The effects of untreated OSA on cardiopulmonary function remain unclear. Cardiorespiratory fitness (CRF), commonly reflected by VO₂ max measured during cardiopulmonary exercise testing (CPET), has gained popularity in evaluating numerous cardiopulmonary conditions and may provide a novel means of identifying OSA patients with the most clinically significant disease. This emerging testing modality provides simultaneous assessment of respiratory and cardiovascular function with results helping uncover evidence of evolving pathology in either organ system. In this review, we highlight the current state of the literature in regards to OSA and CRF with a specific focus on changes in cardiovascular function that have been previously noted. While OSA does not appear to limit respiratory function during exercise, studies seem to suggest an abnormal cardiovascular exercise response in this population including decreased cardiac output, a blunted heart rate response (i.e., chronotropic incompetence) and exaggerated blood pressure response. Surprisingly, despite these observed changes in the cardiovascular response to exercise, results involving VO₂ max in OSA remain inconclusive. This is reflected by VO₂ max studies involving middle-aged OSA patients showing both normal and reduced CRF. As prior studies have not extensively characterized oxygen desaturation burden, we propose that reductions in VO₂ max may exist in OSA patients with only the most significant disease (as reflected by nocturnal hypoxia). Further characterizing this relationship remains important as some research suggests that positive airway pressure (PAP) therapy or aerobic exercise may improve CRF in patients with OSA. In conclusion, while it likely that severe OSA, via an abnormal cardiovascular response to exercise, is associated with decreased CRF; further study is clearly warranted to include determining if OSA with decreased CRF is associated with increased morbidity or mortality.

未经治疗的 OSA 对心肺功能的影响仍不清楚。心肺适能 (CRF)，通常由 VO _2反映在心肺运动试验 (CPET) 期间测得的最大值在评估多种心肺疾病方面已广受欢迎，并可能提供一种新的方法来识别患有临床上最重要疾病的 OSA 患者。这种新兴的测试方式可同时评估呼吸和心血管功能，其结果有助于揭示任一器官系统病理演变的证据。在这篇综述中，我们重点介绍了关于 OSA 和 CRF 的文献现状，特别关注先前提到的心血管功能的变化。虽然 OSA 似乎不会限制运动期间的呼吸功能，但研究似乎表明该人群的心血管运动反应异常，包括心输出量减少、心率反应迟钝（即，变时性无能）和夸大的血压反应。令人惊讶的是，尽管观察到心血管对运动的反应发生了这些变化，但涉及 VO2 的结果_{OSA 中的2} max 仍然没有定论。涉及中年 OSA 患者的 VO ₂ max 研究反映了这一点，这些研究显示 CRF 正常和降低。由于之前的研究没有广泛描述氧饱和度下降的特征，我们建议减少 VO ₂max 可能存在于只有最严重疾病的 OSA 患者中（如夜间缺氧所反映的）。进一步表征这种关系仍然很重要，因为一些研究表明气道正压通气 (PAP) 治疗或有氧运动可能会改善 OSA 患者的 CRF。总之，虽然严重的 OSA 可能通过对运动的异常心血管反应与 CRF 降低相关；进一步的研究显然是必要的，包括确定 CRF 降低的 OSA 是否与发病率或死亡率增加有关。