Genetic ancestry is associated with systolic blood pressure and glucose in Brazilian children and adolescents.

Abstract

Background: Studies in admixed populations show that the prevalence of obesity and related diseases, such as type 2 diabetes and hypertension, may vary by ethnic group. The aim of this study was to investigate the relationship of genetic ancestry with phenotypes associated with obesity in a sample of school children and adolescents from Ouro Preto, Minas Gerais. Methods: We used data from genetic ancestry of 189 individuals previously determined by 15 ancestry informative markers (AIMs), and segregated individuals into three ancestral groups (predominantly African (PAFR), predominantly mixed (PMIX), and predominantly European (PEUR)) using the proportion of ancestry. The ancestral groups were compared with mean values of anthropometric, clinical, biochemical, and demographic variables. The simple linear regression analysis was used to test whether differences in mean values of the dependent variables (blood pressure and glucose) between the ancestral groups were dependent on the other variables. Results: Our results show that the proportions of African (F = 144.2, P < 0.001), Amerindian (F = 15.5, P < 0.001) and European (F = 184.9, P < 0.001) ancestry differed significantly (P < 0.001) among the three ancestral groups. PAFR individuals had higher mean blood pressure (P ≤ 0.029) and glucose (P = 0.025) as compared to PEUR. In the linear regression model, the difference in systolic blood pressure (SBP) values remained significant in all models tested and independent of confounding variables (P ≤ 0.041). The difference in diastolic blood pressure values observed in PAFR and PEUR groups did not remain significant when the metabolic profile was included in the tested model (P = 0.097). The difference in glucose values was significant only between PMIX and PEUR groups and independent of the settings (P ≤ 0.037). Conclusion: The positive correlation between genetic ancestry and SBP and glucose in Brazilian children and adolescents suggests the need for special care in the subgroups of this population.