Ambient temperature and obstructive sleep apnea: effects on sleep, sleep apnea, and morning alertness

Sleep. 2012 Apr 1;35(4):513-7. doi: 10.5665/sleep.1736.


Study objectives: The aim of the study was to investigate the effect of ambient temperature on sleep, sleep apnea, and morning alertness in patients with obstructive sleep apnea.

Design: Randomized controlled trial.

Setting: In-hospital investigations.

Participants: Forty patients with obstructive sleep apnea naïve to treatment, with an apnea-hypopnea index of 10-30.

Interventions: Three different nights in room temperatures of 16°C, 20°C, and 24°C.

Measurements: Overnight polysomnography and Karolinska Sleepiness Scale.

Results: The obstructive apnea-hypopnea index was 30 ± 17 at 16°C room temperature, 28 ± 17 at 20°C, and 24 ± 18 at 24°C. The obstructive apnea-hypopnea index was higher at 16°C room temperature versus 24°C (P = 0.001) and at 20°C room temperature versus 24°C (P = 0.033). Total sleep time was a mean of 30 min longer (P = 0.009), mean sleep efficiency was higher (77 ± 11% versus 71 ± 13% respectively, P = 0.012), and the patients were significantly more alert according to the Karolinska Sleepiness Scale (P < 0.028) in the morning at 16°C room temperature versus 24°C. The amount of sleep in different sleep stages was not affected by room temperature.

Conclusions: Untreated patients with obstructive sleep apnea sleep longer, have better sleep efficiency, and are more alert in the morning after a night's sleep at 16°C room temperature compared with 24°C, but obstructive sleep apnea is more severe at 16°C and 20°C compared with 24°C.

Clinical trial information: This study is registered in number NCT00544752.

Keywords: Sleep apnea syndromes; ambient temperature; daytime sleepiness; polysomnography; randomized controlled trial; sleep quality; sleep stages; sleep time; treatment.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Arousal / physiology*
  • Circadian Rhythm / physiology
  • Cohort Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Polysomnography
  • Sleep Apnea, Obstructive / physiopathology*
  • Sleep Apnea, Obstructive / psychology
  • Sleep Apnea, Obstructive / therapy*
  • Sleep Stages / physiology*
  • Temperature*
  • Time Factors
  • Treatment Outcome

Associated data