title: Association between vitamin D receptor gene polymorphisms and intervertebral disc degeneration: A meta-analysis.
abstract: BACKGROUND
  Studies that have investigated the association between vitamin D receptor (VDR) gene polymorphisms and intervertebral disc degeneration (IDD) have yielded inconsistent results.
  
  
  METHODS
  To investigate the association between VDR gene polymorphisms and IDD, a systematic literature search for relevant published studies was performed on PubMed, Embase, Web of Science, Cochrane library, Wan-Fang, and CNKI databases. A random effects model was used for heterogeneous data; while a fixed effect model was used for homogenous data. Odds ratios (OR) and 95% confidence intervals (CI) were calculated to evaluate the strength of the association.
  
  
  RESULTS
  We observed no association between VDR FokI, TaqI-ApaI polymorphisms and IDD. However, on subgroup analysis by ethnicity, VDR FokI mutation was associated with a significantly lower risk for IDD [dominant model: OR = 0.78, 95% CI = 0.65-0.93; heterozygote model: OR = 0.76, 95% CI = 0.63-0.92; allele model: OR = 0.86, 95% CI = 0.75-0.98] among Caucasians.
  
  
  CONCLUSIONS
  These results suggest that the VDR FokI polymorphism may be associated with IDD among Caucasians. However, the association between VDR TaqI-ApaI polymorphisms and IDD in Asians is still not clear. Further well-designed studies are needed to arrive at a definitive conclusion.
authors.affiliation: Department of Spine Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Spine Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, PR China.
authors.forename: Song
authors.initials: S
authors.lastname: Zhao
authors.affiliation: Department of Spine Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, PR China. Electronic address: niufeng168@hotmail.com.
authors.forename: Feng
authors.initials: F
authors.lastname: Niu
authors.affiliation: Department of Spine Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, PR China.
authors.forename: Gui-Bin
authors.initials: GB
authors.lastname: Bi
mesh_terms: D002681:China / Q000453:epidemiology; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging / Q000235:genetics*; D008297:Male; D011110:Polymorphism, Genetic; D018167:Receptors, Calcitriol / Q000235:genetics*; D018570:Risk Assessment
chemical_list: D018167:Receptors, Calcitriol; C579457:VDR protein, human