Sleeping less than 7 hours linked to elevated all-cause mortality risk in patients with OSA

Key takeaways:

• All-cause mortality risk increased among patients with obstructive sleep apnea who slept for less than 7 hours.
• Most patients slept for 6 to less than 7 hours or 5 to less than 6 hours.

Among patients with obstructive sleep apnea, sleeping less than 7 hours was linked to a heightened risk for all-cause mortality, according to results of a cohort study published in JAMA Network Open.

“Our study reported that compared with participants with OSA with objective sleep duration of at least 7 hours, those with shorter sleep duration were at higher risk of all-cause mortality independent of apnea-hypopnea index (AHI),” Yiqi Lin, MD, of the department of sleep center at Fujian Provincial Hospital and Shengli Clinical Medical College of Fujian Medical University, and colleagues wrote.

Using data from the multicenter community-based Sleep Heart Health Study, Lin and colleagues assessed 2,574 (mean age, 65.4 years; 63.2% men; 86.6% white) patients with OSA followed for a median of 11.7 years to determine if sleep duration is linked to all-cause mortality.

Researchers used baseline total sleep time from patients’ polysomnography (PSG) assessments to group them by objective sleep duration: at least 7 hours (n = 341; 13.3%), 6 to less than 7 hours (n = 909; 35.3%), 5 to less than 6 hours (n = 801; 31.1%) and less than 5 hours (n = 523; 20.3%).

Habitual sleep duration, self-reported sleep duration on PSG nights, sleep perception, wake after sleep onset (WASO), arousal index, sleep efficiency, sleep onset latency, non-rapid eye movement sleep stage 1 percentage and REM percentage all significantly differed between the four groups. Notably, AHI was not significantly different.

According to researchers, there was a significant link between sleep duration and habitual sleep duration, sleep perception, AHI, WASO and arousal index (P < .001 for all).

Of the total cohort, 688 patients died, and the group that slept 6 to less than 7 hours had the most deaths (n = 240), followed by those who slept 5 to less than 6 hours (n = 209), those who slept less than 5 hours (n = 181) and those who slept at least 7 hours (n = 58; P < .001).

Researchers found elevated all-cause mortality risks among shorter sleep duration groups during Cox regression analysis adjusted for age; gender; race; smoking history; BMI; lipid-lowering medication use; antidepressant use; AHI; and a history of diabetes, cardiovascular disease, hypertension or COPD.

Specifically, those who slept 6 to less than 7 hours faced a greater risk for morality vs. those who slept at least 7 hours (adjusted HR = 1.53; 95% CI, 1.13-2.07), and this continued to be the case among those who slept 5 to less than 6 hours (aHR = 1.4; 95% CI, 1.03-1.9) and less than 5 hours (aHR = 1.64; 95% CI, 1.2-2.24) compared with the group with at least 7 hours of sleep.

Habitual sleep duration was not significantly linked to all-cause mortality, according to researchers.

Patients in the three shorter sleep duration groups continued to face increased risks for all-cause mortality during an analysis that did not factor in those who died within 2 years of baseline or those who took benzodiazepines within 2 weeks at baseline assessments.

With the exception of those who slept 5 to less than 6 hours, researchers reported consistent findings in the cohort of patients with positive airway pressure data (n = 2,195).

“Further research would be needed to shed light on its underlying mechanism and possible health benefits of extending sleep length among people with OSA with short sleep duration by sleep education or other sleep intervention,” Lin and colleagues wrote.