Study to Evaluate the Role of Inflammatory Biomarker- IL-6 in Obstructive Sleep Apnea in Correlation with Apnea-Hypopnea Index

Introduction: Many biomarkers are associated with the Apnea-Hypopnea Index (AHI) in the majority of the studies, but most of the explored approaches were not able to identify definitive biomarkers of Obstructive Sleep Apnea (OSA) morbidity. Aim: To evaluate the correlation of AHI with inflammatory biomarker-Interleukin-6 (IL-6). Materials and Methods: Adult patients above 18 years of age, and suffering from OSA or had history suggestive of OSA were included in the study. IL-6 was measured by ELISA kit and immunoassay equipment. Polysomnography (PSG) study was done which included sleep stages, Heart rhythm monitoring, Leg movements recording, Breathing monitoring. Obstructive apnea was taken as cessation of airflow for at least 10 seconds with persistent respiratory effort. Descriptive statistical methods were used such as computing percentage, mean, standard deviation, pivot tables, and correlation. Results: A total number of 46 patients with OSA were evaluated. Out of 46 patients, 9 (19.57%), 6 ( 13.04%) and 31 ( 67.39%) patients belonged into mild, moderate and severe AHI, respectively. ELISA for IL-6 was done in 41 patients. The value ranged from 20.92 to 4145.23 pg/mL with SD +/- 1769.32 and with mean of 1427.94. Average values of biomarker IL-6 was 675.26 pg/mL, 1261.19 pg/mL, 1658.58 pg/mL in mild, moderate and severe OSA respectively. There was a positive correlation between AHI severity and IL-6 with correlation value. Conclusion: In this study, IL-6 appeared to exhibit a favourable profile for a biomarker aiming to discriminate OSA in adult patients. However more large scale studies are required to establish a definitive correlation between OSA and IL-6.