Micro- and macrovascular function in children with sickle cell anaemia and sickle cell haemoglobin C disease

Area of Science:

• Vascular biology
• Pediatric hematology
• Cardiovascular health

Background:

• Sickle cell disease (SCD) encompasses various genetic disorders affecting red blood cells.
• Vascular complications are a hallmark of SCD, but their specific manifestations in different SCD types, like sickle cell anaemia (SS) and sickle haemoglobin C (SC) disease, require further elucidation.
• The impact of physical activity on vascular health in pediatric SCD populations is not well understood.

Purpose of the Study:

• To compare microvascular and macrovascular functions in children with SS disease, SC disease, and healthy controls (AA).
• To investigate the association between physical activity levels and vascular function in these pediatric groups.

Main Methods:

• Utilized Laser Doppler techniques to assess thermal hyperemic response (microvascular function).
• Measured arterial stiffness using pulse wave velocity (macrovascular function).
• Evaluated physical activity via questionnaires and assessed fitness with the six-minute walk test.

Main Results:

• Both SS and SC disease groups exhibited blunted microvascular reactivity compared to healthy controls.
• SS patients demonstrated significantly lower microvascular reactivity and higher arterial stiffness than controls.
• SC patients showed reduced microvascular reactivity but normal arterial stiffness compared to controls.
• Physical activity and fitness levels were lower in both SS and SC patients, but showed no correlation with vascular function parameters.

Conclusions:

• Children with both SS and SC disease have impaired peripheral microvascular function.
• Macrovascular function is specifically impaired in children with SS disease.
• Physical activity levels do not appear to directly influence vascular function in these pediatric SCD cohorts.