α-adducin Gly460Trp polymorphism and essential hypertension risk in Chinese: a meta-analysis

No clear consensus has been reached on the alpha-adducin polymorphism (Gly460Trp) and essential hypertension (EH) risk in Chinese. We conducted a meta-analysis in an effort to systematically explore the possible association. Case-control studies in Chinese and English performed with human subjects were identified by searching the MEDLINE, EMBASE, China Biological Medicine Database, China National Knowledge Infrastructure platform, Wanfang and VIP databases. The fixed-effects model and the random-effects model for dichotomous outcomes were applied to combine the results of the individual studies. We selected 20 studies that met the inclusion criteria, including a total of 5562 patients with hypertension and 4289 controls. Overall, our findings supported the hypothesis that the ADD1 Gly460Trp polymorphism is associated with EH in the Chinese population. A borderline association was found between the tryptophan (Trp) allele of the Gly460Trp variant and hypertension (P=0.05, Odds ratio (OR)=1.08, 95% confidence interval (CI)=1.00-1.17 and P-heterogeneity=0.02). Significantly increased risk was observed in the recessive genetic model (P=0.0009, OR=1.24, 95% CI=1.09-1.41 and P-heterogeneity=0.04) as well as in the homozygote comparison (P=0.006, OR=1.25, 95% CI=1.07-1.46 and P-heterogeneity=0.03). Furthermore, in the subgroup analysis, our results support a positive association among Chinese Han individuals (P=0.001, OR=1.25, 95% CI=1.09-1.42, P-heterogeneity=0.08, recessive genetic model; P=0.009, OR=1.26, 95% CI=1.06-1.50, P-heterogeneity=0.03, homozygote comparison). No apparent association was identified in Kazakhs. Our meta-analysis suggests that the Gly460Trp polymorphism might increase the risk of hypertension in Chinese populations, especially in Han Chinese. Further studies investigating gene-gene, gene-environment and mutual interactions are needed to better understand the role of ADD1 in hypertension. Hypertension Research (2011) 34, 389-399; doi:10.1038/hr.2010.252; published online 13 January 2011