An exploratory study examining the associations between sunlight exposure, sleep behaviours and sleep outcomes during an Arctic summer

摘要

Few evidence-based recommendations exist for maintaining healthy sleep during Arctic summers.Our study aimed to examine associations between sleep hygiene, sunlight exposure and sleepoutcomes in workers living in and/or near the Arctic Circle during a 24-h light period. A survey wasadministered July 2017 to 19 workers at 3 Arctic base camps in Northeastern Alaska. Participantswith poorer sleep hygiene reported increased sleepiness (r=.62, p=0.01); this correlation remainedmoderately strong, albeit not statistically significant (NS), after controlling for shift work (r=.46,p=0.06). No other statistically significant correlations between sleep hygiene and sleep outcomeswere found. Weekly daytime (45 h/week) versus shorter (16 h/week) versus shorter (16 h/week) evening exposures. Participants reporting longer, versusshorter, weekly daytime sunlight exposure had statistically significantly (Mann-Whitney U=18.00, Z=?1.98, p≤0.05) decreased median sleep duration (6 h, 18 min versus 8 h, respectively) during thepast month. Correlations of r≥.3 for longer, vis-à-vis shorter, daylight sunlight exposure suggest itcould be related to poorer sleep outcomes, such as insufficient sleep and sleep quality, yet, as thesecorrelations were NS, future work is needed to determine this. Weak or no correlations (and NSdifferences) were found for longer, versus shorter, weekly evening sunlight exposure and sleepoutcomes. Findings support previous research suggesting self-regulation behaviours alone are notprotective against poor sleep in Arctic environments. Sleep outcomes did not differ statisticallysignificantly by evening sunlight exposure length. Longer weekly daytime sunlight exposure, versusshorter, was significantly associated with decreased sleep duration. Results from this exploratorystudy should be confirmed in studies using larger sample sizes.