Respiratory strength training for patients with amyotrophic lateral sclerosis: A meta-analysis of randomized controlled trials.

INTRODUCTION

Respiratory strength training (RST) has been considered as a possible add-on treatment for amyotrophic lateral sclerosis (ALS). However, the benefits of RST are still controversial. We performed a meta-analysis of randomized controlled trials (RCTs) on the efficacy of RST in patients with ALS.

METHODS

PubMed, Embase and Cochrane Central were searched for RCTs comparing the use of RST with sham therapy or minimal device load in patients with ALS. The main outcomes were maximal expiratory pressure (MEP), maximal inspiratory pressure (MIP) and the ALS functioning rating scale (ALSFRS-R) score. Statistical analysis was performed using R software and heterogeneity was assessed with I2 statistics.

RESULTS

Four RCTs were included with a total of 138 patients. RST was used to treat 69 (50 %) patients. The mean age was 60.2 ± 10.4 years, with 82 (62.3 %) male patients. Follow-up ranged from 2 to 8 months. Subgroup analysis of expiratory muscle training protocols showed a statistically significant improvement in MEP (MD 20.22 cmH2O; 95 % CI 2.66-37.77; p = 0.04). In overall analyses, there was no difference between groups regarding MEP (MD 9.40 cmH2O; 95 % CI -11.57-30.37; p = 0.25), MIP (MD 3.26 cmH2O; 95 % CI -9.23-15.75; p = 0.38), FVC (MD 4.05 %predicted; 95 % CI -0.91-9.01; p = 0.08) and ALSFRS-R score (MD 0.01 points; 95 % CI -0.29-0.32; p = 0.85).

CONCLUSION

In this meta-analysis of RCTs including patients with ALS, expiratory muscle training was associated with increased MEP compared with sham or minimal load. However, no statistically significant associations were found for overall RST in MIP, FVC, MEP, and ALSFRS-R.