A pilot study of sleep, cognition, and respiration under 4 weeks of intermittent nocturnal hypoxia in adult humans.
OBJECTIVE
A pilot study to examine the effects of intermittent nocturnal hypoxia on sleep, respiration and cognition in healthy adult humans.


METHODS
Participants were eight healthy, non-smoking subjects (four male, four female), mean age of 26.4+/-5.2 years, and BMI 22.3+/-2.6 kg/m(2), exposed to 9h of intermittent hypoxia between the hours of 10 P.M. and 7 A.M. for 28 consecutive nights. At a simulated altitude of 13,000 feet (FIO(2) 0.13), intermittent hypoxia was achieved by administering nasal nitrogen, alternating with brief (approximately 5s) boluses of nasal oxygen. Pre- and post-exposure assessments included polysomnography, attention (20-min Psychomotor Vigilance Test), working memory (10-min verbal 2 and 3-back), Multiple Sleep Latency Test, and the Rey Auditory Verbal Learning Test. Obstructive and non-obstructive respiratory events were scored.


RESULTS
Overall sleep quality showed worsening trends but no statistically significant change following exposure. There was no difference after hypoxia in sleepiness, encoding, attention or working memory. Hyperoxic central apneas and post-hyperoxic respiratory instability were noted as special features of disturbed respiratory control induced by intermittent nocturnal hypoxia.


CONCLUSIONS
In this model, exposure to nocturnal intermittent hypoxia for 4 weeks caused no significant deficits in subjective or objective alertness, vigilance, or working memory.
Weiss
Matthew D
MD
Beth Israel Deaconess Medical Center & Harvard Medical School, KB 023, Pulmonary Office, 330 Brookline Avenue, Boston, MA 02215, USA.
Tamisier
Renaud
R
Boucher
Judith
J
Lynch
Mekkin
M
Gilmartin
Geoffrey
G
Weiss
J Woodrow
JW
Thomas
Robert Joseph
RJ
D000328:Adult; D001143:Arousal / Q000502:physiology; D015992:Body Mass Index; D002680:Chin / Q000294:innervation; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology*; D004576:Electromyography; D004585:Electrooculography; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000453:epidemiology* / Q000503:physiopathology*; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation; D009483:Neuropsychological Tests; D010865:Pilot Projects; D017286:Polysomnography; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000453:epidemiology*; D012894:Sleep Stages / Q000502:physiology; D014851:Wakefulness