Éditeur(s) : HAL CCSD Ferrata Storti Foundation
Résumé : International audience
BackgroundRecent evidence suggests that autonomic nervous system activity could be involved in thepathophysiology of sickle cell disease, but it is unclear whether differences in autonomic nervoussystem 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, bloodrheology, and inflammation in patients with sickle cell anemia according to the frequency ofacute pain crisis.Design and MethodsTwenty-four healthy volunteers, 20 patients with sickle cell anemia with milder disease, and15 patients with sickle cell anemia with more severe disease were recruited. Milder disease wasdefined as having no pain crisis within the previous year. More severe disease was defined ashaving had within the previous year three or more pain crises which were documented by aphysician and required treatment with narcotics. The autonomic nervous system activity wasdetermined by spectral analysis of nocturnal heart rate variability. Blood viscosity determinationand measurements of several inflammatory markers (interleukin-6, soluble vascular celladhesion molecule-1, soluble CD40 ligand and sL-selectin) were made on blood samples collectedin steady-state conditions.ResultsResults showed that: 1) patients who had suffered more frequent pain crises had lowerparasympathetic activity and greater sympatho-vagal imbalance than both controls andpatients with milder disease. However, when adjusted for age, no significant difference wasdetected between the two sickle cell anemia patient groups; 2) patients who had suffered morefrequent pain crises had higher blood viscosity than patients with milder disease, and this wasnot dependent on age.ConclusionsResults from the present study indicate that both the autonomic nervous system activity andblood viscosity are impaired in patients with sickle cell anemia exhibiting high frequency ofpain crisis in comparison with those who did not experience a crisis within the previous year.
ISSN: 0390-6078

hal-01163973
https://hal.univ-antilles.fr/hal-01163973
DOI : 10.3324/haematol.2011.047365

Éditeur(s) : HAL CCSD IOS Press
Résumé : International audience
Purpose: The aim of this study was to clarify whether exercising in a tropical climate induces blood rheology alterations despite ad libitum hydration. Methods: Hematological, biochemical and hemorheological changes were investigated in young healthy adults (N = 9 men, 20.7 ± 0.8 yrs) after a 10-km race in hot and humid conditions. Subjects' maximal aerobic abilities were tested using a maximal ramp exercise. Blood was sampled at rest (T R), at the end of the race (T Ex), and after 24 hours of recovery (T 24). Ad libitum hydra-tion was allowed during the race. Blood viscosity (b), red blood cell deformability (EI), aggregation (AI) and disaggregation shear rate (␥) were measured. Results: Hematocrit, hemoglobin and plasma concentration of chlorine, sodium and potassium did not change in response to exercise. No functional consequence was observed on RBC deformability since EI remained unchanged. Percentages of echinocytes, schizocytes and stomatocytes remained in the subclinical range at all times. AI, µ and ßb did not present change. Conclusion: Running exercise in tropical climate with ad libitum hydration does not alter the main rheological properties of blood.
ISSN: 1386-0291

hal-01163975
https://hal.univ-antilles.fr/hal-01163975
DOI : 10.3233/CH-2011-1388