title: BsmI, TaqI, ApaI and FokI polymorphisms in the vitamin D receptor (VDR) gene and risk of fracture in Caucasians: a meta-analysis.
abstract: BACKGROUND
  Vitamin D receptor (VDR) gene polymorphisms have been strongly associated with bone mineral density in some studies. However, in a recent meta-analysis, no relationship of the VDR BsmI or TaqI polymorphism and fracture risk was found in the meta-analysis of published data.
  
  
  OBJECTIVE
  Our meta-analysis studied whether a relationship exists between BsmI, TaqI, ApaI and FokI polymorphisms in the VDR gene and risk of fracture.
  
  
  METHODS
  Relevant studies were identified from the following electronic databases: MEDLINE, EMBASE and Current Contents before January 2010.
  
  
  RESULTS
  This meta-analysis included 17 studies with a total of 21 eligible comparisons, which included 2112 fracture cases and 4521 controls. All of these studies reported on Caucasians. The combined results based on all studies showed that fracture cases had a significantly lower frequency of bb genotype of BsmI [odds ratio (OR) = 0.87, 95% confidence interval (CI)=0.76, 0.98]. When stratifying by fracture type, we found that (1) hip fracture cases had a significantly lower frequency of bb genotype of BsmI (OR=0.82, 95% CI=0.70, 0.97); (2) hip fracture cases had a significantly lower frequency of Tt genotype of TaqI (OR=0.65, 95% CI=0.43, 0.97); (3) hip fracture cases had a significantly higher frequency of tt genotype of TaqI (OR=1.74, 95% CI=1.05, 2.91); (4) vertebral fracture cases had a significantly higher frequency of Aa genotype of ApaI (OR=1.63, 95% CI=1.03, 2.59). No significant difference was found in any genotype of FokI.
  
  
  CONCLUSIONS
  Our meta-analysis suggests that there is a modest but statistically significant association between the BsmI bb genotypes and fracture.
authors.affiliation: Department of Orthopedic, the Second Affiliated Hospital of Harbin Medical University, Harbin 150086, Heilongjiang Province, China. guangrongji@hotmail.com
authors.forename: Guang-Rong
authors.initials: GR
authors.lastname: Ji
authors.forename: Meng
authors.initials: M
authors.lastname: Yao
authors.forename: Chong-Yi
authors.initials: CY
authors.lastname: Sun
authors.forename: Zhi-Hao
authors.initials: ZH
authors.lastname: Li
authors.forename: Zhu
authors.initials: Z
authors.lastname: Han
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016208:Databases, Factual; D005260:Female; D050723:Fractures, Bone / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D018167:Receptors, Calcitriol / Q000235:genetics*; D012307:Risk Factors; D044465:White People / Q000235:genetics*; D055815:Young Adult
chemical_list: D018167:Receptors, Calcitriol