Associations Between Systemic Inflammatory Markers Based on Blood Cells and Polysomnographic Factors in Obstructive Sleep Apnea

Minju Kim, Sung-Woo Cho, Tae-Bin Won, Chae-Seo Rhee, Jeong-Whun Kim

Systemic inflammation plays a key role in the pathogenesis of obstructive sleep apnea (OSA); however, methods to easily evaluate the severity of systemic inflammation are yet to be developed. This study aimed to analyze the association between systemic inflammation markers, which could be derived from the complete blood count (CBC) profile, and sleep parameters in a large number of patients with OSA. Patients who visited our hospital's Otorhinolaryngology Sleep Clinic between January 2017 and February 2022 underwent polysomnography and routine laboratory tests, including CBC. Associations between three systemic inflammatory markers, systemic immune-inflammation index (SII), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR), and polysomnographic and demographic factors including age, sex, body mass index, apnea-hypopnea index (AHI), hypopnea index (HI), lowest oxygen saturation (%), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale, and percentages of non-Rapid Eye Movement (REM) sleep stage 3, REM sleep, and snoring time were analyzed. The inflammation markers of different OSA subgroups were also compared. The association was also analyzed in subgroups with different OSA severities. A total of 1102 (984 male, 134 female) patients were included, and their mean age was 46.70 ± 13.15 + mean AHI. PSQI (p = 0.027) was significantly associated with SII. There were no significant independent factors for the NLR and PLR. Within the simple snorer and mild OSA subgroups, there was no significant association between sleep parameters and the SII. In the severe OSA subgroup, AHI (p=0.004) and PSQI (p=0.012) were independently associated with SII. Our study analyzed systemic inflammatory markers based on a simple, relatively cost-effective test, complete blood count, and showed that AHI and SII were significantly correlated only in the severe OSA subgroup.