Socioeconomic Position, but Not African Genomic Ancestry, Is Associated with Blood Pressure in the Bambui-Epigen (Brazil) Cohort Study of Aging

The study objective is to examine the role of African genome origin on baseline and 11-year blood pressure trajectories in community-based ethnoracially admixed older adults in Brazil. Data come from 1272 participants (aged ≥60 years) of the Bambui cohort study of aging during 11 years of follow-up. Outcome measures were systolic blood pressure, diastolic blood pressure, and hypertension control. Potential confounding variables were demographic characteristics, socioeconomic position (schooling and household income), and health indicators (smoking, sedentary lifestyle, high-density lipoprotein cholesterol, waist circumference, diabetes mellitus, and cardiovascular diseases), including antihypertensive drug use. We used 370 539 single-nucleotide polymorphisms to estimate each individual's African, European, and Native American trihybrid ancestry proportions. Median African, European, and Native American ancestry were 9.6%, 84.0%, and 5.3%, respectively. Among those with African ancestry, 59.4% came from East and 40.6% from West Africa. Baseline systolic and diastolic blood pressure, controlled hypertension, and their respective trajectories, were not significantly (P>0.05) associated with level (in quintiles) of African genomic ancestry. Similar results were found for West and East African subcontinental origins. Lower schooling level (<4 years versus higher) showed a significant and positive association with systolic blood pressure (Adjusted β=2.92; 95% confidence interval, 0.85-4.99). Lower monthly household income per capita (<USD 180.00 versus higher) showed an inverse association with hypertension control (β=-0.35; 95% confidence interval,-0.63 to-0.08, respectively). Our results support the view that favors social and environmental factors as determinants of blood pressure and hypertension control.