0808 SOCIAL JET LAG; ASSOCIATIONS WITH SLEEP DURATION AND QUALITY AMONG HEALTHY ADULTS

Abstract

day following two weeks of normal//baseline sleep, 2) Sleep Extension: day following 7 consecutive nights of extended sleep (10 hours time-in-bed), and 3) Sleep Deprivation: day following one night of total sleep deprivation. The data were analyzed with a 3 (Sleep Condition) x 3 (Time of Day) mixed linear model. Results: There was a significant main effect of day for vigor (p = 0.01), fatigue (p < 0.001), anger (p = 0.001), and happiness (p = 0.02), such that fatigue and anger increased and vigor and happiness decreased following sleep deprivation compared to baseline and extension. Mood was not significantly different between baseline and sleep extension. Conclusion: These preliminary findings mirror the literature in that participants reported higher negative mood and lower positive mood following sleep deprivation compared to baseline, however, no mood changes were reported for sleep extension compared to baseline in the same group of participants. These results suggest that the impact of total sleep deprivation on mood is much greater than the impact, if any, of sleep extension on mood. Introduction: Social jet lag (SJL) is a discrepancy between an indi-vidual's intrinsic circadian preference and their actual sleep times imposed by occupational and social obligations. Greater SJL has been associated with poorer sleep. Many previous studies have relied on self-report measures of SJL. The goal of this study was to examine associations between objectively measured social jet lag with sleep, circadian timing, and daytime sleepiness among healthy adults with habitual sleep duration ≥ 6.5 hours. Methods: This was a secondary analysis of a larger study of circadian timing and health. Participants included adults aged 18-50 with habitual sleep duration ≥6.5 hours who completed 7 days of wrist actigra-phy. Social jet lag was calculated as the difference in midpoint of sleep between work days and free days. Objective sleep variables included: sleep onset and offset times, sleep midpoint, and sleep duration. Self-report measures included the Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index (PSQI). Dim light melatonin onset (DLMO) was evaluated in the clinical research unit. Data were analyzed using bivariate correlations. Results: Participants included 82 adults (n=48 female), with an average age of 26.5 years, SD= 6.9. The average sleep duration on work days and free days was 7.0 hours (SD= 0.9 hours) and 7.5 hours (SD= 1.3 hours), respectively. The average SJL experienced between work days and free days was 0.86 hours (SD= 0.8 hours). 10.8% of participants (n=9) had SJL >2 hours. Greater social jet lag was associated with later sleep onset time on free days (r= 0.36, p= 0.001) and higher ESS scores (r= 0.25, p= 0.02). SJL was not associated with sleep duration on work or free days, sleep timing on work days, sleep midpoint, or DLMO. Conclusion: This study demonstrates that SJL, even among healthy adults with at least 6.5 hours sleep duration, is associated with sleepi-ness and sleep start times. Lack of association with DLMO and wake time on free days suggests that SJL is not associated with sleep duration or objective measures of biological timing among a sample of healthy adults. Support (If Any): 1K23HL109110