Endothelial progenitor cells and vascular dysfunction in children with obstructive sleep apnea

Area of Science:

• Pediatric Cardiology
• Sleep Medicine
• Vascular Biology

Background:

• Obstructive sleep apnea syndrome (OSAS) in children is associated with systemic inflammation and potential endothelial dysfunction.
• However, the variability in endothelial function among children with OSAS is not fully understood.

Purpose of the Study:

• To investigate the role of endothelial progenitor cells (EPCs) in mediating endothelial function variability in pediatric OSAS.
• To explore the relationship between EPCs, stromal cell-derived factor-1 (SDF-1), and endothelial function in children with OSAS.

Main Methods:

• Assessed endothelial function using a modified hyperemic test in children with and without OSAS.
• Quantified EPCs via flow cytometry and measured SDF-1 levels by ELISA in peripheral blood samples.
• Correlated endothelial function parameters with EPC counts, SDF-1 levels, and apnea-hypopnea index (AHI).

Main Results:

• Children with OSAS exhibited delayed capillary reperfusion (Tmax), with significant variability.
• Lower EPC counts and SDF-1 levels were observed in OSAS children with the most impaired endothelial function (longest Tmax).
• Tmax was inversely correlated with EPCs, but neither parameter correlated with AHI.

Conclusions:

• Endothelial dysfunction is common in pediatric OSAS, with varying severity.
• The ability to recruit endothelial repair mechanisms, particularly EPCs, may explain the observed differences in endothelial function among children with OSAS.