Effect of inspiratory muscle training on exercise performance and quality of life in patients with chronic obstructive pulmonary disease

BackgroundChronic obstructive pulmonary disease (COPD) is associated with skeletal muscle dysfunction. This study aimed to evaluate effectiveness of inspiratory muscle training (IMT) as a part of exercise training in COPD patients.MethodsSixty male patients were assigned to 3 groups; twenty in each group. In addition to medical treatment given for all patients; patients in group A received peripheral muscles exercise training plus IMT at an intensity that increased from 30% to 60% of their maximal inspiratory pressure (PImax). Patients in group B received peripheral muscle exercise training alone, and in group C; they received no training. All patients underwent clinical evaluation, chest X-ray, electrocardiogram, body mass index, and spirometry. Outcome measures in the form of respiratory muscle strength [PImax, maximal expiratory pressure (PEmax)], dyspnea, exercise performance (six minutes walk test) and quality of life [BODE index and St. George’s Respiratory questionnaire for COPD patients (SGRQ-C)] were carried out at study entry, after 4 and 8 weeks.ResultsIMT plus peripheral muscle exercise training led to a significant improvement in PImax, PEmax, and 6-min walking distance (6MWD) compared to peripheral muscle exercise training alone. Both IMT plus peripheral muscle exercise training and peripheral muscle exercise training alone improved dyspnea, BODE index and SGRQ-C without significant differences between 2 groups.ConclusionFor PImax, PEmax, and 6MWD; IMT provides additional benefits to peripheral muscle exercise training in COPD patients. However, this did not translate into additional improvement in dyspnea and quality of life compared with what is achieved by peripheral muscle exercise alone.