Dose and time-response effect of photobiomodulation therapy on glycemic control in type 2 diabetic patients combined or not with hypoglycemic medicine: A randomized, crossover, double-blind, sham-controlled trial.

Photobiomodulation therapy (PBMt) combined or not with oral hypoglycemic medication has not been investigated in type 2 diabetes (T2DM) patients. All 10 T2DM patients were assessed randomly at 6 different occasions (3 with and 3 without regular oral hypoglycemic medication). Capillary glycemia was assessed after overnight fast (pre-prandial), 1 h postprandially (standardized meal, 338 kcal), and 30 min, 3 h, 6 h, 12 h post-PBMt (830 nm; 25 arrays of LEDs, 80 mW/array). Three doses (0 J-sham, 100 J, 240 J per site) were applied bilaterally on quadriceps femoris muscles, hamstrings, triceps surae, ventral upper arm and forearm; and randomly combined or not with oral hypoglicemic medication, totaling six different therapies applied for all 10 TDM2 patients (PBMt sham, PBMt 100 J, PBMt 240 J, PBMt sham + medication, PBMt 100 J + medication, PBMt 240 J + medication). Cardiac autonomic control was assessed by heart rate variability (HRV) indices. Without medication, there was reduction in glycemia after all PBMt doses, with 100 J as the best dose that persisted until 12 h and presented lower area under the curve (AUC). With medication, glycemia decreased similarly among doses. No differences between 100 J and sham + medication, but AUC was significantly lower after 100 J, suggesting better glycemic control. Low frequency component of HRV increased after sham + medication and 100 J, suggesting higher sympathetic activation. PBMt showed time- and dose-response effect to reduce glycemia in T2DM patients. Effects on HRV were consistent with glycemic control.

Acute effects of photobiomodulation therapy applied to respiratory muscles of chronic obstructive pulmonary disease patients: a double-blind, randomized, placebo-controlled crossover trial.

To investigate the effects of photobiomodulation applied to respiratory muscles on lung function, thoracoabdominal mobility, respiratory muscle strength, and functional capacity in COPD patients. This is a randomized double-blind crossover clinical trial. Twelve male COPD patients participated in the study. Participants were randomly allocated to receive two photobiomodulation sessions, 1 week apart: (1) an effective photobiomodulation session applied at the main respiratory muscles by means of a cluster with 69 light-emitting diodes (LEDs), containing 35 red (630 ± 10 nm; 10 mW; 0.2 cm2) and 34 near-infrared (830 ± 20 nm; 10 mW; 0.2 cm2) LEDs and (2) a sham photobiomodulation session, following the same procedures without emitting light. The primary outcomes were pulmonary function (spirometric indexes); thoracoabdominal mobility (cirtometry); respiratory muscle strength (maximal respiratory pressures), assessed at three moments: (1) baseline, (2) 1 h after intervention, and (3) 24 h after intervention; and the functional capacity, assessed by the 6-min walk test (6MWT) at baseline and 24 h after intervention. No significant interactions were found for spirometric variables, maximal respiratory pressures, and cirtometry. However, there was a Time × Condition interaction (F = 18.63; p = 0.001; η2p = 0.62) in the walked distance on the 6MWT, with a significant increase after photobiomodulation intervention (p < 0.01) compared with the baseline. Photobiomodulation applied to respiratory muscles was effective in improving acute functional capacity in COPD patients. To the best of our knowledge, this is the first study assessing the effects of photobiomodulation applied to respiratory muscles in patients with COPD.