Polymorphisms of the β1-adrenergic receptor gene are associated with essential hypertension in Chinese

Background: The β1-adrenergic receptor (ADRB1) plays a pivotal role in mediating signal transduction of the sympathetic-adrenal system, which is involved in the regulation of cardiac output and peripheral resistance. Our goal was to determine whether the polymorphisms Arg389Gly (rs1801253) and Ser49Gly (rs1801252) of the ADRB1 gene were associated with essential hypertension in Chinese. Methods: We tested our hypothesis in two independent case-control studies, one comprised 481 patients with hypertension and 529 control subjects, and the other study comprised 212 patients and 325 control subjects. All subjects were genotyped for Arg389Gly and Ser49Gly polymorphisms. Results: The first study showed that the Arg389Arg genotype of the ADRB1 gene was associated with risk of hypertension [odds ratio (OR) 1.77, 95% confidence interval (CI) 1.09–2.98; p=0.008], and the association was replicated in the second independent population (OR 1.65, 95% CI 1.07–2.89, p=0.01). The patients with the Arg389Arg genotype had significantly higher diastolic blood pressure (DBP) than did those with Arg389Gly genotype as well as those with Gly389Gly genotype (100.29±11.01 mm Hg vs. 95.33±13.10 mm Hg and vs. 96.17±12.18 mm Hg, respectively, p=0.01, p=0.02). The association was replicated in the second study (103.7±13.3 mm Hg vs. 97.31±12.9 mm Hg and vs. 96.29±13.4 mm Hg, respectively, p=0.03, p=0.02). Heart rate also showed an association (in first study: 79.43±9.90 bpm vs. 74.87±8.96 bpm, vs. 73.92±8.18 bpm, respectively, p=0.02, p=0.014; in the second study: 81.12±8.99 bpm vs. 74.85±7.97 bpm and vs. 73.89±9.12 bpm, p=0.007, p=0.006, respectively). No association was seen between systolic blood pressure (SBP) and any of the three genotypes at amino acid position 389 in hypertensive patients, neither between the Ser49Gly polymorphisms and hypertension, nor between the Ser49Gly genotypes and DBP and heart rate. Conclusions: The polymorphisms of the ADRB1 gene were associated with essential hypertension. The Arg389Gly polymorphism of the ADRB1 gene confers higher risk for hypertension. Clin Chem Lab Med 2009;47:1227–31.Peer Reviewe