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.

backgroundThe 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.

methodsWe 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.

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