EFFECT OF SLEEP UPON HUMAN CIRCADIAN-RHYTHMS

  • 1 January 1978
    • journal article
    • research article
    • Vol. 5  (1) , 14-27
Abstract
Subjects who slept for 4 h from midnight and for a 2nd 4 h variously distributed over the day, provided values for rectal temperature and for urinary excretion of H2O, K, Na, Cl, PO4, creatinine, C and urate in the sleeping subject. These are compared with similar values in the wakeful subject. Temperature was lower during sleep at all hours except 10 a.m. and noon, and the difference was maximal shortly before midnight. At all hours K excretion was lower and PO4 excretion higher during sleep. Cosinor analysis of the different variables in the sleeping subject is compared with that in subjects following nycthemeral habits, and the interaction between endogenous rhythms and external influences such as sleep is discussed. The phasing of the temperature and urinary rhythms was essentially normal by the end of the studies. In a subject who slept at irregular hours mimicking the habits of an air pilot, a free-running rhythm unrelated to the habits of sleep emerged. When he was living on normal time his temperature and urinary acrophases moved to the middle of the night. PO4 excretion was largely exogenous, falling consistently when subjects rose after 8 h, but not after 4 h of sleep.