CYP1A1 gene polymorphisms and polycystic ovary syndrome risk: a meta-analysis and meta-regression

Emerging evidence suggests that common functional polymorphisms in the CYP1A1 gene are involved in the regulation of the activities of cytochrome P450 enzymes, thereby increasing an individual's susceptibility to polycystic ovary syndrome (PCOS), but individually published results are inconclusive. This meta-analysis aimed to derive a more precise estimation of the relationship between CYP1A1 gene polymorphisms and PCOS risk. A literature search of PubMed, Embase, Web of Science, the Cochrane Library, Chinese National Knowledge Infrastructure, Chinese Bio-medicine Database, and Chinese Sci-tech Journals Database (VIP) databases was conducted from inception to March 1, 2013. The crude odds ratio (OR) with 95% confidence interval (CI) were calculated. Five case-control studies were included with a total of 1,036 subjects, including 521 PCOS cases and 515 healthy controls. Our meta-analysis results indicated that the C variant of the CYP1A1 rs4646903 (T>C) polymorphism was associated with an increased risk of PCOS (allele model: OR=1.62, 95% CI: 1.06-2.48, P=0.025; dominant model: OR=2.37, 95% CI: 1.25-4.48, P=0.008; homozygous model: OR=2.52, 95% CI: 1.17-5.44, P=0.019), especially among the general female population in Turkey and India. However, there was no statistically significant association between the CYP1A1 rs1048943 (A>G) polymorphism and PCOS risk (all P>0.05). No publication bias was detected in this meta-analysis. The current meta-analysis indicates that the CYP1A1 rs4646903 (T>C) polymorphism may contribute to increasing susceptibility to PCOS, especially among the general female population in Turkey and India. However, further studies are still needed to accurately determine whether the CYP1A1 rs1048943 (A>G) polymorphism is associated with PCOS risk.