The involvement of the renin-angiotensin system gene polymorphisms in coronary heart disease

Introduction and objectives. Previous studies angiotensin-converting enzyme gene insertion/deletion polymorphism ACE (I/D), angiotensinogen gene polymorphism, and angiotensin II AT1 receptor polymorphism in relation to coronary heart disease controversial results. This study was designed to analyze the association between these gene polymorphisms and the first coronary event in individuals residing on Grand Canary Island, Spain. Patients and method. Case-control study. Case subjects (n=304) were recruited at the first coronary event; age-matched controls (n=315) were randomly selected from the Grand Canary population. Participants were examined for the usual risk factors. Blood samples were obtained for biochemical analyses and DNA extraction. Genotyping was performed by PCR and restriction analysis. Results. Neither ACE (I/D) nor AT1 receptor polymorphism was associated with coronary heart disease, whereas the frequency distribution of AGT M235T genotypes among patients and control subjects (TT: 29% and 19%; MT: 48% and 50%; MM: 22% and 31%, respectively) was statistically different (P=.003). Multiple logistic regression analysis identified the TT genotype of the angiotensinogen gene (OR=1.9; 95% CI 1.1-3.4), diabetes (OR=4.4; 95% CI 2.0-9.4) and hypertension (OR=2.1; 95% CI, 1.33.3) as risk factors predicting the coronary event. Conclusions. Our results provide no evidence of an association between ACE (I/D) or AT1 receptor polymorphism and coronary heart disease. However, homozygosity for the T allele of the angiotensinogen gene, diabetes and hypertension independently place individuals at higher risk of experiencing a coronary event on Grand Canary Island.