Hypertension, type 2 diabetes, and blood groups in a population of African ancestry

Objective: To evaluate the possible relationship of hypertension and diabetes with the ABO, Rhesus, and Duffy blood groups, which are known markers of African ancestry. Design: Population-based study. Setting and Participants: A random sample of 1253 Barbados residents, ≥40 years of age. Main Outcome Measures: Hypertension was defined as a systolic blood pressure >140 mm Hg or a diastolic blood pressure >90 mm Hg or use of antihypertensive treatment; type 2 diabetes was defined as a glycosylated hemoglobin level >10% and/or a history of treatment in those >30 years of age. Results: In logistic regression analyses, elevated diastolic blood pressure was positively associated with years of age (odds ratio [OR] 1.03, 95% confidence interval CI 1.02-1.05), the Rhesus D+ antigen (OR 2.68, 95% CI 1.21-5.97) and body mass index (OR 1.53, 95% CI 1.19-1.96), but negatively associated with the ABO blood group A allele (OR 0.68, 95% CI .48-.97). A separate logistic regression model indicated that the likelihood of diabetes increased with years of age (OR 1.03, 95% CI 1.01-1.04), hypertension (OR 1.56, 95% CI 1.10-2.20), body mass index (OR 1.68, 95% CI 1.29-2.20), and waist-hip ratio (OR 1.36, 95% CI 1.05-1.75), but decreased with presence of the Rhesus C+ antigen (OR .66, 95% CI .44-.97). Conclusions: The associations of diabetes and hypertension to these blood groups support possible genetic influences on both conditions in this and similar African-origin populations; however, further investigations in other settings are necessary to more fully elucidate these findings.