title: Nitric oxide may contribute to nocturnal hemodynamic changes in cirrhotic patients.
abstract: OBJECTIVE
  Patients with liver cirrhosis have a nocturnal worsening of hemodynamic parameters that has been associated with an increased risk of variceal bleeding at nighttime. The aim of this study was to investigate whether nitric oxide and cytokines are implicated in these hemodynamic changes.
  
  
  METHODS
  Ten cirrhotic patients and eight controls were studied. Mean blood pressure, heart rate, plasma norepinephrine, tumor necrosis factor alpha and interleukin-6 levels, and serum nitrite + nitrate levels were determined at 0800, 1600, and 2400 h. All determinations were performed in supine rest and at least 4 h after meals. In a second study, nitrite + nitrate levels were assessed in 10 cirrhotic patients before and after eating a standard meal.
  
  
  RESULTS
  Mean arterial pressure levels that were always lower in the patient group showed a nocturnal decrease in both groups of subjects. Heart rate values that were always higher in cirrhotic patients showed a nocturnal fall in controls, whereas cirrhotics maintained elevated values at nighttime. Norepinephrine levels were higher in cirrhotics and maintained similar values during the study, whereas controls had a significant nocturnal decrease. Nitrite + nitrate levels that were higher in cirrhotic patients showed a significant mean increase of 40% from morning (0800 h) to night (2400 h) in the patient group, whereas in controls no change was observed (p < 0.05). Tumor necrosis factor alpha and interleukin-6 levels did not change either in patients or controls during the entire period. Cirrhotic patients with or without ascites maintained a pattern of hemodynamic and biochemical changes similar to the pattern observed in the entire group of patients. Finally, no changes in serum nitrite + nitrate levels were observed in patients before and after eating the standard meal.
  
  
  CONCLUSIONS
  An increased nocturnal nitric oxide production might contribute to the hemodynamic changes observed in cirrhotic patients during nighttime.
authors.affiliation: Department of Internal Medicine, Hospital General Universitari Vall d'Hebron, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Genesca
authors.forename: R
authors.initials: R
authors.lastname: Segura
authors.forename: A
authors.initials: A
authors.lastname: Gonzalez
authors.forename: R
authors.initials: R
authors.lastname: Catalan
authors.forename: R
authors.initials: R
authors.lastname: Marti
authors.forename: M
authors.initials: M
authors.lastname: Torregrosa
authors.forename: F
authors.initials: F
authors.lastname: Cereto
authors.forename: M
authors.initials: M
authors.lastname: Martinez
authors.forename: R
authors.initials: R
authors.lastname: Esteban
authors.forename: J
authors.initials: J
authors.lastname: Guardia
mesh_terms: D000368:Aged; D001794:Blood Pressure; D002940:Circadian Rhythm; D016207:Cytokines / Q000502:physiology; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D008103:Liver Cirrhosis / Q000097:blood / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000097:blood; D009569:Nitric Oxide / Q000502:physiology*; D009573:Nitrites / Q000097:blood; D009638:Norepinephrine / Q000097:blood; D012016:Reference Values
chemical_list: D016207:Cytokines; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D009638:Norepinephrine