Reduced Serum Pannexin-1 Levels in Obstructive Sleep Apnea and Their Association with Nocturnal Hypoxemic Burden

Background: Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder characterized by recurrent episodes of intermittent hypoxia and systemic inflammation. Pannexin-1 (Panx1) is a transmembrane channel involved in ATP release and purinergic signaling and has been implicated in hypoxia-related inflammatory responses. However, the clinical relevance of circulating Panx1 levels in patients with OSA remains poorly understood. This study aimed to evaluate serum Panx1 concentrations in patients with OSA and to investigate their association with nocturnal hypoxemic burden. Methods: In this cross-sectional study, 40 patients with obstructive sleep apnea (OSA) and 40 control subjects underwent overnight polysomnography for diagnostic evaluation. Serum Panx1 concentrations were measured using an enzyme-linked immunosorbent assay (ELISA). Logistic regression models were constructed to evaluate the association between Panx1 and OSA status while adjusting for clinical covariates. In addition, a propensity score-matched sensitivity analysis based on age, sex, and body mass index was performed to further assess potential confounding. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of Panx1 alone and in combination with clinical variables. Results: Serum Panx1 levels were significantly lower in patients with OSA than in controls (4.27 ± 2.66 vs. 6.24 ± 4.75 ng/mL, p = 0.013). Although Panx1 was not an independent predictor of OSA after adjustment for age, sex, and body mass index, its integration with clinical variables significantly improved diagnostic discrimination. The area under the receiver operating characteristic curve increased from 0.662 for Panx1 alone to 0.858 in the fully adjusted model. Sensitivity analyses attenuated the observed association after matching for major baseline characteristics, suggesting a potential contribution of demographic and anthropometric factors. In addition, Panx1 concentrations were inversely correlated with markers of nocturnal hypoxemic burden, particularly the cumulative time spent with oxygen saturation below 90% (T90). Conclusions: Lower serum Panx1 concentrations were associated with OSA status and nocturnal hypoxemic burden. While Panx1 alone demonstrated modest discriminatory ability, its integration with established clinical factors improved diagnostic performance. These findings suggest that Panx1 may represent a biologically plausible adjunct biomarker reflecting hypoxic burden and may contribute to multi-parameter approaches for OSA risk assessment; however, further validation in larger matched cohorts is warranted.