Prevalence of IGFBP3, NOS3 and TCF7L2 Polymorphisms and Their Association With Hypertension: A Population-Based Study With Brazilian Women of African Descent

Abstract Background: African ancestry seems to be a risk factor for hypertension; however, few genetic studies have addressed this issue. This study aimed to investigate the prevalence of polymorphisms NOS3; rs1799983, IGFBP3; rs11977526 and TCF7L2; rs7903146 in Brazilian women of African descent and their association with hypertension.Methods: This is a cross-sectional study with a sample of 1021 women (19–59 years old) from the quilombola communities of Alagoas (Brazil). Demographic, socioeconomic, lifestyle, anthropometric, biochemical, and blood pressure data were collected. DNA was extracted from mucosa epithelial cells of the participants’ cheek. Genotyping was performed by PCR allelic discrimination. Prevalence ratio (PR) was the measure of association, calculated by Poisson regression, with a hierarchical selection of variables.Results: The prevalences of the less frequent genotypes were 26.5% TT genotype of NOS3; rs1799983, 16.7% AA genotype of IGFBP3; rs11977526, and 18.3% TT genotype of TCF7L2; rs7903146. For these conditions, the prevalence of hypertension and PR (adjusted) relatively to the ancestral genotype were, respectively: 52.0% vs 24.5% (PR=1.54; p<0.001), 62.0% vs 24.1% (PR=1.59; p<0.001), and 38.9% vs 27.9% (PR=0.86; p=0.166). Associations with hypertension were statistically significant, except for the TCF7L2; rs7903146 polymorphism, after adjusted analysis. Conclusions: Brazilian Afro-descendant women with the TT genotype for the NOS3 gene and the AA genotype for the IGFBP3 gene are more susceptible to hypertension. The understanding of underlying mechanisms involving the pathogenesis of hypertension can motivate research for the development of new therapeutic targets related to nitric oxide metabolism and the management of oxidative stress.