Summary: Data linking cumulative lifetime vitamin D status with skeletal outcomes are lacking. We show that increasing cumulative sun exposure was associated with higher bone mineral density in younger males and protective against fractures in females independent of current vitamin D. This supports the concept that cumulative sun exposure is an important contributor to skeletal health.

Introduction: While low 25-hydroxyvitamin D levels are associated with increased fracture risk, this reflects only recent sun exposure. The Beagley-Gibson (BG) method utilises microtopographical skin changes to quantify cumulative lifetime ultraviolet radiation (sun) exposure. This study aimed to describe the relationship between BG grade, BMD, falls risk and fractures in older adults.

Methods: Eight hundred thirty-five community-dwelling adults aged 53-83 years had silicone casts from the dorsum of both hands graded by the BG method. BMD was measured using DXA and falls risk using the short form of the Physiological Profile Assessment. Vertebral deformities and symptomatic fractures were assessed by DXA and questionnaire, respectively.

Results: The relationship between BG grade, spine BMD and vertebral fracture varied depending upon sex. In females, increasing grade was associated with lower vertebral fracture prevalence (OR = 0.44/grade, p = 0.018) and fewer fractures (OR = 0.82/grade, p = 0.021), particularly major fractures (OR = 0.75/grade, p = 0.03). In males, increasing grade was associated with more DXA-detected vertebral deformities (RR = 1.28/grade, p = 0.001), but not symptomatic fractures. These relationships were independent of BMD, falls risk, smoking and current 25-hydroxyvitamin D. BG grade was not associated with falls risk. For BMD, there were interactions between BG grade and both age and sex and a positive trend with hip BMD in younger males.

Conclusions: BG grade demonstrated beneficial associations with fracture outcomes in females and BMD in younger males independent of current 25-hydroxyvitamin D. These data support the concept that cumulative ultraviolet radiation exposure is an important determinant of skeletal health. The association with vertebral deformities in males may reflect outdoor physical trauma in younger life.

Item Type:	Refereed Article
Keywords:	Beagley-Gibson grade, bone mineral density, fractures, skin photoaging
Research Division:	Biomedical and Clinical Sciences
Research Group:	Clinical sciences
Research Field:	Rheumatology and arthritis
Objective Division:	Health
Objective Group:	Clinical health
Objective Field:	Clinical health not elsewhere classified
UTAS Author:	Thompson, MJW (Dr Michael Thompson)
UTAS Author:	Aitken, DA (Associate Professor Dawn Aitken)
UTAS Author:	Otahal, P (Mr Petr Otahal)
UTAS Author:	Winzenberg, TM (Professor Tania Winzenberg)
UTAS Author:	Jones, G (Professor Graeme Jones)
ID Code:	115507
Year Published:	2017
Web of Science® Times Cited:	10
Deposited By:	Menzies Institute for Medical Research
Deposited On:	2017-03-29
Last Modified:	2022-08-29
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