title: Do weather-related ambient atmospheric-pressure changes influence sleep disordered breathing?
abstract: OBJECTIVE
  High-altitude studies of sleep disordered breathing (SDB) show increases in apnea hypopnea indices with elevation gains. Hypoxic changes, rather than reductions in atmospheric pressure (AP), are thought to be the driving factor. Ambient pressure-related changes in SDB have not been extensively studied at low altitude. We performed a cross-sectional study of weather-related AP effects on measures of SDB at the University of WashingtonMedicine Sleep Institute, a Seattle, Washington-based polysomnography lab located 200 feet above sea level.
  
  
  METHODS
  Obstructive, central, and apnea-hypopnea indices from 537 patients were retrospectively correlated to mean 8-hour date-matched overnight AP data. Linear regression analysis and interquartile comparison of AP-related respiratory indices were performed and adjusted for age, sex, and body mass index.
  
  
  RESULTS
  The obstructive apnea index increased with lower weather-related APs (p = 0.01 for linear trend), interquartile analysis showed significant worsening with lowered mean, minimum, and maximum nightly APs. Similar changes were not seen with central or apnea-hypopnea indices.
  
  
  CONCLUSIONS
  The obstructive apnea index is altered by changes in weather-related AP during diagnostic polysomnography performed at 200 feet above sea level. Small changes in ambient atmospheric pressure due to weather systems may be important in the pathophysiology and diagnosis of obstructive sleep apnea.
authors.affiliation: Swedish Epilepsy Center, Seattle, WA 98122, USA. Michael.doherty@swedish.org
authors.forename: Michael John
authors.initials: MJ
authors.lastname: Doherty
authors.forename: Clover E
authors.initials: CE
authors.lastname: Youn
authors.forename: Alan Matthew
authors.initials: AM
authors.lastname: Haltiner
authors.forename: Nathaniel Fletcher
authors.initials: NF
authors.lastname: Watson
mesh_terms: D001274:Atmospheric Pressure; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000379:methods / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012891:Sleep Apnea Syndromes / Q000503:physiopathology*; D020182:Sleep Apnea, Central / Q000503:physiopathology; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology; D014861:Washington; D014887:Weather
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