Efficacy of threshold inspiratory muscle trainer versus diaphragmatic plus pursed lip breathing in occupational COPD

Abstract Background Smoking mainly induces COPD, but occupational threats play a significant role in the development of COPD. Previous studies concerning pulmonary rehabilitation mainly focus on COPD caused by smoking, but COPD induced by occupational hazards has not been studied yet. We aimed to identify the efficacy of IMT (Inspiratory Muscle training) using classic POWERbreathe versus DB (Diaphragmatic breathing) plus PLB (Pursed-lip Breathing) exercise in dyspnea, exercise capacity and pulmonary function parameters in occupational COPD farmers with moderate-to-severe COPD (GOLD II–III) FEV1% 30–79%. Methods A prospective supervised RCT (Randomized Controlled Trial) included 60 farmers with COPD assigned randomly into two groups; Group A performed IMT using a classic POWERbreathe, and Group B performed DB plus PLB. Both groups completed two daily sessions for three months, seven days/week. Results Between-group differences outcome scores were compared, and there was a more remarkable significant improvement in exercise capacity, lung parameters, and dyspnea using the mMRC scale in the IMT group compared to DB plus PLB group. The 6MWT distance (effect size Cohen’s d: 1.69), FEV1 (effect size Cohen’s d: 0.78), FEV1/FVC (effect size Cohen’s d: 0.86), FVC (effect size Cohen’s d: 1.01), and mMRC score (effect size Cohen's d: 1.12) were significantly improved in group A ( p < 0.05). Conclusion This study demonstrated that the IMT group showed better exercise capacity, dyspnea, and pulmonary function outcomes in occupational COPD farmers. Further studies require COPD patients from different occupations.