The relationship between the systemic immune-inflammation index and obstructive sleep apnea

To investigate the predictive value of the systemic immune-inflammation index (SII) in patients with obstructive sleep apnea (OSA).

Patients diagnosed with OSA formed the patient group, and those with a normal polysomnography (PSG) result formed the control group. The neutrophil, thrombocyte, monocyte, and lymphocyte counts obtained from the hemogram were used to calculate the neutrophil-to-lymphocyte ratio (NLR), thrombocyte-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and the SII values. The two groups were compared with respect to the NLR, PLR, MLR, and SII values. Correlations were examined between the PSG parameters and the NLR, PLR, MLR, and SII values in the patient group.

Evaluation included 146 subjects with 85 in the patient group and 61 in the control group. Statistically significantly higher SII and NLR values were found in the patient group (p = 0.037, p < 0.05; p = 0.015, p < 0.05). A statistically significant negative correlation was observed between the SII and the lowest O2 saturation measurements (r =  - 0.246; p = 0.003; p < 0.01). A statistically significant negative correlation was found between the NLR and the lowest O₂ saturation measurement (r =  - 0.255; p = 0.002; p < 0.01). The cutoff value for SII was found to be 290, with 84.7% sensitivity and 29.5% specificity. A cutoff value of 1.71 for NLR was determined to have 61.2% sensitivity and 60.7% specificity.

SII may be a new, rapid, low-cost, and easy-to-measure biomarker for the prediction of obstructive sleep apnea.