Moisture status of the skin of the feet assessed by the visual test neuropad correlates with foot ulceration in diabetes

Screening tools for diabetic foot ulcers: a narrative review

The prevalence of diabetic foot ulcers (DFUs) is 4 to 10% among people with diabetes mellitus. DFUs are associated with increased morbidity and mortality as well as reduced quality of life and have a significant impact on overall healthcare expenditure. The main predisposing factors for DFU are diabetic neuropathy, peripheral arterial disease, and trauma. The fact that a range of tests can be used to identify patients at risk for DFU often causes confusion among practitioners regarding which screening tests should be implemented in clinical practice. Herein we sought to determine whether tests of somatic nerve function, such as pinprick sensation, thermal (cold/hot) test, ankle reflexes, vibration perception, 10-g monofilament, Ipswich touch test, neuropathy disability score, and nerve conduction studies, predict the development of DFUs. In addition, we examined whether sudomotor function screening tests, such as Neuropad, sympathetic skin response, and other tests, such as elevated plantar pressure or temperature measurements, can be used for DFU screening. If not treated properly, DFUs can have serious consequences, including amputation, early detection and treatment are vital for patient outcomes.

Therapeutic Potential of Extracellular Vesicles from Different Stem Cells in Chronic Wound Healing

Wound healing has long been a complex problem, especially in chronic wounds. Although debridement, skin grafting, and antimicrobial dressings have been used to treat chronic wounds, their treatment period is long, expensive, and has specific rejection reactions. The poor treatment results of traditional methods have caused psychological stress to patients and a substantial economic burden to society. Extracellular vesicles (EVs) are nanoscale vesicles secreted by cells. They play an essential role in intercellular communication. Numerous studies have confirmed that stem cell-derived extracellular vesicles (SC-EVs) can inhibit overactive inflammation, induce angiogenesis, promote re-epithelization, and reduce scar formation. Therefore, SC-EVs are expected to be a novel cell-free strategy for chronic wound treatment. We first summarize the pathological factors that hinder wound healing and discuss how SC-EVs accelerate chronic wound repair. And then, we also compare the advantages and disadvantages of different SC-EVs for chronic wound treatment. Finally, we discuss the limitations of SC-EVs usage and provide new thoughts for future SC-EVs research in chronic wound treatment.

Artificial Intelligence Methodologies Applied to Technologies for Screening, Diagnosis and Care of the Diabetic Foot: A Narrative Review

Diabetic foot syndrome is a multifactorial pathology with at least three main etiological factors, i.e., peripheral neuropathy, peripheral arterial disease, and infection. In addition to complexity, another distinctive trait of diabetic foot syndrome is its insidiousness, due to a frequent lack of early symptoms. In recent years, it has become clear that the prevalence of diabetic foot syndrome is increasing, and it is among the diabetes complications with a stronger impact on patient's quality of life. Considering the complex nature of this syndrome, artificial intelligence (AI) methodologies appear adequate to address aspects such as timely screening for the identification of the risk for foot ulcers (or, even worse, for amputation), based on appropriate sensor technologies. In this review, we summarize the main findings of the pertinent studies in the field, paying attention to both the AI-based methodological aspects and the main physiological/clinical study outcomes. The analyzed studies show that AI application to data derived by different technologies provides promising results, but in our opinion future studies may benefit from inclusion of quantitative measures based on simple sensors, which are still scarcely exploited.

Preulcerous Risk Situation in Diabetic Foot Syndrome: Proposal for a Simple Ulcer Prevention Score

BACKGROUND

Preulcerous risk situations in patients with diabetes are often undiagnosed and care administered too late. Even with regular medical check-ups and status documentation, foot examinations have not been given enough attention. Diagnosing an individual patients' risk of developing diabetic foot ulcers may increase vigilance for diabetic foot syndrome (DFS), and the appropriate prevention measures matching the risk involved may prevent the emergence of diabetic ulcers. The classical DFS risk factors are well established and have been extensively covered in the literature; however, there is a lack of efficient screening tools that could be used for a rapid assessment of diabetic foot ulcer risk.

METHODS

A methodical literature search was conducted to assess relevant publications for the preparation of a simple risk score for amputation related to diabetic foot ulcer. We then analyzed the risk factors for predictive value as odds ratios in foot ulcers and/or amputation. We used the available data to deduce a mean value to reflect the authors' consensus.

RESULTS

In view of the current literature on the matter, we have developed a semi-quantitative scoring system using just a few items to allow rapid and visual risk assessment for diabetic foot ulcers alongside recommendations for prevention and a sensible follow-up strategy to match the risk.

CONCLUSION

This relatively simple score enables rapid risk classification for patients that can ease the way for both physicians and patients in gaining an insight into individual risk situations. The score provides more effective preventative measures for high-risk patients against future complications.

Validation of Neuropad in the Assessment of Peripheral Diabetic Neuropathy in Patients with Diabetes Mellitus Versus the Michigan Neuropathy Screening Instrument, 10g Monofilament Application and Biothesiometer Measurement

Objective:

Sudomotor dysfunction is a feature of Diabetic Peripheral Neuropathy (DPN). The indicator plaster Neuropad can provide an easy and accurate way to diagnose DPN. The aim of the present study was to evaluate Neuropad’s specificity, sensitivity and accuracy in detecting DPN in patients with Diabetes Mellitus (DM).

Methods:

A total of 174 patients with DM (79 with type 1 DM, 88 women), mean age 49.8 ± 16.1 years and mean DM duration 17.3 ± 7.7 years were included in the present study. The following methods were used to diagnose DPN: the Michigan Neuropathy Screening Instrument Questionnaire and Examination (MNSIQ and MNSIE, respectively), application of 10 g monofilament (MONO) and measurement of vibration perception threshold with biothesiometer (BIO). Neuropad was applied to both feet in all patients and according to the presence or absence of color change of the sticker, patients were divided in two groups: group A (n = 82, complete change in color from blue to pink, depicting normal perspiration) and group B (n = 92, incomplete or no change, depicting abnormal perspiration).

Results:

MNSIQ and MNSIE were positive for DPN in 111 and 119 patients, respectively. BIO was abnormal in 109 and MONO in 59 patients. Sensitivity of Neuropad testing was 95% vs. MONO, 73% vs. BIO, 73% vs. MNSIE and 75% vs. ΜNSIQ. Specificity was 69, 81, 90 and 92%, respectively and accuracy of the test was 78, 76, 78 and 83%, respectively.

Conclusion:

Neuropad has a high sensitivity and specificity in detecting DPN vs. MNSIQ, MNSIE and BIO. Neuropad has a high sensitivity but moderate specificity vs. MONO. The accuracy of the test was high in all measurements.

Dryness of Foot Skin Assessed by the Visual Indicator Test and Risk of Diabetic Foot Ulceration: A Prospective Observational Study

Research Question: Previous cross-sectional studies have shown an association between sudomotor dysfunction and diabetic foot ulceration (DFU). The aim of this prospective multicenter study was to determine the role of dryness of foot skin and of established neurological modalities in the prediction of risk for foot ulceration in a cohort of individuals with diabetes mellitus (DM). Design: The study was conducted from 2012 to 2017. A total of 308 subjects with DM without history of DFU or critical limb ischemia completed the study. Diabetic neuropathy was assessed using the neuropathy symptom score (NSS) and neuropathy disability score (NDS). In a subset of participants, vibration perception threshold (VPT) was evaluated. Dryness of foot skin was assessed by the visual indicator plaster method (IPM). The diagnostic performance of the above neurological modalities for prediction of DFU was tested by receiver operating characteristic curve (ROC) analysis. Results: During the 6-year follow-up, 55 patients (annual ulceration incidence 2.97%) developed DFU. Multivariate Cox-regression analysis after controlling for the effect of age, gender, and DM duration demonstrated that the risk (hazard ratio, 95% confidence intervals) of DFU increased significantly with either abnormal IPM (3.319, 1.460-7.545, p = 0.004) or high (≥6) NDS (2.782, 1.546-5.007, p = 0.001) or high (≥25 volts) VPT (2.587, 1.277-5.242, p = 0.008). ROC analysis showed that all neurological modalities could discriminate participants who developed DFU (p < 0.001). IPM testing showed high sensitivity (0.86) and low specificity (0.49), while high vs. low NDS and VPT showed low sensitivity (0.40 and 0.39, respectively) and high specificity (0.87 and 0.89, respectively) for identification of patients at risk for DFU. Conclusion: Dryness of foot skin assessed by the IPM predicts the development of DFU. IPM testing has high sensitivity, whereas high NDS and VPT have high specificity in identifying subjects at risk for DFU. The IPM can be included in the screening methods for identification of the foot at risk.

Prediction of Diabetic Foot Ulceration: The Value of Using Microclimate Sensor Arrays

BACKGROUND

Accurately predicting the risk of diabetic foot ulceration (DFU) could dramatically reduce the enormous burden of chronic wound management and amputation. Yet, the current prognostic models are unable to precisely predict DFU events. Typically, efforts have focused on individual factors like temperature, pressure, or shear rather than the overall foot microclimate.

METHODS

A systematic review was conducted by searching PubMed reports with no restrictions on start date covering the literature published until February 20, 2019 using relevant keywords, including temperature, pressure, shear, and relative humidity. We review the use of these variables as predictors of DFU, highlighting gaps in our current understanding and suggesting which specific features should be combined to develop a real-time microclimate prognostic model.

RESULTS

The current prognostic models rely either solely on contralateral temperature, pressure, or shear measurement; these parameters, however, rarely reach 50% specificity in relation to DFU. There is also considerable variation in methodological investigation, anatomical sensor configuration, and resting time prior to temperature measurements (5-20 minutes). Few studies have considered relative humidity and mean skin resistance.

CONCLUSION

Very limited evidence supports the use of single clinical parameters in predicting the risk of DFU. We suggest that the microclimate as a whole should be considered to predict DFU more effectively and suggest nine specific features which appear to be implicated for further investigation. Technology supports real-time in-shoe data collection and wireless transmission, providing a potentially rich source of data to better predict the risk of DFU.

Monitoring of external predisposing factors for Diabetic Foot: A literature review and physicians' perspectives

Background: Diabetic foot is one of the most important complications of diabetes caused by the existence of some destructive factors in different anatomical locations of feet. Management and monitoring of these factors are very important to decrease or avoid ulcerating lesions of the foot. The purpose of this study is to identify and introduce the predisposing factors and anatomical locations associated with these destructive factors. Methods: First, we conducted a comprehensive review of different databases to identify the factors and associated anatomical locations from the previous studies. Then, we designed a questionnaire and invited physicians and specialists to express their perspectives on these factors and locations. The data were analyzed using SPSS version 23. Frequency, percentage, mean and standard deviation of these variables were calculated. Results: Based on the literature review, four factors, including pressure, moisture and sweat, temperature, and acceleration were identified as factors destructive to the tissues of the diabetic foot and worsen ulcers. The view of specialists approved the results of the literature review. Besides, there was an insignificant difference between the results of the literature review and the specialists' view in terms of anatomical locations that need to be continuously monitored. Conclusion: Monitoring the pressure in heel, first metatarsal, and first metatarsal head; moisture and sweat under the fingers, hallux and heels as well as the temperature at the first metatarsal, first metatarsal head, and the third metatarsal head are important in preventing ulceration, destructing the foot tissue, and accelerating the treatment process.

Topical Erythropoietin Treatment Accelerates the Healing of Cutaneous Burn Wounds in Diabetic Pigs Through an Aquaporin-3-Dependent Mechanism

We have previously reported that the topical application of erythropoietin (EPO) to cutaneous wounds in rats and mice with experimentally induced diabetes accelerates their healing by stimulating angiogenesis, reepithelialization, and collagen deposition, and by suppressing the inflammatory response and apoptosis. Aquaporins (AQPs) are integral membrane proteins whose function is to regulate intracellular fluid hemostasis by enabling the transport of water and glycerol. AQP3 is the AQP that is expressed in the skin where it facilitates cell migration and proliferation and re-epithelialization during wound healing. In this report, we provide the results of an investigation that examined the contribution of AQP3 to the mechanism of EPO action on the healing of burn wounds in the skin of pigs with experimentally induced type 1 diabetes. We found that topical EPO treatment of the burns accelerated their healing through an AQP3-dependent mechanism that activates angiogenesis, triggers collagen and hyaluronic acid synthesis and the formation of the extracellular matrix (ECM), and stimulates reepithelialization by keratinocytes. We also found that incorporating fibronectin, a crucial constituent of the ECM, into the topical EPO-containing gel, can potentiate the accelerating action of EPO on the healing of the burn injury.

Portable System for Monitoring the Microclimate in the Footwear-Foot Interface

A new, continuously-monitoring portable device that monitors the diabetic foot has shown to help in reduction of diabetic foot complications. Persons affected by diabetic foot have shown to be particularly sensitive in the plantar surface; this sensitivity coupled with certain ambient conditions may cause dry skin. This dry skin leads to the formation of fissures that may eventually result in a foot ulceration and subsequent hospitalization. This new device monitors the micro-climate temperature and humidity areas between the insole and sole of the footwear. The monitoring system consists of an array of ten sensors that take readings of relative humidity within the range of 100% ± 2% and temperature within the range of −40 °C to 123.8 ± 0.3 °C. Continuous data is collected using embedded C software and the recorded data is processed in Matlab. This allows for the display of data; the implementation of the iterative Gauss-Newton algorithm method was used to display an exponential response curve. Therefore, the aim of our system is to obtain feedback data and provide the critical information to various footwear manufacturers. The footwear manufactures will utilize this critical information to design and manufacture diabetic footwear that reduce the risk of ulcers in diabetic feet.

Diabetic foot ulcer--A review on pathophysiology, classification and microbial etiology

As the prevalence of diabetes is increasing globally, secondary complications associated to this endocrinal disorder are also ascending. Diabetic foot ulcers are potentially modifying complications. Disruption of harmony in glucose homeostasis causes hyperglycemic status, results in activation of certain metabolic pathways which in their abnormal state subsequently leads to development of vascular insufficiency, nerve damages headed by ulceration in lower extremity due to plantar pressures and foot deformity. Insult to foot caused by trauma at the affected site goes unnoticeable to patient due to loss of sensation. Among the above mention causes, resistance to infection is also considered as chief modulator of pathophysiological image of diabetic foot lesions. Healing as well as non-healing nature of ulcer relies upon the wound microbial communities and the extent of their pathogenicity. A validated classification system of foot ulcer is primarily necessary for clinicians in management of diabetic foot problems. Another aspect which needs management is proper identification of causative pathogen causing infection. The way of approaches presently employed in the diagnosis for treatment of foot ulcer colonized by different microbes is conventional techniques. Conventional diagnostic methods are widely acceptable since decades. But in recent years newly invented molecular techniques are exploring the use of 16S ribosomal regions specific to prokaryotes in bacterial identification and quantification. Molecular techniques would be a better choice if engaged, in finding the specific species harboring the wound.

Use of a urea, arginine and carnosine cream versus a standard emollient glycerol cream for treatment of severe xerosis of the feet in patients with type 2 diabetes: a randomized, 8 month, assessor-blinded, controlled trial

BACKGROUND

No long-term data are available regarding the effects of emollients in treating severe foot skin xerosis in patients with diabetes.

STUDY AIM

We evaluated the efficacy of 8 month urea, arginine and carnosine cream (UC) in comparison with a glycerin-based emollient cream (SEC) in type 2 patients with diabetes who had severe foot xerosis.

SUBJECTS AND METHODS

We assessed the effect of UC and SEC on skin hydration in a randomized, assessor-blinded study in 50 patients treated with UC (N = 25) or SEC (N = 25) for 32 weeks with a twice daily application. Primary outcomes were a 9 point Xerosis Assessment Scale (XAS) score and a 4 point Overall Cutaneous Score (OCS), evaluated at baseline and after 4, 12 and 32 weeks. Skin hydration and desquamation were also objectively evaluated by means of a bio-impedance skin analysis device (Hydr8 * ) at baseline and at week 32.

RESULTS

UC induced greater hydration than SEC (p = 0.001) with a 91% reduction at week 32 in XAS score vs. baseline. After 4 weeks, compared with the SEC treated group, the XAS score in the UC treated group was significantly lower. OCS was reduced by 27% from baseline to end of the study in the UC group, and increased by 8% in the SEC group (p = 0.02; between groups). At month 8, skin hydration and desquamation evaluated by the digital skin analysis system statistically improved in UC treated subjects in comparison with baseline and SEC group values. This study was not double-blind. In order to overcome this problem we performed an assessor-blinded evaluation of the primary endpoints and used an objective measurement tool for skin hydration and desquamation assessment.

CONCLUSION

Using a urea, arginine and carnosine cream for 8 months increases skin hydration and improves skin dryness in type 2 diabetic patients in comparison with a glycerol-based emollient cream, with a greater efficacy observed as early as 4 weeks into treatment.

A novel shear reduction insole effect on the thermal response to walking stress, balance, and gait

Shear stresses have been implicated in the formation of diabetes-related foot ulcers. The aim of this study was to evaluate the effect of a novel shear-reducing insole on the thermal response to walking, balance, and gait. Twenty-seven diabetes peripheral neuropathy patients were enrolled and asked to take 200 steps in both intervention and standard insoles. Thermal foot images of the feet were taken at baseline (1) following a 5-minute temperature acclimatization and (2) after walking. Testing order was randomized, and a 5-minute washout period was used between testing each insole condition. Sudomotor function was also assessed. Gait and balance were measured under single and dual task conditions using a validated body worn sensor system. The mean age was 65.1 years, height was 67.3 inches, weight was 218 pounds, and body mass index was 33.9, 48% were female, and 82% had type 2 diabetes. After walking in both insole conditions, foot temperatures increased significantly in standard insoles. The intervention insole significantly reduced forefoot and midfoot temperature increases (64.1%, P = .008; 48%, P = .046) compared to standard insoles. There were significant negative correlations with sudomotor function and baseline temperatures (r = .53-.57). The intervention demonstrated 10.4% less gait initiation double support time compared to standard insoles (P = .05). There were no differences in static balance measures. We found significantly lower forefoot and midfoot temperature increases following walking with shear-reducing insoles compared to standard insoles. We also found improvements in gait. These findings merit future study for the prevention of foot ulcer.

Effect of intensive nursing education on the prevention of diabetic foot ulceration among patients with high-risk diabetic foot: a follow-up analysis

The aim of the study was to discuss the effect of intensive nursing education on the prevention of diabetic foot ulceration among patients at high risk for diabetic foot. One hundred eighty-five diabetes patients at high risk for foot diseases were enrolled in this study and provided with intensive nursing education, including individualized education about diabetes mellitus and diabetic foot diseases, instruction in podiatric care (the right way of washing the foot, the care of foot skin, appropriate choice of shoes and socks, intense examinations and records of feet by patients themselves every day, and the assistant management of calluses). Study subjects were followed up for 2 years. Once the foot ulceration developed, the inducing factors of foot ulceration were inquired about, the ulcers were evaluated, and the incidence of foot ulceration was analyzed before and after the intensive nursing education according to self-paired data. Results showed there were highly statistically significant improvements in the intensive treatment group compared with the control group in plasma glucose, blood pressure, and high-density lipoprotein cholesterol levels. More important is that intensive nursing education helps to prevent diabetic foot ulceration and to decrease the rate of amputation among patients at high risk for diabetic foot.

Comparison of characteristics and healing course of diabetic foot ulcers by etiological classification: neuropathic, ischemic, and neuro-ischemic type

AIMS

To identify differences in the characteristics of patients with diabetic foot ulcers (DFUs) according to their etiological classification and to compare their healing time.

METHODS

Over a 4.5-year period, 73 patients with DFUs were recruited. DFUs were etiologically classified as being of neuropathic, ischemic, or neuro-ischemic origin. Descriptive analyses were performed to characterize study subjects, foot-related factors, and healing outcome and time. Duration of healing was assessed using the Kaplan-Meier method. Healing time among the three types was compared using the log rank test.

RESULTS

The number of patients manifesting neuropathic, ischemic, and neuro-ischemic ulcers was 30, 20, and 14, respectively. Differences were identified for age, diabetes duration, body mass index, hypertension, and estimated glomerular filtration rate. Patients with neuro-ischemic ulcers had better ankle-brachial index, skin perfusion pressure (SPP), and transcutaneous oxygen pressure values compared to those with ischemic ulcers. The average time in which 50% of patients had healed wounds was 70, 113, and 233 days for neuropathic, neuro-ischemic, and ischemic ulcers, respectively. Main factors associated with healing were age and SPP values.

CONCLUSIONS

Based on the etiological ulcer type, DFU healing course and several patient factors differed. Failure to consider the differences in DFU etiology may have led to heterogeneity of results in previous studies on DFUs.

Plantar pressures, plantar forces, and their influence on the pathogenesis of diabetic foot ulcers: a review

BACKGROUND

Clinical recommendations for the prevention and healing of diabetic foot ulcers (DFUs) are somewhat clear. However, assessment and quantification of the mechanical stress responsible for DFU remain complex. Different pressure variables have been described in the literature to better understand plantar tissue stress exposure. This article reviews the role of pressure and shear forces in the pathogenesis of plantar DFU.

METHODS

We performed systematic searches of the PubMed and Embase databases, completed by a manual search of the selected studies. From 535 potentially relevant references, 70 studies were included in the full-text review.

RESULTS

Variables of plantar mechanical stress relate to vertical pressure, shear stress, and temporality of loading. At this time, in-shoe peak plantar pressure (PPP) is the only reliable variable that can be used to prevent DFU. Although it is a poor predictor of in-shoe PPP, barefoot PPP seems complementary and may be more suitable when evaluating patients with diabetes mellitus and peripheral neuropathy who seem noncompliant with footwear. An in-shoe PPP threshold value of 200 kPa has been suggested to prevent DFU. Other variables, such as peak pressure gradient and peak maximal subsurface shear stress and its depth, seem to be of additional utility.

CONCLUSIONS

To better assess the at-risk foot and to prevent ulceration, the practitioner should integrate quantitative models of dynamic foot plantar pressures, such as in-shoe and barefoot PPPs, with the regular clinical screening examination. Prospective studies are needed to evaluate causality between other variables of mechanical stress and DFUs.

A simple plaster for screening for diabetic neuropathy: a diagnostic test accuracy systematic review and meta-analysis

OBJECTIVE

Neuropad is an adhesive indicator test applied at the plantar surface of the foot that detects sweating through color change. We examined the diagnostic accuracy of this simple plaster as triage test for screening for clinically relevant diabetic sensorimotor polyneuropathy in adult outpatients with type 1 or type 2 diabetes.

MATERIALS/METHODS

Systematic review and meta-analysis of diagnostic accuracy studies. We searched Medline, Embase, Cochrane Library, Biosis Previews, Web of Science, Scopus and gray literature without date or language restrictions. We pooled estimates of sensitivity and specificity, and fitted hierarchical models to produce summary receiver operating characteristic curves. We assessed methodological quality of included studies utilizing the Quality Assessment of Diagnostic Accuracy Studies 2 tool.

RESULTS

Eighteen studies with 3470 participants met the inclusion criteria. Average sensitivity and specificity were 86% (95% CI 79 to 91) and 65% (95% CI 51 to 76) respectively. Likelihood ratios (LRs) were LR+=2.44 and LR-=0.22. Subgroup analyses per reference standard utilized provided similar estimates. Most studies were at risk of bias for patient selection and use of index or reference test, and had concerns regarding applicability due to patient selection.

CONCLUSION

The adhesive indicator test has reasonable sensitivity and could be used for triage of diabetic neuropathy to rule out foot at risk. Patients who tested positive should be referred to specialized care to establish a definite diagnosis. There is insufficient evidence for effectiveness on patient-important outcomes and cost-effectiveness of implementation in the diagnostic pathway compared with the standard clinical examination.

Diabetic neuropathy and foot complications

Foot ulceration and Charcot neuroarthropathy (CN) are well recognized and documented late sequelae of diabetic peripheral, somatic, and sympathetic autonomic neuropathy. The neuropathic foot, however, does not ulcerate spontaneously: it is a combination of loss of sensation due to neuropathy together with other factors such as foot deformity and external trauma that results in ulceration and indeed CN. The commonest trauma leading to foot ulcers in the neuropathic foot in Western countries is from inappropriate footwear. Much of the management of the insensate foot in diabetes has been learned from leprosy which similarly gives rise to insensitive foot ulceration. No expensive equipment is required to identify the high risk foot and recently developed tests such as the Ipswich Touch Test and the Vibratip have been shown to be useful in identifying the high risk foot. A comprehensive screening program, together with education of high risk patients, should help to reduce the all too high incidence of ulceration in diabetes. More recently another very high risk group has been identified, namely patients on dialysis, who are at extremely high risk of developing foot ulceration; this should be preventable. The most important feature in management of neuropathic foot ulceration is offloading as patients can easily walk on active foot ulcers due to the loss of pain sensation. Infection should be treated aggressively and if there is any evidence of peripheral vascular disease, arteriography and appropriate surgical management is also indicated. CN often presents with a unilateral hot, swollen foot and any patient presenting with these features known to have neuropathy should be treated as a Charcot until this is proven otherwise. Most important in the management of acute CN is offloading, often in a total contact cast.

Differences in skin microcirculation on the upper and lower extremities in patients with diabetes mellitus: relationship of diabetic neuropathy and skin microcirculation

INTRODUCTION

During recent years, the role of microcirculation has received increasing attention especially for its potential pathogenic role in the development of diabetes complications, particularly diabetic foot syndrome. The aim of this study was to evaluate the differences in the skin microcirculatory reactivity on the upper and lower extremities (UE and LE, respectively) in the patient with type 2 diabetes mellitus (T2DM). We also evaluated the changes in the skin microcirculation independently of the individual test for peripheral diabetic neuropathy (DN) diagnosis (Semmes-Weinstein monofilaments, Bio-Thesiometer [Bio-Medical Instrument Co., Newbury, OH], and Neuropad(®) [TRIGOcare International GmbH, Wiehl, Germany]).

PATIENTS AND METHODS

Fifty-two patients with T2DM were enrolled. Microvascular reactivity was measured by laser Doppler iontophoresis, using 1% acetylcholine chloride (ACH) and 1% sodium nitroprusside.

RESULTS

Significant reduction of perfusion was found in LE compared with UE when using ACH. In patients with DN skin microvascular reactivity on LE and UE was reduced, compared with patients without DN. Impaired skin microvascular reactivity to ACH (dominant on LE) was demonstrated in all patients who were positive in at least one of the tests for the presence of DN.

CONCLUSIONS

Reactivity of the skin microcirculation is worse on the foot than on the hand. This study confirmed a close relationship of DN and impaired skin microcirculation. It seems that autonomous neuropathy (assessed using the Neuropad) precedes the manifestation of somatosensory neuropathy.

The system of care for the diabetic foot: objectives, outcomes, and opportunities

Most cases of lower extremity limb loss in the United States occur among people with diabetes who have a diabetic foot ulcer (DFU). These DFUs and the associated limb loss that may occur lead to excess healthcare costs and have a large negative impact on mobility, psychosocial well-being, and quality of life. The strategies for DFU prevention and management are evolving, but the implementation of these prevention and management strategies remains challenging. Barriers to implementation include poor access to primary medical care; patient beliefs and lack of adherence to medical advice; delays in DFU recognition; limited healthcare resources and practice heterogeneity of specialists. Herein, we review the contemporary outcomes of DFU prevention and management to provide a framework for prioritizing quality improvement efforts within a resource-limited healthcare environment.

Neurovascular function and sudorimetry in health and disease

In this review of thermoregulatory function in health and disease, we review the basic mechanisms controlling skin blood flow of the hairy and glabrous skin and illustrate the major differences in blood flow to glabrous skin, which is, in essence, sympathetically mediated, while hairy skin is dependent upon neuropeptidergic signals, nitric oxide, and prostaglandin, among others. Laser Doppler methods of quantification of blood flow--in response to iontophoresis of acetylcholine or heat--and nociceptor-mediated blood flow have relatively uniformly demonstrated an impaired capacity to increase blood flow to the skin in diabetes and in its forerunners, prediabetes and the metabolic syndrome. This reduced capacity is likely to be a significant contributor to the development of foot ulcerations and amputations in diabetes, and means of increasing blood flow are clearly needed. Understanding the pathogenic mechanisms is likely to provide a means of identifying a valuable therapeutic target. Thermoregulatory control of sweating is intimately linked to the autonomic nervous system via sympathetic C fibers, and sweat glands are richly endowed with a neuropeptidergic innervation. Sweating disturbances are prevalent in diabetes and its precursors, and quantification of sweating may be useful as an index of diagnosis of somatic and, probably, autonomic dysfunction. Moreover, quantifying this disturbance in sweating by various methods may be useful in identifying the risk of progression from prediabetes to diabetes, as well as responses to therapeutic intervention. We now have the technological power to take advantage of this physiological arrangement to better understand, monitor, and treat disorders of small nerve fibers and the somatic and autonomic nervous system (ANS). Newer methods of sudomotor function testing are rapid, noninvasive, not technically demanding, and accessible to the outpatient clinic. Whether the potential applications are screening for diabetes, following poorly controlled diabetes subjects during alteration of their treatment regimen, or simply monitoring somatic and autonomic function throughout the course of treatment, sudorimetry can be an invaluable tool for today's clinicians.

Influence of peripheral arterial occlusive disease on the Neuropad(®) test performance in patients with diabetes

AIMS

The specificity of the Neuropad(®) test to screen for peripheral neuropathy is moderate, but this test has several advantages, such as self-use, educative value and good sensitivity. Use of the Neuropad is usually contra-indicated in the presence of peripheral arterial occlusive disease, a condition associated with skin dryness. The aim of this study was to assess the influence of peripheral arterial occlusive disease on the performance of the Neuropad for screening peripheral neuropathy, and to compare it with the monofilament test.

METHODS

We included 200 patients with diabetes. Peripheral neuropathy was defined by a neuropathy disability score ≥ 6. The Neuropad was determined as normal or abnormal at 10 and 20 min, respectively, and its performance was compared in patients with and without peripheral arterial occlusive disease diagnosed by colour duplex ultrasonography. The performances of the Neuropad and of the monofilament test were compared.

RESULTS

Prevalences of peripheral neuropathy and of peripheral arterial occlusive disease were 15.8 and 44%, respectively. At 10 min, sensitivity and negative predictive value were high (93.8 and 95.1%), while specificity and positive predictive value were poor (23.2 and 18.9%). The Neuropad performance was not significantly different between patients with and without arteriopathy. Between 10 and 20 min, there was significant loss of sensitivity and gain in specificity. The Neuropad at 10 min was more sensitive but less specific than the monofilament test.

CONCLUSIONS

The reliability of the Neuropad is not significantly different in the presence or absence of peripheral arterial occlusive disease.

A simple new non-invasive sweat indicator test for the diagnosis of diabetic neuropathy

A simple non-invasive indicator test (Neuropad(®)) has been developed for the assessment of sweating and, hence, cholinergic innervation in the diabetic foot. The present review summarizes current knowledge on this diagnostic test. The diagnostic ability of this test is based on a colour change from blue to pink at 10 min, with excellent reproducibility, which lends itself to patient self-examination. It has a high sensitivity (65.1-100%) and negative predictive value (63-100%), with moderate specificity (32-78.5%) and positive predictive value (23.3-93.2%) for the diagnosis of diabetic peripheral neuropathy. It also has moderate to high sensitivity (59.1-89%) and negative predictive value (64.7-91%), but low to moderate specificity (27-78%) and positive predictive value (24-48.6%) for the diagnosis of diabetic cardiac autonomic neuropathy. There are some data to suggest that Neuropad can detect early diabetic neuropathy, but this needs further evaluation. It remains to be established whether this test can predict foot ulceration and amputation, thereby contributing to the identification of high-risk patients.

Predictive factors for diabetic foot ulceration: a systematic review

Improving ability to predict and prevent diabetic foot ulceration is imperative because of the high personal and financial costs of this complication. We therefore conducted a systematic review in order to identify all studies of factors associated with DFU and assess whether available DFU risk stratification systems incorporate those factors of highest potential value. We performed a search in PubMed for studies published through April 2011 that analysed the association between independent variables and DFU. Articles were selected by two investigators-independently and blind to each other. Divergences were solved by a third investigator. A total of 71 studies were included that evaluated the association between diabetic foot ulceration and more than 100 independent variables. The variables most frequently assessed were age, gender, diabetes duration, BMI, HbA(1c) and neuropathy. Diabetic foot ulceration prevalence varied greatly among studies. The majority of the identified variables were assessed by only two or fewer studies. Diabetic neuropathy, peripheral vascular disease, foot deformity and previous diabetic foot ulceration or lower extremity amputation - which are the most common variables included in risk stratification systems - were consistently associated with diabetic foot ulceration development. Existing diabetic foot ulceration risk stratification systems often include variables shown repeatedly in the literature to be strongly predictive of this outcome. Improvement of these risk classification systems though is impaired because of deficiencies noted, including a great lack of standardization in outcome definition and variable selection and measurement.

Useful application of the Neuropad test for assessment of diabetic polyneuropathy

OBJECTIVE

Examination of sudomotor function is now recommended to assess peripheral autonomic dysfunction. The aim of this study was to evaluate the clinical usefulness of Neuropad, a simple visual indicator test, for assessment of diabetic polyneuropathy (DPN).

METHODS

This study examined 87 diabetic patients with a mean age of 61.1±8.8 years, a mean diabetes duration of 13.0±7.5 years and a mean HbA1c of 8.8±1.7%. Diagnosis of DPN was based on clinical examinations using modified Toronto Clinical Neuropathy Score (mTCNS). The patients also underwent 4-g monofilament test and heart rate variability by coefficient of variation of R-R intervals (CV(R-R)) was determined with the patients at rest. The Neuropad test was applied on the plantar aspect of the great toe and removed after 10 minutes to evaluate the color change as normal (blue to completely pink), patchy (patches of blue and pink) and abnormal (remained blue).

RESULTS

Twenty-eight patients showed a normal, 45 patchy and 14 abnormal response to the Neuropad test. Patients with an abnormal response had significantly longer diabetes duration than those with a normal or a patchy response, but HbA1c levels were similar among the three groups. The C(R-R) at rest was significantly lower in patients with an abnormal response than those of normal and patchy response, respectively. Abnormal responders showed significantly higher mTCNS and lower monofilament results as well as higher prevalence of orthostatic hypotension, retinopathy or nephropathy than normal responders.

CONCLUSION

The Neuropad test is a useful screening test for detecting DPN.

Neuropad: evaluation of three cut-off points of sudomotor dysfunction for early detection of polyneuropathy in recently diagnosed diabetes

AIMS

To examine the sensitivity and specificity of three cut-off points of Neuropad for the diagnosis of distal symmetric polyneuropathy and small-fibre dysfunction in patients within the first year after diagnosis of diabetes.

METHODS

Neuropad results were read at 10, 15 and 20 min and evaluated for diagnostic utility in distal symmetric polyneuropathy confirmed by electrophysiology and small-fibre dysfunction in 52 patients with Type 1 diabetes and 99 patients with Type 2 diabetes.

RESULTS

The prevalence of distal symmetric polyneuropathy was 15.4% in Type 1 diabetes and 43.4% in Type 2 diabetes, while that of small-fibre dysfunction was 9.6 and 31.3%, respectively. Sensitivity of Neuropad for the diagnosis of distal symmetric polyneuropathy and small-fibre dysfunction was highest in Type 1 diabetes for the 10-min threshold reaching 87.5 and 80.0%, respectively, while it was modestly high in Type 2 diabetes at 65.1 and 67.7%, respectively. Specificity in both diabetes types was modest for the 10-min threshold (44.7-48.2%). It was highest for the 20-min threshold (83.8-89.3%) at the cost of poor sensitivity at 12.5-34.9%. Negative predictive values were relatively high for all three cut-off points in both types of diabetes (64.1-97.1%) at the cost of poor positive predictive values at 12.5-71.4%.

CONCLUSIONS

In patients within the first year after diagnosis of diabetes, the 10-min cut-off for Neuropad provides a relatively high sensitivity and modest specificity for distal symmetric polyneuropathy and small-fibre dysfunction, rendering the test more suitable as a screening tool than the 15- and 20-min cut-offs.

Screening for the high-risk foot of ulceration: tests of somatic and autonomic nerve function

Diabetic foot ulcers affect almost 5% of the patients with diabetes and carry a huge physical, emotional, and financial burden. Almost 80% of amputations in patients with diabetes are preceded by a foot ulcer. The need for simple screening methods for prevention of foot ulcers and amputations is indisputable. Simple tests such as monofilament, tuning fork, vibration perception threshold determination, ankle reflexes, and pinprick sensation alone or in combination have been studied prospectively and can be used for identification of patients at risk. Newer tests examining sudomotor dysfunction and skin dryness have been introduced in recent years. In cross-sectional studies sudomotor dysfunction assessed by either sympathetic skin response or NEUROPAD™ (Miro Verbandstoffe GmbH, Wiehl-Drabenderhöhe, Germany) testing has been consistently associated with foot ulceration. In addition, NEUROPAD™ testing is simple, reproducible, and widely available and has a high sensitivity for the diagnosis of clinical or subclinical diabetic polyneuropathy. Prospective studies are required to establish whether sudomotor dysfunction can predict foot ulcers and if simple methods assessing sudomotor dysfunction (eg, NEUROPAD™ testing) can be included in the screening tests for the prevention of this complication.

Evaluation of a new foam to increase skin hydration of the foot in type 2 diabetes: a pilot study

The aim of the present study was to evaluate the efficacy of a new product (Neuropad repair foam(®)) in promoting skin hydration of the foot in type 2 diabetes. Included in this study were 20 type 2 diabetic patients (10 men, mean age 61·40 ± 2·44 years). Patients applied Neuropad repair foam(®) on the plantar aspect of the right foot twice daily. No agent was applied on the left foot. Patients were examined at baseline, after 7 treatment days and after 14 treatment days. Evaluation of skin dryness was performed by means of the Multi Skin test Corneometer MC 900. In the right foot, skin capacitance was 26·55 ± 4·14 arbitrary units (a.u.) at baseline, 28·90 ± 4·53 a.u. after 7 days of treatment and 32·05 ± 4·54 a.u. after 14 days of treatment. There was a significant increase in skin capacitance from baseline to 7 days of treatment (P < 0·001), from baseline to 14 treatment days (P < 0·001), as well as from 7 to 14 days of treatment (P < 0·001). The same significant (P < 0·001) increases were observed both in men and in women. No changes were noted in the left foot. At baseline, there was no difference in skin capacitance between right and left foot (P = 0·186). However, skin capacitance was significantly higher on the right versus left foot, both after 7 days (P < 0·001) and after 14 days of treatment (P < 0·001). In conclusion, results with the new foam appear encouraging in ameliorating skin dryness in the diabetic foot and further investigation is warranted.

The ECG vertigo in diabetes and cardiac autonomic neuropathy

The importance of diabetes in the epidemiology of cardiovascular diseases cannot be overemphasized. About one third of acute myocardial infarction patients have diabetes, and its prevalence is steadily increasing. The decrease in cardiac mortality in people with diabetes is lagging behind that of the general population. Cardiovascular disease is a broad term which includes any condition causing pathological changes in blood vessels, cardiac muscle or valves, and cardiac rhythm. The ECG offers a quick, noninvasive clinical and research screen for the early detection of cardiovascular disease in diabetes. In this paper, the clinical and research value of the ECG is readdressed in diabetes and in the presence of cardiac autonomic neuropathy.

Association between foot temperature and sudomotor dysfunction in type 2 diabetes

BACKGROUND AND AIMS

Increased foot skin temperature has been described as a feature of diabetic neuropathy. The aim of this present study was to investigate the association between foot temperature and sudomotor dysfunction in type 2 diabetes mellitus.

PATIENTS AND METHODS

This study included 51 patients (group A: 25 men, mean age 61.14 +/- 6.11 years) without sudomotor dysfunction and 52 patients (group B: 25 men, mean age 59.54 +/- 6.18 years) with sudomotor dysfunction. Sudomotor dysfunction was defined as time until complete Neuropad color change from blue to pink exceeding 600 s in at least one foot. Time until complete color change of the test was also recorded. Foot skin temperature was measured with a handheld infrared thermometer on the plantar aspect of the foot at the level of the first metatarsal head.

RESULTS

On both feet, temperature was significantly higher in group B than in group A (right foot, group A versus group B, 30.62 +/- 1.13 degrees C versus 32.12 +/- 1.06 degrees C, p < .001; left foot, group A versus group B, 30.65 +/- 1.06 degrees C versus 32.19 +/- 1.10 degrees C, p < .001). There was a significant positive correlation between time to complete Neuropad color change and foot skin temperature (right foot, r = 0.742, p < .001; left foot, r = 0.758, p < .001), which was confirmed in both groups.

CONCLUSIONS

Patients with sudomotor dysfunction have significantly higher foot temperature than those without sudomotor dysfunction. Foot temperature is positively correlated with severity of sudomotor dysfunction, as evaluated by the time to complete Neuropad color change.