Abstract 6473: Association of sun-seeking behaviors with indoor tanning habit in US females
Authors: Seo Bojung , Cho Eunyoung , Qureshi Abrar A. , Han Jiali 
Published: June 2023

Abstract
Introduction: Frequent exposure to ultraviolet in early life has more detrimental and long-term effects on skin than in adulthood. Teenagers with strong sun-seeking behaviors are more likely to use an indoor tanning bed than those who seek less sun, probably due to addictive component of ultraviolet exposure. We aimed to examine the associations between sun exposure behaviors and average annual indoor tanning usage frequency during high school/college in US females.
Methods: In this cross-sectional study, we included a total of 76,122 US females who answered the average annual frequency of indoor tanning during high school/college from the Nurses’ Health Study II, a large prospective cohort of US female nurses. We adjusted for age, daily number of cigarettes, number of alcohol drinks, strenuous sports frequency, hair color, family history of melanoma, chronic disease history, and mole numbers.
Results: In multivariable-adjusted multinomial logistic regression models, we demonstrated positive and dose response associations between sun exposure behaviors and annual times of indoor tanning bed usage. Specifically, teenagers who spent daily outdoors in a swimsuit (adjusted odds ratio [aOR], 95% confidence interval [CI] for daily vs. &lt;1/week: 3.17, 1.63-6.15) were more likely to use indoor tanning beds. High school students and undergraduates who spent ≥5hours/week outdoors in direct sunlight during daytime also showed more usage of indoor tanning beds (aOR, 95% CI for ≥5hours vs. &lt;1/week: 2.01, 1.06-3.79). Teenagers who had ≥10 sunburns that blistered also tended to more frequently use indoor tanning beds (aOR, 95% CI for ≥10 vs. Never: 2.32, 1.41-3.82).
Conclusions and Relevance: Teenagers who more spent outdoors in a swimsuit or in direct sunlight during daytime, or got more sunburns tended to use indoor tanning more frequently than those who did not. These findings provide evidence that teenagers with strong sun-seeking behaviors have excessive exposure to ultraviolet through indoor tanning.
Table 1. aORs (95% CIs) on the association between sun-exposure behaviors and tanning bed use habit None 1-2 3-11 ≥12 N N Age-adjusted model Multivariable-adjusted model N Age-adjusted model Multivariable-adjusted model N Age-adjusted model Multivariable-adjusted model Average weekly time spent outdoors in a swimsuit as a teenager &lt;1 7,650 202 1.00 1.00 127 1.00 1.00 51 1.00 1.00 1 5,891 223 1.35 (1.11-1.64) 1.25 (0.88-1.78) 154 1.46 (1.15-1.85) 1.26 (0.80-1.97) 48 1.10(0.74-1.63) 1.70 (0.77-3.73) 2 10,057 425 1.46 (1.23-1.73) 1.32 (0.97-1.79) 314 1.66 (1.34-2.04) 1.32 (0.89-1.96) 103 1.29 (0.92-1.81) 1.47 (0.71-3.02) Several 28,395 1,490 1.75 (1.51-2.04) 1.40 (1.07-1.85) 1,253 2.26 (1.88-2.72) 1.81 (1.28-2.57) 551 2.34 (1.75-3.12) 2.80 (1.47-5.31) Daily 9,761 535 1.80 (1.53-2.13) 1.36 (1.01-1.84) 497 2.55 (2.10-3.11) 1.91 (1.32-2.76) 263 3.18 (2.35-4.30) 3.17 (1.63-6.15) Average percentage of time of wearing sunscreen at the pool or beach as a teenager 100% 858 33 1.00 1.00 17 1.00 1.00 16 1.00 1.00 75% 2,430 122 1.22 (0.82-1.81) 0.94 (0.44-2.00) 86 1.63 (0.96-2.77) 3.12 (0.93-10.49) 41 0.81 (0.45-1.45) 4.96 (0.64-38.39) 50% 5,986 298 1.23 (0.85-1.78) 1.10 (0.56-2.17) 254 2.00 (1.22-3.29) 3.20 (1.00-10.29) 96 0.79 (0.46-1.36) 3.63 (0.49-27.04) 25% 13,617 829 1.55 (1.09-2.22) 1.20 (0.63-2.31) 629 2.28 (1.40-3.72) 3.06 (0.97-9.71) 253 0.98 (0.59-1.63) 4.26 (0.59-30.91) 0% 37,946 1,588 1.25 (0.88-1.78) 1.12 (0.59-2.13) 1,351 2.21 (1.36-3.58) 3.12 (0.99-9.82) 605 1.15 (0.70-1.91) 4.72 (0.65-34.01) Average weekly hours spent outdoors in direct sunlight in the middle of the day during high school/college &lt;1 4,900 136 1.00 1.00 71 1.00 1.00 32 1.00 1.00 2-4 22,416 965 1.44 (1.20-1.72) 1.19 (0.87-1.62) 618 1.71 (1.34-2.19) 1.29 (0.83-2.00) 211 1.25 (0.86-1.82) 0.94 (0.48-1.85) ≥5 40,863 2,133 1.65 (1.38-1.97) 1.20 (0.89-1.62) 1,940 2.74 (2.16-3.49) 2.07 (1.35-3.15) 911 2.70 (1.89-3.85) 2.01 (1.06-3.79) The number of severe sunburns which blistered between ages 15-20 Never 22,970 856 1.00 1.00 735 1.00 1.00 318 1.00 1.00 1-2 26,939 1,393 1.38 (1.27-1.51) 1.40 (1.20-1.63) 1,106 1.28 (1.16-1.40) 1.33 (1.12-1.58) 470 1.25 (1.08-1.45) 1.43 (1.11-1.85) 3-4 11,837 637 1.47 (1.33-1.64) 1.53 (1.27-1.84) 475 1.29 (1.15-1.45) 1.36 (1.10-1.68) 199 1.26 (1.06-1.51) 1.23 (0.89-1.70) 5-9 5,190 265 1.42 (1.23-1.63) 1.54 (1.21-1.96) 242 1.53 (1.32-1.78) 1.52 (1.17-1.98) 116 1.73 (1.39-2.15) 1.88 (1.30-2.74) ≥10 1,747 94 1.50 (1.20-1.87) 1.55 (1.08-2.23) 87 1.64 (1.31-2.07) 1.36 (0.90-2.06) 59 2.64 (1.98-3.50) 2.32 (1.41-3.82)
Citation Format: Bojung Seo, Eunyoung Cho, Abrar A. Qureshi, Jiali Han. Association of sun-seeking behaviors with indoor tanning habit in US females [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6473.