title: Diurnal fluctuation of sleep propensity and hormonal secretion across the menstrual cycle.
abstract: BACKGROUND
  The fact that most women experience sleep changes across the menstrual cycle is thought to be associated with changes in circadian rhythms; however, few studies have investigated this relationship.
  
  
  METHODS
  We applied an ultrashort sleep-wake schedule to eight healthy women and studied diurnal fluctuations in sleep propensity, sleepiness, rectal temperature, and serum concentrations of melatonin, thyroid-stimulating hormone, and cortisol in the follicular and luteal phases.
  
  
  RESULTS
  In the luteal phase, amplitude of core body temperature, total melatonin secretions, and amplitudes of TSH and cortisol rhythms were significantly decreased, whereas sleepiness and occurrence of slow-wave sleep during the daytime were significantly increased. Differences in the amount of daytime slow-wave sleep across the menstrual cycle were positively correlated with differences in the daily mean rectal temperature.
  
  
  CONCLUSIONS
  The findings suggest that the amplitude of circadian oscillation may be dampened in the luteal phase. Increased daytime sleepiness in the luteal phase may be associated with increased daytime slow-wave sleep, due possibly to changes in thermoregulation in the luteal phase.
authors.affiliation: Department of Psychophysiology, National Institute of Mental Health, Ichikawa, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Shibui
authors.forename: M
authors.initials: M
authors.lastname: Uchiyama
authors.forename: M
authors.initials: M
authors.lastname: Okawa
authors.forename: Y
authors.initials: Y
authors.lastname: Kudo
authors.forename: K
authors.initials: K
authors.lastname: Kim
authors.forename: X
authors.initials: X
authors.lastname: Liu
authors.forename: Y
authors.initials: Y
authors.lastname: Kamei
authors.forename: T
authors.initials: T
authors.lastname: Hayakawa
authors.forename: T
authors.initials: T
authors.lastname: Akamatsu
authors.forename: K
authors.initials: K
authors.lastname: Ohta
authors.forename: K
authors.initials: K
authors.lastname: Ishibashi
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001831:Body Temperature / Q000502:physiology; D002940:Circadian Rhythm; D018592:Cross-Over Studies; D004958:Estradiol / Q000378:metabolism; D005260:Female; D005498:Follicular Phase / Q000502:physiology; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D008183:Luteal Phase / Q000502:physiology; D008550:Melatonin / Q000378:metabolism; D008597:Menstrual Cycle / Q000502:physiology*; D017286:Polysomnography; D011374:Progesterone / Q000378:metabolism; D012890:Sleep / Q000502:physiology*; D013972:Thyrotropin / Q000378:metabolism
chemical_list: D011374:Progesterone; D004958:Estradiol; D013972:Thyrotropin; D008550:Melatonin; D006854:Hydrocortisone