Abstract 11760: Impact of Sleep Disordered Breathing on Endothelial Function, Platelet Aggregation and Inflammation in Children

Abstract

Introduction: Sleep disordered breathing (SDB) in adults is an independent risk factor for coronary artery disease and atrial fibrillation. Altered platelet reactivity, endothelial dysfunction and inflammation in adults with SDB are known to contribute to the pathogenesis of its cardiovascular complications. SDB also occurs in children; however little is known about platelet function and inflammation in non-obese children with SDB. Therefore, this study investigated platelet aggregation, inflammation and endothelial function in children with SDB and healthy matched controls.

Methods: 19 children aged 5-12 years participated in this study. All children underwent overnight sleep studies using polysomnography (n=12 were clinically diagnosed with SDB, n=7 were healthy controls), followed by venous blood collection and magnetic resonance imaging studies (MRI). Venous blood samples were analyzed for measurements of platelet aggregation (Multiplate Analyzer) and inflammation (Intracellular cytokine analysis of T cells by flow cytometry). Plasma asymmetric dimethylarginine (ADMA), a marker of endothelial function, was also quantified. MRI studies determined left and right ventricular ejection fraction, aortic blood flows and aortic distensibility.

Results: Platelet aggregation was significantly increased in SDB children compared to controls (57 ± 17 vs 38 ± 4 Aggregation Units, p<0.05). Children with SDB also exhibited an increase in ADMA (0.43 ± 0.5 μ mol/l) versus controls (0.35 ± 0.08μ mol/l, p<0.05) and significant increases in inflammation measured by T-cell interferon (IFN)-gamma (SDB 52 ± 4% vs control 25 ± 3% positive cells, P<0.005) and tumor necrosis factor (TNF)-alpha (SDB 39 ± 4% vs Controls 20 ± 2% positive cells, P<0.005). There was no difference between groups for ejection fraction, mean aortic blood flow or aortic distensibility.

Conclusion: Children with SDB have increased platelet aggregation, inflammation and endothelial dysfunction, but normal heart function compared to healthy controls. These findings are consistent with the profile of cardiovascular abnormalities observed in adult SDB and suggest that children with SBD may be at an increased risk of developing cardiovascular complications in the future.