title: Low levels of 25-hydroxy vitamin D and active 1,25-dihydroxyvitamin D independently associated with type 2 diabetes mellitus in older Australian men: the Concord Health and Ageing in Men Project.
abstract: OBJECTIVE
  To examine the associations between serum 25-hydroxyvitamin D (25OHD) levels and the active vitamin D metabolite, 1,25-hydroxyvitamin D (1,25OHD), with type 2 diabetes mellitus (DM) in community-living men aged 70 and older.
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  A population-based, cross-sectional analysis of the baseline phase of the Concord Health and Ageing in Men Project (CHAMP), a large epidemiological study conducted in Sydney between January 2005 and May 2007.
  
  
  METHODS
  Community dwelling men aged 70 and older taking part in CHAMP (N = 1,659).
  
  
  METHODS
  Serum 25OHD and 1,25OHD levels, presence of DM, age, country of birth, season of blood collection, sun exposure, body mass index, vitamin D supplement use, statin use, income, measures of health, depression, activity of daily living disabilities, parathyroid hormone, estimated glomerular filtration rate, phosphate, and calcium.
  
  
  RESULTS
  The prevalence of DM was 20.0%. There was a significant association between low 25OHD and 1,25OHD levels and DM that remained after adjustment for a wide range of confounders and covariates of clinical significance such as comorbidity, renal function, calciotropic hormones, and medications.
  
  
  CONCLUSIONS
  25OHD and 1,25OHD levels were associated with DM. The independent association between serum 25OHD and 1,25OHD concentrations and DM raises the question of whether each of the two vitamin D metabolites may influence DM through different biological mechanisms and pathways.
authors.affiliation: Centre for Education and Research on Ageing, University of Sydney, Sydney, New South Wales, Australia; School of Public Health, University of Sydney, Sydney, New South Wales, Australia; ARC Centre of Excellence in Population Ageing Research, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Vasant
authors.initials: V
authors.lastname: Hirani
authors.forename: Robert G
authors.initials: RG
authors.lastname: Cumming
authors.forename: David G
authors.initials: DG
authors.lastname: Le Couteur
authors.forename: Vasikaran
authors.initials: V
authors.lastname: Naganathan
authors.forename: Fiona
authors.initials: F
authors.lastname: Blyth
authors.forename: David J
authors.initials: DJ
authors.lastname: Handelsman
authors.forename: Louise M
authors.initials: LM
authors.lastname: Waite
authors.forename: Markus J
authors.initials: MJ
authors.lastname: Seibel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001315:Australia / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000453:epidemiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D; C104450:25-hydroxyvitamin D
keywords: calcitriol; diabetes mellitus; older men; population study; vitamin D