Abstract
Introduction: Patients with obstructive sleep apnea (OSA) have altered cardiovascular and metabolic capacity. However, there are conflicting reports regarding exercise capacity and OSA.
Objective: The aim of the present study was to evaluate the cardiopulmonary exercise test (CPET) in patients with OSA compared to controls, in order to use it for the early identification of OSA in selecting patients at risk for this disorder in the clinical setting.
Methods: Forty-one, comorbidity-free, subjects underwent polysomnography and allocated into two groups [OSA: n=21 (n=7 with AHI=15-30 h-1, n=14 with ΑΗΙ>30 h-1), ΒΜΙ:31.7±4.7; Control: n=20, AHI<5 h-1, BMI: 29.4±2.6]. Subsequently CPET was performed until exhaustion. Univariate analysis included independent samples t-test was performed. Stepwise discriminant function analysis was applied and a predictive model was provided to discriminate the two groups.
Results: Independent samples t-test showed statistically significant differences between groups (OSA vs. Control) regarding VO2peak (p=0.03), time of exercise (p=0.02) and VE/MVV (p=0.07). Incorporating univariate predictors in a discriminant model produced a function which significantly differentiated controls from OSA patients [Wilks' λ=0.684, χ2=14.429, p<0.001]. Overall predictive accuracy was 78%.
Conclusions: Our preliminary data show that OSA is associated with impaired exercise capacity but more trials are needed to establish the utility of CPET as a potential predictive tool of OSA.
- Copyright ©ERS 2015