Rouby, Nihal El

Background There exists a wide interindividual variability in blood pressure ( BP ) response to β 1 ‐blockers. To identify the genetic determinants of this variability, we performed a pharmacogenomic genome‐wide meta‐analysis of genetic variants influencing β 1 ‐blocker BP response. Methods and Results Genome‐wide association analysis for systolic BP and diastolic BP response to β 1 ‐blockers from 5 randomized clinical trials consisting of 1254 patients with hypertension of European ancestry were combined in meta‐analysis and single nucleotide polymorphisms (SNPs) with P <10 −4 were tested for replication in 2 independent randomized clinical trials of β 1 ‐blocker–treated patients of European ancestry (n=1552). Regions harboring the replicated SNP s were validated in a β 1 ‐blocker–treated black cohort from 2 randomized clinical trials (n=315). A missense SNP rs28404156 in BST 1 was associated with systolic BP response to β 1 ‐blockers in the discovery meta‐analysis ( P =9.33×10 −5 , β=−3.21 mm Hg) and replicated at Bonferroni significance ( P =1.85×10 −4 , β=−4.86 mm Hg) in the replication meta‐analysis with combined meta‐analysis approaching genome‐wide significance ( P =2.18×10 −7 ). This SNP in BST 1 is in linkage disequilibrium with several SNP s with putative regulatory functions in nearby genes, including CD 38 , FBXL 5 , and FGFBP 1 , all of which have been implicated in BP regulation. SNP s in this genetic region were also associated with BP response in the black cohort. Conclusions Data from randomized clinical trials of 8 European ancestry and 2 black cohorts support the assumption that BST 1 containing locus on chromosome 4 is associated with β 1 ‐blocker BP response. Given the previous associations of this region with BP , this is a strong candidate region for future functional studies and potential use in precision medicine approaches for BP management and risk prediction.

Abstractβ‐Blockers’ heart rate (HR)‐lowering effect is an important determinant of the effectiveness for this class of drugs, yet it is variable among β‐blocker–treated patients. To date, genetic studies have revealed several genetic signals associated with HR response to β‐blockers. However, these genetic signals have not been consistently replicated across multiple independent cohorts. Here we sought to use data from 3 hypertension clinical trials to validate single‐nucleotide polymorphisms (SNPs) previously associated with the HR response to β‐blockers. Using linear regression analysis, we investigated the effects of 6 SNPs in 3 genes, including ADRB1, ADRB2, and GNB3, relative to the HR response following β‐blocker used in the PEAR (n = 757), PEAR‐2 (n = 368), and INVEST (n = 1401) trials, adjusting for baseline HR, age, sex, and ancestry. Atenolol was used in PEAR and INVEST, and metoprolol was used in PEAR‐2. We found that rs1042714 and rs1042713 in ADRB2 were significantly associated with HR response to both β‐blockers in whites (rs1042714 C‐allele carriers, meta‐analysis β = –0.95 beats per minute [bpm], meta‐analysis P = 3×10–4; rs1042713 A‐allele carriers, meta‐analysis β = –1.15 bpm, meta‐analysis P = 2×10–3). In conclusion, the results of our analyses provide strong evidence to support the hypothesis that rs1042714 and rs1042713 in the ADRB2 gene are important predictors of HR response to cardioselective β‐blockade in hypertensive patient cohorts.

European Americans (EA) have a better antihypertensive response to β‐blockers when compared with African Americans, albeit with some variability. We undertook a genomewide association study to elucidate the underlying genetic determinants in EA contributing to this variability in blood pressure (BP) response. A discovery genomewide association study of change in BP post–metoprolol treatment was performed in EA participants (n = 201) from the Pharmacogenomic Evaluation of Antihypertensive Responses‐2 (PEAR‐2) study and tested for replication in the atenolol‐treated EA from the PEAR study (n = 233). Rs294610 in the FGD5, which encodes for FYVE, RhoGEF and PH Domain Containing 5, (expression quantitative trait loci for FGD5 in the small intestine) was significantly associated with increased diastolic BP response to β‐blockers in the PEAR‐2 study (P = 3.41 × 10−6, β = −2.70) and replicated (P = 0.01, β = −1.17) in the PEAR study. Post–meta‐analysis of these studies, an additional single nucleotide polymorphism rs45545233 in the SLC4A1, encoding for Solute Carrier Family 4 Member 1, (expression quantitative trait loci for dual specificity phosphatase 3 in the artery tibial) was identified that was significantly associated with a poor response to β‐blockers (P = 3.43 × 10−6, β = 4.57) and was replicated in the atenolol add‐on cohort (P = 0.007, β = 4.97). We identified variants in FGD5 and SLC4A1, which have been previously cited as candidate genes for hypertension, to be associated with a β‐blocker BP response in EA. Further elucidation is warranted of the underlying mechanisms of these variants and genes by which they influence the BP response to β‐blockers.