β1-adrenoceptor gene Arg389Gly polymorphism and essential hypertension risk in general population: a meta-analysis

The β1-adrenoceptor (ADRB1) gene Arg389Gly polymorphism has been extensively studied as a candidate gene in essential hypertension (EH), but no consensus has been reached on the relationship between this polymorphism and EH risk. To systematically explore their possible association, a meta-analysis was conducted. All relevant case-control trials in English-language publications before 1 June 2012 were identified by searching the PubMed and Embase databases. Finally, eight articles met our inclusion criteria, including a total of 5,088 patients with EH and 6,515 controls. No evidence of publication bias was found. Fixed-effects model and random-effects model were applied for dichotomous outcomes to combine results from individual studies. Overall, the Gly allelic frequency of Arg389Gly polymorphism was significantly lower in EH subjects than that in controls (Gly versus Arg: P = 0.04, OR = 0.89, 95 % CI [0.80-1.00], P heterogeneity = 0.03, I (2) = 52 %, random-effects model; GlyGly + ArgGly versus ArgArg: P = 0.02, OR = 0.86, 95 % CI [0.76-0.97], P heterogeneity = 0.08 and I (2) = 42 %, random-effect model). Subgroup analysis by ethnicity detected this association only in East Asians. In sensitivity analysis, the study by Bengtsson K was recognized as the main cause of heterogeneity, which was the only one study with the diagnostic standard for EH as systolic blood pressure (SBP) ≥ 160 mmHg or diastolic blood pressure (DBP) ≥ 90 mmHg. We concluded that the Gly allele of ADRB1 Arg389Gly polymorphism might confer lower risk for EH, especially in East Asians.