title: Sleep apnea in hemodialysis patients: risk factors and effect on survival.
abstract: Sleep disorders are common in patients with end-stage renal disease (ESRD). Using a simple questionnaire, we estimate the probability of sleep apnea in ESRD patients, determine the factors associated with a higher probability of sleep apnea, and determine the association between the probability of sleep apnea and cardiovascular and all-cause mortality.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  prevalent hemodialysis patients (n=270) in 7 urban outpatient hemodialysis units.
  
  
  METHODS
  Probability of sleep apnea as quantified by the Flemons questionnaire.
  
  
  METHODS
  Clinical, demographic, and dialysis-related characteristics were obtained at baseline. Total and cardiovascular mortality was ascertained after a median follow-up of 34 months. The probability of sleep apnea was low in 79 (29%) patients, moderate in 116 (43%) patients, and high in 75 (28%) patients. Male gender (odds ratio [OR] 5.13, p<0.001), obesity (BMI >30, OR 7.58, p<0.01), and interdialytic weight gain (OR 1.72/kg change, p<0.004) were independently associated with a high probability of sleep apnea. A high probability of sleep apnea at baseline did not predict total (hazard ratio [HR] 0.81, p=NS) or cardiovascular mortality (HR 0.9, p=NS). The Flemons questionnaire is validated in the general population, but has not been tested specifically in hemodialysis patients. The study may not be adequately powered to detect a difference in mortality. A high proportion of hemodialysis patients are likely to have sleep apnea; a simple bedside questionnaire can be used for screening to identify these patients. Excessive interdialytic weight gain is a potentially modifiable factor that increases the likelihood of sleep apnea. Despite the presence of a strong association between sleep apnea and mortality in the general population, a similar association could not be demonstrated in ESRD patients with a high prevalence of this condition.
authors.affiliation: University Hospitals of Cleveland, Cleveland, Ohio, USA.
authors.forename: Pushkar
authors.initials: P
authors.lastname: Argekar
authors.forename: Valerie
authors.initials: V
authors.lastname: Griffin
authors.forename: David
authors.initials: D
authors.lastname: Litaker
authors.forename: Mahboob
authors.initials: M
authors.lastname: Rahman
mesh_terms: D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology* / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D006435:Renal Dialysis; D012307:Risk Factors; D012891:Sleep Apnea Syndromes / Q000175:diagnosis / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D015996:Survival Rate; D016896:Treatment Outcome