BACKGROUND: This study focused on evaluating the clinical significance of oxidative stress biomarkers in patients with OSAS. We investigated how nasal respiratory obstruction in OSAS patients might affect the oxidative balance. METHODS: Sixty patients were divided into three groups (n = 20 each): severe OSAS (AHI >
30), snoring with AHI <
15 (mild OSAS), and nasal respiratory impairment with AHI <
5. All subjects underwent ENT examination, rhinomanometry, polysomnography, and oxidative stress biomarker analysis. RESULTS: From the measurements of biomarkers associated with oxidative stress, specifically NPBI (non-protein bound iron), AOPP (Advanced Oxidation Protein Products), Isoprostanes (both plasmatic ad urinary), and Thiols, no statistically significant differences emerged among the subjects belonging to the three groups (patients with OSAS, subjects with snoring and AHI <
15, subjects with nasal respiratory impairment only and AHI <
5). CONCLUSIONS: The presence of oxidative stress markers in patients with nasal obstruction, even in the absence of severe OSAS, highlights the potential role of nasal airflow limitation as a contributing factor in the pathogenesis of sleep-disordered breathing. A better understanding of the oxidative stress profile in these conditions might contribute to refining diagnostic and therapeutic approaches, and potentially reduce the reliance on polysomnography in selected cases.