Association Between Redox and Inflammatory Biomarkers with the Presence and Severity of Obstructive Sleep Apnea

Background and Objectives: Obstructive sleep apnea (OSA) represents an increasing public health concern, closely linked with cardiovascular, metabolic, and neurocognitive disorders, as well as impaired quality of life. The complex pathophysiology of OSA involves upper airway dysfunction, oxidative stress, and inflammation, with endothelial dysfunction considered central to its associated comorbidities. Despite notable advances in OSA research, the biological mechanisms driving these complications remain insufficiently understood. The present study aimed to examine the associations between redox status, proinflammatory biomarkers, and the gene expression of full-length receptor for advanced glycation end products (flRAGE) and transforming growth factor beta 1 (TGF-β1) in relation to the presence and severity of OSA. Materials and Methods: The study cohort comprised 125 participants with diagnosed OSA and 42 controls without evidence of OSA. General and clinical characteristics were recorded for all participants. Laboratory analyses included the assessment of redox and inflammatory markers in serum and plasma, while flRAGE and TGF-β1 messenger ribonucleic acids (mRNA) were quantified in peripheral blood mononuclear cells. Results: Patients with OSA demonstrated elevated oxidative stress and inflammation, characterized by increased total antioxidant status (TAS) and C-reactive protein CRP levels, together with reduced concentrations of soluble RAGE (sRAGE). The severity of OSA, indicated by the apnea-hypopnea index, increases total oxidative status (TOS) and TGF-β1 mRNA, while sRAGE decreases. The sRAGE-ROS-related factor was negatively associated with OSA, whereas the redox status factor showed a positive association. TOS was independently and positively correlated with OSA severity. Conclusions: Individuals with OSA exhibit a state of enhanced oxidative stress and inflammation. Increasing severity of OSA was associated with rising TOS and TGF-β1 mRNA expression, accompanied by declining sRAGE concentrations. A combined redox-inflammatory biomarker profile was found to be associated with both the presence and severity of OSA.