Evaluation of acute effect of light-emitting diode (LED) phototherapy on muscle deoxygenation and pulmonary oxygen uptake kinetics in patients with diabetes mellitus: study protocol for a randomized controlled trial

Effect of Modified Laser Transcutaneous Irradiation on Pain and Quality of Life in Patients with Diabetic Neuropathy

Background: Diabetic neuropathy (DN) is one of the major complications developed by individuals with diabetes mellitus. DN is responsible for a high morbidity and mortality rate and impacts the public health and medical assistance resources. Intradermic laser irradiation on blood (ILIB) consists of the application of light beams on the radial arterial, providing anti-inflammatory and vasodilator effects, antiarrhythmic action, reduction of glucose, and stabilization of the hormonal and immunological systems. These effects help to maintain the physiological dynamics of the body. Objective: The goal of this research was to evaluate the effects of ILIB to relieve pain and improve the quality of life in DN patients. The sample comprised 30 diabetic volunteers with DN, randomly distributed into 3 groups: Control-conventional treatment; ILIB-100 mW, 660 ± 10 nm, 30 applications in total, divided into 3 stages of 10 applications, 30 min each, daily, with a 20-day interval between each stage; SILIB-same protocol described for ILIB, with the equipment switched off. Before and after the application of the therapeutic protocols, all volunteers were evaluated by the following instruments: Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), visual analog scale, Leeds Assessment of Neuropathic Symptoms and Signs (LANSS), and PAIN DETECT scale. Collected data were statistically analyzed with a 95% confidence interval, p < 0.05. Results: The ILIB group presented significantly lower pain levels and a better quality of life compared with the control and SILIB groups. Conclusions: This study demonstrated that ILIB therapy was effective in reducing pain and improving quality of life in patients with DN.

Photobiomodulation effect on local hemoglobin concentration assessed by near-infrared spectroscopy in humans

Exposure of biological tissue to photobiomodulation therapy (PBMT) seems to increase the oxygen availability and mitochondrial electrochemical activity. With the advancement of new technologies, such as near-infrared spectroscopy (NIRS), information can be obtained about the balance between oxygen utilization and delivery by assessing local oxy- ([O₂Hb]) and deoxy-myohemoglobin ([HHb]) concentrations, both measured in micromolars (μM). Consequently, NIRS can be used to study ("in vivo") PBMT effects on the oxidative system, including oxygen availability. Thus, the main objective of the present study was to use NIRS to investigate the acute effects of PBMT by light-emitting diode (LED) on the oxygen delivery and utilization in humans. Twelve healthy young participants were treated with a LED device (850 nm, 50 mW, 2 J) and placebo applied over the proximal third of the flexor carpi ulnaris muscle of the left or right forearm selected in a random order. The LED was applied in direct contact with skin and the device was switched on for 40 s in 4 different interventions (I₁, I₂, I₃ and I₄) with a 3-min interval between interventions. The placebo condition was considered as the period before the first PBMT. The NIRS device was used to evaluate the relative changes in [O₂Hb] and [HHb] before and after placebo and interventions. We found that PBMT statistically increased the [O₂Hb] in 0.39 μM. These results demonstrate the potential of PBMT to increase oxygen availability.

Efficacy of phototherapy to treat facial ageing when using a red versus an amber LED: a protocol for a randomised controlled trial

INTRODUCTION

The skin undergoes morphological and physiological changes with the advancing age of an individual. These changes may be caused by intrinsic and extrinsic factors that contribute to cellular ageing and consequent skin ageing. The term photoageing is used to characterise the ageing of the skin caused by solar radiation. Clinically, the skin becomes more flaccid, thicker and hyperpigmented, while there is an early appearance of wrinkles and other skin changes, such as skin cancer. Nowadays, there are numerous treatments for ageing skin, and one of them is with the use of phototherapy, which uses light-emitting diodes (LEDs). The objective of this study will be to evaluate the percentages of reduction in the volume of periocular wrinkles when treated with red and amber LEDs.

METHODS AND ANALYSIS

All of the participants will receive photobiomodulation to treat their periocular wrinkles. They will be using red and amber LEDs, with one colour being used on each hemiface. The facial side to be treated with each colour will be randomised. After an interval of 180 days, the participants will receive a cross-treatment. The primary variable of the study is the volume of periocular wrinkles (crow's feet), which will be measured by a VisioFace equipment. The secondary variables are elasticity (measured by Cutometer) and hydration (measured by Corneometer). Quality of life and self-assessment of the participants will be measured using the adapted Melasma Quality of Life scale - Brazilian Portuguese adaption (MelasQoL-BP) and Skindex-29 questionnaires. All of the variables will be measured before and after a group of 10 sessions.

ETHICS AND DISSEMINATION

This protocol was approved by the Research Ethics Committee of the Nove de Julho University (acceptance number: 2.550.732). This trial has been registered in the Registro Brasileiro de Ensaios Clínicos (Brazilian Clinical Trials Registry) (REBEC number: RBR-6YFCBM). This study is not recruiting yet.

TRIAL REGISTRATION NUMBER

RBR6YFCBM; Pre-results.

Associations Between Heart Rate Recovery Dynamics With Estradiol Levels in 20 to 60 Year-Old Sedentary Women

It is hypothesized that estradiol levels, as well as aging, influence cardiac autonomic function in women. The main aim of this study was to test the correlations between heart rate recovery (HRR) dynamics, as a proxy of cardiac autonomic function, with estradiol levels and age in women. This cross-sectional study involved 44 healthy women. Heart rate (HR) data were obtained beat-by-beat during the entire experiment. Maximal incremental exercise testing (IET) on a cycle ergometer was performed followed by 6 min of recovery. During the IET recovery period, the overall HRR dynamics were evaluated by exponential data modeling (time constant "τ") where shorter τ indicates faster HRR adjustment. Considering the cardiac autonomic complexity, HRR dynamics were also evaluated by delta (Δ) analysis considering different HR data intervals. The relationship between HRR dynamics, estradiol levels and age was tested by Pearson product-moment correlation. The overall HRR dynamics (i.e., τ) were statistically correlated with age (r = 0.58, p < 0.001) and estradiol levels (r = -0.37, p = 0.01). The Δ analysis showed that the slower overall HRR associated with aging was a consequence of slower dynamics occurring within the 45-210 s interval, indicating slower sympathetic withdrawal. In conclusion, aging effects on HRR in women seems to be correlated with a slower sympathetic withdrawal. In addition, the cardioprotective effect previously associated with estradiol seems not to influence the autonomic modulation during exercise recovery periods in women.