Epidemiology of Obesity, Diabetes, and Hypertension in African Caribbeans

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PROJECT SUMMARY/ABSTRACT Obesity is a very strong risk factor for type 2 diabetes (T2D) and hypertension, which disproportionately affect African ancestry populations. The Caribbean region in particular is experiencing an enormous epidemic of cardio-metabolic disease, with obesity, T2D, and hypertension being considerably higher in African Caribbeans compared to Caribbeans of other race/ethnicities. Despite the current and projected growth in obesity, T2D and hypertension among African Caribbeans, the mechanisms underlying racial/ethnic disparities in these devastating and costly conditions remain largely unknown. T2D and hypertension are driven in part by obesity and body fat distribution, especially fat around and within non-adipose tissue organs (known as ectopic adiposity). Our recent discovery that ectopic skeletal muscle adiposity contributes to incident T2D and hypertension in African Caribbean men supports the hypothesis that ectopic adiposity may be a key risk factor contributing to increased risk of T2D and hypertension in African Caribbean populations. However, in contrast to African Caribbean men, very little is known about the importance of body fat distribution and ectopic adiposity for T2D, hypertension, and resultant cardiovascular disease in African Caribbean women. Our preliminary data underscores the need to extend research to include African Caribbean women to unravel the sex-specific and obesity-related mechanisms for T2D, hypertension and cardiovascular disease (CVD) and to discover novel factors related to these major conditions in African ancestry populations. Over the past 20 years we have been studying a unique population-based cohort of African Caribbean men from Tobago. We now propose to expand our research on obesity, T2D, hypertension, and CVD among African Caribbean men to include African Caribbean women in Tobago. We will collect data on lifestyle and medical factors, anthropometrics, DXA and CT body composition measures, carotid ultrasound measures of subclinical cardiovascular disease, and create a specimen biobank for future proposals using our existing infrastructure and well-established procedures. In these newly recruited women, we propose to: 1) determine the overall, and age- and BMI- specific prevalence of T2D and hypertension in African Caribbean women in Tobago, and compare the prevalence with our existing data in men; 2) identify traditional and novel lifestyle, cultural, behavioral, reproductive, nutritional, and medical-related risk factors for T2D and hypertension among African Caribbean women, and 3) evaluate the association of body fat distribution and ectopic adiposity in African Caribbean women with prevalent T2D and hypertension, and compare these associations with those previously observed in African Caribbean men. In addition to accomplishing these aims, the collection and archiving of vital specimens and measures (e.g., fecal samples for microbial distribution; DNA and RNA extraction for omics based approaches), and reading of archived vascular images for subclinical CVD will create the foundation for subsequent, focused funding proposals. Finally, combined with our existing data in men, our study will provide a rich resource for the long-term study of cardio-metabolic health among African Caribbeans and enable future comparisons to similarly phenotyped cohorts of African Americans.