The relationship between apolipoprotein e 2/3/4 polymorphisms and hypertension: A meta-analysis of six studies comprising 1812 cases and 1762 controls

Abstract

We performed a meta-analysis in an effort to systematically explore the association between apolipoprotein E (ApoE) 2/3/4 polymorphisms and hypertension. We searched for case-control studies in English-language publications performed with human subjects using MEDLINE and included appropriate studies that had been published as of 6 May 2009. Fixed-effects models were used to pool data when between-study heterogeneity was absent, and random-effects models were used otherwise. Data and study quality were assessed in duplicate. Publication bias was assessed by calculating the fail-safe number. From six heterogeneous studies that included a total of 1812 patients with hypertension and 1762 controls, we found that the ApoE 4 allele was significantly associated with hypertension using a random-effects model (odds ratio (OR)1.79; 95% confidence interval (CI): 1.04 to 1.19; P0.04). With regard to ApoE genotypes, we observed that the association with hypertension was more prominent when ApoE4/4 was compared with E3/3, with a nearly twofold increased risk identified for the ApoE4/4 genotype using a random-effects model (OR1.97; 95% CI: 1.11 to 3.52; P0.02). Furthermore, after restricting our analysis to Asian populations, the contrasts between the risk of hypertension among individuals possessing ApoE 4 vs. 3 and ApoE4/4 vs. ApoE3/3 were positively reinforced, with ORs of 1.97 (95% CI, 0.93 to 4.15; P0.08) and 2.27 (95% CI, 1.03 to 4.98; P0.04), respectively. The fail-safe number supported these significant associations at a significance level of 0.05. Taken together, our meta-analysis expands the data available regarding genetic risk factors for hypertension by illustrating that the presence of the ApoE 4 allele is associated with an increased risk of developing hypertension and that it appears to be recessive. Of note, this effect was more pronounced in Asians. © 2009 The Japanese Society of Hypertension. All rights reserved.