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Physiological adaptation of shift workers.
Department of Neurology, Montefiore Hospital and Medical Center, Bronx, New York 1977 Jan; :1-51
Health workers in a large municipal hospital participated in this study to define the mode of adaptation of several important physiological measures to acute and chronic sleep/wake cycle shifts in shift workers. The study was divided into two parts: an acute shift work reversal protocol and a more chronic reversal group. A total of nine subjects (eight nurses and one intern) participated. Polygraphic sleep stage patterns, plasma cortisol, body temperature curves, and growth hormones were sampled over several selected 24 hour periods. The findings suggest that a significant and persistent decrement of sleep amount, organization and stability occur when hospital workers assume a night shift schedule. The major effect was a decrease in total sleep time, an increase in sleep stage shifts, and decreases in the minutes spent in both rapid eye movement (REM) and Stages 3 and 4 of sleep. However, the percentage of the sleep occupied by REM, Stage 2 and Stage 3 remained rather constant. Changes in cortisol indicated that the circadian rhythm of secretion was clearly changed during the night work schedule although no mean concentration differences were noted. Following sleep onset there was a consistent decrease in the cortisol concentration, independent of the time of day. In general, the change to an acute shift work schedule produced major changes in sleep patterns and cortisol and growth hormone secretions. These changes did not adapt, but appeared to become more abnormal after 2 weeks.
NIOSH-Grant; Grants-other; Shift-work; Health-care-personnel; Nursing; Physicians; Hormone-activity
Division of Neurology Montefiore Hosp and Med Center Division of Neurology Bronx, N Y 10467
Final Grant Report
NTIS Accession No.
Other Occupational Concerns; Grants-other
Department of Neurology, Montefiore Hospital and Medical Center, Bronx, New York
Montefiore Hospital and Medical Center, New York, New York
Page last reviewed: October 26, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division