The effect of continuous positive airway pressure treatment on the systemic immune-inflammation index in obstructive sleep apnea syndrome

ABSTRACT

Objectives: This study aims to investigate the effect of continuous positive airway pressure (CPAP) treatment on the systemic immune-inflammation index (SII) in patients with obstructive sleep apnea syndrome (OSAS).

Patients and Methods: In this retrospective cohort study, records of 197 OSAS patients (132 males, 65 females; median age: 55 years; range, 26 to 85 years) who underwent polysomnography and hemogram testing and were recommended CPAP therapy between January 2020 and April 2022 were analyzed. Forty-nine healthy volunteers (32 males, 17 females; median age: 31 years; range, 18 to 64 years) without OSAS-related complaints were included as controls. Hemogram-derived neutrophil, lymphocyte, and platelet counts were used to calculate neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and SII. These indices were compared between groups, and pre- and posttreatment values in OSAS patients. Correlations between CPAP duration and inflammatory indices were also examined.

Results: The moderate OSAS group (n=45) showed a nonsignificant decrease in SII after CPAP (p=0.173), whereas the severe OSAS group (n=152) demonstrated a significant increase (p=0.041). Duration of CPAP use was positively correlated with changes in platelet-to-lymphocyte ratio (r=0.151, p=0.034) and SII (r=0.157, p=0.028).

Conclusion: Treatment with CPAP was associated with a nonsignificant reduction in systemic inflammation in moderate OSAS but paradoxically increased SII in severe OSAS. These findings suggest that CPAP alone may be insufficient to normalize systemic inflammation in advanced OSAS, and additional interventions such as weight loss or adjunctive therapies may be required.