title: Associations between frailty and serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D concentrations in older Australian men: the Concord Health and Ageing in Men Project.
abstract: BACKGROUND
  Poor vitamin D status and frailty are common in older people and associated with adverse health outcomes. The aim of this study was to examine the associations between serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels and frailty and components of frailty in older Australian men.
  
  
  METHODS
  Cross-sectional analysis of the Concord Health and Ageing in Men Project, a large epidemiological study conducted in Sydney, Australia, between January 2005 and May 2007. Participants included 1,659 community-dwelling men. Main outcome measurements were frailty (assessed using the Cardiovascular Health Study), frailty criteria comprising five core components: weight loss; reduced muscular strength/weakness; slow walking speed; exhaustion; and low activity level, and the separate components of frailty. Covariates included serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels measured by radioimmunoassay, age, country of birth, season of blood collection, sun exposure, body mass index, vitamin D supplement use, income, measures of health, parathyroid hormone, estimated glomerular function.
  
  
  RESULTS
  Frailty was present in 9.2% of the sample. Low serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels were independently associated with frailty and with four of the five components of frailty (except weight loss).
  
  
  CONCLUSIONS
  1,25-dihydroxyvitamin D and 25-hydroxyvitamin D levels were independently associated with frailty in older men. This suggests that there might be a number of different biological mechanisms for how low vitamin D status might contribute to the frailty syndrome. In addition, the possibility that improving vitamin D status may specifically influence the incidence and progression of frailty needs to be explored.
authors: Centre for Education and Research on Ageing, Concord Hospital, University of Sydney, Sydney, NSW 2139, Australia. vasant.hirani@sydney.edu.au
authors: Vasant
authors: V
authors: Hirani
authors: Vasi
authors: V
authors: Naganathan
authors: Robert G
authors: RG
authors: Cumming
authors: Fiona
authors: F
authors: Blyth
authors: David G
authors: DG
authors: Le Couteur
authors: David J
authors: DJ
authors: Handelsman
authors: Louise M
authors: LM
authors: Waite
authors: Markus J
authors: MJ
authors: Seibel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood* / Q000502:physiology*; D003430:Cross-Sectional Studies; D005221:Fatigue / Q000097:blood; D016330:Frail Elderly / Q000706:statistics & numerical data; D006801:Humans; D016015:Logistic Models; D008297:Male; D009043:Motor Activity / Q000502:physiology; D018908:Muscle Weakness / Q000097:blood; D009517:New South Wales / Q000453:epidemiology; D012307:Risk Factors; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D016138:Walking / Q000502:physiology; D015431:Weight Loss / Q000502:physiology
chemical_list: D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D; C104450:25-hydroxyvitamin D
keywords: Frailty; Older men.; Vitamin D