title: Frequency of pain crises in sickle cell anemia and its relationship with the sympatho-vagal balance, blood viscosity and inflammation.
abstract: BACKGROUND
  Recent evidence suggests that autonomic nervous system activity could be involved in the pathophysiology of sickle cell disease, but it is unclear whether differences in autonomic nervous system activity are detectable during steady state in patients with mild and severe disease. The aim of the present study was to compare the autonomic nervous system activity, blood rheology, and inflammation in patients with sickle cell anemia according to the frequency of acute pain crisis.
  
  
  METHODS
  Twenty-four healthy volunteers, 20 patients with sickle cell anemia with milder disease, and 15 patients with sickle cell anemia with more severe disease were recruited. Milder disease was defined as having no pain crisis within the previous year. More severe disease was defined as having had within the previous year three or more pain crises which were documented by a physician and required treatment with narcotics. The autonomic nervous system activity was determined by spectral analysis of nocturnal heart rate variability. Blood viscosity determination and measurements of several inflammatory markers (interleukin-6, soluble vascular cell adhesion molecule-1, soluble CD40 ligand and sL-selectin) were made on blood samples collected in steady-state conditions.
  
  
  RESULTS
  Results showed that: 1) patients who had suffered more frequent pain crises had lower parasympathetic activity and greater sympatho-vagal imbalance than both controls and patients with milder disease. However, when adjusted for age, no significant difference was detected between the two sickle cell anemia patient groups; 2) patients who had suffered more frequent pain crises had higher blood viscosity than patients with milder disease, and this was not dependent on age.
  
  
  CONCLUSIONS
  Results from the present study indicate that both the autonomic nervous system activity and blood viscosity are impaired in patients with sickle cell anemia exhibiting high frequency of pain crisis in comparison with those who did not experience a crisis within the previous year.
authors.affiliation: Inserm U763, Pointe-à-Pitre, Guadeloupe.
authors.forename: Danitza
authors.initials: D
authors.lastname: Nebor
authors.forename: Andre
authors.initials: A
authors.lastname: Bowers
authors.forename: Marie-Dominique
authors.initials: MD
authors.lastname: Hardy-Dessources
authors.forename: Jennifer
authors.initials: J
authors.lastname: Knight-Madden
authors.forename: Marc
authors.initials: M
authors.lastname: Romana
authors.forename: Harvey
authors.initials: H
authors.lastname: Reid
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Barthélémy
authors.forename: Vanessa
authors.initials: V
authors.lastname: Cumming
authors.forename: Olivier
authors.initials: O
authors.lastname: Hue
authors.forename: Jacques
authors.initials: J
authors.lastname: Elion
authors.forename: Marvin
authors.initials: M
authors.lastname: Reid
authors.forename: Philippe
authors.initials: P
authors.lastname: Connes
mesh_terms: D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000097:blood* / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology*; D001341:Autonomic Nervous System / Q000378:metabolism / Q000503:physiopathology*; D001809:Blood Viscosity; D005260:Female; D006339:Heart Rate; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology; D018836:Inflammation Mediators / Q000097:blood*; D008297:Male; D010146:Pain / Q000097:blood* / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology*
chemical_list: D018836:Inflammation Mediators