ASPO Abstracts
Use of a spectrophotometer as an objective measure of recent ultraviolet radiation exposure
Category: Molecular Epidemiology & Environment
Conference Year: 2019
Abstract Body:
Purpose: Spectrophotometer based measurements of skin pigmentation are objective measuresthat may be useful for tracking an individual’s sun exposure over time in relation toother time-dependent biomarkers of disease risk. To better understand the recency of sunexposure measured by spectrophotometer readings of skin pigmentation, we examined theirassociation with self-reported recent sun exposure among a subsample of participantsenrolled in the Viruses in Skin Cancer (VIRUSCAN) Study. Methods: Spectrophotometer basedskin pigmentation readings were obtained from 159 skin cancer screening patients. Thedifference between each of the sun-exposed pigmentation readings (forehead and forearm)and the sun-unexposed pigmentation reading (axilla) was calculated as an objective measureof ultraviolet radiation (UVR) exposure in response to recent tanning. Participantscompleted a questionnaire previously validated for the assessment of sun exposure in thepast week using UVR dosimeter readings. Associations between the spectrophotometerreadings and self-reported sun exposure were assessed by logistic regression, adjusted forage and sex. Results: Greater variation was observed in the forearm spectrophotometerreadings (median=11.55, IQR=8.21) as compared to the forehead readings (median=10.14,IQR=6.33), and the two readings were significantly correlated within individuals (r=0.45;p=3.14x10-9). After adjustment for age and sex, individuals in the highest tertile of theself-reported sun exposure were 2.5 times more likely to have a higher than median forearmspectrophotometer readings compared to those in the lowest tertile of sun exposure (OR2.48, 95% CI 1.01-6.33, p-trend=0.06). Similarly, when a ration of the summary measures ofsun exposure and sun protective behaviors was considered, a positive trend was observedbetween tertiles of the ration and high versus low forearm spectrophotometer readings (ORtertile 3 vs 1=2.89, 95% CI 1.24-6.95, p-trend=0.01). No significant associations wereobserved with the forehead readings. Conclusions: Our findings demonstrate thatspectrophotometer based measurements of forearm pigmentation may be useful inepidemiologic studies seeking to incorporate objective measures of recent UVR exposure.
Keywords: ultravioletradiation, epidemiology