Abstract

Abstract
Background: Chronic Obstructive Pulmonary Disease (COPD) patients have decreased physical activity (PA) levels compared to healthy controls. Their diurnal PA patterns are much less documented. Disturbed sleep is another common feature in COPD. The relationship between PA and sleep has never been reported in COPD patients. The project’s aims were to characterize objectively measured diurnal PA patterns and sleep quality, and explore the association between PA and sleep in COPD.
Methods: Fourteen patients (aged 71±9 years) with mostly moderate COPD (FEV1: 58±13% predicted) participated. PA and sleep parameters (Sleep Onset Latency[SOL], Wake After Sleep Onset[WASO], Total Sleep Time[TST], Sleep Efficiency[SE%], Fragmentation Index[FI]) were assessed via actigraphy for seven consecutive days, 24 hours/day. Diurnal PA patterns were evaluated by three handling approaches: arbitrary, mealtimes and equal tertiles. The interaction of period of the day by handling approach was tested with two-way repeated-measured ANOVA. Associations between sleep parameters and mean daily PA and PA in each tertile was assessed with bivariate correlations.
Results: There was a significant interaction effect of period of the day by handling approach (p<0.001). Regardless of the approach, PA significantly decreased in the evening compared to morning and afternoon. Participants had, on average: SOL: 22±17min, WASO: 65±29min, TST: 383±59min, SE: 79±9% and FI: 45±23%. Mean daily PA and PA in each tertile showed very weak to moderate associations with sleep parameters (r = -0.50 to 0.42).
Conclusion: PA levels drop in the evening in patients with moderate COPD. The relationship between PA and sleep quality appears modest in these patients, but the PA-sleep relationship warrants further investigation.