0702 FUNCTIONAL NEUROIMAGING INSIGHTS INTO THE EFFECT OF SHIFT WORK ON SLEEP, EMOTION AND ATTENTION

Abstract

Introduction: Shift work is known to disrupt workers' normal circadian rhythms and social life, and to be associated with increased health problems. In contrast to the considerable literature regarding attention in shift work, evidence for the impact of shift work on brain functional imaging is limited. The aim of this study was to compare sleep quality and quantity, which was measured by actigraphy, between shift workers (SW) and day workers (SW). Secondly, we performed comparisons of perfusion brain MRI between two groups. Methods: Ten DW and 10 SW (all female nurses, mean age 35.1 y) were enrolled. Measures of habitual sleep were obtained from two weeks of wrist actigraphy for determination of total sleep time (TST), sleep latency (SL), sleep efficiency (SE), minutes of wakefulness after sleep onset (WASO), and sleep fragmentation. We compared demographics, emotional states (mood and anxiety), insomnia severity, daytime sleepiness and automated battery of psychometric measures between two groups. The perfusional differences of regional brain were measured in the morning in after finishing night shifts in SW and in the afternoon in DW. Results: SW was associated with higher anxiety (HADS-A score 8.0 +/- 3.3 vs. 4.7 +/- 2.6, p=0.024) and depressive mood (HADS-D score 9.5 +/- 3.2 vs. 5.6 +/- 4.5, p=0.039) and reported more severe insomnia (ISI score 13.9 +/- 4.7 vs. 4.7 +/- 3.5, p<0.001) than day worker. Shift workers' actigraphy showed that total sleep time was different depending on their work schedule, less sleep time during night shift(287.1 +/- 148.7 vs. 400.9 +/- 105.6, 365.6 +/- 100.1,382.0 +/- 96.8, p<0.001; day shift, evening shift and DW respectively). There was no significant difference when it comes to SE, SL and WASO between SW and DW. SW showed increased mean transit time at right inferior frontal gyrus, left cerebellum, left parahippocampal gyrus, right insula and left superior occipital gyrus compared to SW. neurocognitive performance showed no significant difference between two groups Conclusion: The findings may reflect the disruption of the SW's sleep-wake cycles resulting in anxiety and depressive mood. Perfusion MRI finding suggests the early functional changes in the brains of SW.