title: Hypoxia during sleep and the risk of falls and fractures in older men: the Osteoporotic Fractures in Men Sleep Study.
abstract: OBJECTIVE
  To test the hypothesis that low arterial oxygen saturation during sleep is associated with a greater risk of falls and fractures.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Six U.S. clinical centers.
  
  
  METHODS
  Men aged 67 and older (N = 2,911).
  
  
  METHODS
  The primary exposure measure was percentage of sleep time with arterial oxygen saturation less than 90% measured using polysomnography. The main outcome measures were incident falls within 1 year and incident nonspine fractures over an average follow-up of 6.8 years.
  
  
  RESULTS
  Men with 10% or more of sleep time at an arterial oxygen saturation of less than 90% were older, reported more comorbidities, had poorer physical function, and were more likely to have sleep disordered breathing than men with less than 10% sleep time at an arterial oxygen saturation of less than 90%. After multivariate adjustment, men with 10% or more of sleep time with arterial oxygen saturation of less than 90% had a greater risk of having one or more falls (relative risk (RR) = 1.25, 95% confidence interval (CI) = 1.04-1.51) and two or more falls (RR = 1.43, 95% CI = 1.06-1.92) than those with less than 10% of sleep time with less than 90% arterial oxygen saturation. Men with greater percentage of sleep time with arterial oxygen saturation less than 90% had a 30% to 40% greater risk of nonspine fracture than those with normal nocturnal oxygen saturation in models adjusting for sleep disordered breathing.
  
  
  CONCLUSIONS
  Hypoxia during sleep may be a risk factor for falls and fractures in older men. Interventions aimed at decreasing nocturnal hypoxia may decrease falls and fractures.
authors.affiliation: University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Jane A
authors.initials: JA
authors.lastname: Cauley
authors.forename: Terri L
authors.initials: TL
authors.lastname: Blackwell
authors.forename: Susan
authors.initials: S
authors.lastname: Redline
authors.forename: Kristine E
authors.initials: KE
authors.lastname: Ensrud
authors.forename: Sonia
authors.initials: S
authors.lastname: Ancoli-Israel
authors.forename: Howard A
authors.initials: HA
authors.lastname: Fink
authors.forename: Eric S
authors.initials: ES
authors.lastname: Orwoll
authors.forename: Katie L
authors.initials: KL
authors.lastname: Stone
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data*; D000203:Activities of Daily Living; D000368:Aged; D015897:Comorbidity; D006304:Health Status; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000453:epidemiology*; D008297:Male; D015999:Multivariate Analysis; D058866:Osteoporotic Fractures / Q000097:blood / Q000453:epidemiology*; D017286:Polysomnography; D011446:Prospective Studies; D012307:Risk Factors; D012891:Sleep Apnea Syndromes / Q000097:blood / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology
keywords: falls; fractures; mortality; nocturnal hypoxia; older men