Relationships between systemic vascular resistance, blood rheology and nitric oxide in children with sickle cell anemia or sickle cell-hemoglobin C disease
Affiliations: Inserm U665, Pointe-à-Pitre, F-97159 Guadeloupe, Université des Antilles et de la Guyane, Guadeloupe | CIC-EC 802 Inserm, pôle Guadeloupe, Centre Hospitalier et Universitaire de Pointe-à-Pitre, Pointe-à-Pitre, France | Unité Transversale de la Drépanocytose du Centre Hospitalier et Universitaire de Pointe-à-Pitre, Pointe-à-Pitre, France | Unité d'explorations cardiovasculaire du Centre Hospitalier et Universitaire de Pointe-à-Pitre, Pointe-à-Pitre, France | Service de cardiologie du Centre Hospitalier et Universitaire de Pointe-à-Pitre, Pointe-à-Pitre, France | Service de Pédiatrie du Centre Hospitalier et Universitaire de Pointe-à-Pitre, Pointe-à-Pitre, France | Centre de référence maladies rare pour la drépanocytose aux Antilles-Guyane, Centre Hospitalier et Universitaire de Pointe-à-Pitre, Pointe-à-Pitre, France
Note: [] Corresponding author: Philippe Connes, PhD, UMR Inserm 665, CHU de Pointe à Pitre, Hôpital Ricou, 97159 Pointe-à-Pitre, Guadeloupe. Tel.: +590 690 36 76 28; Fax: +590 590 83 05 13; E-mail: [email protected]
Abstract: 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.
Keywords: Blood rheology, nitric oxide, sickle cell disease, vascular function
