INSPIRATORY MUSCLE TRAINING IN INDIAN SUBJECTS WITH COPD: EFFECT ON RESPIRATORY MUSCLE STRENGTH, FUNCTIONAL EXERCISE CAPACITY AND QUALITY OF LIFE

V.K. Nambiar¹, S. Ravindra¹, S.K. Veluswamy¹

Background: Inspiratory muscle weakness in COPD is of major clinical relevance. Wasting and weakness of inspiratory muscles contributes to reduced maximal inspiratory pressure (MIP) and exercise tolerance. Studies have indicated a relationship between inspiratory muscle weakness with exercise tolerance and quality of life. Exercise interventions forms the mainstay of treatment in COPD but inspiratory muscle training (IMT) is not a part of it despite evidences on its beneficial effects. Within an Indian context, there is limited data on effects IMT in persons with COPD. As part of pulmonary rehab programs, assessment of respiratory muscle strength and training is underutilised.,  

Purpose: We aimed at investigating the effect of inspiratory muscle training (IMT) on MIP, MEP, functional exercise capacity and quality of life in persons with COPD.  

Methods: A randomised controlled interventional study was conducted on 32 male persons with COPD (power of study at 80% and precision level of 5%) who were clinically stable, and having inspiratory muscle weakness (MIP< 60 cm H2O measured using respiratory pressure meter). Participants were randomly allocated to either an inspiratory muscle training (T) group (N=16) or to a standard care (C) group (N=16) by means of an online random sequence generator. Allocation concealment was centrally maintained by an independent investigator. The trial was registered with clinical trial registry of India. Informed consent was taken from all participants of the study. Both groups received supervised exercise training program for 6 weeks and core components included flexibility, aerobic, resistance and neuromuscular training. The treatment group received an adjunct of Inspiratory muscle training (IMT) program for 15 minutes twice a day for 6 weeks. The outcomes like maximal inspiratory pressure (MIP), six-minute walk distance (6MWD) and chronic respiratory questionnaire (CRQ) were measured at baseline and after 6 weeks of the program in both groups.  Statistical analysis was done using SPSS 16.

Results: The mean age and BMI of the participants in both groups was 69 years and 20 kg/m2  respectively.  Within the group and between the group analysis was done using Wilcoxon signed ranks test and Mann Whitney -U test respectively. After six weeks of exercise training there was a significant increase in MIP in cm H2O by 32% as compared to 6% in the control group. The 6 MWD in the training group increased by 222 m as compared to 30 m in the control group. There was an improvement in all domains of CRQ scores such as dyspnoea, emotion and mastery at p<0.001, except fatigue which was significant at p< 0.05   in the training group as compared to the control group. There were no significant improvements seen in MEP values between the groups.  

Conclusion(s): IMT has additional benefits when combined with exercise training program in persons with COPD than exercise training program alone, in terms of MIP, functional exercise capacity (6 MWD) and quality of life (CRQ).

Implications: IMT should be included in pulmonary rehabilitation program and started much early in the course of the disease. Inclusion of inspiratory muscle training in the clinical practice guidelines for management in COPD is warranted.

Funding, acknowledgements: Unfunded

Keywords: Chronic obstructive pulmonary disease, Inspiratory muscle training, Pulmonary rehabilitation

Topic: Cardiorespiratory

Did this work require ethics approval? Yes

Institution: M.S.Ramaiah Medical College,Bangalore,Karnataka,India

Committee: M.S.Ramaiah Medical College and Teaching Hospital Ethical Review Board

Ethics number: MSRMC/ERB/2011