Cardiovascular capacity in adults with obstructive sleep apnoea

Area of Science:

• Cardiology
• Sleep Medicine
• Exercise Physiology

Background:

• Obstructive sleep apnoea (OSA) is linked to decreased exercise capacity.
• Potential cardiovascular capacity in OSA patients of varying severity, without pre-existing cardiovascular disease, remains underexplored.

Purpose of the Study:

• To assess impaired exercise cardiovascular capacity in OSA patients using cardiopulmonary exercise testing (CPET).
• To compare cardiovascular performance responses across different OSA severity levels during graded exercise.

Main Methods:

• Cardiopulmonary exercise testing (CPET) was performed on participants without known cardiovascular disease.
• Comparison of exercise parameters between non-OSA subjects and OSA patients with varying severity.

Main Results:

• OSA patients showed lower peak oxygen uptake (VO₂), heart rate (HR), heart rate recovery (HRR), and respiratory reserve (BR) compared to controls.
• Higher peak exercise diastolic blood pressure (DBP) and ventilatory equivalent for CO₂ (EQCO₂) were observed in OSA patients.
• Significant correlations were found between OSA severity (apnea-hypopnea index) and VO₂, DBP, EQCO₂, HRR, and BR.
• Severe OSA demonstrated more pronounced differences in HR and HRR during anaerobic threshold stages.

Conclusions:

• OSA patients, even without diagnosed cardiovascular disease, have reduced potential cardiovascular capacity.
• Severe OSA leads to impaired exercise capacity at earlier exercise stages.
• OSA patients exhibit exaggerated hemodynamic responses to exercise and delayed cardiovascular recovery post-exercise.
• CPET can serve as a valuable tool for assessing OSA severity.