Obstructive Sleep Apnea with Excessive Daytime Sleepiness is an Independent Risk Factor for Mortality
Authors List
Ding Zou1, Ying Li2, Ludger Grote1,3, Ulf Lindblad2, Jan Hedner1,3*, Bledar Daka2*
1Center for Sleep and Vigilance Disorders, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; 2School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; 3Sleep Medicine Center, Department of Pulmonary Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
*Co-last author
Introduction
Excessive daytime sleepiness (EDS) increases cardiovascular risk in the presence of obstructive sleep apnea (OSA). We studied the prognostic role of EDS in OSA on long-term all-cause mortality in a sex-stratified community-based population of hypertensive patients and normotensive controls (Skara Sleep Cohort).[1]
Methods
341 participants (46.6% hypertensives, 50.7% males, 61.2±6.5 years, body mass index 28.6±4.8 kg/m2) underwent ambulatory polysomnography investigation (Embla A10 system, Flaga, Iceland). Apnea/hypopnea events were defined as a >50% reduction of airflow amplitude compared with baseline or an evident airflow reduction associated with an oxygen desaturation of >3% or an arousal. A multi-dimensional EDS definition was applied including either an Epworth Sleepiness Scale (ESS) ≥10 or self-reported “moderate/severe/very severe sleepy during the day” in a multiple-choice question. The association of OSA/EDS with all-cause mortality was assessed using multivariate Cox regression analysis.
Results
At baseline, 46.6% had moderate-to-severe OSA (AHI ≥20 events/h) and 35.8% had EDS. The mean follow-up time was 15.8±3.9 years and 85 deaths occurred. Compared to the AHI<20 & non-EDS group, moderate-to-severe OSA with EDS group was associated with increased risk of all-cause mortality (see figure, fully adjusted hazard ratio 2.32 [95%CI: 1.19, 4.54], P=0.014).
Sensitivity analysis revealed that single EDS question 2.26 [1.15, 4.41], P=0.017) but not ESSbased EDS (2.10 [0.93, 4.77], P=0.076) showed significant prognostic value for OSA patients.
Conclusions
Moderate-to-severe OSA with EDS symptoms was associated with increased risk for all-cause death. A multi-dimensional definition of EDS in OSA patients is important for phenotyping patients at risk.
Research Funding Source: The study was supported by the Swedish Heart and Lung Foundation (project 20050467, 20080587, 20180585, 20210500).
1. Hedner, J., et al., Hypertension prevalence in obstructive sleep apnoea and sex: a population-based case-control study. Eur Respir J, 2006. 27(3): p. 564-70.
Ding Zou1, Ying Li2, Ludger Grote1,3, Ulf Lindblad2, Jan Hedner1,3*, Bledar Daka2*
1Center for Sleep and Vigilance Disorders, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; 2School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; 3Sleep Medicine Center, Department of Pulmonary Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
*Co-last author
Introduction
Excessive daytime sleepiness (EDS) increases cardiovascular risk in the presence of obstructive sleep apnea (OSA). We studied the prognostic role of EDS in OSA on long-term all-cause mortality in a sex-stratified community-based population of hypertensive patients and normotensive controls (Skara Sleep Cohort).[1]
Methods
341 participants (46.6% hypertensives, 50.7% males, 61.2±6.5 years, body mass index 28.6±4.8 kg/m2) underwent ambulatory polysomnography investigation (Embla A10 system, Flaga, Iceland). Apnea/hypopnea events were defined as a >50% reduction of airflow amplitude compared with baseline or an evident airflow reduction associated with an oxygen desaturation of >3% or an arousal. A multi-dimensional EDS definition was applied including either an Epworth Sleepiness Scale (ESS) ≥10 or self-reported “moderate/severe/very severe sleepy during the day” in a multiple-choice question. The association of OSA/EDS with all-cause mortality was assessed using multivariate Cox regression analysis.
Results
At baseline, 46.6% had moderate-to-severe OSA (AHI ≥20 events/h) and 35.8% had EDS. The mean follow-up time was 15.8±3.9 years and 85 deaths occurred. Compared to the AHI<20 & non-EDS group, moderate-to-severe OSA with EDS group was associated with increased risk of all-cause mortality (see figure, fully adjusted hazard ratio 2.32 [95%CI: 1.19, 4.54], P=0.014).
Sensitivity analysis revealed that single EDS question 2.26 [1.15, 4.41], P=0.017) but not ESSbased EDS (2.10 [0.93, 4.77], P=0.076) showed significant prognostic value for OSA patients.
Conclusions
Moderate-to-severe OSA with EDS symptoms was associated with increased risk for all-cause death. A multi-dimensional definition of EDS in OSA patients is important for phenotyping patients at risk.
Research Funding Source: The study was supported by the Swedish Heart and Lung Foundation (project 20050467, 20080587, 20180585, 20210500).
1. Hedner, J., et al., Hypertension prevalence in obstructive sleep apnoea and sex: a population-based case-control study. Eur Respir J, 2006. 27(3): p. 564-70.
