title: Vitamin D status and markers of bone turnover in Caucasian and South Asian postmenopausal women living in the UK.
abstract: Suboptimal vitamin D status among the South Asian UK population is widely reported; however, its impact on bone health is unclear. The aim of the present study was to conduct a comparative investigation of vitamin D status in postmenopausal South Asian (SA) and Caucasian (C) women and its relationship to parathyroid hormone (PTH) concentration, biochemical markers of bone turnover and bone quality. A cross-sectional study of community-dwelling women aged 50-66 years was carried out. A total of sixty-six SA women of Pakistani origin and forty-two C women living in the same community were recruited. Fasting blood was taken for the measurement of vitamin D, PTH and biochemical markers of bone turnover, including type-1 collagen beta C-telopeptide (betaCTX), procollagen type-1 amino-terminal propeptide (P1NP), and bone-specific alkaline phosphatase (BAP) activity. Bone quality was assessed using broadband ultrasound attenuation (BUA). Total serum 25-hydroxyvitamin D (25(OH)D) was significantly lower in the SA women than the C women (medians: SA 10.5 v. C 47.1 nmol/l; P < 0.001) This was associated with a significantly elevated serum PTH concentration in the SA group (medians: SA 7.3 v. C 4.5 pmol/l; P < 0.01). BAP activity was also significantly higher in the SA group, indicating elevated osteoblast activity and bone turnover (medians: SA 23.0 v. C 20.0 U/l; P < 0.05). No significant differences were observed between the two groups for P1NP, betaCTX or BUA. Although the SA women had significantly higher serum PTH and lower 25(OH)D concentrations than C women, this was not associated with significantly higher markers of bone resorption, or reduced bone quality in the SA women.
authors.affiliation: Centre for Applied Sport and Exercise Sciences, University of Central Lancashire, Preston, Lancashire, UK. nmlowe@uclan.ac.uk
authors.forename: Nicola M
authors.initials: NM
authors.lastname: Lowe
authors.forename: Soma R
authors.initials: SR
authors.lastname: Mitra
authors.forename: Peter C
authors.initials: PC
authors.lastname: Foster
authors.forename: Issak
authors.initials: I
authors.lastname: Bhojani
authors.forename: John F
authors.initials: JF
authors.lastname: McCann
mesh_terms: D000368:Aged; D000469:Alkaline Phosphatase / Q000378:metabolism; D044466:Asian People; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D050071:Bone Density Conservation Agents / Q000008:administration & dosage*; D001862:Bone Resorption / Q000097:blood*; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000378:metabolism; D024042:Collagen Type I / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D010006:Osteoblasts / Q000378:metabolism*; D010024:Osteoporosis / Q000378:metabolism; D010154:Pakistan / Q000208:ethnology; D010281:Parathyroid Hormone / Q000097:blood*; D010455:Peptides / Q000097:blood; D010748:Phosphopeptides / Q000097:blood; D017698:Postmenopause; D011347:Procollagen / Q000097:blood; D014463:Ultrasonography; D006113:United Kingdom; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000208:ethnology; D044465:White People
chemical_list: D015415:Biomarkers; D050071:Bone Density Conservation Agents; D024042:Collagen Type I; C062121:N-propeptide type I collagen; D010281:Parathyroid Hormone; D010455:Peptides; D010748:Phosphopeptides; D011347:Procollagen; C052929:collagen type I trimeric cross-linked peptide; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D000469:Alkaline Phosphatase