title: Predictors of Beagley-Gibson skin cast grade in older adults.
abstract: OBJECTIVE
  The Beagley-Gibson (BG) grading system utilizes microtopographical skin changes to generate an individualized, objective estimate of cumulative, lifetime ultraviolet radiation (UVR) exposure. However, predictors of BG grade are ill-defined, particularly in older populations. The aim of this cross-sectional study was to describe the factors associated with skin damage as measured by the BG method in 835 community-dwelling older adults.
  
  
  METHODS
  Study participants aged 53-83 years had silicone casts taken from the dorsum of both hands and graded by the BG method. Lifetime sun exposure, skin phenotypic traits and smoking status were assessed by questionnaire. 25-hydroxyvitamin D and melanin density were measured using radioimmunoassay and spectrophotometry, respectively. Ordered logistic regression was used to compute a single odds ratio (OR) by taking BG grade as the outcome variable.
  
  
  RESULTS
  Higher 25-hydroxyvitamin D was associated with increasing BG grade (OR = 1.39, P = 0.02) in adjusted analysis. Age (OR = 1.14, P < 0.001), occupational sun exposure (OR = 1.62, P < 0.001), ability to tan (OR = 1.40, P < 0.001), melanin density (OR=0.79, P = 0.001), lifetime leisure time sun exposure (OR = 1.21, P = 0.004), current smoking (OR = 1.82, P = 0.007), propensity to sunburn (OR = 1.18, P = 0.016), and waist-hip ratio (OR = 1.10, P = 0.02) were independent predictors of BG grade. Hair colour, number of sunburns, body mass index and gender were not independent predictors of BG grade.
  
  
  CONCLUSIONS
  Beagley-Gibson skin cast grade is a biologically relevant marker of UVR exposure in older adults influenced by both intrinsic and extrinsic factors.
authors: Menzies Research Institute Tasmania, University of Tasmania, Hobart, TAS, Australia.
authors: M J W
authors: MJ
authors: Thompson
authors: Menzies Research Institute Tasmania, University of Tasmania, Hobart, TAS, Australia.
authors: D A
authors: DA
authors: Aitken
authors: Menzies Research Institute Tasmania, University of Tasmania, Hobart, TAS, Australia.
authors: I A
authors: IA
authors: van der Mei
authors: Menzies Research Institute Tasmania, University of Tasmania, Hobart, TAS, Australia.
authors: P
authors: P
authors: Otahal
authors: University of Otago, Otago, New Zealand.
authors: J
authors: J
authors: Cicolini
authors: Menzies Research Institute Tasmania, University of Tasmania, Hobart, TAS, Australia.
authors: T M
authors: TM
authors: Winzenberg
authors: Menzies Research Institute Tasmania, University of Tasmania, Hobart, TAS, Australia.
authors: G
authors: G
authors: Jones
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D046169:Dermoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010787:Photosensitivity Disorders / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D015995:Prevalence; D000069079:Radiation Exposure / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012867:Skin / Q000737:chemistry* / Q000528:radiation effects; D012907:Smoking / Q000453:epidemiology*; D013648:Tasmania / Q000453:epidemiology; D014466:Ultraviolet Rays; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: Beagley-Gibson; actinic damage; older adults; skin; sun exposure