Aldosterone synthase gene (CYP11B2) promoter polymorphism as a risk factor for ischaemic stroke in Tunisian Arabs

Abstract

Introduction. We investigated the contribution of aldosterone synthase CYP11B2 polymorphism (C—344T) to the age-related changes in blood pressure in stroke patients. Subjects and methods. Study subjects comprised 329 stroke patients (121 normotensive, 208 hypertensive) and 444 healthy controls. Genotyping was done by PCR-RFLP, and the contribution of CYP11B2 polymorphism to the risk of stroke was analysed by regression analysis. Results. The T allele, and CT, TT, and CT + TT genotypes, independently of sex and age, were significantly associated with increased stroke risk. Varied distributions of CYP11B2 genotypes were noted among patients with respect to gender, age and hypertension status, being pronounced in hypertensive patients. Both systolic and diastolic blood pressure were positively correlated with the presence of T allele. Mean systolic and diastolic blood pressure were significantly higher among young (< 60 years) CT and TT genotype carriers. Regression analysis confirmed the positive association of CT and TT genotypes and systolic blood pressure, and the negative association of diastolic blood pressure with odds of stroke development. Taking normotensive patients as reference, regression analysis identified TT genotype, age and female gender to be independently associated with increased odds of stroke. Conclusion. Compared to CC genotype, CT and TT CYP11B2 genotypes are independently associated with increased stroke index.