Protocol for a randomized controlled trial of moderate intensity interval training in individuals with chronic obstructive pulmonary disease and obstructive sleep apnea overlap syndrome who have excessive daytime sleepiness

Abstract

Background: The term "Overlap Syndrome" (OS) describes the presence of both chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) in a single individual. Excessive daytime sleepiness (EDS) is a common symptom of OS shown to be associated with an increased risk of cardiovascular disease (CVD) that could be reduced through exercise. Thus, we propose to investigate a novel exercise intervention in individuals with the EDS-OS phenotype as they are at highest risk of CVD yet have the greatest barriers to exercise.

Methods: We will conduct a single-site, randomized, two-arm, parallel group-controlled exercise trial in individuals with EDS-OS. The Epworth Sleepiness Scale (ESS) will be assessed at baseline. Individuals with OS and the EDS-OS phenotype (ESS >10) (n = 46) will be randomized to a moderate intensity interval training (MIIT, i.e. intervals of 5 min at 50% VO2peak followed by 3 min of active recovery at 10% VO2peak) or a control group of standard of care. We will investigate if MIIT intervention decreases the risk of CVD in EDS-OS, which will be assessed by: 1) quality of life, measured by the 36-Item Short Form Health Survey; 2) physical activity, measured by daily step counts; and 3) cardiovascular health, assessed as VO2peak, flow-mediated dilation and serum high sensitivity C-reactive protein, lipids, and glucose.

Conclusion: Our findings will guide future development and implementation of exercise interventions that could reduce the risk of CVD in the understudied EDS-OS phenotype.

Keywords: Chronic obstructive pulmonary disease; Interval, exercise; Moderate intensity; Obstructive sleep apnea; Overlap syndrome.