title: Sleep quality in patients with chronic renal failure: a 3-year longitudinal study.
abstract: BACKGROUND
  Despite the high prevalence of sleep disorders in patients with kidney disease, no relationship has been demonstrated between sleep quality and the degree of renal function in cross-sectional studies. A prospective trial was, therefore, started in patients with chronic renal failure (CRF) to evaluate whether a link exists between the modifications of these parameters observed during a three-year follow-up period.
  
  
  METHODS
  Sleep quality was determined by the Pittsburgh Sleep Quality Index (PSQI) at baseline and after two and three years (Time 0, 2 and 3, respectively) in 78 patients with various degrees of CRF in association with the main clinical and biochemical variables.
  
  
  RESULTS
  The baseline PSQI averaged 6.2+/-3.8 (range: 0-21, with higher values indicating worse sleep quality) and was significantly increased at both Time 2 and 3 (8.8+/-3.7 and 10.2+/-3.5, respectively, P<0.0001 vs baseline), whereas creatinine clearance progressively decreased (45+/-24 vs 41+/-26 and 32+/-20ml/min, at time 0, 2 and 3, respectively, P<0.0001), although an independent association with PSQI could not be demonstrated after adjustment for confounding factors (P=0.90, mixed linear model).
  
  
  CONCLUSIONS
  Our data suggest that the progression of renal disease is accompanied by a progressive worsening of sleep quality; age is strongly related to both phenomena. PSQI represents an easy tool to use to detect sleep disorders and to more effectively evaluate renal patients; the prevention of sleep disorders by early and appropriate treatments could beneficially influence the course of the disease.
authors.affiliation: Department of Nephrology, University Federico II, Naples, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Sabbatini
authors.forename: Antonio
authors.initials: A
authors.lastname: Pisani
authors.forename: Anna
authors.initials: A
authors.lastname: Crispo
authors.forename: Annalisa
authors.initials: A
authors.lastname: Ragosta
authors.forename: Riccardo
authors.initials: R
authors.lastname: Gallo
authors.forename: Andrea
authors.initials: A
authors.lastname: Pota
authors.forename: Vittorio
authors.initials: V
authors.lastname: Serio
authors.forename: Giovanni
authors.initials: G
authors.lastname: Tripepi
authors.forename: Bruno
authors.initials: B
authors.lastname: Cianciaruso
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D003404:Creatinine / Q000097:blood; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D005293:Ferritins / Q000097:blood; D006452:Hemoglobinometry; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D007677:Kidney Function Tests; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D011446:Prospective Studies; D012709:Serum Albumin / Q000378:metabolism; D012893:Sleep Wake Disorders / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D013223:Statistics as Topic; D014527:Uric Acid / Q000097:blood
chemical_list: D010281:Parathyroid Hormone; D012709:Serum Albumin; D014527:Uric Acid; D005293:Ferritins; D003404:Creatinine