Association of rs731236 polymorphism in the vitamin D receptor gene with degenerative disc disease: evidence from a meta-analysis.

The purpose of this study was to investigate the association between the rs731236 polymorphism in the vitamin D receptor gene and degenerative disc disease, especially in Chinese. We elaborately searched the relevant studies through China National Knowledge Infrastructure (CNKI), PubMed and EMBASE databases. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the strength of the association. A total of 10 studies involving 1,220 cases and 1,225 controls were included in the present study. Overall, no evidence of significant risk between rs731236 polymorphism and degenerative disc disease was found in any genetic models. In addition, stratified analyses by ethnicity revealed similar results. However, stratified analyses by sample size in Chinese population show that sample size may be the primary source of heterogeneity. This meta-analysis suggested that the rs731236 polymorphism may not be associated with degenerative disc disease. However, for Asians, there existed some diversities, especially in Chinese population. Therefore, a large number of well-designed studies are still required to assess this polymorphism and degenerative disc disease.