Aim/objectives/background: Hypertension is a risk factor for cardiovascular and kidney disease and is most prevalent in African-American adults. The renin-angiotensin-aldosterone system is integral in blood pressure regulation; angiotensin-converting enzyme inhibitors such as ramipril are first-line treatment options. As decreases in angiotensin result in catecholamine release, β-adrenergic receptor (ADRB) polymorphisms may influence blood pressure response to ramipril.
Methods: Associations between ADRB polymorphisms and blood pressure response to ramipril were analyzed in the African American Study of Kidney Disease and Hypertension, a randomized clinical trial. A total of 336 participants were included in this analysis. Six polymorphisms were analyzed here: (a) ADRB1 rs1801252 (Ser49Gly) and rs1801253 (Gly389Arg); and (b) ADRB2 rs2053044, rs1042711, rs1042713 (Arg16Gly), and rs1042714 (Gln27Glu). Time to reach a mean arterial pressure (MAP) of 107 mmHg within the first 60 days after randomization was studied using Kaplan-Meier and Cox proportional hazards modeling for univariate and adjusted analyses.
Results: Genotypes at rs2053044, upstream from the ADRB2 5' untranslated region, were associated with time to reach target MAP among those randomized to the usual treatment group. Participants with the GG genotype achieved target MAP on average 12.2 days (38.1%) later than in comparison with those with the A allele (P=0.01). After adjusting for covariates, those with the AA/AG genotype had 2.09 greater odds of reaching MAP of 107 mmHg or less within 60 days of treatment in comparison with those with a GG genotype (hazard ratio=2.09, 95% confidence interval=1.21-3.60).
Conclusion: Results suggest that ADRB2 rs2053044 genotypes may be a determinant of blood pressure response to ramipril. Additional studies are needed to clarify the effect of rs2053044 and other 5' untranslated region polymorphisms on gene expression and blood pressure response to angiotensin-converting enzyme inhibitors.