title: Association of genetic variants of vit D binding protein (DBP/GC) and of the enzyme catalyzing its 25-hydroxylation (DCYP2R1) and serum vit D in postmenopausal women.
abstract: OBJECTIVE
  To determine if GC (group-specific component globulin) and CYP2R1 genetic variants have an association with serum 25-OHD3 levels, BMD or bone turnover markers in a population of Chinese postmenopausal women.
  
  
  METHODS
  We randomly selected 1494 postmenopausal women of the Han ethnic group from seven communities in Beijing. BMD was determined by dual energy X-ray absorptiometry; serum bone turnover markers and 25-OHD3 were measured by the automated Roche electrochemiluminescence system; genotypes of GC and CYP2R1 were detected by the TaqMan allelic discrimination assay. Multiple statistic methods were used to test the associations of SNP genotypes and vitamin D levels.
  
  
  RESULTS
  In our sample, 89.6% women had vitamin D deficiency and another 9.8% had vitamin D insufficiency. The variants of rs2298849 (β=0.105, P<0.001) in GC were significantly associated with serum 25-OHD3 levels. Allele G of rs2298849 might be protective for serum 25-OHD3 level. Among the haplotypes of rs222020-rs2298849, CG (β=0.104, P=0.001) corresponded to increasing serum 25-OHD3 concentrations. CYP2R1 polymorphisms showed some significant association with serum β-CTX and P1NP levels.
  
  
  CONCLUSIONS
  We found that GC variants had a significant association with serum 25-OHD3 levels among postmenopausal women of the Han ethnic group in Beijing, while CYP2R1 variants were not found to be significant.
authors: Department of Endocrinology, Key Laboratory of Endocrinology, Ministry of Health, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors: Wen
authors: W
authors: Xu
authors: Department of Endocrinology, Key Laboratory of Endocrinology, Ministry of Health, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors: Jing
authors: J
authors: Sun
authors: Department of Endocrinology, Peking University Shougang Hospital, Beijing, China.
authors: Wenbo
authors: W
authors: Wang
authors: Department of Cadre Unit, General Hospital of the second Artillery Force, Beijing, China.
authors: Xiran
authors: X
authors: Wang
authors: Department of Endocrinology, Key Laboratory of Endocrinology, Ministry of Health, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors: Yan
authors: Y
authors: Jiang
authors: Department of Endocrinology, BeiJing Haidian Hospital; Beijing, China.
authors: Wei
authors: W
authors: Huang
authors: Department of Endocrinology, China Rehabilitation Research Center, Beijing, China.
authors: Xin
authors: X
authors: Zheng
authors: Department of Endocrinology, Beijing Liangxiang Hospital, Beijing, China.
authors: Qiuping
authors: Q
authors: Wang
authors: Department of Endocrinology, Beijing Chaoyang Hospital, Beijing, China.
authors: Zhiwei
authors: Z
authors: Ning
authors: Department of Geriatric Endocrinology, Chinese PLA General Hospital, Beijing, China.
authors: Yu
authors: Y
authors: Pei
authors: Department of Endocrinology, Key Laboratory of Endocrinology, Ministry of Health, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors: Min
authors: M
authors: Nie
authors: Department of Endocrinology, Key Laboratory of Endocrinology, Ministry of Health, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors: Mei
authors: M
authors: Li
authors: Department of Endocrinology, Key Laboratory of Endocrinology, Ministry of Health, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors: Ou
authors: O
authors: Wang
authors: Department of Endocrinology, Key Laboratory of Endocrinology, Ministry of Health, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors: Xiaoping
authors: X
authors: Xing
authors: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors: Wei
authors: W
authors: Yu
authors: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors: Qiang
authors: Q
authors: Lin
authors: Department of Gynaecology and Obstetrics, Peking Union Medical College Hospital, Chinese Academy of Medical Science; Beijing, China.
authors: Ling
authors: L
authors: Xu
authors: Department of Endocrinology, Key Laboratory of Endocrinology, Ministry of Health, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors: Weibo
authors: W
authors: Xia
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D044466:Asian People / Q000235:genetics; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000235:genetics; D002112:Calcifediol / Q000097:blood*; D002681:China; D053493:Cholestanetriol 26-Monooxygenase / Q000235:genetics*; D024042:Collagen Type I / Q000097:blood; D000072467:Cytochrome P450 Family 2; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D006239:Haplotypes; D006801:Humans; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood; D010455:Peptides / Q000097:blood; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D017698:Postmenopause / Q000097:blood* / Q000208:ethnology / Q000235:genetics*; D011237:Predictive Value of Tests; D011347:Procollagen / Q000097:blood; D012307:Risk Factors; D012621:Seasons; D013997:Time Factors; D014808:Vitamin D Deficiency / Q000097:blood* / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics*; D014809:Vitamin D-Binding Protein / Q000235:genetics*
chemical_list: D015415:Biomarkers; D024042:Collagen Type I; D010446:Peptide Fragments; D010455:Peptides; D011347:Procollagen; D014809:Vitamin D-Binding Protein; C052929:collagen type I trimeric cross-linked peptide; C047202:procollagen Type I N-terminal peptide; D000072467:Cytochrome P450 Family 2; C506833:CYP2R1 protein, human; D053493:Cholestanetriol 26-Monooxygenase; D002112:Calcifediol