Sasseville Alexandre, Benhaberou-Brun Dalila, Fontaine Charlotte, Charon Marie-Claude, Hebert Marc
Centre de Recherche Universite Laval Robert-Giffard/Department of Oto Rhino Laryngology and Ophtalmology, Universite Laval, Quebec, Canada.
Chronobiol Int. 2009 Jul;26(5):913-25. doi: 10.1080/07420520903044398.
Night shiftworkers often complain of disturbed sleep during the day. This could be partly caused by morning sunlight exposure during the commute home, which tends to maintain the circadian clock on a daytime rhythm. The circadian clock is most sensitive to the blue portion of the visible spectrum, so our aim was to determine if blocking short wavelengths of light below 540 nm could improve daytime sleep quality and nighttime vigilance of night shiftworkers. Eight permanent night shiftworkers (32-56 yrs of age) of Quebec City's Canada Post distribution center were evaluated during summertime, and twenty others (24-55 yrs of age) during fall and winter. Timing, efficacy, and fragmentation of daytime sleep were analyzed over four weeks by a wrist activity monitor, and subjective vigilance was additionally assessed at the end of the night shift in the fall-winter group. The first two weeks served as baseline and the remaining two as experimental weeks when workers had to wear blue-blockers glasses, either just before leaving the workplace at the end of their shift (summer group) or 2 h before the end of the night shift (fall-winter group). They all had to wear the glasses when outside during the day until 16:00 h. When wearing the glasses, workers slept, on average +/-SD, 32+/-29 and 34+/-60 more min/day, increased their sleep efficacy by 1.95+/-2.17% and 4.56+/-6.1%, and lowered their sleep fragmentation by 1.74+/-1.36% and 4.22+/-9.16% in the summer and fall-winter group, respectively. Subjective vigilance also generally improved on Fridays in the fall-winter group. Blue-blockers seem to improve daytime sleep of permanent night-shift workers.
夜班工作者常常抱怨白天睡眠受到干扰。这可能部分是由于通勤回家途中暴露于早晨的阳光下，这往往会使昼夜节律维持在白天的节奏上。昼夜节律对可见光谱中的蓝光部分最为敏感，因此我们的目的是确定阻挡540纳米以下的短波长光是否可以改善夜班工作者的白天睡眠质量和夜间警觉性。对魁北克市加拿大邮政配送中心的8名长期夜班工作者（32 - 56岁）在夏季进行了评估，另外20名（24 - 55岁）在秋冬季节进行了评估。通过手腕活动监测仪在四周内分析白天睡眠的时间、效率和碎片化情况，并且在秋冬组的夜班结束时额外评估主观警觉性。前两周作为基线期，其余两周为实验期，在此期间工作者必须佩戴防蓝光眼镜，夏季组是在轮班结束即将离开工作场所前佩戴（夏季组），秋冬组是在夜班结束前2小时佩戴（秋冬组）。他们在白天外出时都必须佩戴眼镜直至16:00。佩戴眼镜时，夏季组和秋冬组的工作者平均每天多睡32±29分钟和34±60分钟，睡眠效率分别提高了1.95±2.17%和4.56±6.1%，睡眠碎片化程度分别降低了1.74±1.36%和4.22±9.16%。在秋冬组，周五的主观警觉性总体上也有所改善。防蓝光眼镜似乎可以改善长期夜班工作者的白天睡眠。
