TNF and obstructive sleep apnea syndrome: Interestingly, continuous positive airway pressure (CPAP) therapy in patients with OSA lowers the levels of pro-inflammatory and oxidative stress markers, including lipid, protein, and DNA oxidation products, C-reactive protein (CRP), IL-6, IL-8, TNF-α, nitric oxide (NO), nitrosative stress compounds, and markers of endothelial dysfunction [33].