title: Association of the vitamin D binding protein polymorphisms with the risk of type 2 diabetes mellitus: a meta-analysis.
abstract: OBJECTIVE
  Previous studies on the association between vitamin D binding protein (DBP) polymorphisms and the risk of type 2 diabetes mellitus (T2DM) have produced conflicting results. The purpose of this meta-analysis was to examine whether DBP polymorphisms are associated with the risk of T2DM.
  
  
  METHODS
  Systematic review and meta-analysis.
  
  
  METHODS
  All eligible studies were searched and acquired from the Cochrane, Pubmed, ISI, CNKI (Chinese) and Wanfang (Chinese) databases. ORs with corresponding 95% CIs were computed to estimate the association between DBP polymorphisms and T2DM. In addition, heterogeneity test, meta-regression and sensitivity analysis were also conducted.
  
  
  RESULTS
  Six studies, which included 1191 cases and 882 controls, met the inclusion criteria and were included in the meta-analysis. The results showed that no significant associations were found between codon 416 and codon 420 polymorphisms in the DBP and the risk of T2DM in the overall analyses. In stratified analysis, significant associations between the codon 420 polymorphism and T2DM were found in Asians (allele Lys vs Thr: OR (95% CI) 1.49 (1.19 to 1.85), genotype Lys/Thr versus Thr/Thr: OR (95% CI) 1.80 (1.36 to 2.38), and Lys/Thr+Lys/Lys versus Thr/Thr: OR (95% CI) 1.81 (1.37 to 2.39), respectively) but not in Caucasians. For the codon 416, the significant association with T2DM was also detected in Asians (genotype Glu/Asp+Glu/Glu vs Asp/Asp: OR (95% CI) 1.36 (1.04 to 1.78)) but not in Caucasians.
  
  
  CONCLUSIONS
  This meta-analysis demonstrated that the DBP polymorphism was moderately associated with increased susceptibility to T2DM in Asians, but a similar association was not found in Caucasians. It suggested that ethnicity might be the potential factor associated with heterogeneity.
authors.affiliation: Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, People's Republic of China.
authors.forename: Gaoshuai
authors.initials: G
authors.lastname: Wang
authors.affiliation: Department of Clinical Pharmacology, School of Pharmaceutical Science, Zhengzhou University, Zhengzhou, Henan, People's Republic of China.
authors.forename: Yuqian
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, People's Republic of China.
authors.forename: Linlin
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, People's Republic of China.
authors.forename: Fei
authors.initials: F
authors.lastname: Yu
authors.affiliation: Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, People's Republic of China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Cui
authors.affiliation: Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, People's Republic of China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Ba
authors.affiliation: Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, People's Republic of China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan, People's Republic of China.
authors.forename: Chongjian
authors.initials: C
authors.lastname: Wang
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D006801:Humans; D011110:Polymorphism, Genetic; D012306:Risk; D014809:Vitamin D-Binding Protein / Q000235:genetics*
chemical_list: D014809:Vitamin D-Binding Protein
keywords: EPIDEMIOLOGY; STATISTICS & RESEARCH METHODS