title: The relationship between solar UV exposure, serum vitamin D levels and serum prostate-specific antigen levels, in men from New South Wales, Australia: the CHAMP study.
abstract: OBJECTIVE
  We aim to determine the relationship between season, personal solar UV exposure, serum 25(OH)D and 1,25(OH)2D and serum prostate-specific antigen (PSA) levels.
  
  
  METHODS
  Questionnaire data and blood samples were collected at baseline from participants of the Concord Health and Ageing in Men Project (n = 1,705), aged 70 and above. They were grouped as men 'free of prostate disease' for those with no record of having prostate cancer, benign prostatic hyperplasia, or prostatitis and with serum PSA levels below 20 ng/mL, and 'with prostate disease' for those with a record of either of these diseases or with serum PSA levels 20 ng/mL or above. Personal solar UV exposure (sUV) was estimated from recalled hours of outdoor exposure and weighted against ambient solar UV radiation. Sera were analysed to determine levels of PSA, 25(OH)D and 1,25(OH)2D, and analysed using multiple regression, adjusting for age, BMI and region of birth.
  
  
  RESULTS
  The association between sUV and serum PSA levels was conditional upon season (p interaction = 0.04). There was no direct association between serum PSA and 25(OH)D in both groups of men. There was a positive association between serum PSA and 1,25(OH)2D in men with prostate disease (mean = 110.6 pmol/L; p heterogeneity = 0.03), but there was no such association in men free of prostate disease (mean = 109.3 pmol/L; p heterogeneity = 0.8).
  
  
  CONCLUSIONS
  The association between PSA and sUV may only be evident at low solar UV irradiance, and this effect may be independent of serum vitamin D levels.
authors.affiliation: Cancer Research Division, Cancer Council New South Wales, 153 Dowling Street, Wooloomooloo, Sydney, NSW, 2011, Australia, visalinin@nswcc.org.au.
authors.forename: Visalini
authors.initials: V
authors.lastname: Nair-Shalliker
authors.forename: David P
authors.initials: DP
authors.lastname: Smith
authors.forename: Mark
authors.initials: M
authors.lastname: Clements
authors.forename: Vasikaran
authors.initials: V
authors.lastname: Naganathan
authors.forename: Melisa
authors.initials: M
authors.lastname: Litchfield
authors.forename: Louise
authors.initials: L
authors.lastname: Waite
authors.forename: David
authors.initials: D
authors.lastname: Handelsman
authors.forename: Markus J
authors.initials: MJ
authors.lastname: Seibel
authors.forename: Robert
authors.initials: R
authors.lastname: Cumming
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Armstrong
mesh_terms: D000368:Aged; D006801:Humans; D008297:Male; D009517:New South Wales; D017430:Prostate-Specific Antigen / Q000097:blood*; D012621:Seasons; D013472:Sunlight; D014466:Ultraviolet Rays; D014807:Vitamin D / Q000097:blood*
chemical_list: D014807:Vitamin D; D017430:Prostate-Specific Antigen