Association of IL-6 and MMP-3 gene polymorphisms with susceptibility to adolescent idiopathic scoliosis: a meta-analysis.

Recently, several institutions have investigated the associations of MMP-3-1171 5A/6A and IL-6-174-G/C gene polymorphisms with adolescent idiopathic scoliosis (AIS), while reports from different institutions are not consistent. Therefore, we, comprehensively and systematically performed this meta-analysis to detect whether the two gene polymorphisms are correlated with AIS. From January 1994 to October 2015, all case-control studies focussed on the relationship between the two aforementioned gene polymorphisms and the susceptibility to AIS were retrieved from bibliographic databases. A total of 16 articles were found, of which five consisted of 944 cases and 1177 controls, were finally included after being assessed by two reviewers. We calculated the pooled odds ratio (OR) with 95% confidence interval (95% CI) to assess the associations. The pooled data analyses were based on allele contrast, homozygote, heterozygote, dominant and recessive models. Overall, there was no significant association of IL-6-174-G/C gene polymorphism with AIS risk. Significant association was observed in homozygote model of MMP-3-1171-5A/6A gene polymorphism (5A5A versus 6A6A: OR = 1.69, 95% CI = 1.11-2.58, P = 0.02). When stratified into Caucasian and Asian populations, positive association was found in Caucasian population (5A versus 6A: OR = 1.43, 95% CI = 1.11-1.84, P = 0.006; 5A5A versus 6A6A: OR = 1.90, 95% CI = 1.13-3.19, P = 0.015); however, there was no significant association in Asian population. The present study concluded that 5A5A genotype of MMP-3-1171 5A/6A gene polymorphism was associated with AIS, especially in Caucasian population. However, no significant association was detected between IL-6-174-G/C gene polymorphism and AIS.