Effects of a prolonged 3-hour sleep-wake cycle on sleep stages, plasma cortisol, growth hormone and body temperature in man.
Weitzman-ED; Nogeire-C; Perlow-M; Fukushima-D; Sassin-J; McGregor-P; Gallagher-TF; Hellman-L
J Clin Endocrinol Metab 1974 Jun; 38(6):1018-1030
A clinical study is presented on the effects of a prolonged 3-hour sleep-wake cycle on sleep stages, plasma cortisol, growth hormone, and body temperature in humans. After 1 week of a normal control (baseline) period, 7 healthy young adult subjects were subjected to a 3-hour sleep-wake schedule, (ultradian) which was adhered to for 10 days. They were allowed eight 1-hour sleep times, equally spaced throughout each 24-hour period. They were then allowed a normal nocturnal 8-hour sleep time for 7 days. During all lights-out sleep periods, polygraphic definition of sleep stages and waking time was made. On the sixth 24-hour period of the first week (baseline) and on the eighth 24-hour period of the ultradian period, sequential 10- minute plasma samples were obtained by means of an indwelling intravenous catheter. Rectal temperature was obtained at regularly spaced frequent intervals. Despite significant sleep deprivation, a circadian pattern of total sleep time persisted throughout the 10- day ultradian condition. The distribution and amount of REM sleep time was most affected with stages 3-4 sleep least affected. The time of maximum sleep was delayed by approximately 6 hours. The temporal pattern of the secretory episodes of cortisol and the body temperature curves demonstrated a persistence of the 24-hour (circadian) periodicity for all subjects during the ultradian condition. A 3-hour cortisol cycle was superimposed on the 24-hour pattern. This 3-hour cycle was entrained to the 3-hour sleep-waking cycle such that low plasma concentrations of cortisol were associated with the dark (sleep) period and high concentrations with the first hour after "lights on." No correlation could be demonstrated between a specific sleep stage and the subsequent release of hormone even though a correlation was present for total sleep. The mean 24-hour output of growth hormone (GH) was not different for the baseline and ultradian conditions. However the sharp peak of GH secretion found between 11 PM to 1 AM in the baseline condition was not present in the ultradian condition. The persistence of a 24-hour temperature curve sleep-waking cycle and cortisol pattern in spite of the attempt to disrupt these functions for 10 days demonstrates the highly resistant nature of these systems.
NIOSH-Publication; NIOSH-Grant; Endocrinology; Hormones; Physiology; Chronobiology; Bibliographies; Rhythms; PM9002726
Division of Neurology Montefiore Hosp and Med Center Division of Neurology Bronx, N Y 10467
Journal of Clinical Endocrinology and Metabolism
Montefiore Hospital and Medical Center, New York, New York