Abstract
STUDY OBJECTIVES: Studies of older and less active patients with obstructive sleep apnea (OSA) have reported decreased exercise capacity as measured by peak oxygen uptake (VO(2) max) during cardiopulmonary exercise testing (CPET). We looked to determine whether VO(2) max was decreased in younger patients with OSA who regularly exercise as would be encountered in the military. METHODS: We evaluated military personnel who had undergone pulmonary function testing (PFT), CPET, and polysomnography (PSG) as part of the larger STAMPEDE III study for comprehensive evaluation of exertional dyspnea. For analysis, patients were classified into two groups, the OSA group with an apnea-hypopnea index (AHI) ≥ 15 events/h and a control group with an AHI < 15 events/h. RESULTS: Mean AHI was 32.7 in the OSA group (n = 40) versus 5.8 in the control group (n = 58) with no significant difference in age (40.7 years versus 39.4 years) or body mass index (30.4 kg/m(2) versus 29.9 kg/m(2)). PFT was normal in both groups including diffusing capacity (100.7% versus 96.5%) and FEV(1) (89.2% versus 86.2%). VO(2) max was not significantly different in the OSA group compared to the control group (101.3% versus 102.8%; P = .60) with both groups having normal exercise capacity. Exercise blood pressure response was normal and peak heart rate trended toward a blunted response in the OSA group (166.0 bpm versus 171.6 bpm, P = .09). CONCLUSIONS: Younger military personnel with moderate to severe OSA do not have decreased exercise capacity. The effect of OSA on exercise tolerance may be influenced by additional factors and is likely too small to be noted in this population. COMMENTARY: A commentary on this article appears in this issue on page 819.