Photobiomodulation: systematic review and meta-analysis of the most used parameters in the resolution diabetic foot ulcers

Effects and parameterization of low-level laser therapy in diabetic ulcers: an umbrella review of systematic reviews and meta-umbrella

This study aimed to systematically verify the available systematic reviews and meta-analyses of Low-level laser therapy (LLLT) in diabetic foot ulcer (DFUs) to identify the effects and optimal parameters of LLLT in the management of DFUs. This umbrella review was written according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) report items and registered in the International Prospective Register of Systematic Review (PROSPERO). The search for articles was performed in the Pubmed, Scopus, Web of Science and Embase databases. The following terms were used: Diabetic Foot, Diabetic Neuropathies, Peripheral Vascular Diseases, Peripheral Neuropathy, Diabetic Foot Ulcer, LASER Therapy, Low-Level Light Therapy, LLLT, LASER Biostimulation, Low Intensity LASER Irradiation, Low Power LASER Irradiation, Low Intensity LASER Therapy, Low Power LASER Therapy. A search was performed in the references section of the included studies. The systematic review (SR) included studies that compared LLLT with non-therapeutic doses (parameters considered low to modify healing), sham irradiation, and conventional DFU treatment. The interventions were performed using red and infrared wavelengths. Although two studies included in the SR used wavelengths below 600 nm, these were combined with diodes with infrared wavelengths within the same device. Another study performed a comparative analysis of LLLT at different wavelengths (632 nm and 904 nm), with area reduction rates of 63.7% and 56.8%, respectively, with no statistically significant difference. This is study indicated that, compared with standard treatment and non-irradiation treatments, the use of photobiomodulation (PBM) with different parameters was effective in promoting UPD healing. Further studies are warranted to determine the ideal parameters for improving patient outcomes. (International Prospective Register of Systematic Review Registration number: CRD42022362447).

Effect of photobiomodulation as preventive treatment of diabetic foot ulcer: randomised, controlled, double-blind, clinical trial protocol

INTRODUCTION

The prevention of diabetic foot ulcer (DFU) involves the classification of risk, systemic care, regular examinations, foot care, therapeutic education and adjunct treatments. Photobiomodulation (PBM) has been successfully administered for the healing of DFU and its preventive effects have drawn the interest of researchers.

METHODS AND ANALYSIS

The purpose of the study is to assess the effect of PBM for the prevention of DFU through a randomised, controlled, double-blind, clinical trial. Individuals from 18 to 75 years of age of both sexes with type 2 diabetes mellitus (DM) at moderate to high risk of developing DFU will be randomly allocated to two groups of 32 participants each. The PBM group will wear a boot with 1344 light-emitting diodes (LEDs)-504 with a wavelength of 660 nm located on the sides of the boot (28.5 mW, 10 J per LED), 504 with a wavelength of 850 nm also on the sides of the boot (23 mW, 8 J per LED), 168 with a wavelength of 660 nm on the base of the boot (28.5 mW, 10 J per LED) and 168 with a wavelength of 850 nm also on the base of the boot (23 mW, 8 J per LED). The boot will be worn once a day for 6 min over 60 days and the participants will also receive therapeutic education. The control group will wear a non-therapeutic LED boot (sham) under the same conditions and will also receive therapeutic education. Assessments will be performed at the beginning of the study, after 30 days (clinical examination) and after 60 days (clinical examination, assessment of peripheral neuropathy (PN) and peripheral artery disease (PAD), blood and urine examinations and quality of life).

ETHICS AND DISSEMINATION

This protocol received approval from the Human Research Ethics Committee of Nove de Julho University and the Mandaqui Hospital Complex (certificate number: 66098522.0.3001.5511; final approval date: 22 June 2023). The findings will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT06353568, ClinicalTrials.gov.

Inflammatory markers, oxidative stress, and mitochondrial dynamics: Repercussions on coronary artery disease in diabetes

Inflammatory markers and mediators that affect the development of car-diovascular diseases have been the focus of recent scientific work. Thus, the purpose of this editorial is to promote a critical debate about the article titled "Nε-carboxymethyl-lysine and inflammatory cytokines, markers, and mediators of coronary artery disease progression in diabetes", published in the World Journal of Diabetes in 2024. This work directs us to reflect on the role of advanced glycation end products, which are pro-inflammatory products arising from the metabolism of fatty acids and sugars whose main marker in tissues is Nε-carboxymethyl-lysine (NML). Recent studies have linked high levels of pro-inflammatory agents with the development of coronary artery disease (CAD), especially tumor necrosis factor alpha, interleukins, and C-reactive protein. These inflammatory agents increase the production of reactive oxygen species (ROS), of which people with diabetes are known to have an increased production. The increase in ROS promotes lipid peroxidation, which causes damage to myocytes, promoting myocardial damage. Furthermore, oxidative stress induces the binding of NML to its receptor RAGE, which in turn activates the nuclear factor-kB, and conse-quently, inflammatory cytokines. These inflammatory cytokines induce endo-thelial dysfunction, with increased expression of adhesion molecules, changes in endothelial permeability and changes in the expression of nitric oxide. In this sense, the therapeutic use of monoclonal antibodies (inflammatory reducers such as statins and sodium-glucose transport inhibitors) has demonstrated positive results in the regression of atherogenic plaques and consequently CAD. On the other hand, many studies have demonstrated a relationship between mito-chondrial dynamics, diabetes, and cardiovascular diseases. This link occurs since ROS have their origin in the imbalance in glucose metabolism that occurs in the mitochondrial matrix, and this imbalance can have its origin in inadequate diet as well as some pathologies. Photobiomodulation (PBM) has recently been considered a possible therapeutic agent for cardiovascular diseases due to its effects on mitochondrial dynamics and oxidative stress. In this sense, therapies such as PBM that act on pro-inflammatory mediators and mitochondrial modulation could benefit those with cardiovascular diseases.

The validity and safety of multispectral light emitting diode (LED) treatment on grade 2 pressure ulcer: Double-blinded, randomized controlled clinical trial

PURPOSE

The management of pressure ulcers (PUs) poses challenges due to their chronic nature and the lack of established conservative treatment methods. In this clinical trial, our objective was to examine the validity and safety of using a light-emitting diode device contained four wavelengths in the treatment of grade 2 sacral PUs.

METHOD

A total of 38 patients were randomly assigned to two groups: sham device (Sham) and experimental device (LED) group. The treatment sessions were conducted over a period of four weeks, with a frequency of three times per week. The study was conducted in a double-blinded manner. The study assessed the primary validity by measuring wound size and re-epithelialization after 0 and 4 weeks. Secondary evaluations included epidermal regeneration, collagen density, and immunological markers. Safety was evaluated by monitoring adverse reactions throughout the trial.

RESULT

The presence of eschar was found to have a significant impact on wound healing. Sham consisted of 15 wounds without eschar, while LED had nine. After treatment in without eschar situation, the post-treatment size of wounds in Sham was 13.80 ± 20.29%, while it was 3.52 ± 6.68% in LED. However, there was no significant difference (p = 0.070). And analysis of epidermal thickness showed a significant increase in LED (495.62 ± 327.09 μm) compared to Sham (195.36 ± 263.04 μm) (p < 0.0001).

CONCLUSION

While LED treatment had a potential for wound reduction in PUs without eschar, we could not uncover evidence to support the efficacy of LED treatment in grade 2 PUs.

Diabetic foot wound ulcer management by laser therapy: A meta-analysis

A meta-analysis examination was implemented to review diabetic foot wound ulcer (DFWU) management by laser therapy (LT). A broad literature examination until May 2023 was done and 1357 interconnected examinations were revised. The 26 elected examinations, enclosed 1067 personals with DFWU were in the utilized examinations 'starting point, 540 of them were utilizing LT, and 527 were utilizing control. Odds ratio (OR) and 95% confidence intervals (CIs) were utilized to appraise the DFWUs management by LT by the dichotomous and continuous approach and a fixed or random model. LT had significantly higher ulcer size decreases (MD, 17.04; 95% CI, 12.48-21.59, p < 0.001) with high heterogeneity (I2  = 99%), and complete healing rate (OR, 2.88; 95% CI, 1.89-4.37, p < 0.001) with no heterogeneity (I2  = 0%) compared with control in personals with DFWU. LT had significantly higher ulcer size decreases, and complete healing rate compared to control in personals with DFWU. Nevertheless, exercise caution while interacting with its values since all the chosen examinations were found with a low sample size for the comparisons in the meta-analysis.

Bibliometric Analysis to Global Research Status Quo on Photobiomodulation

Background: Photobiomodulation (PBM) becomes a remedial technology with growing popularity. The primary goal of this article is to conduct a PBM literature review, providing an overall systematic understanding of current and future trends. Methods: A dataset was made with topic retrieval, concerning PBM research retrieved from the Web of Science Core Collection. We analyzed to forecast research frontiers in this field using the softwares: VOSviewer, CiteSpace, and Biblioshiny. Results: Four thousand five hundred thirty pieces of literature were retrieved from our database. Current trends were characterized by keywords of "light," "spinal cord injury," "skeletal muscle," and so on. Future trends were characterized probably by six cutting-edge terms: "wound healing," "pain," "oral mucositis," "Alzheimer's disease," "Parkinson's disease," and "orthodontics." Conclusions: This study finds that the inadequacy of in-depth reliable interpretation of current clinical data calls for molecular biological mechanisms together with well-designed, large-sample, multicenter clinical trials. The study of oral, wound, and neural-related mechanisms and the exploration of therapeutic effects may be the popular trend at present and in the next few years.

Photobiomodulation therapy on skeletal muscles exposed to diabetes mellitus: a systematic review of animal studies

Diabetes-related muscle damage has been overlooked despite its known association with increased morbidity and mortality in DM individuals. PBMT is a recognized alternative to improve skeletal muscle health in other populations, but its effectiveness in DM is still unclear. To address this issue, we reviewed preclinical studies, available in any language and period, in ten sources of information. The methods were previously registered at PROSPERO (CRD42021271041), based on PRISMA recommendations. Studies in murine models of T1DM or T2DM that reported quantitative analyses of skeletal muscles treated with low-level light therapy could be included after a blind selection process. Most of the seven included studies focus on decompensated T1DM rats with acute muscle injury (cryoinjury or contusion). In these five studies, PBMT improved muscle regeneration, by reducing inflammation and stimulating factors pro-angiogenesis and pro-myogenesis. Some positive effects could also be observed in two studies on muscles without acute injury: control of oxidative stress (T1DM) and reduction of myosteatosis (T2DM). Although infrared laser applied locally appears to be a promising approach, optimal parameters are undefined due to the heterogeneity of outcomes and high risk of bias, which prevented a quantitative synthesis. Several aspects of this growing field have yet to be investigated, particularly regarding the DM model (e.g., aged animals, T2DM), intervention (e.g., comparison with LED), and outcomes (e.g., muscle mass, strength, and function). Future research should aim to improve the internal validity by following guidelines for animal studies and enhance the translatability to clinical trials by using animal models that closely mimic patients with DM in rehabilitation settings.

EFEITOS DO LED AZUL NA CICATRIZAÇÃO DE ÚLCERA VENOSA EM DIABÉTICOS

Úlceras em pacientes com Diabetes Mellitus são frequentes e consideradas uma das complicações de maior relevância durante a evolução clínica da doença. Analisar a aplicação do light-emitting diode (LED) azul no reparo tecidual de úlcera venosa de membro inferior. Consistiu na aplicação de LED azul, com comprimento de onda em torno de 680 THz e 620 THz no local da ferida, durante 10 minutos, 2 vezes por semana, durante 5 semanas. Foram utilizados instrumentos avaliativos de dor e sintomas neuropáticos, testes de sensibilidade, registro fotográfico diário, mensuração do tamanho das úlceras e índice do tempo de fechamento completo da ferida. Foi observada melhora no reparo tecidual das feridas, atingindo fechamento total em ambos os lados e redução da intensidade de dor referida. O LED como tratamento curativo de úlceras diabéticas crônicas mostrou efetividade na taxa de fechamento total da ferida e melhora de sintomas neuropáticos.

Invitro impact of a combination of red and infrared LEDs, infrared laser and magnetic field on biomarkers of oxidative stress and hemolysis of erythrocytes sampled from healthy individuals and diabetes patients

AIMS

Low-intensity infrared laser irradiation with output emissions of the laser and LED for in vitro irradiation of plasma and erythrocyte samples collected from healthy individuals and diabetes mellitus (DM) patients was used in the current study.

METHODS

The generated emission was in the range 0.85-0.89 nm with pulse duration near 130 ns and repetition rates of pulses 50, 150, 600, and 1500 Hz, average power 0, 50, or 100 mW, in the range of 1-9 min for different 30 variants of irradiation. The levels of 2-thiobarbituric-acid reactive substances (TBARS), aldehydic and ketonic derivatives of oxidatively modified proteins (OMP), total antioxidant capacity (TAC), acid-induced resistance of erythrocytes, and activities of the main antioxidant enzymes were assessed in erythrocyte and plasma samples after irradiation.

RESULTS

The low-intensity infrared laser irradiation and low-intensity light emitted by a red LED decreased the lipid peroxidation levels in the erythrocytes of both healthy individuals and DM patients. A statistically significant decrease in TBARS and OMP levels and an increase in the TAC level were observed at the irradiation energy of 34.39 and 68.79 J/cm² for samples collected from both healthy individuals and DM patients. The effects of the irradiation were accompanied by a statistically significant decrease in catalase activity of both healthy individuals and DM patients.

CONCLUSIONS

In many variants of the laser irradiation and low-intensity light emitted by a red LED used in our study, a decrease in the percent of hemolyzed erythrocytes was observed, suggesting that laser therapy protocols should take into account fluencies, frequencies, and wavelengths of the laser before the beginning of treatment, especially in DM patients.

Visible light. Part I: Properties and cutaneous effects of visible light

Approximately 50% of the sunlight reaching the Earth's surface is visible light (400-700 nm). Other sources of visible light include lasers, light-emitting diodes, and flash lamps. Photons from visible light are absorbed by photoreceptive chromophores (e.g., melanin, heme, and opsins), altering skin function by activating and imparting energy to chromophores. Additionally, visible light can penetrate the full thickness of the skin and induce pigmentation and erythema. Clinically, lasers and light devices are used to treat skin conditions by utilizing specific wavelengths and treatment parameters. Red and blue light from light-emitting diodes and intense pulsed light have been studied as antimicrobial and anti-inflammatory treatments for acne. Pulsed dye lasers are used to treat vascular lesions in adults and infants. Further research is necessary to determine the functional significance of visible light on skin health without confounding the influence of ultraviolet and infrared wavelengths.