Association of angiotensin-converting enzyme gene insertion/deletion polymorphism with polycystic ovary syndrome: a meta-analysis

Introduction: Epidemiological studies investigating the association of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism with polycystic ovary syndrome (PCOS) produced inconsistent results. To derive a more precise estimation of the relationship between I/D polymorphism and PCOS, we conducted the current meta-analysis. Materials and methods: PubMed, Web of Science and CNKI were searched for eligible publications up to 1 February 2012. The association was evaluated under different genetic models. Results: Six studies with 1451 cases and 773 controls were finally included in our meta-analysis. The results showed that no significant association between I/D polymorphism and PCOS was observed in the overall population. However, in subgroup analyses stratified by ethnicity, significant association was observed in Caucasians (OR = 1.48, 95% CI, 1.00-2.19 for D vs. I; OR = 1.61, 95% CI, 1.14-2.27 for DD vs. II; OR = 1.43, 95% CI, 1.04-1.97 for DD and DI vs. II), but not in Asians. Conclusions: Our meta-analysis suggested that the ACE I/D polymorphism was associated with increased risk of PCOS in Caucasians, but not in Asians. However, considering that the conclusions were based on a relatively small sample size, larger studies involving various ethnic populations should be warranted in future studies to validate our findings.