Exercise capacity and comorbidities in patients with obstructive sleep apnea

Area of Science:

• Pulmonary Medicine
• Sleep Medicine
• Cardiorespiratory Physiology

Background:

• Obstructive sleep apnea (OSA) is a prevalent condition affecting millions globally.
• Exercise capacity is a crucial indicator of health and functional status.
• Limited research exists on exercise capacity, specifically the 6-minute walking distance (6MWD), in large OSA populations and its correlation with comorbidities.

Purpose of the Study:

• To evaluate exercise capacity using the 6-minute walking distance (6MWD) in a large cohort of patients with obstructive sleep apnea (OSA).
• To investigate the correlations between 6MWD and various patient comorbidities and OSA characteristics.

Main Methods:

• A cluster analysis was performed on data from 1,228 patients diagnosed with OSA.
• Exercise limitation severity was determined using the 6-minute walking distance (6MWD) test.
• Statistical analyses explored correlations between 6MWD and clinical variables, including comorbidities and OSA severity.

Main Results:

• Sixty-one percent of OSA patients exhibited exercise limitation (mild or severe).
• Two patient clusters emerged: CL1 (younger, better exercise tolerance, higher apnea/desaturation/hypertension prevalence) and CL2 (older, with COPD, chronic respiratory failure, severe desaturation, and worse exercise limitation).
• Chronic obstructive pulmonary disease (COPD), chronic respiratory failure (CRF), older age, and OSA severity class I were significantly associated with reduced exercise capacity.

Conclusions:

• A substantial proportion of patients with OSA experience exercise limitation.
• Factors such as older age, comorbidities (COPD, CRF), OSA severity, severe nocturnal desaturation, and daytime hypoxemia are linked to poorer exercise tolerance in OSA patients.