title: Quality of sleep and day-time sleepiness in chronic hemodialysis: a study of 400 patients.
abstract: OBJECTIVE
  Impaired sleep has potential health consequences in chronic hemodialysis patients. To date, this issue has not been examined in studies involving a large number of subjects. This study aimed to identify factors associated with poor sleep quality and excessive day-time sleepiness (EDS) in dialysis patients.
  
  
  METHODS
  This cross-sectional observational study involved 400 patients (59% male) from three hemodialysis centers (SD-HEMOFOR). Quality of sleep was evaluated by the Pittsburgh Sleep Quality Index (PSQI), EDS by the Epworth Sleepiness Scale (ESS), risk of obstructive sleep apnea (OSA) by the Berlin questionnaire and comorbidity severity by the Charlson Comorbidity Index (CCI).
  
  
  RESULTS
  Poor sleep quality (PSQI >5) was found in 227 individuals (57%) and was associated with older age (p = 0.001), diabetes (p = 0.03), heart failure (p < 0.005), hypoalbuminemia (p = 0.01), low transferrin saturation (TSAT) (p = 0.009), higher CCI score (p = 0.01) and depression (p < 0.005). Independent factors were older age, heart failure, low TSAT and depressive symptoms. Day-time somnolence was present in 108 patients (27%) and was independently associated with stroke [odds ratio (OR) = 2.84, CI 1.03-7.76), lower hemoglobin concentration (OR = 2.45, CI 0.95-3.03) and high risk of OSA (OR = 1.65, CI 1.03-2.63). High risk of OSA (n = 120; 30%), was associated with hypertension (p < 0.001), overweight/obesity (p = 0.001), older age (p = 0.003) and symptoms of depression (p = 0.01).
  
  
  CONCLUSIONS
  Poor sleep quality and EDS were prevalent on chronic hemodialysis. Heart failure, low TSAT and depressive symptoms were independently associated with poor sleep quality. Stroke, anemia and high risk of OSA were independently associated with EDS. These results provide new insight into possible treatment strategies.
authors.affiliation: Department of Medicine, School of Medicine, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil.
authors.forename: Sônia M H A
authors.initials: SM
authors.lastname: Araujo
authors.forename: Veralice M S
authors.initials: VM
authors.lastname: Bruin
authors.forename: Elizabeth Francesco
authors.initials: EF
authors.lastname: Daher
authors.forename: Camila Andrade Mendes
authors.initials: CA
authors.lastname: Medeiros
authors.forename: Gilson H
authors.initials: GH
authors.lastname: Almeida
authors.forename: Pedro F C
authors.initials: PF
authors.lastname: Bruin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000628:therapy; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D006435:Renal Dialysis / Q000009:adverse effects*; D012893:Sleep Wake Disorders / Q000453:epidemiology / Q000209:etiology*; D055815:Young Adult