Association of Systemic Immune-Inflammation Index with the Presence and Severity of Obstructive Sleep Apnea Syndrome

INTRODUCTION: The systemic immune-inflammation (SII) index provides information about the inflammatory status. Therefore, in the present study, we aimed to show the role of the SII index in patients with OSAS.
METHODS: Patients who were taken to a tertiary center for apnea, excessive daytime sleepiness, or snoring between May 2019 and December 2022 were analyzed. The SII index was calculated as follows: (neutrophil × platelet) / lymphocyte.
RESULTS: The study included 300 OSAS patients with an apnea-hypopnea index (AHI) of over 5 according to PSG.A control group of 106 people with an AHI of less than 5 was also part of the study. OSAS patients were separated into three groups according to their AHI: mild (5 ≥ AHI < 15), moderate (15 ≥ AHI < 30), and severe (AHI ≥ 30). The SII index had a larger area under the ROC curve for the presence and severity of OSAS than other CBC parameters (AUC for AHI 5 = 0.733 and AHI 30 = 0.699). After adjustment, multivariable logistic regression analyses revealed that the SII index, age, and BMI were independent predictors of OSAS [ORs (CI 95%) = 1.053 (1.030-1.076); p<0.001, 1.009 (1.006-1.012); p<0.001 and 1.360 (1.244-1.487); p<0.001], respectively.
DISCUSSION AND CONCLUSION: In our study, we showed that an increased SII index was associated with the presence and severity of OSAS. We believe that it can be used as a novel and important marker since the higher SII index provided relevant information regarding the presence and severity of OSAS patients.