0465 Increased All-cause Mortality and Associated Factors in Korean OSA Patients

Abstract Introduction Obstructive sleep apnea (OSA) has been known to be associated with increased cardiovascular, metabolic diseases and mortality. As few studies reported associated factors on relationship between OSA and mortality, we aimed to investigate all-cause mortality and associated factors in OSA patients. Methods We performed retrospective study in group of 1547 subjects who referred to the Center for Sleep and Chronobiology, Seoul National University Hospital, from June 2004 to December 2013. Subjects who had other sleep disorders including parasomnia, restless legs syndrome, possible periodic limb movement disorder (PLMI15), narcolepsy, etc were excluded (N=331) and a total of 1216 subjects was included for analysis. Deaths out of final subjects that occurred up to December 31, 2020 from Statistics of Korea, the national bureau of statistics were examined. We divided subjects into four groups: no-sleep disorder (N=276, AHI 5), mild (N=268, 5≤AHI 15), moderate (N=275, 15≤AHI 30) and severe OSA groups (N=397, AHI≥30). We employed cox proportional hazard regression analysis to estimate hazard ratios (HRs) against no-sleep disorder and 95% confidence intervals adjusted for age, sex, hypertension, diabetes, dyslipidemia and longest apnea duration on polysomnography. Results HR of all-cause mortality was increased in the severe, moderate and mild OSA groups (HR=5.515, 95% CI=1.337-22.425, p-value=0.017, HR=5.443, 95% CI=1.555-19.054, p-value=0.008, HR=4.179, 95% CI=1.305-13.382, p-value=0.016, respectively). Longest apnea duration showed a significant association with decreased mortality (HR=0.955, 95% CI=0.932-0.979, p-value 0.001). Age was associated with increased mortality (HR=1.103, 95% CI=1.071-1.136, p-value 0.001). However, sex, diabetes, hypertension and dyslipidemia showed no significant association with mortality (All p-values 0.05). Conclusion Current results suggest increased mortality in patients with OSA. In particular, severity of OSA based on AHI was related with increased mortality. We found longest apnea duration was associated with decreased mortality as well. Previous notion on adverse effect of shorter apnea duration associated with frequent arousal might attribute to these results. Since CPAP compliance was not considered in this study, association between CPAP use and apnea duration also can be considered as another possible cause. We need further study to confirm the associated factors on mortality in OSA including apnea duration. Support (if any) National Research Foundation (RS-2023-00242754).