Association between rs1800795 polymorphism in the interleukin-6 gene and the risk of polycystic ovary syndrome: A meta-analysis

OBJECTIVE: Several published articles have investigated the association between the −174 G/C (rs1800795) polymorphism in the interleukin-6 (IL-6) gene and the risk of polycystic ovary syndrome (PCOS). However, the results were inconsistent. In the present study, a meta-analysis was performed to resolve this inconsistency. METHODS: Eligible studies reporting an association between the IL-6 rs1800795 polymorphism and PCOS susceptibility were included from PubMed, Embase, Web of Science, and the Cochrane Library up to December 1, 2017. The odds ratio (OR) with the 95% confidence interval (CI) was used to calculate the strength of the associations. Publication bias detection was conducted using Begg test. We used STATA 11.0 software to perform the statistical analyses. RESULTS: Six articles detailing case-control studies were included, reporting a total of 512 cases and 606 controls. The meta-analysis results indicated that rs1800795 was associated with decreased PCOS susceptibility in the overall population under the allelic model (G vs. C, OR = 0.59, 95% CI: 0.41–0.85, P = .005), the homozygous model (GG vs. CC, OR = 0.45, 95% CI: 0.28–0.73, P = .001), heterozygous model (GG vs. CG, OR = 0.50, 95% CI: 0.26–0.95, P = .036), and the dominant model (GC + CC vs. GG, OR = 0.48, 95% CI: 0.26–0.89, P = .020). However, a threshold P value of .05 was found under the recessive model (CC vs. GG + CG, OR = 0.62, 95% CI: 0.39–1.00). CONCLUSIONS: This meta-analysis concluded that IL-6 rs1800795 polymorphism has a decreased association with PCOS risk among all populations studied. The results suggested that the IL-6 rs1800795 polymorphism is a protective factor for PCOS susceptibility. Given the limited ethnic groups and sample size, further studies are required to validate the association.