The pathway to foot ulceration in diabetes

The risk factors in diabetic foot ulcers and predictive value of prognosis of wound tissue vascular endothelium growth factor

Diabetic foot ulcer (DFU) is a leading cause of high-level amputation in DM patients, with a low wound healing rate and a high incidence of infection. Vascular endothelial growth factor (VEGF) plays an important role in diabetes mellitus (DM) related complications. This study aims to explore the VEGF expression and its predictive value for prognosis in DFU, in order to provide basis for the prevention of DFU related adverse events. We analyzed 502 patients, with 328 in healing group and 174 in non-healing/recurrent group. The general clinical data and laboratory indicators of patients were compared through Spearman correlation analysis, ROC analysis and logistic regression analysis. Finally, the independent risk factors for adverse prognosis in DFU patients were confirmed. Spearman analysis reveals a positive correlation between the DFU healing rate and ABI, VEGF in wound tissue, and positive rate of VEGF expression, and a negative correlation with DM duration, FPG, HbA1c, TC, Scr, BUN, and serum VEGF. Further logistic regression analysis finds that the DM duration, FPG, HbA1c, ABI, serum VEGF, VEGF in wound tissue, and positive rate of VEGF expression are the independent risk factors for adverse prognosis in DFU (p < 0.05). DM duration, FPG, HbA1c, ABI, serum VEGF, VEGF in wound tissue, and positive rate of VEGF expression are the independent risk factors for prognosis in DFU patients. Patients with these risk factors should be screened in time, which is of great significance to prevent DFU related adverse events and improve outcomes.

Mesenchymal stem cell therapy in diabetic foot ulcer: An updated comprehensive review

Background

Diabetes has evolved into a worldwide public health issue. One of the most serious complications of diabetes is diabetic foot ulcer (DFU), which frequently creates a significant financial strain on patients and lowers their quality of life. Up until now, there has been no curative therapy for DFU, only symptomatic relief or an interruption in the disease's progression. Recent studies have focused attention on mesenchymal stem cells (MSCs), which provide innovative and potential treatment candidates for several illnesses as they can differentiate into various cell types. They are mostly extracted from the placenta, adipose tissue, umbilical cord (UC), and bone marrow (BM). Regardless of their origin, they show comparable features and small deviations. Our goal is to investigate MSCs' therapeutic effects, application obstacles, and patient benefit strategies for DFU therapy.

Methodology

A comprehensive search was conducted using specific keywords relating to DFU, MSCs, and connected topics in the databases of Medline, Scopus, Web of Science, and PubMed. The main focus of the selection criteria was on English-language literature that explored the relationship between DFU, MSCs, and related factors.

Results and Discussion

Numerous studies are being conducted and have demonstrated that MSCs can induce re-epithelialization and angiogenesis, decrease inflammation, contribute to immunological modulation, and subsequently promote DFU healing, making them a promising approach to treating DFU. This review article provides a general snapshot of DFU (including clinical presentation, risk factors and etiopathogenesis, and conventional treatment) and discusses the clinical progress of MSCs in the management of DFU, taking into consideration the side effects and challenges during the application of MSCs and how to overcome these challenges to achieve maximum benefits.

Conclusion

The incorporation of MSCs in the management of DFU highlights their potential as a feasible therapeutic strategy. Establishing a comprehensive understanding of the complex relationship between DFU pathophysiology, MSC therapies, and related obstacles is essential for optimizing therapy outcomes and maximizing patient benefits.

Early identification of delayed wound healing in complex diabetic foot ulcers treated with a dermal regeneration template: a novel clinical target and its risk factors

BACKGROUND

The dermal regeneration template (DRT), a tissue-engineered skin substitute composing a permanent dermal matrix and an upper temporary silicone layer that serves as the epidermis, has demonstrated efficacy in treating uncomplicated diabetic foot ulcers (DFUs). Our institution has obtained good outcomes with DRT in patients with more complicated DFUs. Because of its chronicity, the authors are working to identify a clinical target that anticipates delayed healing early in the treatment in addition to determining the risk factors linked to this endpoint to increase prevention.

MATERIALS AND METHODS

This retrospective single-center study analyzed patients with DFUs who underwent wound reconstruction using DRT between 2016 and 2021. The patients were categorized into poor or good graft-take groups based on their DRT status on the 21st day after the application. Their relationship with complete healing (CH) rate at day 180 was analyzed. Variables were collected for risk factors for poor graft take at day 21. Independent risk factors were identified after multivariable analysis. The causes of poor graft take were also reported.

RESULTS

This study examined 80 patients (38 and 42 patients in the poor and good graft-take groups, respectively). On day 180, the CH rate was 86.3% overall, but the poor graft-take group had a significantly lower CH rate (76.3 vs. 95.2%, P =0.021) than the good graft-take group. Our analysis identified four independent risk factors: transcutaneous oxygen pressure less than 30 mmHg (odds ratio, 154.14), off-loading device usage (0.03), diabetic neuropathy (6.51), and toe wound (0.20). The most frequent cause of poor graft take was infection (44.7%), followed by vascular compromise (21.1%) and hematoma (15.8%).

CONCLUSION

Our study introduces the novel concept of poor graft take at day 21 associated with delayed wound healing. Four independent risk factors were identified, which allows physicians to arrange interventions to mitigate their effects or select patients more precisely. DRT represents a viable alternative to address DFUs, even in complicated wounds. A subsequent split-thickness skin graft is not always necessary to achieve CH.

Hand loading, rates of perceived exertion, and usability during assisted walking in patients with type 2 diabetes mellitus

BACKGROUND

Patients suffering from a diabetic foot ulcer often receive a non-weight bearing prescription of the affected limb to promote healing. Total unilalteral offloading of the affected foot necessitates walking aids that require loading at the hands during ambulation. Excessive loading at the hands can increase of the risk of crutch palsy. In addition, certain walking aids can also be more strenuous and less comfortable to use than others, resulting in lower prescription compliance. This study aimed to investigate hand loading, rates of perceived exertion, and usability of typically prescribed walking aids in patients with Type 2 Diabetes.

METHODS

Twenty patients (12 F | 8 M, 61.0 ± 10.36 yrs., 90.54 ± 13.34 kg, 1.71 ± 0.08 m) walked as much as 200 m without assistance and with crutches, walkers, and a wheeled knee walker instrumented with flexible force-sensing pads on walking aid handles. Patients rated exertion using a Modified Borg Scale and completed a System Usability Scale questionnaire after each walking condition with or without walking aids.

FINDINGS

Results show that using a wheeled knee walker required 94% less hand loading than crutches and walkers. Patients reported 45% lower exertion with the WKW compared to crutches and walkers, and scored the usability of the wheeled knee walker 106% higher than crutches and walkers.

INTERPRETATION

The wheeled knee walker could be the preferred walking aid for total unilateral offloading because of the reduced loading demand at the hands, lower exertion during use, and greater usability compared to crutches and walkers.

Effects of Hypericin on Cultured Primary Normal Human Dermal Fibroblasts Under Increased Oxidative Stress

INTRODUCTION

Wound healing is a dynamic process that begins with inflammation, proliferation, and cell migration of a variety of fibroblast cells. As a result, identifying possible compounds that may improve fibroblast cell wound healing capacity is crucial. Hypericin is a natural quinine that has been reported to possess a wide range of pharmacological profiles, including antioxidant and anti-inflammatory, activities. Herein we examined for the first time the effect of hypericin on normal human dermal fibroblasts (NHDFs) under oxidative stress.

METHODS

NHDF were exposed to different concentrations of hypericin (0-20 μg/mL) for 24 h. For the oxidative stress evaluation, H2O2 was used as a stressor factor. Cell viability and proliferation levels were evaluated. Immunohistochemistry and flow cytometry were performed to assess cell apoptosis levels and with confocal microscopy we identified the mitochondrial superoxide production under oxidative stress and after the treatment with hypericin. Scratch assay was performed under oxidative stress to evaluate the efficacy of hypericin in wound closure. To gain an insight into the molecular mechanisms of hypericin bioactivity, we analyzed the relative expression levels of genes involved in oxidative response and in wound healing process.

RESULTS

We found that the exposure of NHDF to hypericin under oxidative stress resulted in an increase in cell viability and ATP levels. We found a decrease in apoptosis and mitochondrial superoxide levels after treatment with hypericin. Moreover, treatment with hypericin reduced wound area and promoted wound closure. The levels of selected genes showed that hypericin upregulated the levels of antioxidants genes. Moreover, treatment with hypericin in wound under oxidative stress downregulated the levels of proinflammatory cytokines, and metalloproteinases; and upregulated transcription factors and extracellular matrix genes.

CONCLUSION

These findings indicated that hypericin possesses significant in vitro antioxidant activity on NHDF and provide new insights into its potential beneficial role in the management of diabetic ulcers.

Corneal Confocal Microscopy Predicts Cardiovascular and Cerebrovascular Events and Demonstrates Greater Peripheral Neuropathy in Patients with Type 1 Diabetes and Foot Ulcers

OBJECTIVE

In this study, we evaluate small and large nerve fibre pathology in relation to diabetic foot ulceration (DFU) and incident cardiovascular and cerebrovascular events in type 1 diabetes (T1D).

METHODS

A prospective observational study was conducted on people with T1D without diabetic peripheral neuropathy (DPN) (n = 25), T1D with DPN (n = 28), T1D with DFU (n = 25) and 32 healthy volunteers. ROC analysis of parameters was conducted to diagnose DPN and DFU, and multivariate Cox regression analysis was performed to evaluate the predictive ability of corneal nerves for cardiac and cerebrovascular events over 3 years.

RESULTS

Corneal nerve fibre length (CNFL), fibre density (CNFD) and branch density (CNBD) were lower in T1D-DPN and T1D-DFU vs. T1D (all p < 0.001). In ROC analysis, CNFD (sensitivity 88%, specificity 87%; AUC 0.93; p < 0.001; optimal cut-off 7.35 no/mm2) and CNFL (sensitivity 76%, specificity 77%; AUC 0.90; p < 0.001; optimal cut-off 7.01 mm/mm2) had good ability to differentiate T1D with and without DFU. Incident cardiovascular events (p < 0.001) and cerebrovascular events (p < 0.001) were significantly higher in T1D-DPN and T1D-DFU. Corneal nerve loss, specifically CNFD predicted incident cardiovascular (HR 1.67, 95% CI 1.12 to 2.50, p = 0.01) and cerebrovascular (HR 1.55, 95% CI 1.06 to 2.26, p = 0.02) events.

CONCLUSIONS

Our study provides threshold values for corneal nerve fibre metrics for neuropathic foot at risk of DFU and further demonstrates that lower CNFD predicts incident cardiovascular and cerebrovascular events in T1D.

Crural and Plantar Fasciae Changes in Chronic Charcot Diabetic Foot: A Cross-Sectional Ultrasound Imaging Study-An Evidence of Fascial Continuity

Crural fascia (CF) and plantar fascia (PF) are biomechanically crucial in the gait and in the proprioception, particularly in the propulsion phase of the foot during the gait cycle and in the dissipation of forces during weight-bearing activities. Recent studies have revealed an association between increases in PF thickness and diabetes. The purpose of this study was to measure and compare by ultrasound (US) imaging the thickness of the CF and PF at different regions/levels in chronic Charcot diabetic foot patients (group 1) and in healthy volunteers (group 2). A cross-sectional study was performed using US imaging to measure the CF with Pirri et al.'s protocol and PF with a new protocol in a sample of 31 subjects (15 patients and 16 healthy participants). The findings for CF and PF revealed statistically significant differences in the poster region of CF (Post 1: group 1 vs. group 2: p = 0.03; Post 2: group 1 vs. group 2: p = 0.03) and in PF at two different levels (PF level 1: group 1 vs. group 2: p < 0.0001; PF level 2: group 1 vs. group 2: p < 0.0001). These findings suggest that chronic Charcot diabetic foot patients have CF and PF thicker compared to healthy volunteers. The US examination suggests that fascial thicknesses behavior in these patients points out altered fascial remodeling due to diabetes pathology and biomechanical changes.

Plantar threshold sensitivity assessment using an automated tool-Clinical assessment comparison between a control population without type 2 diabetes mellitus, and populations with type 2 diabetes mellitus, with and without neuropathy symptoms

Diabetic peripheral neuropathy is often classified as a loss of sensation in the extremities, particularly in elderly populations. The most common diagnosis technique is with the use of the hand-applied Semmes-Weinstein monofilament. This study's first aim was to quantify and compare sensation on the plantar surface in healthy and type 2 diabetes mellitus populations with the standard Semmes-Weinstein hand-applied methodology and a tool that automates this approach. The second was to evaluate correlations between sensation and the subjects' medical characteristics. Sensation was quantified by both tools, at thirteen locations per foot, in three populations: Group 1-control subjects without type 2 diabetes, Group 2-subjects with type 2 diabetes and with neuropathy symptoms, and Group 3-subjects with type 2 diabetes without neuropathy symptoms. The percentage of locations sensitive to the hand-applied monofilament, yet insensitive to the automated tool was calculated. Linear regression analyses between sensation and the subject's age, body mass index, ankle brachial index, and hyperglycemia metrics were performed per group. ANOVAs determined differences between populations. Approximately 22.5% of locations assessed were sensitive to the hand-applied monofilament, yet insensitive to the automated tool. Age and sensation were only significantly correlated in Group 1 (R2 = 0.3422, P = 0.004). Sensation was not significantly correlated with the other medical characteristics per group. Differences in sensation between the groups were not significant (P = 0.063). Caution is recommended when using hand-applied monofilaments. Group 1's sensation was correlated to age. The other medical characteristics failed to corelate with sensation, despite group.

Incidence of Lower Extremity Amputation in Romania: A Nationwide 5-Year Cohort Study, 2015-2019

Background and Objectives: The primary objective of this study was to investigate the incidence of lower extremity amputations (LEAs) in a representative population from Romania, in both diabetic and non-diabetic adults, including trauma-related amputations. The secondary objective was to evaluate the trends in LEAs and the overall ratio of major-to-minor amputations. Material and Methods: The study was retrospective and included data from the Romanian National Hospital Discharge Records, conducted between 1 January 2015 and 31 December 2019. Results: The overall number of cases with LEAs was 88,102, out of which 38,590 were aterosclerosis-related LEAs, 40,499 were diabetes-related LEAs, and 9013 were trauma-related LEAs, with an ascending trend observed annually for each of these categories. Of the total non-traumatic amputations, 51.2% were in patients with diabetes. Most LEAs were in men. The total incidence increased from 80.61/100,000 in 2015 to 98.15/100,000 in 2019. Conclusions: Our study reported a 21% increase in total LEAs, 22.01% in non-traumatic LEAs, and 19.65% in trauma-related amputation. The minor-to-major amputation ratio increased over the study period in patients with diabetes. According to these findings, it is estimated that currently, in Romania, there is one diabetes-related amputation every hour and one non-traumatic amputation every 30 min.

Cholesterol Levels and Monocyte Phenotype Are Predictors of Nonhealing in Individuals with Low-Grade Diabetic Foot Ulcers: A Prospective Cohort Study

Objective: Inflammation has been linked to progression of diabetic foot ulcers (DFU); however, specific predictive markers of nonhealing are scarce. The goal of this study was to identify biochemical and immunological parameters from the blood as predictors of nonhealing in grade 1 and grade 2 DFU. Approach: Individuals with low-grade foot ulcers were enrolled in the study to determine if histopathological, biochemical, and immunological parameters could be used to predict individuals whose ulcers would not heal. Data analysis was performed using traditional univariate analyses as well as univariate and multivariable logistic regression, and STROBE guidelines were used for reporting data. Results: Among the 52 individuals who completed the study, we observe that no single histopathological and biochemical parameter was predictive. Conventional univariate analysis and univariate logistic regression analysis showed that the expression of the cell surface proteins CD63, HLA-DR, and CD11b on monocytes was significantly lower in nonhealed individuals, but with moderate discriminative ability. In comparison, a multivariable logistic regression model identified four of the 31 parameters to be salient predictors with low density lipoprotein (LDL) cholesterol (odds ratio [OR] 18.83, confidence interval [CI] 18.83-342) and cell-surface expression of CD63 on monocytes (OR 0.12, CI 0.12-0.45) showing significance and demonstrating high discrimination ability. Innovation: The approach of using a combination of biochemical and immunological parameters to predict ulcer healing is new. Conclusion: Through this study we conclude that LDL cholesterol and cell-surface expression of CD63 on monocytes strongly correlate with nonhealing in individuals with grade 1 and grade 2 DFU.

A Review of Recent Pharmacological Advances in the Management of Diabetes-Associated Peripheral Neuropathy

Diabetic peripheral neuropathy is a common complication of longstanding diabetes mellitus. These neuropathies can present in various forms, and with the increasing prevalence of diabetes mellitus, a subsequent increase in peripheral neuropathy cases has been noted. Peripheral neuropathy has a significant societal and economic burden, with patients requiring concomitant medication and often experiencing a decline in their quality of life. There is currently a wide variety of pharmacological interventions, including serotonin norepinephrine reuptake inhibitors, gapentanoids, sodium channel blockers, and tricyclic antidepressants. These medications will be discussed, as well as their respective efficacies. Recent advances in the treatment of diabetes mellitus with incretin system-modulating drugs, specifically glucagon-like peptide-1 agonists, have been promising, and their potential implication in the treatment of peripheral diabetic neuropathy is discussed in this review.

Offloading effects of a removable cast walker with and without modification for diabetes-related foot ulceration: a plantar pressure study

BACKGROUND

Removable cast walkers (RCWs), with or without modifications, are used to offload diabetes-related foot ulcers (DRFUs), however there is limited data relating to their offloading effects. This study aimed to quantify plantar pressure reductions with an RCW with and without modification for DRFUs.

METHODS

This within-participant, repeated measures study included 16 participants with plantar neuropathic DRFUs. Walking peak plantar pressures at DRFU sites were measured for four conditions: post-operative boot (control condition), RCW alone, RCW with 20 mm of felt adhered to an orthosis, and RCW with 20 mm of felt adhered to the foot.

RESULTS

Compared to the control condition, the greatest amount of peak plantar pressure reduction occurred with the RCW with felt adhered to the foot (83.1% reduction, p < .001). The RCW with felt adhered to the foot also offered greater peak plantar pressure reduction than the RCW alone (51.3%, p = .021) and the RCW with felt adhered to an orthosis (31.4%, p = .009).

CONCLUSION

The largest offloading effect recorded was with the RCW with felt adhered to the foot. High-quality randomised trials are now needed to evaluate the effectiveness of this device for healing DRFUs.

Nagging Pain and Foot Ulcers Can be Treated into Remission

Lower extremity ulcerations are very common in patients with diabetes. These wounds lead to amputation in a surprisingly large percentage of patients with diabetes. The mortality rate following amputation in a patient with diabetes is alarmingly high. Preventive treatment is pivotal to avoid the numerous complications associated with diabetic ulcerations. However, at the onset of ulceration, early treatment under the supervision and guidance of a specialist can result in remission. Diabetic peripheral neuropathy is also a life-altering and debilitating disease. Although some patients experience numbness, some experience pain that can be sharp, shooting, and tingling. Although treatment is challenging and often requires medication, newer modalities, such as stimulation and physical therapy, have shown promise in reversing the devastating effects of peripheral neuropathy.

Efficacy of Polydeoxyribonucleotide in Promoting the Healing of Diabetic Wounds in a Murine Model of Streptozotocin-Induced Diabetes: A Pilot Experiment

We assessed the efficacy of polydeoxyribonucleotide (PDRN) in accelerating the healing of diabetic wounds in a murine model of streptozotocin (STZ)-induced diabetes. After the creation of diabetic wounds, the mice of the PDRN SC, PDRN IP and PBS groups received a subcutaneous, an intra-peritoneal injection of PDRN and a subcutaneous injection of PBS, respectively. After euthanasia, time-dependent changes in the wound diameter and histologic scores were measured and vascular endothelial growth factor (VEGF), transforming growth factor-β1 (TGF-β1) and collagen types I and III were assessed for their expression levels. The PDRN SC and the PDRN IP groups showed a significantly smaller diameter of diabetic wounds, significantly higher histologic scores, a significantly greater expression of VEGF, a significantly lower expression of TGF-β1 and a significantly greater expression of collagen types I and III as compared with the PBS group (p < 0.05 or 0.0001). In conclusion, PDRN might be effective in promoting the healing of diabetic wounds in a murine model of STZ-induced diabetes.

Etiology, Epidemiology, and Disparities in the Burden of Diabetic Foot Ulcers

Diabetic foot ulcers (DFU) are a major source of preventable morbidity in adults with diabetes. Consequences of foot ulcers include decline in functional status, infection, hospitalization, lower-extremity amputation, and death. The lifetime risk of foot ulcer is 19% to 34%, and this number is rising with increased longevity and medical complexity of people with diabetes. Morbidity following incident ulceration is high, with recurrence rates of 65% at 3-5 years, lifetime lower-extremity amputation incidence of 20%, and 5-year mortality of 50-70%. New data suggest overall amputation incidence has increased by as much as 50% in some regions over the past several years after a long period of decline, especially in young and racial and ethnic minority populations. DFU are a common and highly morbid complication of diabetes. The pathway to ulceration, involving loss of sensation, ischemia, and minor trauma, is well established. Amputation and mortality after DFU represent late-stage complications and are strongly linked to poor diabetes management. Current efforts to improve care of patients with DFU have not resulted in consistently lower amputation rates, with evidence of widening disparities and implications for equity in diabetes care. Prevention and early detection of DFU through guideline-directed multidisciplinary care is critical to decrease the morbidity and disparities associated with DFU. This review describes the epidemiology, presentation, and sequelae of DFU, summarizes current evidence-based recommendations for screening and prevention, and highlights disparities in care and outcomes.

Development and validation of a risk prediction model for early diabetic peripheral neuropathy based on a systematic review and meta-analysis

Background

Early identification and intervention of diabetic peripheral neuropathy is beneficial to improve clinical outcome.

Objective

To establish a risk prediction model for diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes mellitus (T2DM).

Methods

The derivation cohort was from a meta-analysis. Risk factors and the corresponding risk ratio (RR) were extracted. Only risk factors with statistical significance were included in the model and were scored by their weightings. An external cohort were used to validate this model. The outcome was the occurrence of DPN.

Results

A total of 95,604 patients with T2DM from 18 cohorts were included. Age, smoking, body mass index, duration of diabetes, hemoglobin A1c, low HDL-c, high triglyceride, hypertension, diabetic retinopathy, diabetic kidney disease, and cardiovascular disease were enrolled in the final model. The highest score was 52.0. The median follow-up of validation cohort was 4.29 years. The optimal cut-off point was 17.0, with a sensitivity of 0.846 and a specificity of 0.668, respectively. According to the total scores, patients from the validation cohort were divided into low-, moderate-, high- and very high-risk groups. The risk of developing DPN was significantly increased in moderate- (RR 3.3, 95% CI 1.5-7.2, P = 0.020), high- (RR 15.5, 95% CI 7.6-31.6, P < 0.001), and very high-risk groups (RR 45.0, 95% CI 20.5-98.8, P < 0.001) compared with the low-risk group.

Conclusion

A risk prediction model for DPN including 11 common clinical indicators were established. It is a simple and reliable tool for early prevention and intervention of DPN in patients with T2DM.

Factors Associated with the Local Increase of Skin Temperature, 'Hotspot,' of Callus in Diabetic Foot: A Cross-Sectional Study

BACKGROUND

Increased local skin temperature (hotspot) on a callus site as detected by thermography is a well-known precursor of diabetic foot ulcers. This study aimed to determine the factors associated with callus hotspots in order to predict the risk of callus hotspots and then provide information for specific interventions.

METHODS

In this cross-sectional study, 1,007 patients' data from a diabetic foot prevention clinic between April 2008 and March 2020 were used. Data regarding patients' characteristics, foot calluses, and callus hotspots were collected and analyzed. Callus and callus hotspot were confirmed from foot photos and thermographs, respectively. A callus hotspot was defined as a relative increase in temperature compared to the skin surrounding the callus on the thermograph. Plantar pressure was measured with a pressure distribution measurement system. A generalized linear mixed model was used to identify the factors associated with callus hotspots.

RESULTS

Among the 2,014 feet, 28.5% had calluses, and 18.5% of feet with calluses had callus hotspots. The factors associated with callus hotspots were number of calluses (Adjusted odds ratio (aOR): 1.540, P = .003), static forefoot peak plantar pressure (SFPPP) (aOR: 1.008, P = .001), and body mass index (aOR: 0.912, P = .029).

CONCLUSIONS

Patients with a higher SFPPP were more likely to have callus hotspots suggesting that SFPPP might contribute to callus inflammation. SFPPP has the potential to be a useful predictor of callus hotspots in people with diabetes and at the same time provide information for off-loading interventions to prevent callus hotspots.

Immunomodulatory Bandage for Accelerated Healing of Diabetic Wounds

Diabetic foot ulcers are challenging to treat. Current strategies to treat these wounds focus on preventing infection and promoting tissue regrowth but are ineffective in many individuals. Low-grade chronic inflammation is present in individuals with diabetes, and altering the inflammatory responses at the wound site could be an alternate approach to promote healing. We hypothesized that immunomodulation of the wound microenvironment would result in accelerated healing. To test this hypothesis, we began by characterizing the changes in the myeloid cell phenotype in a mouse model [leptin receptor knockout (KO) mouse] that closely mimics the type 2 diabetes condition observed in humans. We observed increased numbers of monocytes and neutrophils in the circulation of the KO mice compared to that in wild-type control mice. We also observed several phenotypic changes in neutrophils from the KO diabetic mice, suggesting low-grade systemic inflammation. Hence, we developed a rapamycin-loaded chitosan scaffold that may be used to modulate immune responses. The use of these immunomodulatory scaffolds at a wound site resulted in accelerated healing compared to the healing using blank scaffolds. In summary, our data suggest that immunomodulation may be a viable strategy to promote the healing of wounds in individuals with diabetes.

DPSC Products Accelerate Wound Healing in Diabetic Mice through Induction of SMAD Molecules

Despite advances in diabetic wound care, many amputations are still needed each year due to their diabetic wounds, so a more effective therapy is warranted. Herein, we show that the dental pulp-derived stem cell (DPSC) products are effective in wound healing in diabetic NOD/SCID mice. Our results showed that the topical application of DPSC secretory products accelerated wound closure by inducing faster re-epithelialization, angiogenesis, and recellularization. In addition, the number of neutrophils producing myeloperoxidase, which mediates persisting inflammation, was also reduced. NFκB and its downstream effector molecules like IL-6 cause sustained pro-inflammatory activity and were reduced after the application of DPSC products in the experimental wounds. Moreover, the DPSC products also inhibited the activation of NFκB, and its translocation to the nucleus, by which it initiates the inflammation. Furthermore, the levels of TGF-β, and IL-10, potent anti-inflammatory molecules, were also increased after the addition of DPSC products. Mechanistically, we showed that this wound-healing process was mediated by the upregulation and activation of Smad 1 and 2 molecules. In sum, we have defined the cellular and molecular mechanisms by which DPSC products accelerated diabetic wound closure, which can be used to treat diabetic wounds in the near future.

Diabetic Neuropathy in Hands: An Endemic Complication Waiting to Unfold?

In this cross-sectional study we aimed to quantify the somatosensory dysfunction in the hand in people with diabetes with distal symmetrical polyneuropathy (DSPN) in hands and explore early signs of nerve dysfunction in people with diabetes without DSPN in hands. The clinical diagnosis of DSPN was confirmed with electrodiagnosis and corneal confocal microscopy. Thermal and mechanical nerve function in the hand was assessed with quantitative sensory tests. Measurements were compared between healthy participants (n = 31), individuals with diabetes without DSPN (n = 35), individuals with DSPN in feet but not hands (DSPNFEET ONLY) (n = 31), and individuals with DSPN in hands and feet (DSPNHANDS & FEET) (n = 28) with one-way between-group ANOVA. The somatosensory profile of the hand in people with DSPNHANDS & FEET showed widespread loss of thermal and mechanical detection. This profile in hands is comparable with the profile in the feet of people with DSPN in feet. Remarkably, individuals with DSPNFEET ONLY already showed a similar profile of widespread loss of nerve function in their hands. People with diabetes without DSPN in feet already had some nerve dysfunction in their hands. These findings suggest that nerve function assessment in hands should become more routine in people with diabetes.

Is in-Shoe Microclimate a Neglected Contributor in the Pathway to Diabetic Foot Ulceration?

The identification of the key contributing factors which predispose the foot to ulceration, increasing the risk of recurrence and slow wound healing in diabetes mellitus (DM), has led to some significant research studies over the last 30 years, providing valuable insight into the mechanism leading to diabetic foot ulceration (DFU). Although, these contributory factors are similar to those identified in pressure ulceration occurring in other parts of the body (such as "bed pressure sores') where magnitude and/or duration of mechanical stress in the presence of sensory deficits are key causal factors, research investigating pressure ulceration has also included measurement of temperature and relative humidity at the interface between the skin and supporting surface. The possible influence of these parameters (in-shoe temperature and humidity) does not appear frequently in diabetic foot ulceration research. Referred to as "microclimate", this has an important role in the pathway to tissue breakdown evidenced in pressure ulcer research and may be particularly relevant in countries with warm and humid climates. As the microclimate is influential in the ulceration pathway for other body sites, its role in the DFU causal pathway justifies further investigation.

Hyperbaric oxygen therapy as an adjunct to the standard wound care for the treatment of diabetic foot ulcers in Indian patients: a cost utility analysis

BACKGROUND

Diabetic foot ulcer (DFU) is a common complication of diabetes. Hyperbaric oxygen therapy (HBOT) is an adjunct treatment that expedites the healing of DFU.

AIM

To evaluate the cost-utility of using standard wound care (SWC) plus HBOT as compared to SWC alone for the treatment of DFU from a societal perspective in the Indian context.

METHOD

A Markov decision analysis model comparing SWC with and without HBOT was developed. Data for the model were derived from relevant literature and secondary data from India. The main outcome measures were minor and major lower extremity amputations (LEA) averted, incremental quality-adjusted-life-years (QALY) gained, incremental costs, incremental cost-effectiveness ratio (ICER) per amputation averted and ICER per QALY gained. Sensitivity and threshold analyses were also done.

RESULT

HBOT, when added to SWC, lowered the proportion of minor LEA and major LEA among patients with DFU by 6.1% and 4.2%, respectively. The discounted ICER was INR 193,939 [95% CI: 186,745-203,753] or US$ 2,621 [95% CI: 2,524-2,753] per QALY gained.

CONCLUSION

SWC plus HBOT is not cost-effective in India. Additional information is required on patient experiences with adjunctive HBOT, if it were to be adopted as the standard of care in India.

Enhanced growth factor expression in chronic diabetic wounds treated by cold atmospheric plasma

AIMS

Cold atmospheric plasma (CAP) has been proven to enhance wound healing in superficial, chronically infected, diabetic foot ulcers. We aimed to investigate the molecular drivers responsible for this macroscopically observed improvement in diabetic wound healing.

METHODS

Wound exudate was available from each change of dressing within a prospective, randomised, patient-blinded clinical trial. Specific protein level analyses were conducted via multiplex ELISA for wound samples of a representative subcohort (placebo: n = 13; CAP: n = 14). Expression of fibroblast growth factor 2 (FGF-2), vascular endothelial growth factor A (VEGF-A), cytokines and matrix metalloproteinases (MMPs) were evaluated over a treatment period of about 14 days.

RESULTS

Analysis revealed increased levels of the growth factors FGF-2 (placebo: median 46.9 range [32.0-168.6] AU vs. CAP: 113.7[55.8-208.1] AU) and VEGF-A (placebo: 79.7 [52.4-162.7] AU vs. CAP: 120.8 [51.1-198.1] AU) throughout the treatment period and in head-to-head comparison in a daily assessment. CAP-treated wounds showed increased levels of tumour necrosis factor-alpha, interleukins 1α and 8. However, the total protein amounts were not significantly elevated. The total protein amounts of MMPs were not altered by CAP.

CONCLUSIONS

Induction of crucial growth factors, like FGF-2 and VEGF-A, and interleukins appears to be an important component of CAP-mediated promotion of granulation, vascularisation and reepithelialisation in the diabetic foot. These findings demonstrate for the first time that CAP-mediated growth factor induction also occurs in persons with diabetes, as previously described only in several in vitro and rodent experiments. Clinical Trial registration KPWTRIAL: NCT04205942, ClinicalTrials.gov.

Efficacy Comparison Study of Human Epidermal Growth Factor (EGF) between Heberprot-P® and Easyef® in Adult Zebrafish and Embryo under Presence or Absence Combination of Diabetic Condition and Hyperlipidemia to Mimic Elderly Patients

Recombinant human epidermal growth factor (EGF) has been used to treat adult diabetic foot ulcers and pediatric burns by facilitating wound healing and epithelization, especially for elderly patients. Several formulation types of EGF from different expression hosts are clinically available, such as intralesional injection and topical application. On the other hand, no study has compared the in vivo efficacy of EGF products directly in terms of tissue regeneration and wound healing activity. The present study compared two commercial products, Heberprot-P75® and Easyef®, in terms of their tissue regeneration activity in adult zebrafish and the developmental speed of zebrafish embryos. Fluorescence spectroscopy showed that the two EGF products had different Trp fluorescence emission spectra: Easyef® showed a wavelength of maximum fluorescence (WMF) of 337 nm with weak fluorescence intensity (FI), while Heberprot-P75® showed WMF of 349 nm with a 4.1 times stronger FI than that of Easyef®. The WMF of Heberprot-P75® was quenched by adding singlet oxygen in ozonated oil, while the WMF of Easyef® was not quenched. Treatment with Heberprot-P75® induced greater embryo development speed with a higher survival rate after exposure to EGF in water and microinjection into embryos. Under normal diet (ND) consumption, Heberprot-P75® showed a 1.4 times higher tail fin regeneration activity than Easyef® during seven days from the intraperitoneal injection (10 μL, 50 μg/mL) after amputating the tail fin. Under ND consumption and diabetic condition caused by streptozotocin (STZ) treatment, Heberprot-P75® showed 2.1 times higher tail fin regeneration activity than Easyef® from the same injection and amputation protocol. Under a high-cholesterol diet (HCD) alone, Heberprot-P75® showed 1.2 times higher tail fin regeneration activity than the Easyef® group and PBS group from the same injection and amputation. Under diabetic conditions (STZ-injected) and HCD consumption, the Heberprot-P75® group showed 1.7 and 1.5 times higher tail fin regeneration activity than the Easyef® group and PBS group, respectively, with a distinct and clean regeneration pattern. In contrast, the Easyef® group and PBS group showed ambiguous regeneration patterns with a severe fissure of the tail fin, which is a typical symptom of a diabetic foot. In conclusion, Heberprot-P75® and Easyef® have different Trp fluorescence properties in terms of the WMF and fluorescence quenching. Treatment of Heberprot-P75® induced a greater developmental speed of zebrafish embryos in both water exposure and microinjection. Heberprot-P75® induced significantly higher wound healing and tissue regeneration activity than Easyef® and PBS in the presence or absence of diabetic conditions and cholesterol supplementation.

The Gut-Skin Microbiota Axis and Its Role in Diabetic Wound Healing-A Review Based on Current Literature

Diabetic foot ulcers (DFU) are a growing concern worldwide as they pose complications in routine clinical practices such as diagnosis and management. Bacterial interactions on the skin surface are vital to the pathophysiology of DFU and may control delayed wound healing. The microbiota from our skin directly regulates cutaneous health and disease by interacting with the numerous cells involved in the wound healing mechanism. Commensal microbiota, in particular, interact with wound-repairing skin cells to enhance barrier regeneration. The observed microbes in DFU include Staphylococcus, Streptococcus, Corynebacterium, Pseudomonas, and several anaerobes. Skin commensal microbes, namely S. epidermidis, can regulate the gamma delta T cells and induce Perforin-2 expression. The increased expression of Perforin-2 by skin cells destroyed S. aureus within the cells, facilitating wound healing. Possible crosstalk between the human commensal microbiome and different cell types involved in cutaneous wound healing promotes the immune response and helps to maintain the barrier function in humans. Wound healing is a highly well-coordinated, complex mechanism; it can be devastating if interrupted. Skin microbiomes are being studied in relation to the gut-skin axis along with their effects on dermatologic conditions. The gut-skin axis illustrates the connection wherein the gut can impact skin health due to its immunological and metabolic properties. The precise mechanism underlying gut-skin microbial interactions is still unidentified, but the immune and endocrine systems are likely to be involved. Next-generation sequencing and the development of bioinformatics pipelines may considerably improve the understanding of the microbiome-skin axis involved in diabetic wound healing in a much more sophisticated way. We endeavor to shed light on the importance of these pathways in the pathomechanisms of the most prevalent inflammatory conditions including the diabetes wound healing, as well as how probiotics may intervene in the gut-skin axis.

Detection of diabetic polyneuropathy in a family medicine clinic by using monofilament

Background/Aim. Diabetic polyneuropathy (DPN) is the most common microvascular complication of diabetes mellitus (DM), which may be present at the time of disease detection. Screening for DPN is performed for the patients with type 2 diabetes at the time of diagnosis and for type 1 diabetes 5 years after diagnosis. The primary aim of this study was to determine the prevalence of DNP among family medicine patients with DM aged 18 to 70 years using nylon monofilament. Methods. The cross-sectional study estimated the prevalence of DPN among primary care patients with DM in Banja Luka, Republic of Srpska, Bosnia and Herzegovina. Semmes-Weinstein nylon 10 g monofilament was used to detect DPN. Age, gender, duration of DM, type of therapy, symptoms, glycosylated hemoglobin (HbA1c), and risk factors (hypertension, smoking, dyslipidemia, obesity, physical inactivity) were analyzed. Data collection took place from June 1st, 2017 to May 31st, 2018. Results. The study included 228 patients, 132 (57.9%) men and 96 (42.1%) women. There was a statistically significant difference in the presence of all symptoms of DPN (tingling, burning, light burning, and stinging) among patients with different duration of DM (p < 0.01). Multivariate logistic regression revealed that patients who had hypertension [odds ratio (OR) = 26.2; 95% confidence interval (CI): 4.070?168.488; p = 0.001], used oral anti-diabetic therapy (OR = 12.3; 95% CI: 1.300?116.309; p = 0.029), had tingling (OR = 5.2; 95% CI: 1.431?18.571; p = 0.012) and a longer duration of diabetes (OR = 4.27; 95% CI: 1.983?9.175; p = 0.000) were more likely to have DPN. Conclusion. The prevalence of DPN in family medicine patients with DM using nylon monofilament was 24.2%. Determinants of DNP were the presence of symptoms of tingling, duration of diabetes, hypertension, and the use of oral antidiabetic therapy alone.

Evaluation of Immunomodulatory Responses and Changed Wound Healing in Type 2 Diabetes-A Study Exploiting Dermal Fibroblasts from Diabetic and Non-Diabetic Human Donors

The dermis is the connective layer between the epidermis and subcutis and harbours nerve endings, glands, blood vessels, and hair follicles. The most abundant cell type is the fibroblast. Dermal fibroblasts have a versatile portfolio of functions within the dermis that correspond with different types of cells by either direct contact or by autocrine and paracrine signalling. Diabetic skin is characterized by itching, numbness, ulcers, eczema, and other pathophysiological changes. These pathogenic phenotypes have been associated with the effects of the reactive glucose metabolite methylglyoxal (MGO) on dermal cells. In this study, dermal fibroblasts were isolated from diabetic and non-diabetic human donors. Cultured dermal fibroblasts from diabetic donors exhibited reduced insulin-induced glucose uptake and reduced expression of the insulin receptor. This diabetic phenotype persists under cell culture conditions. Secretion of IL-6 was increased in fibroblasts from diabetic donors. Increased secretion of IL-6 and MIF was also observed upon the treatment of dermal fibroblasts with MGO, suggesting that MGO is sufficient for triggering these immunomodulatory responses. Remarkably, MIF treatment resulted in decreased activity of MGO-detoxifying glyoxalase-1. Given that reduced glyoxalase activity results in increased MGO levels, these findings suggested a positive-feedback loop for MGO generation, in which MIF, evoked by MGO, in turn blocks MGO-degrading glyoxalase activity. Finally, secretion of procollagen Type I C-Peptide (PICP), a marker of collagen production, was reduced in fibroblast from diabetic donors. Remarkably, treatment of fibroblasts with either MGO or MIF was sufficient for inducing reduced PICP levels. The observations of this study unravel a signalling network in human dermal fibroblasts with the metabolite MGO being sufficient for inflammation and delayed wound healing, hallmarks of T2D.

MiR-770-5p, miR-661 and miR-571 expression level in serum and tissue samples of foot ulcer caused by diabetes mellitus type II in Iranian population

BACKGROUND

Microvascular complications related to diabetes mellitus type II such as foot ulcers are the reason of many mortalities among T2DM patients. The role of microRNAs (miRNAs, miRs) as potent regulators of gene expression is studied in different diseases such as diabetes mellitus and primary studies revealed their importance as early detecting biomarkers. Therefore, in this study it is tried to evaluate the expression level of some miRNAs (miR-770-5p, miR-661 and miR-571) in serum and tissue samples of T2DM related foot ulcer among Iranian patients.

METHODS

30 samples of blood and 30 muscle tissue were collected from T2DM patients suffering foot ulcer (T2DM + FU), 30 blood samples collected from T2DM patients without foot ulcer (T2DM-FU). 30 tissue samples collected from patients with trauma and 30 blood samples were selected as healthy controls.

RESULTS

The three studied miRNAs were statistically significant in all groups in comparison to control blood group. Also, comparison between other groups showed a significant increase of all studied miRNAs especially in the blood and tissues of T2DM + FU patients. The only significant correlation detected between the FBS level and miR-571 expression pattern in blood samples of T2DM + FU group. Finally, the results showed that miR-571, -661, and -770 has a statistically significant discriminative character for differentiating T2DM + FU patients from T2DM-FU both in tissue and blood samples.

CONCLUSION

Although more studies are essential for certifying these findings, our results showed that miR-770-5p, miR-661 and miR-571 are correlated with the microvascular complications related with T2DM such as foot ulcer.

Risk factors for diabetic foot ulcers in metreleptin naïve patients with lipodystrophy

AIM

Patients with lipodystrophy are at high risk for chronic complications of diabetes. Recently, we have reported 18 diabetic foot ulcer episodes in 9 subjects with lipodystrophy. This current study aims to determine risk factors associated with foot ulcer development in this rare disease population.

METHODS

Ninety metreleptin naïve patients with diabetes registered in our national lipodystrophy database were included in this observational retrospective cohort study (9 with and 81 without foot ulcers).

RESULTS

Patients with lipodystrophy developing foot ulcers had longer diabetes duration (p = 0.007), longer time since lipodystrophy diagnosis (p = 0.008), and higher HbA1c levels (p = 0.041). Insulin use was more prevalent (p = 0.003). The time from diagnosis of diabetes to first foot ulcer was shorter for patients with generalized lipodystrophy compared to partial lipodystrophy (p = 0.036). Retinopathy (p < 0.001), neuropathy (p < 0.001), peripheral artery disease (p = 0.001), and kidney failure (p = 0.003) were more commonly detected in patients with foot ulcers. Patients with foot ulcers tended to have lower leptin levels (p = 0.052). Multiple logistic regression estimated significant associations between foot ulcers and generalized lipodystrophy (OR: 40.81, 95% CI: 3.31-503.93, p = 0.004), long-term diabetes (≥ 15 years; OR: 27.07, 95% CI: 2.97-246.39, p = 0.003), and decreased eGFR (OR: 13.35, 95% CI: 1.96-90.67, p = 0.008).

CONCLUSIONS

Our study identified several clinical factors associated with foot ulceration among patients with lipodystrophy and diabetes. Preventive measures and effective treatment of metabolic consequences of lipodystrophy are essential to prevent the occurrence of foot ulcers in these high-risk individuals.

Concomitant Peripheral Neuropathy and Type 2 Diabetes Impairs Postexercise Cutaneous Perfusion and Flowmotion

CONTEXT

Type 2 diabetes and peripheral neuropathy exhibit microvascular dysfunction at rest. However, data regarding their microvascular perfusion during exercise remain scarce.

OBJECTIVE

This study investigated changes in microvascular perfusion during postexercise recovery in those with type 2 diabetes, with or without peripheral neuropathy, as well as in healthy controls and those with obesity.

METHODS

Skin blood perfusion was assessed in each group using laser Doppler flowmetry (LDF) and laser speckle contrast imaging before and immediately after a 6-minute walking test. LDF recordings underwent wavelet transformation to allow specific control mechanisms of blood perfusion to be studied (eg, endothelial nitric oxide-independent and -dependent, neurogenic, myogenic, respiratory, and cardiac mechanisms).

RESULTS

Skin blood perfusion increased after exercise in all groups (22.3 ± 28.1% with laser speckle contrast imaging and 22.1 ± 52.5% with LDF). Throughout postexercise recovery, the decrease was blunted in those with subclinical peripheral neuropathy and confirmed peripheral neuropathy when compared to the other 3 groups. After exercise, total spectral power increased in all groups. The relative contributions of each endothelial band was lower in those with confirmed peripheral neuropathy than in the healthy controls and those with obesity (nitric oxide-dependent function: 23.6 ± 8.9% vs 35.5 ± 5.8% and 29.3 ± 8.8%, respectively; nitric oxide-independent function: 49.1 ± 23.7% vs 53.3 ± 10.4% and 64.6 ± 11.4%, respectively). The neurogenic contribution decreased less in those with confirmed peripheral neuropathy and in those with type 2 diabetes alone, compared to those with subclinical peripheral neuropathy and those with obesity (-14.5 ± 9.9% and -12.2 ± 6.1% vs -26.5 ± 4.7% and -21.7 ± 9.4%, respectively).

CONCLUSION

Peripheral neuropathy, whatever the stage, altered the microvascular response to exercise via impaired endothelial and neurogenic mechanisms.

Improved healing of chronic diabetic foot wounds in a prospective randomised controlled multi-centre clinical trial with a microvascular tissue allograft

This study assesses the impact of a processed microvascular tissue (PMVT) allograft on wound closure and healing in a prospective, single‐blinded, multi‐centre, randomised controlled clinical trial of 100 subjects with Wagner Grade 1 and 2 chronic neuropathic diabetic foot ulcerations. In addition to standard wound care, including standardised offloading, the treatment arm received PMVT while the control arm received a collagen alginate dressing. The primary endpoint was complete wound closure at 12 weeks. Secondary endpoints assessed on all subjects were percent wound area reduction, time to healing, and local neuropathy. Novel exploratory sub‐studies were conducted for wound area perfusion and changes in regional neuropathy. Weekly application of PMVT resulted in increased complete wound closure at 12 weeks (74% vs 38%; P = .0003), greater percent wound area reduction from weeks four through 12 (76% vs 24%; P = .009), decreased time to healing (54 days vs 64 days; P = .009), and improved local neuropathy (118% vs 11%; P = .028) compared with the control arm. Enhanced perfusion and improved regional neuropathy were demonstrated in the sub‐studies. In conclusion, this study demonstrated increased complete healing with PMVT and supports its use in treating non‐healing DFUs. The observed benefit of PMVT on the exploratory regional neuropathy and perfusion endpoints warrants further study.

A potent weighted risk model for evaluating the occurrence and severity of diabetic foot ulcers

BACKGROUND

Diabetic foot ulcer (DFU) is a serious chronic complication of diabetes. This study aimed to establish weighted risk models for determining DFU occurrence and severity in diabetic patients.

METHODS

This was a multi-center hospital-based cross-sectional study. A total of 1488 diabetic patients with or without an ulcer from three tertiary hospitals were included in the study. Random forest method was used to develop weighted risk models for assessing DFU risk and severity. Receiver operating characteristic curves were used to validate the models and calculate the optimal cut-off values of the important risk factors.

RESULTS

We developed potent weighted risk models for evaluating DFU occurrence and severity. The top eight important risk factors for DFU onset were plasma fibrinogen, neutrophil percentage and hemoglobin levels in whole blood, stroke, estimated glomerular filtration rate, age, duration of diabetes, and serum albumin levels. The top 10 important risk factors for DFU severity were serum albumin, neutrophil percentage and hemoglobin levels in whole blood, plasma fibrinogen, hemoglobin A1c, estimated glomerular filtration rate, hypertension, serum uric acid, diabetic retinopathy, and sex. Furthermore, the area under curve values in the models using plasma fibrinogen as a single risk factor for determining DFU risk and severity were 0.86 (sensitivity 0.74, specificity 0.87) and 0.73 (sensitivity 0.76, specificity 0.58), respectively. The optimal cut-off values of plasma fibrinogen for determining DFU risk and severity were 3.88 g/L and 4.74 g/L, respectively.

CONCLUSIONS

We have established potent weighted risk models for DFU onset and severity, based on which precise prevention strategies can be formulated. Modification of important risk factors may help reduce the incidence and progression of DFUs in diabetic patients.

Major Lower Limb Amputations: Recognizing Pitfalls

Major lower extremity amputations have been an area of much concern in the Caribbean population. Hence, the purpose of this research was to investigate the current trends in major lower-extremity amputations. Data regarding all major lower-extremity amputations performed at a tertiary care institution in Trinidad and Tobago, from January 2010 to December 2016 were reviewed. The variation of yearly trends, gender, type of amputation and reason for amputation were analysed. The yearly amputation rate demonstrated a progressive increase from 2010 to 2016, the average for the seven years was 28 per 105/year. Males accounted for 59% of cases, and 60% of amputations were done above the level of the knee joint. The most common reason for amputation was control of sepsis in 71.5% of cases. A strong association between major amputations and prior intervention for a foot-related problem was observed, as 52% of the sample had a pre-existing wound or a prior minor amputation (32%). Overall, 14.5% of all amputees were able to acquire a prosthesis. Diabetes mellitus was the most consistently associated co-morbidity occurring in 91% of the study population. Major limb amputations continue to affect our population significantly, with a rise in the amputation rate despite the introduction of a Vascular Surgical Unit. Diabetes and its foot-related complications are one of the leading causes of major lower extremity amputations. Prosthetic limb acquisition for our amputee population continues to be lacking, reflected by the low prosthetic acquisition rate observed.

Not Only Antimicrobial: Metronidazole Mitigates the Virulence of Proteus mirabilis Isolated from Macerated Diabetic Foot Ulcer

Diabetic foot ulcers are recognized to be a severe complication of diabetes, increasing the risk of amputation and death. The bacterial infection of Diabetic foot ulcers with virulent and resistant bacteria as Proteus mirabilis greatly worsens the wound and may not be treated with conventional therapeutics. Developing new approaches to target bacterial virulence can be helpful to conquer such infections. In the current work, we evaluated the anti-virulence activities of the widely used antibacterial metronidazole. The minimum inhibitory concentrations (MIC) and minimum biofilm eradication concentrations (MEBC) were determined for selected antibiotics which P. mirabilis was resistant to them in the presence and absence of metronidazole in sub-MIC. The effect of metronidazole in sub-MIC on P. mirabilis virulence factors as production of exoenzymes, motilities, adhesion and biofilm formation, were evaluated. Furthermore, molecular docking of metronidazole into P. mirabilis adhesion and essential quorum sensing (QS) proteins, was performed. The results revealed a significant ability of metronidazole to in-vitro inhibit P. mirabilis virulence factors and antagonize its essential proteins. Moreover, metronidazole markedly decreased the MICs and MBECs of tested antibiotics. Conclusively, metronidazole in sub-MIC is a plausible anti-virulence and anti-QS agent that can be combined to other antibiotics as anti-virulence adjuvant to defeat aggressive infections.

Common late complications of longitudinal forefoot amputations in neuropathic foot treatment

OBJECTIVE

To describe and quantify the complications arising in consecutive neuropathic patients undergoing partial longitudinal amputations of the foot.

METHOD

A retrospective study was conducted with data collected from the medical records of patients monitored at the Insensitive Foot Clinic of the Foot and Ankle Group of our institution who underwent partial amputation of foot rays from 2000 to 2016.

RESULTS

A total of 28 patients met the inclusion criteria, with a total of 31 amputated/partially amputated feet. Of these, 18 (58.1%) feet were amputated/partially amputated due to diabetes, seven (22.6%) due to leprosy, two (6.5%) due to alcoholic neuropathy, two (6.5%) secondary to traumatic peripheral nerve injury, and two (6.5%) due to other causes. Fifth ray amputation was the most frequent type (n=12). The cause of amputation was the presence of an infected ulcer in 93.6% of the samples. At a mean follow-up time of 60 months, 13 (41.9%) feet required new amputations-five (38.5%) transtibial, five (38.5%) transmetatarsal, two (15.4%) of the toes, and one (7.7%) at Chopart's joint. Patients with diabetes had a 50.0% reamputation rate. Patients who initially underwent amputation of the fifth ray had a 58.3% reamputation rate.

CONCLUSION

Partial longitudinal amputation of the foot in neuropathic patients exhibited a high reoperation rate, especially in patients with diabetes or in patients with initial amputation of the peripheral rays. Declaration of interest: The authors have no conflicts of interest.

Risk Factors for Major Amputation for Midfoot Ulcers in Hospitalized Patients With Diabetes: A Retrospective Study

PURPOSE

The purpose of this study was to investigate the risk factors for major amputation in persons hospitalized with diabetic foot ulcers involving the midfoot.

DESIGN

Retrospective study.

SUBJECTS AND SETTING

Between January 2003 and May 2019, a total of 1931 patients with diabetes were admitted to the diabetic wound center for the management of foot ulcers. Among the admitted patients, 169 patients with midfoot ulcers were included in this study. One hundred fifty-four patients (91%) healed without major amputation, while 15 patients (9%) healed post-major amputation.

METHODS

Data related to 88 potential risk factors including demographics, ulcer condition, vascularity, bioburden, neurology, and serology were collected from patients in these 2 groups for comparison. Univariate and multivariate logistic regression analyses were performed to analyze risk factors for major amputation.

RESULTS

Among the 88 potential risk factors, 15 showed statistically significant differences between the 2 groups. Using univariate analysis of 88 potential risk factors, 8 showed statistically significant differences. Using stepwise multiple logistic regression analysis, 3 of the 8 risk factors remained statistically significant. Multivariate-adjusted odds ratios for deep ulcers invading bone, cardiac disorders, and Charcot foot were 26.718, 18.739, and 16.997, respectively.

CONCLUSION

The risk factors for major amputation in patients hospitalized with diabetic midfoot ulcers included deep ulcers invading the bone, cardiac disorders, and Charcot foot.

Sedentary behaviour is an independent predictor of diabetic foot ulcer development: An 8-year prospective study

AIMS

To prospectively explore the association between sedentary time (SED-time) and the development of diabetic foot ulcer (DFU) in people with diabetic peripheral neuropathy (DPN).

METHODS

175 DPN individuals who attended the annual evaluation for the SAMBA Study (2012-2019) were included. Main outcome measure was the first diagnosis of DFU. SED-time was measured by the PAS 2.1 questionnaire. Nerve function was evaluated by nerve conduction studies. Vascular function was assessed by Ankle-brachial index (ABI) and pedal pulses. Foot deformity and skin dryness were examined by visual inspection.

RESULTS

62 participants (35.5%) developed a DFU during the study. SED-time was significantly higher in people who developed DFUs (12.8 ± 3.0 vs 9.4 ± 3.1 h/day). Logistic regression showed that among several nervous (motor amplitude, OR 0.33, 95% CI, 0.18-0.60; sensory amplitude, 0.85, 0.77-0.94) and vascular parameters (ABI, 0.23, 0.1-0.61; pedal pulses, 2.81, 0.12-0.63) and foot characteristics (deformity, 2.63, 1.30-5.32; skin dryness, 2.04, 0.95-4.37), SED-time was one of the strongest variables contributing to the development of DFUs (2.95, 1.45-6.44).

CONCLUSIONS

SED-time is an independent predictor of the risk of DFU in people with DPN. The monitoring of SED-time with strategies aimed at reducing it should be included in the standard care of diabetic patients.

Plantar soft tissues and Achilles tendon thickness and stiffness in people with diabetes: a systematic review

BACKGROUND

Diabetes mellitus is associated with changes in soft tissue structure and function. However, the directionality of this change and the extent to which either tissue thickness or stiffness contributes to the pathogenesis of diabetes-related foot ulcerations is unclear. Hence, this systematic review aims to summarise the existing evidence for soft tissue structural differences in the feet of people with and without diabetes.

METHODS

In compliance with MOOSE and PRISMA guidelines, AMED, CINAHL, MEDLINE, ProQuest Health & Medical Collection, ProQuest Nursing & Allied Health Database, and Web of Science electronic databases were systematically searched for studies published from database inception until 1st October 2020 [Prospero CRD42020166614]. Reference lists of included studies were further screened. Methodological quality was appraised using a modified critical appraisal tool for quantitative studies developed by McMaster University.

RESULTS

A total of 35 non-randomised observational studies were suitable for inclusion. Within these, 20 studies evaluated plantar tissue thickness, 19 studies evaluated plantar tissue stiffness, 9 studies evaluated Achilles tendon thickness and 5 studies evaluated Achilles tendon stiffness outcomes. No significant differences in plantar tissue thickness were found between people with and without diabetes in 55% of studies (11/20), while significantly increased plantar tissue stiffness was found in people with diabetes in 47% of studies (9/19). Significantly increased Achilles tendon thickness was found in people with diabetes in 44% of studies (4/9), while no significant differences in Achilles tendon stiffness were found between people with and without diabetes in 60% of studies (3/5).

CONCLUSIONS

This systematic review found some evidence of soft tissue structural differences between people with and without diabetes. However, uncertainty remains whether these differences independently contribute to diabetes-related foot ulcerations. The heterogeneity of methodological approaches made it difficult to compare across studies and methodological quality was generally inadequate. High-quality studies using standardised and validated assessment techniques in well-defined populations are required to determine more fully the role of structural tissue properties in the pathogenesis of diabetes-related foot ulcerations.

Assessment of Registration Methods for Thermal Infrared and Visible Images for Diabetic Foot Monitoring

This work presents a revision of four different registration methods for thermal infrared and visible images captured by a camera-based prototype for the remote monitoring of diabetic foot. This prototype uses low cost and off-the-shelf available sensors in thermal infrared and visible spectra. Four different methods (Geometric Optical Translation, Homography, Iterative Closest Point, and Affine transform with Gradient Descent) have been implemented and analyzed for the registration of images obtained from both sensors. All four algorithms' performances were evaluated using the Simultaneous Truth and Performance Level Estimation (STAPLE) together with several overlap benchmarks as the Dice coefficient and the Jaccard index. The performance of the four methods has been analyzed with the subject at a fixed focal plane and also in the vicinity of this plane. The four registration algorithms provide suitable results both at the focal plane as well as outside of it within 50 mm margin. The obtained Dice coefficients are greater than 0.950 in all scenarios, well within the margins required for the application at hand. A discussion of the obtained results under different distances is presented along with an evaluation of its robustness under changing conditions.

Quercetin Attenuates Diabetic Peripheral Neuropathy by Correcting Mitochondrial Abnormality via Activation of AMPK/PGC-1α Pathway in vivo and in vitro

The AMPK/PGC-1α pathway-mediated mitochondrial dysfunction has been supposed to play a crucial role in pathogenesis of diabetic peripheral neuropathy (DPN). The present study investigated the neuroprotective potential of quercetin, a natural AMPK activator. Streptozotocin (STZ)-induced diabetic rats that developed DPN phenotype were orally administrated with quercetin (30 and 60 mg/kg per day) for 6 weeks. The morphologic changes in the sciatic nerves (SN), the pathological structure of neurons in dorsal root ganglion (DRG), and the expressions of myelin proteins were assessed. The ATP content and the mitochondrial ultrastructure were measured. Furthermore, key proteins in the AMPK/PGC-1α pathway were determined. As a result, quercetin administration at both doses improved the paw withdrawal threshold, nerve conduction velocity, and the pathologic changes in SN and DRG of DPN rats. The expressions of myelin basic protein and myelin protein zero were also increased by quercetin. The oxidative stress, decreased ATP generation, and morphological changes of mitochondria were corrected by quercetin. In vitro study found that quercetin treatment significantly decreased the high-glucose-induced generation of reactive oxygen species, as well as attenuated the mitochondrial morphologic injuries and oxidative DNA damages of RSC96 cells. Quercetin treatment promoted the expressions of phosphorylated AMPK, PGC-1α, SIRT1, NRF1, and TFAM under hyperglycemic state in vivo and in vitro. This study revealed that the neuroprotective effect of quercetin was mainly related to mitochondrial protection by activation of the AMPK/PGC-1α pathway for the first time and proved quercetin as a potential therapeutic agent in the management of diabetic neuropathy.

Peripheral Neuropathy and All-Cause and Cardiovascular Mortality in U.S. Adults : A Prospective Cohort Study

BACKGROUND

Growing evidence indicates that peripheral neuropathy (PN) is common even in the absence of diabetes. However, the clinical sequelae of PN have not been quantified in the general population.

OBJECTIVE

To assess the associations of PN with all-cause and cardiovascular mortality in the general adult population of the United States.

DESIGN

Prospective cohort study.

SETTING

NHANES (National Health and Nutrition Examination Survey), 1999 to 2004.

PARTICIPANTS

7116 adults aged 40 years or older who had standardized monofilament testing for PN.

MEASUREMENTS

Cox regression to evaluate the associations of PN with all-cause and cardiovascular mortality after adjustment for demographic and cardiovascular risk factors, overall and stratified by diabetes status.

RESULTS

The overall prevalence of PN (±SE) was 13.5% ± 0.5% (27.0% ± 1.4% in adults with diabetes and 11.6% ± 0.5% in adults without diabetes). During a median follow-up of 13 years, 2128 participants died, including 488 of cardiovascular causes. Incidence rates (per 1000 person-years) of all-cause mortality were 57.6 (95% CI, 48.4 to 68.7) in adults with diabetes and PN, 34.3 (CI, 30.3 to 38.8) in adults with PN but no diabetes, 27.1 (CI, 23.4 to 31.5) in adults with diabetes but no PN, and 13.0 (CI, 12.1 to 14.0) in adults with no diabetes and no PN. In adjusted models, PN was significantly associated with all-cause mortality (hazard ratio [HR], 1.49 [CI, 1.15 to 1.94]) and cardiovascular mortality (HR, 1.66 [CI, 1.07 to 2.57]) in participants with diabetes. In those without diabetes, PN was significantly associated with all-cause mortality (HR, 1.31 [CI, 1.15 to 1.50]), but the association between PN and cardiovascular mortality was not statistically significant after adjustment (HR, 1.27 [CI, 0.98 to 1.66]).

LIMITATION

Prevalent cardiovascular disease was self-reported, and PN was defined by monofilament testing only.

CONCLUSION

Peripheral neuropathy was common and was independently associated with mortality in the U.S. population, even in the absence of diabetes. These findings suggest that decreased sensation in the foot may be an underrecognized risk factor for death in the general population.

PRIMARY FUNDING SOURCE

National Institute of Diabetes and Digestive and Kidney Diseases and National Heart, Lung, and Blood Institute of the National Institutes of Health.

[Multidisciplinary management of diabetic foot ulcer infection]

Infection is one of the most common complications of diabetic foot ulceration resulting in lower extremity amputations and early mortality in this population. Several factors influence the course of diabetic foot ulceration infection and in that context, integrated multidisciplinary management is required as soon as possible. In fact, a holistic interdisciplinary approach should be the standard of care. Whether the infection is categorized as mild, moderate or severe, with or without bone infection, the overall individual's characteristics must be addressed, in addition to local wound care, offloading and antibiotic therapy. Some severe infections have potential indications for hospitalization and are considered as surgical emergencies. In some DFU cases, surgical revascularization of the limb is mandatory to treat the infection. However, surgical interventions and amputations, are sometimes inevitable, they are predictors of bad prognosis. Although some adjuvant therapies are effective to promote wound healing, their use is not recommended to treat diabetic foot ulcer infection. Infection management can be divided into three general interventions: proper clinical diagnosis, microbiological and imaging investigations, and treatment. This review is an update on the up-to-date evidences in scientific literature and includes the latest recommendations from the International Working Group on the Diabetic Foot (IWGDF).

Prevalence and Risk Evaluation of Diabetic Complications of the Foot Among Adults With Type 1 and Type 2 Diabetes in a Large Canadian Population (PEDAL Study)

OBJECTIVES

The lower limb complications of diabetes contribute significantly to patient morbidity and health-care costs in Canada. Despite practice guidelines, awareness of and screening for modifiable early pathologies has been inconsistent. Our study objective was to determine the prevalence and types of early foot pathology in a large, Canadian, community care-based diabetes population.

METHODS

This study was a retrospective, observational analysis of the LMC Diabetes & Endocrinology foot care program launched in 2017. We examined foot pathologies associated with vascular, nerve, nail and dermatologic complications, as well as foot deformities. Individuals ≥18 years of age and with diabetes, assessed by an LMC chiropodist in Ontario between February 2018 and April 2019, were included in the analysis.

RESULTS

Of the 5,084 individuals assessed, 470 with type 1 diabetes and 3,903 with type 2 diabetes met the study criteria. Mean age, body mass index and diabetes duration was 61.5 years, 31.3 kg/m² and 13.9 years, respectively. Reduced pedal pulses, sensory neuropathy and onychomycosis were reported in 8.9%, 16.7% and 14.5% of those in the type 1 diabetes group, and 19.4%, 26.6% and 28.7% of those in the type 2 group, respectively. Hyperkeratosis was present in 51% and foot deformities were present in 44.5% among both groups. Foot ulcer prevalence was 1.7% and pedal pulses, sensory neuropathy, hyperkeratosis and onychauxis, adjusted for age, sex, body mass index and diabetes duration, were each significantly associated with ulceration.

CONCLUSIONS

In a large foot screening program of community-based adults with diabetes, modifiable early foot pathologies were prevalent and provided further evidence of the value of consistent screening to alleviate the morbidity and economic burden of lower limb complications.

Metatarsal Head Resection Versus a Removable Mechanical Device for Offloading of the Neuropathic Diabetic Plantar Forefoot Ulcer

Although surgical offloading seems a more permanent solution for prevention and treatment of neuropathic plantar diabetic forefoot ulcers (DFUs), the evidence for this assumption is weak and needs further studies to be established. The aim of this retrospective study is to compare the healing efficacy, associated morbidity, and recurrence rates of surgical versus removable knee-high offloading for neuropathic plantar (DFUs) healing. From January 2016 to January 2018, 70 neuropathic plantar forefoot DFUs were nonrandomly assigned to either removable knee-high cam-walker (n = 35), or metatarsal head, or accessory bone resection (n = 35). The primary endpoints were the frequency and rate of complete healing, and the rate of ulcer area reduction within 4 months. The secondary endpoints were 4 months morbidity and ulcer recurrence within 12 months. After 4 months, complete healing was significantly inferior with cam-walker compared with surgical offloading; 24 (67.6%) versus 31 patients (88.6%), respectively, P = .015. Ulcer area reduction was 2.4 cm² (66.7%) versus 2.6 cm² (83.9%), P = .001, in the mechanical versus the surgical groups, respectively. The mean healing time was 3.6 ± 2.1 versus 2.8 ± 0.6 months in the mechanical versus the surgical groups, respectively, P = .012. Morbidity and recurrence show nonsignificant differences between both groups. Ulcer recurrence was noted in 5/35 (14.3%) versus 2/35 (5.7%), in mechanical versus surgical groups, respectively, P = .23. Therefore, metatarsal head/accessory bone resection offered improved healing efficacy but similar morbidity and recurrence to the removable cam-walker.

The effects of curcumin intake on wound healing and metabolic status in patients with diabetic foot ulcer: A randomized, double-blind, placebo-controlled trial

This study was conducted to determine the effects of curcumin intake on wound healing and metabolic status in patients with diabetic foot ulcer (DFU). The current randomized, double-blind, placebo-controlled trial was conducted among 60 patients with grade 3 DFU. Participants were randomly allocated into two groups (30 participants each group), received either 80 mg nanocurcumin daily for 12 weeks or placebo. Primary endpoints in this study were serum insulin levels and insulin resistance. Curcumin intake significantly decreased fasting plasma glucose (p = .02), insulin (p = .01), insulin resistance (p = .02), and significantly increased insulin sensitivity (p = .008) compared with the placebo. Moreover, curcumin intake led to a significant reduction in total- (p < .001), LDL-cholesterol (p < .001), and a significant increase in total antioxidant capacity (TAC) (p < .001) and total glutathione (GSH) (p = .01) compared with the placebo. However, there was no significant improvement in wound healing parameters. Overall, our study demonstrated that nanocurcumin intake in patients with DFU resulted in a significant improvement of glycemic control, total- and LDL-cholesterol, TAC, and GSH but did not affect the indicators of ulcer size.

Mortality in Patients with Diabetic Foot Ulcers: Causes, Risk Factors, and Their Association with Evolution and Severity of Ulcer

Background: This study reviews the mortality of patients with diabetic foot ulcers (DFU) from the first consultation with a Multidisciplinary Diabetic Foot Team (MDFT) and analyzes the main cause of death, as well as the relevant clinical factors associated with survival. Methods: Data of 338 consecutive patients referred to the MDFT center for a new DFU during the 2008–2014 period were analyzed. Follow-up: until death or until 30 April 2020, for up to 12.2 years. Results: Clinical characteristics: median age was 71 years, 92.9% had type 2 diabetes, and about 50% had micro-macrovascular complications. Ulcer characteristics: Wagner grade 1–2 (82.3%), ischemic (49.2%), and infected ulcers (56.2%). During follow-up, 201 patients died (59.5%), 110 (54.7%) due to cardiovascular disease. Kaplan—Meier curves estimated a reduction in survival of 60% with a 95% confidence interval (95% CI), (54.7–65.3) at 5 years. Cox regression analysis adjusted to a multivariate model showed the following associations with mortality, with hazard ratios (HRs) (95% CI): age, 1.07 (1.05–1.08); HbA1c value < 7% (53 mmol/mol), 1.43 (1.02–2.0); active smoking, 1.59 (1.02–2.47); ischemic heart or cerebrovascular disease, 1.55 (1.15–2.11); chronic kidney disease, 1.86 (1.37–2.53); and ulcer severity (SINBAD system) 1.12 (1.02–1.26). Conclusion: Patients with a history of DFU have high mortality. Two less known predictors of mortality were identified: HbA1c value < 7% (53 mmol/mol) and ulcer severity.

Gene-activated dermal equivalents to accelerate healing of diabetic chronic wounds by regulating inflammation and promoting angiogenesis

Diabetic chronic wound, characterized by prolonged inflammation and impaired angiogenesis, has become one of the most serious challenges in clinic and pose a significant healthcare burden worldwide. Although a great variety of wound dressings have been developed, few of encouraged achievements were obtained so far. In this study, the gene-activated strategy was applied to enhance sustained expression of vascular endothelial growth factor (VEGF) and achieve better healing outcomes by regulating inflammation and promoting angiogenesis. The gene-activated bilayer dermal equivalents (Ga-BDEs), which has good biocompatibility, were fabricated by loading the nano-sized complexes of Lipofectamine 2000/plasmid DNA-encoding VEGF into a collagen-chitosan scaffold/silicone membrane bilayer dermal equivalent. The DNA complexes were released in a sustained manner and showed the effective transfection capacities to up-regulate the expression of VEGF in vitro. To overcome cutaneous contraction of rodents and mimic the wound healing mechanisms of the human, a reformative rat model of full-thickness diabetic chronic wound was adopted. Under the treatment of Ga-BDEs, speeding wound healing was observed, which is accompanied by the accelerated infiltration and phenotype shift of macrophages and enhanced angiogenesis in early and late healing phases, respectively. These proved that Ga-BDEs possess the functions of immunomodulation and pro-angiogenesis simultaneously. Subsequently, the better regeneration outcomes, including deposition of oriented collagen and fast reepithelialization, were achieved. All these results indicated that, being different from traditional pro-angiogenic concept, the up-regulated expression of VEGF by Ga-BDEs in a sustained manner shows versatile potentials for promoting the healing of diabetic chronic wounds.

Saving the Diabetic Foot During the COVID-19 Pandemic: A Tale of Two Cities

Of all the late complications of diabetes, those involving the foot have traditionally required more face-to-face patient visits to clinics to treat wounds by debridement, offloading, and many other treatment modalities. The advent of the coronavirus disease 2019 (COVID-19) pandemic has resulted not only in the closing of most outpatient clinics for face-to-face consultations but also in the inability to perform most laboratory and imaging investigations. This has resulted in a paradigm shift in the delivery of care for those with diabetic foot ulcers. The approaches to this challenge in two centers with an interest in diabetic foot disease, including virtual consultations using physician-to-patient and physician-to-home nurse telemedicine as well as home podiatry visits, are described in this review and are illustrated by several case vignettes. The outcomes from these two centers suggest that we may be witnessing new possibilities in models of care for the diabetic foot.

Neuropathy, claw toes, intrinsic muscle volume, and plantar aponeurosis thickness in diabetic feet

BACKGROUND

The objective of this study was to explore the relationships between claw toe deformity, peripheral neuropathy, intrinsic muscle volume, and plantar aponeurosis thickness using computed tomography (CT) images of diabetic feet in a cross-sectional analysis.

METHODS

Forty randomly-selected subjects with type 2 diabetes were selected for each of the following four groups (n = 10 per group): 1) peripheral neuropathy with claw toes, 2) peripheral neuropathy without claw toes, 3) non-neuropathic with claw toes, and 4) non-neuropathic without claw toes. The intrinsic muscles of the foot were segmented from processed CT images. Plantar aponeurosis thickness was measured in the reformatted sagittal plane at 20% of the distance from the most inferior point of the calcaneus to the most inferior point of the second metatarsal. Five measurement sites in the medial-lateral direction were utilized to fully characterize the plantar aponeurosis thickness. A linear mixed-effects analysis on the effects of peripheral neuropathy and claw toe deformity on plantar aponeurosis thickness and intrinsic muscle volume was performed.

RESULTS

Subjects with concurrent neuropathy and claw toes had thicker mean plantar aponeurosis (p < 0.006) and may have had less mean intrinsic muscle volume (p = 0.083) than the other 3 groups. The effects of neuropathy and claw toes on aponeurosis thickness were synergistic rather than additive. A similar pattern may exist for intrinsic muscle volume, but results were not as conclusive. A negative correlation was observed between plantar aponeurosis thickness and intrinsic muscle volume (R² = 0.323, p < 0.001).

CONCLUSIONS

Subjects with concurrent neuropathy and claw toe deformity were associated with the smallest intrinsic foot muscle volumes and the thickest plantar aponeuroses. Intrinsic muscle atrophy and plantar aponeurosis thickening may be related to the development of claw toes in the presence of neuropathy.