Effect of continuous positive airway pressure (CPAP) therapy on IL-23 in patients with obstructive sleep apnea.

Obstructive sleep apnea syndrome (OSAS) is a common sleep disorder characterized by repeated episodes of apnea and hypopnea during sleep. Continuous positive airway pressure (CPAP) is the most effective method for treating OSAS and alleviating the patients' symptoms. The aim of this study was to assess the effect of 3-month CPAP therapy on serum levels of IL-23 in patients with OSAS. Twenty-three patients with newly diagnosed moderate-to-severe OSAS who had not yet started nasal CPAP treatment were prospectively enrolled. All of the subjects underwent simple spirometry and an overnight sleep study. Twenty-seven healthy individuals without OSAS were also recruited as the control group. Serum IL-23 and C-reactive protein (CRP) levels were measured before and after 3 months of CPAP therapy. There was no significant difference between moderate and severe OSAS patients in IL-23 and CRP, but both parameters were significantly higher than control group. The CPAP treatment produced a significant decrease in the levels of the inflammatory mediators CRP and IL-23 in patients. Changes in IL-23 were positively correlated with changes in AHI and in CRP. In conclusion, based on these results, serum IL-23 levels reflect OSAS-related systemic inflammation and are a useful marker for improvement in OSAS following CPAP therapy.