Association between interleukin-6 gene polymorphism and idiopathic scoliosis: a meta-analysis

Idiopathic scoliosis (IS) is considered to be a multifactorial disease. Interleukin-6 (IL-6) is an important proinflammatory and anti-inflammatory cytokine. There is some controversy regarding whether IL-6 gene polymorphism (rs1800795 G/C) is associated with IS susceptibility. A systematic search in PubMed, EMBASE, and Cochrane CENTERAL database until the end of November, 2015 were carried out. Pooled ORs were performed for the allelic comparison (C vs. G) and genotypic comparisons of codominant (CC vs. GG and CG vs. GG), dominant (CC + CG vs. GG), and recessive (CC vs. CG + GG) genetic models. We calculated ORs and 95% CIs using random or fixed effects model. Newcastle-Ottawa Scale was used to evaluate the methodological quality, and Stata 11.0 was used to analyze data. The associations between IL-6 gene polymorphism and IS susceptibility were investigated. Five eligible case-control studies were included in our meta-analysis. All of the studies were of high methodological quality. There were a total of 2121 subjects, including 944 cases and 1177 controls, from Asia and Europe. The meta-analysis showed that no significant difference was detected in all genetic models (P > 0.05). However, the results of this meta-analysis should be interpreted with caution because of the heterogeneity among the studies, and additional high quality studies are still necessary to assist with this finding.