Browsing by Author "Pereira, Rinaldo Wellerson"

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    Genetic ancestry is associated with systolic blood pressure and glucose in Brazilian children and adolescents.
    (2016) Queiroz, Erica Maria de; Barbosa, Priscila Oliveira; Candido, Ana Paula; Castro, Ieso de Miranda; Coelho, George Luiz Lins Machado; Leite, Tailce Moura; Pereira, Rinaldo Wellerson; Freitas, Renata Nascimento de
    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.
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    Genetic composition of a Brazilian population : the footprint of the Gold Cycle.
    (2013) Queiroz, Erica Maria de; Santos, A. M.; Castro, Ieso de Miranda; Coelho, George Luiz Lins Machado; Mendes, Ana Paula Carlos Cândido; Leite, Tailce Moura; Pereira, Rinaldo Wellerson; Freitas, Renata Nascimento de
    Ancestry-informative markers (AIMs) are powerful tools for inferring the genetic composition of admixed populations. In this study, we determined the genetic ancestry of the Ouro Preto (Brazil) population and evaluated the association between ancestry and self-reported skin color. The genetic ancestry of 189 children and adolescents was estimated by genotyping 15 AIMs. The estimate of population admixture was determined using the Bayesian Markov Chain Monte Carlo (MCMC) method implemented in two different programs (STRUCTURE and ADMIXMAP). Volunteers self-reported their skin colors. The European ancestry contribution ranged from 0.503 to 0.539, the African contribution ranged from 0.333 to 0.425, and the Amerindian component ranged from 0.04 to 0.164. The relative contributions of African (P < 0.016) and European (P < 0.011) ancestry differed significantly among skin color groups, except between black and dark-brown groups. The population of Ouro Preto has a higher contribution of African ancestry compared to the mean for the southeast region of Brazil. Therefore, extrapolating the African ancestry contribution for southeastern Brazil to the Ouro Preto population would underestimate the actual value for this city. We also showed that self-reported skin color could be appropriate for describing the genetic structure of this particular population.