Abstract MP77: Both Racial/Ethnic Residential Segregation and Exposure to Outdoor Artificial Light at Night May Impact Cardiovascular Health but Perhaps Not Through Self-Reported Sleep

Abstract

Introduction: Due to structural racism, minoritized racial/ethnic groups are overrepresented in racially segregated areas of concentrated disadvantage in which residences may be less protective against outdoor artificial light at night (ALAN). Both racial/ethnic residential segregation (RRS) and ALAN are associated with disparities in both sleep duration, potentially through ALAN exposures in segregated areas disrupting melatonin production, and cardiovascular health (CVH). However, few studies have investigated pathways between RRS and ALAN, sleep, and CVH. We sought to investigate sleep duration as a potential mediator between RRS and ALAN exposures and CVH among US adults. Hypothesis: We hypothesized that (1) ALAN would disproportionately burden minoritized racial/ethnic groups, (2) sleep duration would mediate associations between both RRS and ALAN and CVH, and (3) associations would vary by race/ethnicity. Methods: We used data collected from 2011 National Health Interview Survey adult participants reporting sleep duration (short [<7 hours(h)]), recommended [7-9 h], long [>9 h]) and CVH (defined as yes vs. no to all: never/former smoking, BMI 18-<25 kg/m 2 , meets physical activity guidelines, and no prior diagnosis of dyslipidemia, hypertension, or pre-diabetes/diabetes). Participants’ home addresses were geographically linked to the 2012 American Community Survey 5-year estimates to assess RRS, measured by the local Getis-Ord G i * statistic (z-scores) categories: low (z<0), medium (0≤z≤1.96), and high (z>1.96). Quintiles of residential ALAN were estimated from 2010-2011 US Defense Meteorological Satellite Program’s Operational Linescan System values. We used robust Poisson regression adjusted for sociodemographic characteristics, estimated mediation through sleep duration with the Sobel’s test, and assessed effect modification by race/ethnicity. Results and Conclusions: Among 18,057 participants (mean age±SE =45±0.2 years); 35%, 44%, and 21% resided in low, medium, and highly segregated neighborhoods, respectively. ALAN was highest among non-Hispanic White adults. Prevalence of short and long sleep duration overall were 31% and 3% and highest among Black adults (39% and 4%). High (vs. low) RRS was associated with a higher prevalence of CVH (PR=1.13 [95% CI:1.01-1.26]). However, higher ALAN (Q5 vs. Q1) was associated with a lower prevalence of CVH (PR=0.79 [95% CI:0.66-0.95]). Sleep did not appear to mediate associations, which did not vary by race/ethnicity. In conclusion, self-reported sleep did not mediate associations between RRS or ALAN and CVH. Nonetheless, further study using objective measures is warranted given the biological plausibility. The findings/conclusions in this research are those of the authors and do not necessarily represent the views of the Research Data Center, National Center for Health Statistics, or CDC.