The Comparison of Inspiratory Muscle Training Effectiveness in COPD Patients with Obesity and Normal Weight

Abstract

The objective of this study was to compare the effectiveness of inspiratory muscle training in COPD patients with obesity and patients with normal body weight. Materials and Methods: The study involved 2 groups of patients with COPD (clinical Group D) similar in spirometric parameters with signs of airflow limitation on spirometry (FEV 1 <50% of predicted, a post-bronchodilator FEV 1 /FVC ratio<70% of predicted). Group 1 consisted of 45 obese COPD patients (BMI>30 kg/m 2). Group 2 included 44 COPD patients with normal body weight (BMI from 18.5 kg/m 2 to 24.9 kg/m 2). The groups were comparable in age, gender, severity of bronchial obstruction, concomitant pathology, and drug therapy. All patients underwent IMT for 8 weeks. Breathe-Link Live Feedback Software was used to evaluate such parameter as SI (Strength Index), PIF (Peak Inspiratory Flow), Average Pressure, Average Power, Average Flow, Average Volume for the entire sessions were estimated. At the baseline and after 8 weeks all patients underwent an assessment of the lung function using spirometry (including FVC, FEV 1), and the severity of dyspnea using the mMRC questionnaire (The Modified Medical Research Council). Results: A comparative analysis of the estimated parameters of training sessions showed a significant increase in SI, PIF, Average Power, and Average Flow in patients of Group 1. In patients of Group 2, we found only a tendency to be increased in these parameters, with the exception of Average Flow. A statistically significant increase in the FEV 1 and FVC parameters was observed only in Group 1. Statistical analysis showed a close correlation between the SI and the severity of dyspnea on the mMRC scale (r=-0.52, P<0.05) in Group 1. Conclusion: The results of our study indicate a positive effect of IMT in patients with COPD, and a greater effect in patients with obesity than in those with normal body weight. Clinically, an improvement in the IMT parameters was expressed in a decrease in dyspnea and an improvement in spirometric indicators.