?

OBJECTIVE—To compare the prevalence of type 2 diabetes in white Europeans and individuals of African-Caribbean and Pakistani descent. RESEARCH DESIGN AND METHODS—Random sampling of population-based registers in inner-city Manchester, Britain’s third most impoverished area. A total of 1,318 people (25–79 years of age) were screened (minimum response 67%); 533 individuals without known diabetes underwent 2-h glucose tolerance testing, classified by 1999 World Health Organization criteria. RESULTS—More than 60% of individuals reported household annual income <£10,000 ($15,000) per year. Energetic physical activity was rare and obesity was common. Age-standardized (35–79 years) prevalence (mean 95% CI) of known and newly detected diabetes was 20% (17–24%) in Europeans, 22% (18–26%) in African-Caribbeans, and 33% (25–41%) in Pakistanis. Minimum prevalence (assuming all individuals not tested were normoglycemic) was 11% (8–14%), 19% (15–23%), and 32% (24–40%), respectively. Marked changes in prevalence represent only small shifts in glucose distributions. Regression models showed that greater waist girth, lower height, and older age were independently related to plasma glucose levels, as was physical activity. Substituting BMI and waist-to-hip ratio revealed their powerful contribution. CONCLUSIONS—A surprisingly high prevalence of diabetes, despite expected increases with new lower criteria, was found in Europeans, as previously established in Caribbeans and Pakistanis. Lower height eliminated ethnic differences in regression models. History and relative poverty, which cosegregate with obesity and physical inactivity, are likely contributors. Whatever the causes, the implications for health services are alarming, although substantial preventive opportunities through small reversals of glucose distributions are the challenge. Rates of type 2 diabetes have been rising around the world (1,2). The increase in prevalence has accelerated due to aging population structures in developed countries and increasing obesity globally. High prevalence occurs in the Caribbean (3,4), West Africa (5,6), and among these communities in Britain (7,8,9,10,11,12), as in individuals of Indian subcontinental origin, with heterogeneity in subgroups (13). Whether these occur as a result of genetic or environmental factors remains unclear; the case against a major genetic contribution has been made elsewhere (14,15). Poverty has been underrecognized as a contributor to prevalence of type 2 diabetes. However, in Britain, standardardized mortality ratios from reported diabetes, known to be seriously underrecorded (16), correlate closely with deprivation scores and inner cities (17). Prevalence is higher in individuals exposed to more deprivation, individually and at the level of the electoral ward (18,19,20,21). Patients in more deprived areas were less likely to receive insulin therapy, and those who did receive insulin had poorer diabetes control (22). Herein we compare the prevalence of type 2 diabetes among African-Caribbeans in inner-city Manchester (part of an international collaborative study examining nutrition and the emergence of cardiovascular disease in African origin populations) (6,23,24,25,26,27) with data from individuals of local European origin (aged 25–79 years) and a smaller sample of the local residents of Pakistani descent (aged 35–79 years). We examine the contribution of deprivation, measured by reported income in an area with poor socioeconomic indexes, education level, physical activity, and obesity.