IL6 and obstructive sleep apnea syndrome: The literature also links elevated inflammatory markers in OSA patients—such as C-reactive protein, tumor necrosis factor-alpha, interleukins 6 and 8, intercellular adhesion molecule, and vascular cell adhesion molecule—with the severity of OSA assessed by the apnea–hypopnea index (AHI) (Nadeem et al., 2013; Arnaud et al., 2020).