Cardiopulmonary Exercise Testing for Patients With Neuromuscular Disease and Limited Mobility

Background Patients with neuromuscular disease (NMD) have progressive muscle weakness and limited mobility that contributes to a sedentary lifestyle. A sedentary lifestyle often leads to deconditioning and decreases cardiorespiratory fitness (CRF). Cardiopulmonary exercise testing (CPX) is the gold standard for the evaluation of CRF but has not been widely applied in patients with NMD. Methods Patients with NMD were recruited from the Neuromuscular Clinic at the Stanford Neurosciences Health Center at Stanford University. Matched controls were recruited by staff from the local community by word of mouth. All participants performed CPX using a wheelchair-accessible total body trainer and a wearable metabolic cart system to volitional exhaustion. Results Participants with NMD and limited mobility (n = 37) were able to perform high-quality CPX with no adverse events or safety concerns of comparable quality to controls. Average respiratory exchange ratio for NMD patients was 1.08 ± 0.16, and average rating of perceived exertion was 18 ± 2 compared with 1.16 ± 0.12 and 18 ± 2 for controls, respectively ( P = 0.17 and P = 0.78, respectively). Patients with NMD on average showed markedly reduced percent predicted VO 2 max and impaired ventilatory efficiency. Conclusion High-quality CPX in patients with NMD may reveal distinct physiological profiles that may lead to a better understanding of pathology in these individuals. CPX on total body trainers may be a viable method for improving exercise prescription for patients with NMD.