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1.
Blood Cells Mol Dis ; 65: 23-28, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28411485

RESUMO

The present study investigated cerebral and muscle hemoglobin oxygen saturation (tissue oxygen index, TOI) in children with sickle cell anemia (SS), sickle cell hemoglobin C disease (SC) and healthy children (AA). TOI was measured by near-infrared spectroscopy (NIRS) and spectral analysis of the TOI variability was used to assess flowmotion and vasomotion. Arterial oxyhemoglobin saturation (SpO2), hemorheological and hematological parameters were also measured in SS and SC children. Both TOI were lower in SS compared to both AA and SC children, with SC exhibiting lower values than AA children. Cerebral vasomotion expressed in absolute values was enhanced in SS compared to AA and SC children. Muscle vasomotion did not differ between the three groups. Hematocrit, SpO2 and red blood cell deformability were positively associated with cerebral TOI in SS children. We demonstrated that 1) cerebral and muscle TOI were markedly decreased in SS children while the decrease of TOI was milder in SC children, 2) cerebral TOI level was associated with several biological markers in SS children only and 3) cerebral vasomotion was enhanced in SS, possibly to counterbalance the effects of chronic cerebral hypoxia.


Assuntos
Anemia Falciforme/metabolismo , Anemia Falciforme/fisiopatologia , Córtex Cerebral/irrigação sanguínea , Córtex Cerebral/metabolismo , Músculos/irrigação sanguínea , Músculos/metabolismo , Oxigênio/metabolismo , Adolescente , Anemia Falciforme/sangue , Anemia Falciforme/genética , Criança , Deformação Eritrocítica , Feminino , Genótipo , Hematócrito , Hemodinâmica , Hemoglobina Falciforme/genética , Hemorreologia , Humanos , Masculino , Consumo de Oxigênio , Espectroscopia de Luz Próxima ao Infravermelho
2.
Blood Cells Mol Dis ; 56(1): 41-5, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26603723

RESUMO

Vascular resistance and tissue perfusion may be both affected by impaired vascular function and increased blood viscosity. Little is known about the effects of vascular function on the occurrence of painful vaso-occlusive crises (VOC) in children with sickle cell anemia (SCA). The aim of the present study was to determine which side of the balance (blood viscosity or vascular function) is the most deleterious in SCA and increases the risk for frequent hospitalized VOC. Microvascular function, microcirculatory oxygenation and blood viscosity were determined in a group of 22 SCA children/adolescents at steady state and a group of 13 healthy children/adolescents. Univariate analyses demonstrated blunted microvascular reactivity during local thermal heating test and decreased microcirculatory oxygenation in SCA children compared to controls. Multivariate analysis revealed that increased blood viscosity and decreased microcirculatory oxygenation were independent risk factors of frequent VOC in SCA. In contrast, the level of microvascular dysfunction does not predict VOC rate. In conclusion, increased blood viscosity is usually well supported in healthy individuals where vascular function is not impaired. However, in the context of SCA, microvascular function is impaired and any increase of blood viscosity or decrease in microcirculatory oxygenation would increase the risks for frequent VOC.


Assuntos
Anemia Falciforme/sangue , Anemia Falciforme/fisiopatologia , Viscosidade Sanguínea , Microvasos/fisiopatologia , Oxigênio/metabolismo , Adolescente , Anemia Falciforme/complicações , Anemia Falciforme/metabolismo , Criança , Feminino , Humanos , Masculino , Microcirculação , Microvasos/metabolismo , Dor/etiologia
4.
Pediatr Blood Cancer ; 62(11): 1962-7, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25989908

RESUMO

BACKGROUND: Autonomic nervous system (ANS) activity has been suggested to modulate the clinical severity of sickle cell anemia (SCA) by increasing the risk for vaso-occlusive events. Regular physical activity (PA) is known to improve ANS activity and health status in several cardiovascular and metabolic diseases. Whether regular PA improves the health status of SCA patients remains unknown. PROCEDURE: Twenty-two patients with SCA and 15 healthy (AA) children/adolescents participated to the study. Heart rate variability was measured in supine position and after a tilt-test to quantify the ANS activity. PA energy expenditure (PAEE) was assessed with questionnaire. RESULTS: 1) PAEE was lower in SCA compared to AA (190 ± 152 vs. 432 ± 277 kcal · d(-1), respectively, P < 0.01), 2) overall ANS activity was lower in SCA compared to AA, 3) parasympathetic withdrawal was observed in SCA with aging, 4) ANS reactivity was slightly impaired in SCA compared to AA (reduction in HFnu: -38 ± 27 vs. -58 ± 14%, respectively, P < 0.05), 5) ANS indices, PAEE, and rates of clinical events were not correlated. CONCLUSION: Both the level of PA and ANS activity are reduced in SCA compared to AA children/adolescents, particularly in those older than 15 years. Neither PAEE, nor ANS activity seem to influence the clinical severity of children/adolescents with SCA.


Assuntos
Anemia Falciforme/fisiopatologia , Sistema Nervoso Autônomo/fisiopatologia , Nível de Saúde , Atividade Motora , Qualidade de Vida , Adolescente , Fatores Etários , Anemia Falciforme/complicações , Anemia Falciforme/terapia , Arteriopatias Oclusivas/etiologia , Arteriopatias Oclusivas/fisiopatologia , Arteriopatias Oclusivas/terapia , Criança , Feminino , Humanos , Masculino , Projetos Piloto
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