Does obstructive sleep apnea affect aerobic fitness?

Objectives: We sought to determine whether patients with obstructive sleep apnea (OSA) had an objective change in aerobic fitness during cycle ergometry compared to a normal population. The most accurate test of aerobic fitness is measurement of maximum oxygen consumption (V) over dot O2max with cycle ergometry. Methods: We performed a retrospective cohort analysis (247 patients with OSA) of (V) over dot O2max from annual cycle ergometry tests compared to a large control group (normative data from 1.4 million US Air Force tests) in a tertiary care setting. Results: Overall, individuals with OSA had increased (V) over dot O2max when compared to the normalized US Air Force data (p <.001). Patients with an apnea-hypopnea index of greater than 20 demonstrated a decreased (V) over dot O2max as compared to normalized values (p <.001). No differences in (V)over dot O2max were observed after either medical or surgical therapy for OSA. Conclusions: Overall, in a US Air Force population, OSA does not predict a decrease in aerobic fitness as measured by cycle ergometry. However, patients with an apnea-hypopnea index of greater than 20 have a statistically significant decrease in aerobic fitness compared to the normal population. This study demonstrates the effects of OSA on aerobic fitness. Further correlation of fitness testing results with OSA severity and treatment is needed.