Éditeur(s) : HAL CCSD IOS Press
Résumé : International audience
Vascular function has been found to be impaired in patients with sickle cell disease (SCD). The present study investigated the determinants of systemic vascular resistance in two main SCD syndromes in children: sickle cell anemia (SCA) and sickle cell-hemoglobin C disease (SCC). Nitric oxide metabolites (NOx), hematological, hemorheological, and hemodynamical parameters were investigated in 61 children with SCA and 49 children with SCC. While mean arterial pressure was not different between SCA and SCC children, systemic vascular resistance (SVR) was greater in SCC children. Although SVR and blood viscosity (ηb) were not correlated in SCC children, the increase of ηb (+18%) in SCC children compared to SCA children results in a greater mean SVR in this former group. SVR was positively correlated with ηb, hemoglobin (Hb) level and RBC deformability, and negatively with NOx level in SCA children. Multivariate linear regression model showed that both NOx and Hb levels were independently associated with SVR in SCA children. In SCC children, only NOx level was associated with SVR. In conclusion, vascular function of SCC children seems to better cope with higher ηb compared to SCA children. Since the occurrence of vaso-occlusive like complications are less frequent in SCC than in SCA children, this finding suggests a pathophysiological link between the vascular function alteration and these clinical manifestations. In addition, our results suggested that nitric oxide metabolism plays a key role in the regulation of SVR, both in SCA and SCC.
ISSN: 1386-0291

inserm-00849031
http://www.hal.inserm.fr/inserm-00849031
http://www.hal.inserm.fr/inserm-00849031/document
http://www.hal.inserm.fr/inserm-00849031/file/2013_Lamarre_-_Relationships_between_SVR_BR_and_NO_in_children_with_sickle_cell_anemia_or_sickle_cell-hemoglobin_C_disease.pdf
DOI : 10.3233/CH-121661

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
The levels and duration of physical activity that can be considered as completely safe in patients with sickle cell anemia (SCA) is unknown. The present study compared the hemorheological and hematological profile, cell density distribution and basic biochemistry between a group of 17 patients with SCA and 21 healthy subjects before and after a 20 min duration submaximal cycling exercise at the same absolute workload. Blood was sampled at rest and 3 min after the end of exercise for measurement of biological parameters. Exercise did not affect the hematocrit and blood viscosity in the two groups. Plasma viscosity was not different between the two groups at rest and similarly increased with exercise. The proportion of intermediary dense cells (with density between 1.11 and 1.12 g/ml) decreased with exercise in the SCA group resulting in an increase in the proportion of red blood cells with a density > 1.12 g/ml. No change was observed in the control group. The present study suggests that mild-moderate exercise is not very harmful for SCA patients. The hemorheological and hematological changes very mild, except for the formation of dense cells but no clinically significant signs of medical complication were present in any of the patients.
ISSN: 0007-1048

hal-00640629
https://hal.archives-ouvertes.fr/hal-00640629
https://hal.archives-ouvertes.fr/hal-00640629/document
https://hal.archives-ouvertes.fr/hal-00640629/file/PEER_stage2_10.1111%252Fj.1365-2141.2011.08728.x.pdf
DOI : 10.1111/j.1365-2141.2011.08728.x