Association of rs2228570 polymorphism of vitamin D receptor gene with degenerative disc disease: a meta-analysis involving 2947 subjects.

This study aimed to explore the association between the rs2228570 polymorphism in the vitamin D receptor gene and degenerative disc disease (IDD), especially in European. We perform a meta-analysis to analyze the association after searching the relevant studies through China National Knowledge Infrastructure (CNKI), PubMed, Medline and EMBASE databases. And odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of the association. A total of 10 studies involving 1,465 cases and 1,482 controls were included in the meta-analysis. Overall, there was not significant risk between rs2228570 polymorphism and degenerative disc disease in any genetic models. In addition, stratified analyses by ethnicity revealed similar results. However, stratified analyses by others indicates an association between IDD and the FF genotype (OR=0.62, 95% CI=0.43- 0.90, P=0.486) in age =40, and the F allele (OR=0.84, 95% CI=0.73-0.96, P=0.992), FF genotype (OR=0.78, 95% CI=0.65-0.93, P=0.853) in sample size > 300, and ff genotype (OR=0.91, 95% CI=1.11-3.29, P=0.783), FF genotype (OR=0.70, 95% CI=0.51-0.96, P=0.258) in Northern European. This meta-analysis suggested that the rs2228570 polymorphism may not be associated with degenerative disc disease. However, there existed some diversities, especially in age < 40, sample size > 300, countries in Northern Europe, suggesting that carrying the VDR FokI F allele may be a protective factor against IDD development. But a large number of well-designed studies are still required to assess this polymorphism and degenerative disc disease.