Genetic epidemiologuy of primary the arterial hypertension in brazilian populations: study of polymorphisms in genes of the renin-angiotensin-aldosterone system and clinical/anthropometrical factors.

by Sampaio Freitas, Silvia Regina

Abstract (Summary)
Essential hypertension (EH) is a multifactorial disease triggered by several genetic and multiple environmental factors. Epidemiological studies have suggested that genetic variants, including those of the genes for angiotensinogen (AGT), angiotensin-converting enzyme (ACE), angiotensin II receptor type 1 (AGTR1), aldosterone synthase (CYP11B2) and mineralocorticoid receptor (MR), can increase the risk for EH. However, associative studies among polymorphic forms of these genes and EH have showed conflicting results in different populations. This scenario may be reflecting the variable impact of the genetic background of populations and the interaction of environmental factors, which can be modulating this molecular background. In this work, we aimed to investigate the association among AGT*M235T, ACE*AluI/D, AGTR1*A1166C, CYP11B2*C344T, MR*G3514C and MR*A4582C genetic markers and clinical/anthropometrical factors (gender, age, ethnical profile, body mass index [BMI], smoking and alcohol consumption), with essential hypertension in two Brazilian population. In this study, 221 individuals from Rio de Janeiro/RJ (106 hypertensives and 115 normotensives), and 160 from Santa Isabel do Rio Negro/AM (82 hypertensives and 78 normotensives) were evaluated. Genetic determination was conduced by polymerase chain reaction, while clinical/anthropometrical characterization was realized through clinical examination. The influence of genetic polymorphisms on blood pressure variation was assessed by analysis of ODDS Ratio and stepwise linear regression. Results from Rio de Janeiro sample indicated an increase in risk for hypertension associated with AGT*235T/235T, AGTR1*1166A/1166A, AGTR1*1166A/1166C, CYP11B2*344T/344T, MR*4582C/4582C genotypes (p lt; 0.05). Moreover, genotype combinations contribute to an increased EH risk (p lt; 0.05). In RJ sample, clinical/anthropometrical factors as age, BMI and ethnical profile were associated to raise blood pressure (p lt; 0.05). The clinical-genetics analysis in Santa Isabel do Rio Negro/Amazon sample indicates that increase of blood pressure was favoured by ACE*AluD/AluD and MR*4582C/4582C genotypes, and advanced age and alcoholv consumption (p lt; 0.05). Our findings suggest that unfavorable genetic patterns combined with clinical/anthropometrical factors contribute to EH development, however, the single influence impact of each factor vary among populations.
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Pedro Hernan Cabello Acero; Rodrigo Soares de Moura Neto

School:Faculdades Oswaldo Cruz

School Location:Brazil

Source Type:Master's Thesis

Keywords:Hypertension Polymorphism Genetic Risk Factors Polymerase Chain Reaction Renin-Angiotensin System


Date of Publication:11/23/2006

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