0321 Examining the Impact of Present-Day Redlining on Racial and Ethnic Disparities in Sleep and Circadian Health

Introduction Structural racism is considered a fundamental determinant of racial and ethnic disparities in health, yet few studies have examined how structural racism impacts sleep and circadian health. We investigated the associations between present-day redlining, a marker of institutional racism, sleep, and circadian health. Methods The study population included men and women enrolled in 2006-2013 in the Cancer Prevention Study-3. Present-day redlining was calculated for census tracts using 2007-2013 Home Mortgage Disclosure Act data and linked to participants’ geocoded address. In 2018, participants (N=111,863) self-reported their average sleep duration, sleep midpoint, social jetlag, sleep quality, and chronotype. Using linear and logistic regression models adjusted for sociodemographic factors, we estimated associations and 95% confidence intervals (CI) between redlining (redlined vs. non-redlined) and each sleep and circadian health dimension, overall and stratified by gender, race, and ethnicity. Results At baseline, the study population was 47.1 (SD=9.25) years old, 78.7% women, and majority White (92.4%). Overall, 29% lived in redlined census tracts, but the prevalence was higher among Black (59%) and Hispanic (34%) participants. On average, participants slept 7.9 hours, and 9.5%, 20.3%, and 35.8% had high social jetlag (>120 minutes), poor sleep quality, and an evening chronotype, respectively. Living in a redlined versus non-redlined census tract was associated with a modest increase in short (< 7 hours, odds ratio [OR]=1.06, 95% CI 1.02-1.10) and long (>9 hours, OR=1.05, 95% CI 1.00-1.10) sleep duration and poor sleep quality (OR=1.04, 95% CI 1.01-1.08). Present-day redlining was also associated with a 12% higher odds of high social jetlag (>120 vs. ≤120 minutes; OR=1.12, 95% CI 1.07-1.17), which was most pronounced among Black participants (OR=1.28, 95% 1.02-1.60; White: OR=1.12, 95% 1.07-1.17; Hispanic: OR=1.08, 95% 0.92-1.26). Redlining was not associated with sleep midpoint or chronotype, overall or in stratified analyses. Conclusion In this study, present-day redlining was associated with poor sleep health and some indicators of circadian health, particularly high social jetlag. Given that minoritized populations are more likely to live in redlined areas, present-day redlining may contribute to observed disparities in sleep and circadian health. Support (if any)