title: Are there any seasonal changes of cognitive impairment, depression, sleep disorders and quality of life in hemodialysis patients?
abstract: OBJECTIVE
  Cognitive impairment, depression, sleep disorders and impaired quality of life are very common in hemodialysis (HD) patients. However, whether there are any seasonal changes of cognitive impairment, depression, sleep disorders and quality of life in HD patients is not known.
  
  
  METHODS
  The laboratory parameters, depressive symptoms, health-related quality of life, sleep quality (SQ) and cognitive function, were measured twice.
  
  
  RESULTS
  A total of 66 HD patients were enrolled. Pre-dialysis systolic blood pressure (BP) and pre-dialysis diastolic BP were higher, whereas predialysis creatinine and sodium were lower in January compared to July. Among domains of Short Form 36 (SF-36), physical functioning, role-physical limitation, general health perception, vitality, role emotional, Physical Component Summary Score (PCS) were higher, whereas Beck Depression Inventory (BDI) score was lower in July compared to January. Stepwise linear regression analysis revealed that only change in albumin and smoking status were related with seasonal change of BDI scores. Additionally only change in Mental Component Summary score of SF-36 were related with change in PCS score of SF-36 scores.
  
  
  CONCLUSIONS
  Depressive symptoms and quality of life but not SQ and cognitive function showed seasonal variability in HD patients.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Konya Numune State Hospital, 42690 Konya, Turkey. afsarbrs@yahoo.com
authors.forename: Baris
authors.initials: B
authors.lastname: Afsar
authors.forename: Alper
authors.initials: A
authors.lastname: Kirkpantur
mesh_terms: D000328:Adult; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000523:psychology*; D003863:Depression / Q000523:psychology*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000523:psychology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life / Q000523:psychology; D006435:Renal Dialysis / Q000523:psychology*; D012621:Seasons; D012890:Sleep / Q000502:physiology; D012893:Sleep Wake Disorders / Q000523:psychology*; D011795:Surveys and Questionnaires