title: The influence of the menstrual cycle on upper airway resistance and breathing during sleep.
abstract: OBJECTIVE
  Female hormones, specifically progesterone, that peak in the luteal phase may play a significant role in protecting premenopausal women from sleep-disordered breathing. The influence of female hormones on upper airway resistance during sleep was investigated during the follicular and luteal phases of normal menstrual cycles.
  
  
  METHODS
  Hospital-based sleep laboratory.
  
  
  METHODS
  Healthy women with verified ovulatory cycles and without sleep complaints were recruited into the study. Sleep and upper airway resistance data (mean +/- SD) were collected on 2 nights from 11 women (21-49 years of age [28 +/- 9 years], body mass index of 22.8 +/- 3.6 kg/m2), once during the follicular phase (day 6-11) and once in the luteal phase (day 19-23) in random order.
  
  
  RESULTS
  Nasal resistance, standardized to a flow rate of 0.3 L/second, measured using posterior active rhinomanometry immediately prior to the sleep study, did not differ between the 2 phases. The respiratory disturbance index tended to be higher in the follicular phase than in the luteal phase and was above 5 per hour for 3 women in the follicular phase. Upper airway resistance, controlled for flow rate and body position, was calculated for 50 random breaths during wakefulness, stage 1, stage 2, slow-wave, and rapid eye movement sleep. During wake and stage 2 sleep, upper airway resistance was significantly higher in the follicular phase than in the luteal phase, as was the overall upper airway resistance combined for wake and across all sleep stages. Combining data from the 2 nights, compared to wake, upper airway resistance increased in stage 2, slow-wave, and rapid eye movement sleep.
  
  
  CONCLUSIONS
  Within the menstrual cycle, upper airway resistance is lower in the luteal compared with the follicular phase.
authors.affiliation: Department of Medicine, Sleep Disorders Laboratory, Richardson House, Rm 20-303, Queen's University, 102 Stuart Street, Kingston, Ontario K7L 2V6, Canada. driverh@kgh.kari.net
authors.forename: Helen S
authors.initials: HS
authors.lastname: Driver
authors.forename: Heather
authors.initials: H
authors.lastname: McLean
authors.forename: David V
authors.initials: DV
authors.lastname: Kumar
authors.forename: Nancy
authors.initials: N
authors.lastname: Farr
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Day
authors.forename: Michael F
authors.initials: MF
authors.lastname: Fitzpatrick
mesh_terms: D000328:Adult; D015992:Body Mass Index; D018592:Cross-Over Studies; D005260:Female; D005498:Follicular Phase / Q000502:physiology; D006801:Humans; D008183:Luteal Phase / Q000502:physiology; D008597:Menstrual Cycle / Q000502:physiology*; D008875:Middle Aged; D015508:Nasal Obstruction / Q000150:complications / Q000503:physiopathology*; D017286:Polysomnography; D011374:Progesterone / Q000502:physiology; D011446:Prospective Studies; D012119:Respiration; D025363:Rhinomanometry; D012890:Sleep / Q000502:physiology*; D012891:Sleep Apnea Syndromes / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D012895:Sleep, REM / Q000502:physiology; D013147:Spirometry; D016683:Supine Position
chemical_list: D011374:Progesterone