title: Low holotranscobalamin and cobalamins predict incident fractures in elderly men: the MrOS Sweden.
abstract: In a population-based study on cobalamin status and incident fractures in elderly men (n = 790) with an average follow-up of 5.9 years, we found that low levels of metabolically active and total cobalamins predict incident fractures, independently of body mass index (BMI), bone mineral density (BMD), plasma total homocysteine (tHcy), and cystatin C.
  
  
  BACKGROUND
  Cobalamin deficiency in elderlies may affect bone metabolism. This study aims to determine whether serum cobalamins or holotranscobalamin (holoTC; the metabolic active cobalamin) predict incident fractures in old men.
  
  
  METHODS
  Men participating in the Gothenburg part of the population-based Osteoporotic Fractures in Men (MrOS) Sweden cohort and without ongoing vitamin B medication were included in the present study (n = 790; age range, 70-81 years).
  
  
  RESULTS
  During an average follow-up of 5.9 years, 110 men sustained X-ray-verified fractures including 45 men with clinical vertebral fractures. The risk of fracture (adjusted for age, smoking, BMI, BMD, falls, prevalent fracture, tHcy, cystatin C, 25-OH-vitamin D, intake of calcium, and physical activity (fully adjusted)), increased per each standard deviation decrease in cobalamins (hazard ratio (HR), 1.38; 95% confidence intervals (CI), 1.11-1.72) and holoTC (HR, 1.26; 95% CI, 1.03-1.54), respectively. Men in the lowest quartile of cobalamins and holoTC (fully adjusted) had an increased risk of all fracture (cobalamins, HR = 1.67 (95% CI, 1.06-2.62); holoTC, HR = 1.74 (95% CI, 1.12-2.69)) compared with quartiles 2-4. No associations between folate or tHcy and incident fractures were seen.
  
  
  CONCLUSIONS
  We present novel data showing that low levels of holoTC and cobalamins predicting incident fracture in elderly men. This association remained after adjustment for BMI, BMD, tHcy, and cystatin C. However, any causal relationship between low cobalamin status and fractures should be explored in a prospective treatment study.
authors.affiliation: Section of Hematology and Coagulation, Department of Internal Medicine, Institute of Medicine, Sahlgrenska AcademyUniversity of Gothenburg, Gothenburg, Sweden, catharina.lewerin@vgregion.se.
authors.forename: C
authors.initials: C
authors.lastname: Lewerin
authors.forename: H
authors.initials: H
authors.lastname: Nilsson-Ehle
authors.forename: S
authors.initials: S
authors.lastname: Jacobsson
authors.forename: H
authors.initials: H
authors.lastname: Johansson
authors.forename: V
authors.initials: V
authors.lastname: Sundh
authors.forename: M K
authors.initials: MK
authors.lastname: Karlsson
authors.forename: Ö
authors.initials: Ö
authors.lastname: Ljunggren
authors.forename: M
authors.initials: M
authors.lastname: Lorentzon
authors.forename: J A
authors.initials: JA
authors.lastname: Kanis
authors.forename: U H
authors.initials: UH
authors.lastname: Lerner
authors.forename: S R
authors.initials: SR
authors.lastname: Cummings
authors.forename: C
authors.initials: C
authors.lastname: Ohlsson
authors.forename: D
authors.initials: D
authors.lastname: Mellström
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D005500:Follow-Up Studies; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D015994:Incidence; D007501:Iron / Q000097:blood; D008297:Male; D058866:Osteoporotic Fractures / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D014155:Transcobalamins / Q000172:deficiency / Q000378:metabolism*; D014805:Vitamin B 12 / Q000097:blood; D014806:Vitamin B 12 Deficiency / Q000150:complications* / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D006454:Hemoglobins; D014155:Transcobalamins; D007501:Iron; D014805:Vitamin B 12