0584 Association of Novel Polysomnographic Parameters with Charlson Comorbidity Index and Mortality Risk in Sleep Apnea

Abstract Introduction Previous studies demonstrate an association between conventional polysomnographic parameters, including apnea-hypopnea index (AHI), respiratory disturbance index, and oxygen desaturation index, and increased mortality risk in patients with sleep apnea. Given the drawbacks of these conventional parameters, this study aims to explore the association between novel polysomnographic parameters—oxygen desaturation rate (ODR), oxygen resaturation rate (ORR), cumulative hypoxic burden (HBc), and event-specific hypoxic burden (HBe)—and the Charlson Comorbidity Index (CCI), a 10-year mortality risk score, as well as its relative Charlson mortality risk (CMR). Methods This cross-sectional study included patients who underwent diagnostic polysomnography. Conventional and novel polysomnographic parameters were analyzed for their correlation with CCI and CMR at the time of the study. Stepwise linear regression was used to identify predictors of CCI. Results A total of 1,505 patients (498 no OSA, 724 mild, 219 moderate, 65 severe; mean age 44 years) were analyzed. CCI and CMR were higher in patients with OSA than without (1.7±1.92 vs. 1.42±1.63, p< 0.001; 14.33% vs 10.8%, p=0.022) and increased with OSA severity (mild 1.68±1.91, moderate 1.70±1.97, severe 1.97±1.85; p< 0.001). All polysomnographic parameters, except ODR, significantly correlated with CCI and CMR. Stepwise regression identified minSpO2, baselineSpO2, and ORR as independent predictors of both CCI (coefficients −1.59, −5.97, 83.81; p=0.035, 0.035, 0.023) and CMR (−24.63, −71.92, 976.84; p=0.006, 0.034, 0.026). When CCI was grouped as no comorbidity (0), low (1–2), moderate (3–4), and high (≥5), ORR increased progressively with risk (0.345, 0.360, 0.367, 0.375 %/s; p=0.001). Conclusion Our study identified novel polysomnographic parameters, including HBc, HBe, and ORR, as associated with CCI and CMR. Among these, ORR was the only independent predictor of both CCI and CMR, alongside conventional parameters minSpO2 and baselineSpO2. Higher ORR may increase reactive oxygen species, contributing to greater comorbidities and higher CCI. ORR represents a promising novel marker for further exploration in the context of OSA and mortality risk. Support (if any)