Effect of continuous positive airway pressure therapy on exhaled nitric oxide and C-reactive protein as markers of inflammation in Egyptian patients with obstructive sleep apnea

Abstract

Background Obstructive sleep apnea syndrome (OSAS) is associated with the respiratory tract inflammation. Fractional exhaled nitric oxide (FeNO) and high-sensitivity C-reactive protein (Hs-CRP) are indicators of airway and systemic inflammation. Few revisions have explored the effect of continuous positive airway pressure (CPAP) on both indicators in OSAS. Purpose To study the influence of CPAP therapy on exhaled NO and Hs-CRP in OSAS. Patients and methods This is a case–control study that included 27 participants with OSAS and 10 controls enlisted from a sleep outpatient clinic. Full-night polysomnography was performed, and the next morning, FeNO and Hs-CRP were evaluated. CPAP for patients with moderate to severe OSA was advised with measurement of FeNO and Hs-CRP after 3 months of CPAP. Results Both FeNO and Hs-CRP in patients with OSA were statistically significantly increased against the control group. However, after 3 months of CPAP therapy, there was a statistically significant decrease in both FeNO and Hs-CRP. Conclusion Upper airway and systemic inflammation are extant in OSAS, reinforced by increases in both FeNO and CRP, and CPAP therapy diminishes FeNO levels in patients with OSA.

Keywords

• continuous positive airway pressure
• fractional exhaled nitric oxide
• high-sensitivity c-reactive protein
• obstructive sleep apnea