Sleep Disturbance and Physical Activity in Chronic Obstructive Pulmonary Disease

Background: Chronic obstructive pulmonary disease (COPD) is a highly prevalent chronic respiratory disease and the third-leading cause of death in the U.S. Physical inactivity and sleep disturbance are much more problematic in this population than in healthy individuals; the related negative health outcomes include COPD exacerbation, hospitalization, and increased mortality. Research examining the association between sleep and physical activity (PA) in this population is limited. The purpose of this study was to identify the impact of night-time sleep on next-day PA in people with co-existing COPD and disturbed sleep using both subjectively and objectively measured sleep variables. Method: In this secondary analysis with a repeated-measure, quantitative design, 56 mild-to-severe COPD patients who reported disturbed sleep were drawn from the baseline dataset of an ongoing randomized control trial examining efficacy and mechanisms of components of insomnia therapy on insomnia and fatigue in COPD patients. Sleep and PA were measured using the accelerometer (Actiwatch-2, Philips Respironics, Murrysville, PA) over 5 days. Night-time sleep variables included sleep onset latency (SL), sleep efficiency (SE), wake after sleep onset (WASO), total sleep time (TST), and number of awakenings (NA); PA variables included averaged daily (from awakening to bedtime) and hourly activity counts per minute. Spearman correlations and mixed-effect modeling were performed using the SPSS 24.0 program (SPSS Inc., Chicago, IL). Results: The mean age of the participants was 65.1 years; and 53.6% were male. The mean predicted FEV1% was 69.5; and 60.7% of participants had moderate pulmonary function based on the GOLD standard. Greater mean daily PA negatively associated with SL (r=-0.48, p <.001), NA (r=-0.38, p <.01), TST (r=-0.50, p<.001), and age (r=-0.32, p<.05). Increased SL was associated with less next-day PA during afternoon and evening (4-6 p.m.). Greater WASO and NA were associated with less next-morning PA (5-8 a.m.). Greater TST was associated with less next-morning PA (12 a.m.-12 p.m.), and greater SE was associated with less next-morning (1-4 a.m.) and more evening PA (5-7 p.m.). Conclusion: This study identified a significant influence of night-time sleep on next-day PA in people with co-existing COPD and sleep disturbance. These results provide evidence supporting the potential value of effective sleep management to promote physical activity in people with COPD. Further research is needed to identify mechanisms underlying the sleep-PA relationship.