Increased circulating endothelial progenitor cells and anti-oxidant capacity in obstructive sleep apnea after surgical treatment

Background: Obstructive sleep apnea (OSA) has increased risk of cardiovascular diseases. Profiles of endothelial progenitor cells (EPCs) reflect the degree of endothelial impairment. This study tested the hypothesis that surgical treatment not only improves clinical outcomes but also increases the number of circulating EPCs and antioxidant capacity. Methods: The number of circulating EPCs (CD133⁺/CD34⁺ [%], KDR⁺/CD34⁺ [%]), biomarkers for oxidative stress (thiols and TBARS), and polysomnography (PSG) study was prospectively evaluated in 62 OSA patients at two time points (pre-operative and at least 3-month post-operative). The biomarkers and PSG were compared with those of 31 age- and body mass index (BMI)-matched healthy controls. Results: Levels of HbA1c and LDL-C were significantly higher while CD133⁺/CD34⁺ (%) and HDL were significantly lower in OSA patients than in healthy controls. The levels of CD133⁺/CD34⁺ (%) and thiols significantly increased in both mild/moderate and severe OSA. The TBAR levels also significantly decreased in severe OSA patients after >3months of follow-up. The number of CD133⁺/CD34⁺ (%) negatively correlated with both age and mO₂ of <90% but positively correlated with thiols. Clinical efficiency after OSA surgery assessed by PSG showed improvement and mean systolic blood pressure (SBP) (night and morning) reduction and improved lipid profile in the severe OSA group while only the snoring index improved in the mild/moderate OSA group. Conclusions: OSA surgery not only improves clinical outcomes, SBP reduction and improved lipid profile but also increases the number of circulating EPCs and antioxidant capacity, especially in patients with severe OSA.