Several studies of sleep-breathing physiology have suggested that sleep deprivation may worsen obstructive sleep apnea. The aim of the study was to determine the direct effect of night work on breathing variables during sleep in fast-rotating shift workers. Twenty one men - police officers, fast-rotating shift workers, underwent polysomnography on 2 occasions: under a normal sleeping condition after day work and after sleep deprivations after night work. Both sleep studies were conducted within 2 to 3 weeks of each other. Approximately half of the group was tested under control conditions (day work) first, with the remaining subjects tested under sleep deprivation conditions (night work) first. After a night shift the subjects did not show a significantly different apnea-hypopnea-index (AHI). However, night work significantly increased several breathing variables recorded during sleep after it: total duration of obstructive apneas (OA) during REM sleep, mean duration of OA during arousal, total duration of OA during NREM sleep, apnea index during arousal, mean length of OA during sleep period time, total duration of OA during sleep period time, mean length of OA during total sleep time, mean length of hypopnea during REM sleep, total duration of hypopnea during sleep period time and during total sleep time, maximal length of central apnea and OA, and total sleep time. Night work does not favor obstructive sleep apnea episodes during sleep, but worsens many an obstructive sleep apnea variable, as measured by polysomnography.
