Association of the C-344T aldosterone synthase gene variant with essential hypertension:: a meta-analysis

Background The CYP11B2 gene (CYP11B2) encoding aldosterone synthase has been associated with essential hypertension and some, but not all, studies have reported that the C-344T variant may influence the risk of the disease. Objective We performed a systematic review of the literature by means of a meta-analysis to evaluate the influence of the C-344T CYP11B2 polymorphism on arterial hypertension and intermediate phenotypes. Methods From 485 reports, we included 42 observational studies, case-control and cohort at baseline. Fixed and random effect models were used to pool data from individual studies. Results From 19 heterogeneous studies including 5343 essential hypertensive and 5882 control subjects, we found a significant association between hypertension and the C-344T variant in fixed but not in random effect models [for homozygous CC: odds ratio (OR), 0.834; 95% confidence interval (Cl), 0.760-0.914; P < 0.0001, n = 11 225]. Besides, homozygous CC subjects had lower plasma renin activity (D, -0.161; 95% Cl, -0.279 to -0.043; P < 0.01, n = 1428) but no difference in plasma alclosterone levels (D, -0.006; 95% Cl, -0.081 to 0.07; P = 0.88, n = 2872). Limiting the quantitative analysis of blood pressure to 13 studies including only untreated individuals, no significant association was found for systolic arterial blood pressure (D, 0.042; 95% Cl, -0.057 to 0.141; P = 0.41, n = 1775) and diastolic arterial blood pressure (D, 0.026; 95% Cl, -0.073 to 0.125; P = 0.61, n = 1775). Conclusion Homozygous individuals for the -344C CYP11B2 allele are at 17% lower risk of hypertension with respect to homozygous TT subjects.