Respiratory Muscle Strength and Aerobic Performance Among Chronic Obstructive Pulmonary Disease (COPD) Patients: A Correlational Study.

Background Chronic obstructive pulmonary disease (COPD) is a heterogeneous lung condition, yielding various respiratory symptoms and categorized under several descriptors: early, mild, young, pre-COPD, and preserved ratio impaired spirometry. COPD is synonymous with symptoms such as dyspnea and cough, in addition to others like exercise intolerance, which result from respiratory muscle weakness. Therefore, the emergence of respiratory strength assessment tools for such patients is not surprising. However, evidence is limited regarding the impact of respiratory muscle strength on the physical performance of COPD patients. Therefore, this study employs the MicroRPM device (Medikart HealthCare Systems Pvt. Ltd., Delhi, India) to measure maximum inspiratory and expiratory pressure utilizing mouth pressure. Methodology We recruited a total of 40 patients for the study. All patients received a thorough assessment for hemodynamic stability and were categorized according to the Global Initiative for Chronic Obstructive Lung Disease criteria of COPD. The patients then underwent a training session for the MicroRPM device. We took each patient's inspiratory and expiratory pressure measurements, then determined their six-minute walk distance and modified the Borg scale rating. Results We observed no significant correlation between maximum inspiratory pressure (Pimax) and six-minute walk distance (r=-0.023, p=0.890) or modified Borg scale (r=-0.044, p=0.788); additionally, the correlation between maximum expiratory pressure (Pemax) and modified Borg scale was not significant (r=-0.192, p=0.235). However, the correlation between Pemax and six-minute walk distance was both negative and significant (r=-0.384, p=0.014). Conclusion Based on our results, respiratory muscle strength can influence the aerobic performance of COPD patients.