Angiotensin-converting enzyme I/D polymorphism and aortic aneurysm risk: a meta-analysis.

OBJECTIVES Angiotensin-converting enzyme (ACE) I/D polymorphism has been implicated in aortic aneurysm risk, but individual published studies show inconclusive results. The aim of this study was to explore a more precise estimation of its relation with aortic aneurysm using meta-analysis. METHODS Electronic searches of PubMed and EMBASE databases were conducted for all publications through February 2014. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to access the strength of this association in the random-effects model or fixed-effects model. RESULTS Fourteen case-control studies, including a total of 3938 cases and 5748 controls, were included. This meta-analysis showed a significant association between ACE I/D polymorphism and aortic aneurysm risk (OR = 1.53, 95% CI 1.26-1.87, P <0.01). In the subgroup analysis by ethnicity, a statistically significant association was found in Caucasians (OR = 1.46, 95% CI 1.20-1.77, P <0.01), but not in Asians. In the subgroup analysis by type of aortic aneurysm, this polymorphism was significantly associated with abdominal aortic aneurysm risk (OR = 1.38, 95% CI 1.10-1.74, P <0.01), thoracic aortic aneurysm risk (OR = 1.59, 95% CI 1.11-2.29, P = 0.01) and aortic dissection risk (OR = 2.43, 95% CI 1.07-5.52, P = 0.03). Stratification by hypertension status showed that hypertensive patients with this polymorphism were associated with increased aortic aneurysm risk (OR = 1.47, 95% CI 1.03-2.09, P = 0.03), whereas normotensive individuals with this polymorphism did not have an increased aortic aneurysm risk. CONCLUSIONS This meta-analysis suggested that ACE I/D polymorphism was associated with aortic aneurysm risk.