Photic resetting in night-shift work: impact on nurses' sleep

DB Boivin, P Boudreau, FO James… - Chronobiology …, 2012 - Taylor & Francis
DB Boivin, P Boudreau, FO James, NMKNY Kin
Chronobiology international, 2012Taylor & Francis
The objective of this study was to quantify daytime sleep in night-shift workers with and
without an intervention designed to recover the normal relationship between the
endogenous circadian pacemaker and the sleep/wake cycle. Workers of the treatment group
received intermittent exposure to full-spectrum bright light during night shifts and wore dark
goggles during the morning commute home. All workers maintained stable 8-h daytime
sleep/darkness schedules. The authors found that workers of the treatment group had …
The objective of this study was to quantify daytime sleep in night-shift workers with and without an intervention designed to recover the normal relationship between the endogenous circadian pacemaker and the sleep/wake cycle. Workers of the treatment group received intermittent exposure to full-spectrum bright light during night shifts and wore dark goggles during the morning commute home. All workers maintained stable 8-h daytime sleep/darkness schedules. The authors found that workers of the treatment group had daytime sleep episodes that lasted 7.1 ± .1 h (mean ± SEM) versus 6.6 ± .2 h for workers in the control group (p = .04). The increase in total sleep time co-occurred with a larger proportion of the melatonin secretory episode during daytime sleep in workers of the treatment group. The results of this study showed reestablishment of a phase angle that is comparable to that observed on a day-oriented schedule favors longer daytime sleep episodes in night-shift workers. (Author correspondence: diane.boivin@douglas.mcgill.ca)
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