Acute Effects of Inspiratory Muscle Training on Peripheral Muscle Metabolism and Autonomic Response in COPD Patients

Acute Effects of Inspiratory Muscle Training With Different Loads on Peripheral Muscle Metabolism and Autonomic Response in COPD Patients: A Randomized Crossover Trial

The study will evaluate the acute effects of inspiratory muscle training (IMT) on peripheral muscle metabolism and autonomic response in patients with chronic obstructive pulmonary disease (COPD). This is a randomized, crossover study, with blinding of the evaluator and the researcher responsible for the statistical analysis. Participants will be divided into three groups at different times: TMI- strength (F), TMI to gain inspiratory muscle strength; IMT- resistance (R), IMT for improving inspiratory muscle resistance; and TMI sham. All participants randomized in the study will participate in the three groups, with a minimum interval of 48 hours between participation in each group. Randomization will determine the sequence of participation in the three groups for all participants.

For statistical analysis, an intention-to-treat approach will be used, and the groups will be compared using the Student's t test for continuous variables or the chi-square test for categorical variables. A split-plot ANOVA with repeated measures will be used for primary outcomes, and analysis of covariance will be conducted to identify differences between groups using baseline scores as covariates. Effect sizes and confidence intervals will be calculated using eta squared.

It is expected that IMT applied at different loads can promote effects on vascular function, peripheral muscle metabolism and the response of the autonomic nervous system in patients with COPD, which can greatly contribute to the understanding of the physiological effects of this therapy and support its prescription. as a therapeutic intervention in the rehabilitation of patients with pulmonary diseases.

Inclusion Criteria:

• Patients with COPD according to the Global Initiative for COPD (GOLD, 2023);
• Aged 40 years or older and under 75 years;
• Providing both oral and written informed consent.

Exclusion Criteria:

• Inability to perform the IMT protocol and/or functional tests;
• Presence of psychiatric disorders or cognitive impairments, progressive neurological disorders, cancer, or chronic pain;
• Cognitive impairment or inability to understand commands.
• Patients who have experienced any health issue or had a COPD exacerbation in the previous month will also be excluded to ensure that the patient's symptoms are stable.