Efeitos agudos da fotobiomodulação sobre variáveis respiratórias e a capacidade funcional em tabagistas e ex-tabagistas: ensaio clínico randomizado, triplo-cego e placebo controlado

Abstract

Introduction: Smoking, in addition to affecting the functionality of the respiratory muscles, can increase resistance to airflow and reduce the individual's functional capacity, impairing their quality of life. Photobiomodulation (FBM) has gained prominence for being an effective resource in promoting the improvement of muscle performance in athletes and in the face of some diseases. However, studies on the acute effects of FBM on respiratory variables and functional capacity in smokers and ex-smokers are scarce in the literature. Objectives: To evaluate the acute effects of FBM applied to respiratory muscles, on lung function and respiratory muscle strength. Material and methods: A randomized, crossover, triple blind and placebo-controlled clinical trial was conducted. 16 volunteers participated in the study, 10 smokers and 06 ex-smokers. All volunteers were randomly subjected to two intervention sessions: 1) an effective FBM session applied to the region of the main respiratory muscles through a cluster of 69 LEDs (light-emitting diodes) with a total power of 690 mW and energy total of 62 Joules, containing 35 LEDs in the red range (630 ± 10 nm; 10 mW; 0.2 cm2; 31.5 J) and 34 LEDs in the infrared range (830 ± 20 nm; 10 mW; 0.2 cm2; 30.6 J); irradiation time in each treatment region was 90 seconds. 2) a placebo FBM session, in which the same procedures as the effective session were followed, but the equipment did not emit light. All volunteers were assessed at 3 times: 1) pre intervention, 2) 1 hour after the intervention and 3) 24 hours after the intervention. A one-week washout was performed between the FBM and placebo sessions. All volunteers underwent pulmonary function assessment using spirometry, thoracoabdominal mobility using axillary, xiphoid and abdominal levels. In the post intervention moments, functional capacity was also assessed using the 6-minute walk test. For data analysis, a 5% significance level was adopted. Results: There were no significant differences for any of the variables of spirometric outcome, cirtometry and 6MWT minutes (p> 0.05) in the comparison between groups. Conclusion: the main results of this study showed that a single FBM session with the parameters used, applied to the respiratory muscles was not effective in improving lung function, respiratory muscle strength, thoracoabdominal mobility and functional capacity in smokers and ex-smokers.