Overall Mortality and Comorbidities in Obstructive Sleep Apnea in Poland

BACKGROUND Obstructive sleep apnea (OSA) is associated with increased risk of systemic comorbidities, leading to significant morbidity and mortality. This study investigates predictors of all-cause and OSA-related mortality, emphasizing the interplay of clinical symptoms, polysomnographic findings, and comorbidities. The aim of this study was to identify and compare predictors of all-cause and OSA-related mortality over 5, 10, and 15 years of follow-up. MATERIAL AND METHODS In this single-center study conducted at our Sleep Medicine Department between 2005 and 2019, 4025 patients with suspected OSA underwent polysomnography and were enrolled in this longitudinal study. Patients were categorized based on their mortality status, with a follow-up time of up to 15 years, and the cause of death if applicable. Based on the underlying cause of death, we identified 2 study groups: all-cause mortality (n=853) and OSA-related mortality (n=460). We performed Cox regression analyses to evaluate predictors of mortality. RESULTS Prevalence of OSA was high - 75.6% in the cohort: 929 patients with mild OSA (23.1%), 770 with moderate OSA (19.1%), and 1343 with severe OSA (33.4%). Survival rates were 89.7%, 81.9%, and 78.8% at 5, 10, and 15 years, respectively. Cardiovascular causes dominated mortality (33.3%), followed by cancer (26.5%). We compared the apnea-hypopnea index (AHI) a well-known, widely used metric for indicating the severity of OSA, in 0-5, 0-10, and 0-15 years of observation of all-cause mortality and OSA-related mortality. Comparing the AHI during rapid eye movement (REM) sleep, non-rapid eye movement (NREM) sleep, and total sleep time (TST), AHIREM was associated with a higher mortality risk than AHINREM and AHITST. Sleepiness (HR 1.17 95% CI: 1.09-1.26), episodes of stroke (HR 1.77 95% CI: 1.38-2.28), and use of new oral anticoagulants (HR 1.71 95% CI: 1.21-2.43) were associated with mortality at 15 years. CONCLUSIONS OSA management requires a holistic approach that extends beyond AHI, integrating clinical symptoms, comorbidities, and polysomnographic indices.