Effects of Inspiratory Muscle Training in Type 2 Diabetes: A Systematic Review

INTRODUCTION: People with type 2 diabetes mellitus present multiple complications and comorbidities, such as peripheral autonomic neuropathies and reduced peripheral force and functional capacity. Inspiratory muscle training is a widely used intervention with numerous benefits for various disorders. The present study aimed to conduct a systematic review to identify inspiratory muscle training effects on functional capacity, autonomic function, and glycemic indexes in patients with type 2 diabetes mellitus. METHODS: A search was carried out by two independent reviewers. It was performed in PubMed®, Cochrane Library, Latin American and Caribbean Literature in Health Sciences (or LILACS), Physiotherapy Evidence Database (PEDro), Embase, Scopus, and Web of Science databases. There were no restrictions of language or time. Randomized clinical trials of type 2 diabetes mellitus with inspiratory muscle training intervention were selected. Studies’ methodological quality was assessed using PEDro scale. RESULTS: We found 5,319 studies, and six were selected for qualitative analysis, which was also conducted by the two reviewers. Methodological quality varied - two studies were classified as high quality, two as moderate quality, and two as low quality. CONCLUSION: It was found that after inspiratory muscle training protocols, there was a reduction in the sympathetic modulation and an increase in functional capacity. The results should be carefully interpreted, as there were divergences in the methodologies adopted, populations, and conclusions between the studies evaluated in this review.