Angiopoietin-2 and soluble Tie-2 receptor plasma levels in children with obstructive sleep apnea and obesity.

Abstract

ObjectiveObstructive sleep apnea (OSA) is a prevalent condition, especially in obese children, and is associated with increased risk for metabolic syndrome. Angiopoietins have been identified as potential biomarkers of endothelial dysfunction, and MetS. In adults, angiopoietin-2 (Ang-2) and its soluble receptor (sTie-2) are associated with diabetes, hypertension and obesity, and could be increased in children with OSA, obesity, particularly those with evidence of cardiometabolic alterations.Methods126 children (7.4±2.0 years) were consecutively recruited, underwent overnight polysomnography, endothelial function, and BMI z score assessments and a fasting blood draw the morning after the sleep study. In addition to lipid profile, glucose and insulin levels and calculation of HOMA-IR, Ang-2 and sTie-2 concentrations were determined.ResultsObese and OSA children had significantly elevated plasma Ang-2 and sTie-2 levels compared to corresponding non-obese and obese controls. Furthermore, endothelial function (Tmax) and HOMA-IR were linearly and independently associated with Ang-2 and sTie-2 levels. In a small subset of children (n=14), treatment of OSA by adenotonsillectomy resulted in reductions of Ang-2 and sTie-2 (p<0.01).ConclusionsAng-2 and sTie-2 plasma levels are increased in pediatric OSA and obesity, particularly when endothelial dysfunction or insulin resistance are detectable, and appear to decrease upon OSA treatment.