title: Polymorphonuclear leucocyte priming in long intermittent nocturnal haemodialysis patients--is melatonin a player?
abstract: BACKGROUND
  The relationships between sleep quality, melatonin circadian rhythm and polymorphonuclear leucocyte (PMNL) priming during the night of dialysis treatment compared with a night without dialysis were studied in a group of nocturnal haemodialysis (HD) patients.
  
  
  METHODS
  Twenty-eight long intermittent nocturnal HD patients were included. Sleep quality was assessed by a questionnaire and wrist actigraphy. Plasma melatonin levels were assayed every 2 h, from 9 p.m. to 5 a.m. PMNL priming was assessed by the rate of superoxide release from separated PMNLs at 9 p.m. and 5 a.m., on a night of dialysis and a night with sleepover in the dialysis unit without being dialysed.
  
  
  RESULTS
  Melatonin levels increased similarly during a night with and without dialysis, reaching peak level at 5 a.m. Most (73%) of the patients had severe sleep disturbances. A significant negative correlation was found between the sleep quality score, the rate of superoxide release from separated PMNLs and melatonin levels. While during a night without dialysis a significant reduction of the rate of superoxide release was found at 5 a.m. (compared with 9 p.m.), no significant reduction was observed when the patients were dialysed. Patients with flat melatonin curves, with <10 pg/ml, showed a faster rate of superoxide release than those with higher levels.
  
  
  CONCLUSIONS
  The nocturnal HD process does not affect plasma melatonin levels or rhythms, suggesting that melatonin is not dialysed. Higher endogenous melatonin levels are associated with better sleep and lower PMNL priming. The lower PMNL priming in patients with higher plasma melatonin levels suggests that melatonin overrides the oxidative burden induced by the dialysis process.
authors.affiliation: Department of Nephrology and Hypertension, Eliachar Research Laboratory, Western Galilee Hospital, Nahariya 22100, Israel. ronit.geron@naharia.health.gov.il
authors.forename: Ronit
authors.initials: R
authors.lastname: Geron
authors.forename: Revital
authors.initials: R
authors.lastname: Shurtz-Swirski
authors.forename: Shifra
authors.initials: S
authors.lastname: Sela
authors.forename: Yevgeny
authors.initials: Y
authors.lastname: Gurevitch
authors.forename: Tatiana
authors.initials: T
authors.lastname: Tanasijtchouk
authors.forename: Zila Shenn
authors.initials: ZS
authors.lastname: Orr
authors.forename: Galina
authors.initials: G
authors.lastname: Shkolnik
authors.forename: Olga
authors.initials: O
authors.lastname: Tanhilevski
authors.forename: Batya
authors.initials: B
authors.lastname: Kristal
mesh_terms: D002908:Chronic Disease; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D008297:Male; D008550:Melatonin / Q000097:blood* / Q000378:metabolism; D008875:Middle Aged; D018375:Neutrophil Activation; D009504:Neutrophils / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology; D006435:Renal Dialysis; D012893:Sleep Wake Disorders / Q000097:blood / Q000209:etiology / Q000503:physiopathology; D013481:Superoxides / Q000097:blood; D011795:Surveys and Questionnaires
chemical_list: D013481:Superoxides; D008550:Melatonin