Evaluation of inflammatory markers in obstructive sleep apnea

Objectives: In recent years, studies have been published showing that inflammation plays an important role in obstructive sleep apnea syndrome, as in many systemic diseases. In this study, we aimed to investigate the relationship between tumor necrosis factor alpha (TNF alpha), interleukin 6 (IL-6) and serum free DNA (ccfDNA) concentrations with disease severity and treatment. Material and Method: In this study, 52 participant patients who underwent polysomnography between 2017-2019 and had an apnea hypopnea index (AHI) above 5, and 10 participants with an AHI below 5 were included as the control group. Detailed demographic and clinical characteristics of all participants and PSG recording results were recorded. TNF alpha and IL-6 levels were measured using ELISA bioassay method, and ccfDNA was measured using DNA isolation kits. The relationship with disease severity and some clinical parameters was investigated. Results: There was no significant difference between the patient and control groups in terms of inflammatory markers we looked at. However, the mean ccfDNAs were higher in the patient group than the control group but were not statistically significant (p = 0.71). When the relationship of these markers with disease severity was evaluated, there was no statistically significant difference between the mild-moderate and severe groups. The mean IL-6 and ccfDNA were higher in the severe group but were not statistically significant (p = 0.47; p = 0.58). The same weak correlation was found between the Epworth scale and BMI and IL-6 among the clinical features examined. Again, there was no significant difference in these markers between the patients using NIMV and those who did not. Conclusion: In this study, no significant relationship was found between the inflammatory markers evaluated (TNF alpha, IL-6 and ccfDNA) and disease severity. However, some of these markers were found to be poorly correlated with a few clinical features. Further studies are needed to demonstrate the role of inflammatory markers in obstructive sleep apnea syndrome. Keywords: obstructive sleep apnea, inflammation, TNF alpha, IL-6, ccfDNA