Effectiveness and safety of photobiomodulation therapy in diabetic peripheral neuropathy: Protocol for a systematic review and meta-analysis.

INTRODUCTION: Diabetic peripheral neuropathy (DPN), a widely prevalent complication in patients with type 2 diabetes, exerts a significant influence on patients' overall health and financial circumstances. Photobiomodulation therapy is one of the means of physical therapy for DPN. Although preliminary findings suggest the efficacy of photobiomodulation therapy in alleviating peripheral neuropathy, the existing literature lacks substantial evidence regarding its safety and effectiveness specifically in the context of diabetes-related peripheral neuropathy. Therefore, we plan to arrive at more distinct findings through systematic evaluation and meta-analysis. METHODS: We will conduct a comprehensive search for studies published from the beginning until October 1, 2023, using various databases including Web of Science, Embase, Cochrane Library, PubMed, AMED, Wanfang database, VIP database, China National Knowledge Infrastructure, and the Chinese Biomedical Literature database. Simultaneously, we will also search for the WHO International Clinical Trial Registration Platform, China Clinical Trial Registration Platform, and Clinical Trials.gov. Gray literature will be retrieved using Google Scholar and opengrey.edu. Only randomized controlled trials in Chinese and English were included, with no restrictions on publication status. The primary outcomes will include change of symptom scores, change of nerve conduction velocity. Additional outcomes will encompass quality of life, change in pain, blood glucose levels after fasting and 2 hours after eating, levels of glycosylated hemoglobin, and any adverse events associated with photobiomodulation therapy. Reman V.5.4 and R language will be used for the meta-analysis. Assessment of potential bias will be conducted through Cochrane risk of bias 2 tool (RoB 2.0) and Physiotherapy Evidence Database (PEDro) scale. Registration: PROSPERO (registration number: CRD42023466586). DISCUSSION: This meta-analysis aims to assess the efficacy and safety of photobiomodulation therapy as a potential treatment for diabetic peripheral neuropathy (DPN), and providing a straightforward and convenient therapeutic for patients. Additionally, it expands the range of treatment alternatives available to healthcare professionals managing DPN.

Comparison of cellular responses to ionizing radiation in keratinocytes isolated from healthy donors and type II diabetes patients.

PURPOSE: Due to the expanding repertoire of treatment devices that use radiation, the possibility of exposure to both low-dose and high-dose radiation continues to increase. Skin is the outermost part of the body and thus directly exposed to radiation-induced damage. In particular, the skin of diabetes patients is fragile and easily damaged by external stimuli, such as radiation. However, damage and cellular responses induced by ionizing irradiation in diabetic skin have not been explored in detail. In this study, we investigated the effects of several irradiation dose on normal keratinocytes and those from type II diabetes patients, with particular focus on DNA damage. MATERIALS AND METHODS: Cellular responses to low-dose radiation (0.1 Gy) and high-dose radiation (0.5 and 2 Gy) were evaluated. Cell cycle analysis was conducted via flow cytometry and cell viability analyzed using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Proteins related to the DNA damage response (DDR) and repair signaling pathways and apoptosis were detected via immunoblot analysis. Apoptosis and cell differentiation were additionally examined in 3D skin organoids using immunohistochemistry. RESULTS: Compared to respective control groups, no significant changes were observed in cell cycle, DDR and repair mechanisms, cell survival, and differentiation in response to 0.1 Gy irradiation in both normal and diabetes type II keratinocytes. On the other hand, the cell cycle showed an increase in the G2/M phase in both cell types following exposure to 2 Gy irradiation. At radiation doses 2 Gy, activation of the DDR and repair signaling pathways, apoptosis, and cell differentiation were increased and viability was decreased in both cell types. Notably, these differences were more pronounced in normal than diabetes type II keratinocytes. CONCLUSIONS: Normal keratinocytes respond more strongly to radiation-induced damage and recovery than diabetes type II keratinocytes.

Effectiveness of Photobiomodulation Therapy on Neuropathic Pain, Nerve Conduction and Plantar Pressure Distribution in Diabetic Peripheral Neuropathy - A Systematic Review.

BACKGROUND: Diabetic peripheral neuropathy is a severe complication of type 2 diabetes mellitus. The most common symptoms are neuropathic pain and altered sensorium due to damage to small nerve fibers. Altered plantar pressure distribution is also a major risk factor in diabetic peripheral neuropathy, leading to diabetic foot ulcers. OBJECTIVE: The objective of this systematic review was to analyze the various studies involving photobiomodulation therapy on neuropathic pain and plantar pressure distribution in diabetic peripheral neuropathy. METHODS: We conducted a systematic review (PubMed, Web of Science, CINAHL, and Cochrane) to summarise the evidence on photobiomodulation therapy for Diabetic Peripheral Neuropathy with type 2 diabetes mellitus. Randomized and non-randomized studies were included in the review. RESULTS: This systematic review included eight studies in which photobiomodulation therapy showed improvement in neuropathic pain and nerve conduction velocity. It also reduces plantar pressure distribution, which is a high risk for developing foot ulcers. CONCLUSION: We conclude that photobiomodulation therapy is an effective, non-invasive, and costefficient means to improve neuropathic pain and altered plantar pressure distribution in diabetic peripheral neuropathy.

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.

Effects of photobiomodulation on oxidative stress in rats with type 2 diabetes mellitus.

The present study aimed to evaluate photobiomodulation effects on oxidative stress in type 2 diabetes mellitus (DM2). Thirty-one male Wistar rats were used and divided into 4 groups: group 1 - animals without diabetes mellitus 2 without laser 21 J/cm2 (C-SHAM), group 2 - animals with diabetes mellitus 2 without laser 21 J/cm2 (C-DM2), group 3 - animals without diabetes mellitus 2 with laser 21 J/cm2 (L-SHAM), group 4 - animals with diabetes mellitus 2 with laser 21 J/cm2 (L-DM2). The protocol was performed 5 days/week, for 6 weeks. The animals that received photobiomodulation had one dose irradiated at two spots in the right gastrocnemius muscle. Twenty-four hours after the last intervention, the animals were euthanized. Heart, diaphragm, liver, right gastrocnemius, plasma, kidneys, weighed, and stored for further analysis. In rats with DM2, photobiomodulation promoted a decrease in thiobarbituric acid reactive substance assay (TBARS) in plasma levels. On the other hand, photobiomodulation demonstrated an increase in non-protein thiol levels (NPSH) in the heart, diaphragm and gastrocnemius. Moreover, photobiomodulation produced in the heart, diaphragm and plasma levels led to an increase in superoxide dismutase (SOD). Interestingly, photobiomodulation was able to increase superoxide dismutase in rats without DM2 in the heart, diaphragm, gastrocnemius and kidneys. These findings suggested that 6 weeks of photobiomodulation in rats with DM2 promoted beneficial adaptations in oxidative stress, with a decrease in parameters of oxidant activity and an increase in antioxidant activity.

Photobiomodulation reduces hepatic lipogenesis and enhances insulin sensitivity through activation of CaMKKß/AMPK signaling pathway.

Photobiomodulation (PBM) could improve systemic blood glucose and insulin resistance in diet-induced diabetic mice. A few possible molecular mechanisms for the beneficial effects of PBM on diabetes have been proposed, but there is still an urgent need to explore the underlying mechanisms that support the application of PBM in the treatment of diabetes. Our study aimed to evaluate the effects of PBM on lipid metabolism in the liver of high-fat diet (HFD)-induced mice and explore the potential mechanisms of PBM on obesity and type 2 diabetes. Here, we administered PBM therapy (wavelength: 635 nm, energy density: 8 J/cm2) daily for eight weeks to HFD-induced mice. We detected that eight-week daily administration of PBM ameliorated HFD-induced gain weight, hyperlipidemia, and hyperglycemia, but also protected against diet-induced hepatic steatosis and insulin resistance. Furthermore, PBM increased AMP-activated protein kinase (AMPK) activation, lowered nuclear translocation of sterol regulatory element binding protein 1 (SREBP1), decreased aberrant lipogenesis, and enhanced insulin sensitive in HFD-induced mice livers. We also observed that Ca2+/calmodulin-dependent protein kinase kinase ß (CaMKKß) activation was responsible for AMPK activation in insulin-resistant HepG2 cells exposed to PBM. In summary, PBM at 635 nm and 8 J/cm2 improved hepatic lipid metabolism and inhibited the development of HFD-induced obesity and type 2 diabetes. Moreover, increased intracellular Ca2+ content and CaMKKß-dependent AMPK activation were possible molecular mechanisms underlying the PBM-induced improvement on obesity and type 2 diabetes.

Nutritional Ketosis and photobiomodulation remediate mitochondria warding off Alzheimer's disease in a diabetic, ApoE4+ patient with mild cognitive impairment: A case report.

Alzheimer's Disease (AD) is a neurodegenerative progressive disorder for which there is currently no cure. Recent research demonstrates a robust correlation between type-2 diabetes mellitus (T2DM) and the development of MCI and AD, now referred to as type-3 diabetes. Both AD and T2DM, as metabolic pathologies, can be traced to the level of mitochondrial function. The metabolic hypothesis suggests that the cause of AD might be rooted in mitochondrial dysfunction accompanied by fuel shortage in the brain. Although glucose is known to be the deferred source of fuel for cells, ketone bodies have been observed to provide metabolically compromised brain cells with an alternative fuel source, bypassing deficiencies in GLUT transport due to increased insulin resistance. By keeping glucose and insulin levels low to allow for the production of ketones, there is evidence that mitochondrial function will be restored and cognition/memory improved. Further, visible red or near-infrared (NIR) light has been shown to heal and stimulate damaged tissue by interacting with the mitochondria to restore function. This case study evaluates the effects of a 10-week clinically prescribed ketogenic nutrition protocol combined with transcranial photobiomodulation (PBM) with a 59-year-old male, heterozygous ApoE4 carrier, with a dual diagnosis of mild AD and an 11 year history of insulin dependent type 2 diabetes (T2DM). Statistically significant results reflect an 83% reduction in HOMA-IR; 64% decrease in the triglyceride/HDL ratio; HgA1c reduction from 9.44% to 6.4%; 57% decrease in VLDL and triglycerides; and normalized cognition as measured via the MoCA (Montreal Cognitive Assessment), 26/30 post intervention.

Photobiomodulation therapy decreases free fatty acid generation and release in adipocytes to ameliorate insulin resistance in type 2 diabetes.

Excessive circulating free fatty acids (FFA) cause insulin resistance in peripheral tissues by inhibiting the proximal insulin signaling pathway. White adipose tissue (WAT) is a primary source of FFA generation and release through triglyceride (TG) hydrolysis. Thus, reducing excessive lipolysis in adipocytes ameliorates whole-body insulin resistance in type 2 diabetes. Here, we found that a noninvasive photobiomodulation therapy (PBMT), decreased FFA generation and release in WATs from high-fat diet (HFD)-fed mice and diabetic db/db mice. Meanwhile, plasma FFA and TG levels were reduced in two mouse models after PBMT. PBMT promoted mitochondrial reactive oxygen species (ROS) generation, which inhibited phosphatase and tensin homologue (PTEN) and promoted protein kinase B (AKT) activation. Photoactivation of AKT inhibited the transcriptional activity of Forkhead box transcription factor O1 (FoxO1), reducing expression of lipolytic enzymes and FFA generation and release. Eliminating ROS elimination or inhibiting AKT blocked the effects of the laser therapy in vivo and in vitro. Taken together, PBMT suppresses FFA generation and release in insulin-resistant adipocytes, contributing to improvement of insulin resistance in mouse models of type 2 diabetes.

Photobiomodulation for the treatment of periodontal pockets in patients with type 2 diabetes: 1-year results of a randomized clinical trial.

This study investigated the local effect of photobiomodulation (PBM) for the treatment of periodontal pockets in patients with periodontitis and type 2 diabetes. Thirty-eight periodontal pockets presenting probing depth (PD) and clinical attachment level (CAL) ≥ 5 mm were selected from 19 patients (two pockets/patient). The selected periodontal pockets were randomly assigned to receive mechanical debridement only (control group) or mechanical debridement with PBM (PBM group). Clinical measures, such as PD, CAL, bleeding on probing (BoP), and presence of supragingival biofilm (PI), were collected and compared at baseline, 3, 6, and 12 months. After 12 months, no statistically difference was observed for mean PD and mean CAL when control and PBM groups were compared. The frequency of pockets with PD 5-6 mm was significantly lower for the PBM group at 6 months when compared to the control group. Pockets with PD ≥ 7 mm changed significantly between baseline and 3, 6, and 12 months for the PBM group, while for the control group, statistical significance was only observed between baseline and 6 months. The PBM protocol used in this study did not provide significant changes for PD and CAL in periodontal pockets when compared to mechanical therapy only. However, PBM was more effective in reducing the percentage of moderate periodontal pockets at 6 months in patients with type 2 DM.

Moderate intensity exercise improves heart rate variability in obese adults with type 2 diabetes.

AIM: The aim of this study was to determine the effect of moderate aerobic exercise on heart rate variability (HRV) in obese adults with type 2 diabetes. METHODS: Forty-one obese adults with type 2 diabetes participated in this study. Anthropometric and metabolic parameters were measured, and resting electrocardiogram (ECG) for the HRV analysis at spontaneous respiration was recorded for 5 min in supine position before and after six months of supervised aerobic training given thrice-a-week. RESULTS: The mean age, body mass index (BMI), and duration of diabetes of the study population were 44.1 ± 4.5 years, 30.94 ± 1.36 kg/m2, and 16.3 ± 2.7 years, respectively. In time domain variables, standard deviation of all RR intervals (SDNN), the square root of the mean of the sum of the squares of differences between adjacent RR intervals (RMSSD) and percentage of consecutive RR intervals that differ by more than 50 ms (pNN50) were significantly increased after exercise. In frequency domain variables, high frequency (HF) (ms2) and HF (nu) were significantly increased while low frequency (LF) (ms2) and LF/HF ratio were significantly decreased after exercise. But LF (nu) was unaffected after exercise. CONCLUSION: This study suggests that thrice-a-week moderate intensity aerobic exercise for six months improves cardiac rhythm regulation as measured by HRV in obese adults with type 2 diabetes.

NaoXinTong Capsules inhibit the development of diabetic nephropathy in db/db mice.

NaoXinTong Capsule (NXT), a Chinese medicine, is currently used to treat patients with cardiovascular and cerebrovascular diseases. Clinical observations indicate its anti-diabetic functions with unclear mechanisms. Herein, we report the effect of NXT on diabetic nephropathy (DN). Type 2 diabetic db/db mice were treated with NXT for 14 weeks. In the course of treatment, NXT reduced diabetes-increased glucose levels and improved renal functions. At the end of treatment, we found that NXT ameliorated serum lipid profiles and other biochemical parameters. In the kidney, NXT inhibited mesangial matrix expansion, expression of vascular endothelial growth factor A, fibronectin, advanced glycation end product and its receptor. Meanwhile, it reduced the diabetes-induced podocyte injury by increasing WT1 and nephrin expression. In addition, NXT inhibited accumulation of extracellular matrix proteins by increasing MMP2/9 expression through inactivation of TGFß/Smad pathway and CTGF expression. Mechanically, NXT activated insulin signaling pathway by increasing expression of INSR, IRS and FGF21, phosphorylation of Akt and AMPKα in the liver, INSR phosphorylation in the kidney, and FGF21 and GLUT4 expression in adipose tissue and skeletal muscle. Taken together, our study demonstrates that NXT inhibits DN by ameliorating glucose/lipid metabolism, maintaining tissue structure integrity, and correcting diabetes-induced renal dysfunctions.

Low-level laser therapy as an adjunct to conventional therapy in the treatment of diabetic foot ulcers.

Foot ulcers are serious complications of diabetes mellitus (DM) and are known to be resistant to conventional treatment. This study was conducted to evaluate the efficacy of low-level laser therapy (LLLT) for the treatment of diabetic foot ulcers in a tertiary care centre (Department of Surgery, Mahatma Gandhi Memorial Medical College and Maharaja Yashwantrao Hospital, A.B. Road, Indore). A total of 30 patients with type 2 DM having Meggitt-Wagner grade I foot ulcers of more than 6 weeks duration with negative culture were studied. Patients were randomized into two groups of 15 each. Patients in study group received LLLT (660 ± 20 nm, 3 J/cm2) along with conventional therapy and those in control group were treated with conventional therapy alone. The primary outcome measure was the absolute and relative wound size reduction at 2 weeks compared to the baseline parameter. Percentage ulcer area reduction was 37 ± 9% in the LLLT group and 15 ± 5.4% in the control group (p < 0.001). For ∼75% of wounds of the treatment group, wound area reduction of 30-50% was observed. In contrast, for the control group, ∼80% of wounds showed a wound area reduction of <20% on day 15. Further, the wounds with initial wound area 1000-2000 mm2 seems to have better final outcome than the groups with larger areas. The treated groups showed higher amount of granulation than the control group. The results suggest that LLLT is beneficial as an adjunct to conventional therapy in the treatment of diabetic foot ulcers.

Correlation between Total Solar Irradiance and Glycated Hemoglobin 2 to 3 Months Later in Patients with Diabetes: A Big-Data Analysis.

OBJECTIVES: Much attention has been paid recently to a relationship between glucose metabolism and weather. This study investigated the temporal correlation between total solar irradiance (TSI) and glycated hemoglobin (A1C) values in patients with diabetes. METHODS: In 1531 patients with diabetes who received follow-up care between 2009 and 2013 (type 1 diabetes, 123 patients; type 2 diabetes, 1408 patients; male 53.6%; mean age, 61.2 years), A1C levels were measured a total of 58,830 times. The correlation between mean monthly TSI and mean A1C values from 1 to 4 months later was then examined. RESULTS: The mean values for TSI and A1C throughout the entire study period were 13.7 MJ/m2 and 7.7%, respectively. The correlation coefficient between TSI and mean monthly A1C values at 1 to 4 months was -0.516, -0.734, -0.726 and -0.475, respectively (all p<0.001). CONCLUSIONS: There was a highly negative correlation between TSI and mean A1C values 2 to 3 months later in this population; thus, this fact may need to be considered when using A1C levels as a glycemic control index in patients with diabetes. Further studies are warranted.

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.

BACKGROUND: Type 2 diabetes mellitus (DM) is responsible for a significant reduction in the quality of life due to its negative impact on functional capacity. Cardiopulmonary fitness impairment in DM patients has been associated with limited tissue oxygenation. Phototherapy is widely utilized to treat several disorders due to expected light-tissue interaction. This type of therapy may help to improve muscular oxygenation, thereby increasing aerobic fitness and functional capacity. METHODS/DESIGN: This study is a randomized, double-blind, placebo-controlled crossover trial approved by the Ethics Committee of the Federal University of São Carlos and registered at ClinicalTrials.gov. Four separate tests will be performed to evaluate the acute effect of phototherapy. All participants will receive both interventions in random order: light-emitting diode therapy (LEDT) and placebo, with a minimum 14-day interval between sessions (washout period). Immediately after the intervention, participants will perform moderate constant workload cycling exercise corresponding to 80 % of the pulmonary oxygen uptake [Formula: see text] during the gas exchange threshold (GET). LEDT will be administered with a multidiode cluster probe (50 GaAIA LEDs, 850 ηm, 75 mW each diode, and 3 J per point) before each exercise session. Pulmonary oxygen uptake, muscle oxygenation, heart rate, and arterial pressure will be measured using a computerized metabolic cart, a near-infrared spectrometer, an electrocardiogram, and a photoplethysmography system, respectively. DISCUSSION: The main objective of this study is to evaluate the acute effects of muscular pre-conditioning using LED phototherapy on pulmonary oxygen uptake, muscle oxygenation, heart rate, and arterial pressure dynamics during dynamic moderate exercise. We hypothesize that phototherapy may be beneficial to optimize aerobic fitness in the DM population. Data will be published after the study is completed. TRIAL REGISTRATION: Registered at ClinicalTrials.gov under trial number NCT01889784 (date of registration 5 June 2013).

Additive protection by LDR and FGF21 treatment against diabetic nephropathy in type 2 diabetes model.

The onset of diabetic nephropathy (DN) is associated with both systemic and renal changes. Fibroblast growth factor (FGF)-21 prevents diabetic complications mainly by improving systemic metabolism. In addition, low-dose radiation (LDR) protects mice from DN directly by preventing renal oxidative stress and inflammation. In the present study, we tried to define whether the combination of FGF21 and LDR could further prevent DN by blocking its systemic and renal pathogeneses. To this end, type 2 diabetes was induced by feeding a high-fat diet for 12 wk followed by a single dose injection of streptozotocin. Diabetic mice were exposed to 50 mGy LDR every other day for 4 wk with and without 1.5 mg/kg FGF21 daily for 8 wk. The changes in systemic parameters, including blood glucose levels, lipid profiles, and insulin resistance, as well as renal pathology, were examined. Diabetic mice exhibited renal dysfunction and pathological abnormalities, all of which were prevented significantly by LDR and/or FGF21; the best effects were observed in the group that received the combination treatment. Our studies revealed that the additive renal protection conferred by the combined treatment against diabetes-induced renal fibrosis, inflammation, and oxidative damage was associated with the systemic improvement of hyperglycemia, hyperlipidemia, and insulin resistance. These results suggest that the combination treatment with LDR and FGF21 prevented DN more efficiently than did either treatment alone. The mechanism behind these protective effects could be attributed to the suppression of both systemic and renal pathways.

Blue or red: which intravascular laser light has more effects in diabetic patients?

The effects of intravascular laser irradiation of blood (ILIB), with 405 and 632.8 nm on serum blood sugar (BS) level, were comparatively studied. Twenty-four diabetic type 2 patients received 14 sessions of ILIB with blue and red lights. BS was measured before and after therapy. Serum BS decreased highly significant after ILIB with both red and blue lights (p < 0.0001), but we did not find significant difference between red and blue lights. The ILIB effect would be of benefit in the clinical treatment of diabetic type 2 patients, irrespective of lasers (blue or red lights) that are used.

Ultraviolet radiation suppresses obesity and symptoms of metabolic syndrome independently of vitamin D in mice fed a high-fat diet.

The role of vitamin D in curtailing the development of obesity and comorbidities such as the metabolic syndrome (MetS) and type 2 diabetes has received much attention recently. However, clinical trials have failed to conclusively demonstrate the benefits of vitamin D supplementation. In most studies, serum 25-hydroxyvitamin D [25(OH)D] decreases with increasing BMI above normal weight. These low 25(OH)D levels may also be a proxy for reduced exposure to sunlight-derived ultraviolet radiation (UVR). Here we investigate whether UVR and/or vitamin D supplementation modifies the development of obesity and type 2 diabetes in a murine model of obesity. Long-term suberythemal and erythemal UVR significantly suppressed weight gain, glucose intolerance, insulin resistance, nonalcoholic fatty liver disease measures; and serum levels of fasting insulin, glucose, and cholesterol in C57BL/6 male mice fed a high-fat diet. However, many of the benefits of UVR were not reproduced by vitamin D supplementation. In further mechanistic studies, skin induction of the UVR-induced mediator nitric oxide (NO) reproduced many of the effects of UVR. These studies suggest that UVR (sunlight exposure) may be an effective means of suppressing the development of obesity and MetS, through mechanisms that are independent of vitamin D but dependent on other UVR-induced mediators such as NO.

Efficacy of pre-exercise low-level laser therapy on isokinetic muscle performance in individuals with type 2 diabetes mellitus: study protocol for a randomized controlled trial.

BACKGROUND: Type 2 diabetes, also known non-insulin-dependent diabetes, is the most prevalent type of the disease and involves defects in the secretion and action of insulin. The aim of the proposed study is to evaluate the efficacy of pre-exercise low-level laser therapy (LLLT) on muscle performance of the quadriceps femoris in individuals with type 2 diabetes. METHODS/DESIGN: A double-blind, randomized, controlled clinical trial will be carried out in two treatment phases. In the first phase, quadriceps muscle performance will be evaluated using an isokinetic dynamometer and the levels of creatine kinase and lactate dehydrogenase (biochemical markers of muscle damage) will be determined. The participants will then be allocated to four LLLT groups through a randomization process using opaque envelopes: Group A (4 Joules), Group B (6 Joules), Group C (8 Joules) and Group D (0 Joules; placebo). Following the administration of LLLT, the participants will be submitted to an isokinetic eccentric muscle fatigue protocol involving the quadriceps muscle bilaterally. Muscle performance and biochemical markers of muscle damage will be evaluated again immediately after as well as 24 and 48 hours after the experimental protocol. One week after the last evaluation the second phase will begin, during which Groups A, B and C will receive the LLLT protocol that achieved the best muscle performance in phase 1 for a period of 4 weeks. At the end of this period, muscle performance will be evaluated again. The protocol for this study is registered with the World Health Organization under Universal Trial Number U1111-1146-7109. DISCUSSION: The purpose of this randomized clinical trial is to evaluate the efficacy of pre-exercise LLLT on the performance of the quadriceps muscle (peak torque, total muscle work, maximum power and fatigue index - normalized by body mass) in individuals with DM-2. The study will support the practice of evidence-based to the use of LLLT in improving muscle performance in Individuals with DM-2. Data will be published after the study is completed.

Testing infrared laser phototherapy (810 nm) to ameliorate diabetes: irradiation on body parts of diabetic mice.

BACKGROUND AND OBJECTIVES: Irradiation of left flank of genetic diabetic mice with 660 nm wavelength laser, 100 mW, 20 seconds/day for 7 days did not significantly alter blood plasma glucose compared to nonirradiated controls. Infrared light would provide for a greater amount of photoenergy penetrating the skin and muscle. Genetic diabetic mice were irradiated with 810 nm wavelength laser to test for antidiabetic effect. MATERIALS AND METHODS: Sixty-five diabetic mice were used. Body weight and water intake of mice were measured daily for 7 days prior to start of treatment (Day 0). Mice were irradiated with 810 nm wavelength laser, 50 mW, 40 seconds/day, 7 days on left flank (n = 11), mid-upper abdomen (n = 14), or left inguinal region (n = 14); some mice were not irradiated (control, n = 26). Body weight and water intake of mice were measured to Day 7. On Day 7, mice were fasted for 4 hours, anesthetized with sodium pentobarbitone (s.c.) and blood collected by cardiac puncture into EDTA-treated tubes. Blood plasma was assayed for glucose and fructosamine. Blood was collected and assayed from nonirradiated nondiabetic mice (n = 12). RESULTS: On Day 7 body weight was significantly lower and water intake significantly higher compared to Day 0 for diabetic mice irradiated on left flank (40.7 ± 0.5 vs. 42.2 ± 0.4 g, 28.2 ± 1.5 vs. 23.4 ± 1.5 g, respectively); there was no significant change for diabetic mice irradiated on mid-upper abdomen or left inguinal region and also for nonirradiated diabetic mice. On Day 7 blood plasma glucose levels for irradiated diabetic mice were not significantly different to nonirradiated diabetic mice. Blood plasma fructosamine level of diabetic mice irradiated on left inguinal region was significantly lower than for nonirradiated diabetic mice (312 ± 6 vs. 377 ± 15 µmol/L); for diabetic mice irradiated on left flank or mid-upper abdomen (362 ± 22, 357 ± 19 µmol/L) it was not significantly different to nonirradiated diabetic mice. CONCLUSION: Irradiation of left inguinal region in diabetic mice with 810 nm laser has potential to ameliorate diabetes as shown by decreased blood plasma fructosamine.

[Impact of diabetes mellitus on clinicopathological factors and relation with radiation pneumonitis in 332 patients with lung cancer].

OBJECTIVE: To explore the relation between diabetes mellitus and clinicopathological factors and the incidence of radiation pneumonitis in patients with non-small cell lung cancer. METHODS: The data of 332 patients with non-small cell lung cancer, who were admitted to the Department of Oncology of Third Xiangya Hospital of Central South University between January 2007 and August 2009, were collected retrospectively. The patients were divided into a diabetes mellitus (DM) group (n=45) and a non-diabetes mellitus (NDM) group (n=287). The clinicopathological factors were compared between the two groups. The patients who received radiotherapy were further divided into a diabetes mellitus (DMR) group (n=33) and a non-diabetes mellitus group (NDMR) group(n=287), and the incidence of radiation pneumonitis was compared. RESULTS: A total of 45 patients (13.55%)developed diabetes mellitus. There was significant difference in the body-weight, age and hypertension (P<0.05), while no significant difference in the pathologic factors, such as tumor pathological type, degree of differentiation, and classification of malignant tumors (TNM) stage between the two groups(P>0.05). No significant difference in the irradiation area was found between the DM group and the NDM group(P>0.05). The incidence of radiation pneumonitis in the DMR group was 42.42%(14 out of 33), while 21.31%(39 out of 183) in the NDMR group, with significant difference in the incidence of radiation pneumonitis between the DMR group and the NDMR group(P<0.05). The risk value in the DMR group was 2.721 folds (95%CI, 1.253-5.910) that in the NDMR group in patients with non-small cell lung cancer companied with diabetes mellitus. CONCLUSION: Diabetes mellitus is the risk factor of radiation pneumonitis for patients with nonsmall cell lung cancer who receive radiotherapy.