Shorter Sleep Predicts Longer Subsequent Day Sedentary Duration in Healthy Midlife Adults, but Not in Those with Sleep Apnea

Saurabh S Thosar,1– 4 Meera C Bhide,1 Isabel Katlaps,1 Nicole P Bowles,1 Steven A Shea,1,4 Andrew W McHill1,2 1Oregon Institute of Occupational Health Sciences; 2School of Nursing; 3Knight Cardiovascular Institute, School of Medicine; 4OHSU-PSU School of Public Health, Oregon Health and Science University, Portland, OR, 97239, USACorrespondence: Saurabh S ThosarOregon Institute of Occupational Health Sciences, 3181 SW Sam Jackson Park Road, L606/RJH1586, Portland, OR, 97239, USATel +1 503 494-2064Fax +1 503 494-4278Email thosar@ohsu.eduPurpose: Sedentary behavior and suboptimal sleep increase risks for chronic diseases. We hypothesized that sedentary behavior and sleep affect each other and that an underlying sleep disorder would alter these relationships. To test these hypotheses, we studied the bidirectional relationships between sedentary behavior and sleep (duration and efficiency) in healthy controls (HC) and people with untreated obstructive sleep apnea (OSA).Patients and Methods: Fifty-two volunteers (18 HC, 19 mild OSA [apnea/hypopnea index [AHI] range 5– 14.9/hour], 15 moderate OSA [AHI range 15– 29.9/hour]) were studied with actigraphy and sleep diaries across ∼ 9 consecutive nights of self-selected consistent ∼ 8-hour sleep episodes at home (range 4– 21/nights per person). We analyzed whether total time asleep and sleep efficiency affected the subsequent daytime sedentary duration while controlling for body mass index and whether the severity of OSA altered this relationship. We also tested the reverse relationship, namely whether daytime sedentary duration affected the subsequent night’s sleep and if any such relationship differed with OSA severity.Results: Overnight sleep duration and efficiency negatively predicted the subsequent day’s sedentary duration in HC (p 0.05). There was no significant reverse relationship between daytime sedentary duration and the subsequent night’s sleep duration or efficiency (p≥ 0.2).Conclusion: In healthy adults, short nighttime sleep predicts a longer duration of sedentary behavior on a subsequent day, but we did not observe this relationship in people with OSA. The mechanisms underlying this association in healthy individuals and its disruption in the presence of OSA need to be studied.Keywords: sitting time, sedentary behavior, cardiometabolic risk, sleep quality, chronic diseases, sleep disorder