Incremental shuttle walk test in the assessment of patients with obstructive sleep apnea-hypopnea syndrome

Obstructive sleep apnea-hypopnea syndrome is associated independently with an increase in cardiovascular risk factors and is associated with self-reported lack of exercise. We aimed to investigate the utility of the incremental shuttle walk test in routine clinical practice to monitor physical capacity of patients with obstructive sleep apnea-hypopnea syndrome and explore whether continuous positive airway pressure therapy alters exercise capacity. Participants with symptomatic moderate/severe obstructive sleep apnea-hypopnea syndrome attending for a trial of continuous positive airway pressure therapy completed questionnaires assessing sleepiness and physical activity and underwent an incremental shuttle walk test. Subjects compliant or partially compliant with continuous positive airway pressure therapy underwent reassessment at 2 weeks, 3 months and 6 months post-initiation of therapy. Participants unable to tolerate continuous positive airway pressure therapy completed a single reassessment 6 months after their initial visit. Continuous positive airway pressure therapy resulted in an increased distance walked during the incremental shuttle walk test. Improvements in cardiovascular responses to exercise were identified. Compliant patients reported increased daily activity. The incremental shuttle walk test is a simple, reproducible and safe test that is responsive to continuous positive airway pressure treatment. Our findings support the use of the incremental shuttle walk test for monitoring the effects of continuous positive airway pressure treatment and may suggest its use in rehabilitation programmes designed to reduce obesity and cardiovascular risk factors in patients with obstructive sleep apnea-hypopnea syndrome.