Comparative roles of microvascular and nerve function in foot ulceration in type 2 diabetes

Impairment of Microcirculation Parameters in Patients with a History of Diabetic Foot Ulcers

Background and Objectives: According to the International Working Group on Diabetic Foot (IWGDF) risk classification, the estimated risk of developing a diabetic foot ulcer (DFU) is much higher in patients with a history of DFUs (Grade 3) compared to those with a peripheral neuropathy but without a history of DFUs (Grades 1 and 2). It has been suggested that microcirculation impairment is involved in DFU genesis and could be taken into account to refine the existing risk classification. The aim of this study was to evaluate microcirculation parameters in patients with diabetes according to their estimated DFU risk. Materials and Methods: A total of 172 patients with type 2 diabetes associated with a peripheral neuropathy and/or a history of DFUs were included and classified into two groups (Grade 1-2 and Grade 3) according to the IWGDF classification. All patients underwent an evaluation of peripheral neuropathy, plantar sudomotor function, and skin microcirculation parameters. These different parameters were compared between both groups. Results: There was no significant difference between the two groups in terms of age, diabetes duration, transcutaneous oxygen pressure level, skin microcirculatory reactivity, neuropathy disability score, neuropathy symptom score, or thermal sensitivity. Patients in Grade 3 were more likely to present with retinopathy (OR 3.15, 95%CI [1.53; 6.49]) and severe sudomotor dysfunction (OR 2.73 95%CI [1.29; 5.80] but less likely to have abnormal VPT (OR 0.20 95%CI [0.05; 0.80]). Conclusions: The present study found more retinopathy and a more pronounced alteration to sudomotor function in Grade 3 patients, suggesting that these parameters could be considered to better identify patients at high risk of DFUs.

Recurrence rates after healing in patients with neuroischemic diabetic foot ulcers healed with and without sucrose octasulfate-impregnated dressings: A 1-year comparative prospective study

To compare recurrence rates after a 1-year follow-up period of healed neuroischemic diabetic foot ulcers after treatment with or without sucrose octasulfate impregnated dressing. A 1-year prospective study with two arms was conducted between April 2021 and April 2023 on 92 patients with healed neuroischemic diabetic foot ulcers. Patients were divided into two groups; the treatment group, that includes patients healed with a sucrose octasulfate-impregnated dressing, and the control group, which includes patients treated with other local treatments different from sucrose octasulfate-impregnated dressings. After healing, patients were prospectively followed up during 1-year and assessed monthly in the specialised outpatient clinics. The main outcome of the study was ulcer recurrence after wound healing within 1 year follow-up. Secondary outcomes were minor or major amputation and all causes of death. Fifty patients in the treatment group and 42 patients in the control group were included. Fourteen (28%) patients suffered from a reulceration event in the treatment group compared to 28 (66.7%) in the control group, p < 0.001. Time to recurrence in the treatment group was 10 (16.26-2.75) and 11.50 (30.75-5.25) weeks in the control group, p = 0.464. There were no observed differences in the minor amputation rates between the two groups: 15.2% (n = 7) in the treatment group and 7.1% (n = 3) in the control group (p = 0.362). Major amputations and death outcomes were exclusively observed in the treatment group. Specifically, four major amputations (8.7%) in the treatment group were complications arising from recurring events complicated by infection during the SARS-CoV-2 period. Seven patients died due to complications not related with local therapy. The relative risk of recurrence was 20.18 times higher in the control group compared with those treated with octasulfate dressing (p < 0.001). Treatment with sucrose octasulfate-impregnated dressings can decrease recurrence rates of neuroischaemic diabetic foot ulcers more effectively than neutral dressings. Besides, it may enhance the foot's clinical properties in patients with poor microcirculation, which could aid in preventing future recurrences.

Early Detection of Diabetic Peripheral Neuropathy: A Focus on Small Nerve Fibres

Diabetic peripheral neuropathy (DPN) is the most common complication of both type 1 and 2 diabetes. As a result, neuropathic pain, diabetic foot ulcers and lower-limb amputations impact drastically on quality of life, contributing to the individual, societal, financial and healthcare burden of diabetes. DPN is diagnosed at a late, often pre-ulcerative stage due to a lack of early systematic screening and the endorsement of monofilament testing which identifies advanced neuropathy only. Compared to the success of the diabetic eye and kidney screening programmes there is clearly an unmet need for an objective reliable biomarker for the detection of early DPN. This article critically appraises research and clinical methods for the diagnosis or screening of early DPN. In brief, functional measures are subjective and are difficult to implement due to technical complexity. Moreover, skin biopsy is invasive, expensive and lacks diagnostic laboratory capacity. Indeed, point-of-care nerve conduction tests are convenient and easy to implement however questions are raised regarding their suitability for use in screening due to the lack of small nerve fibre evaluation. Corneal confocal microscopy (CCM) is a rapid, non-invasive, and reproducible technique to quantify small nerve fibre damage and repair which can be conducted alongside retinopathy screening. CCM identifies early sub-clinical DPN, predicts the development and allows staging of DPN severity. Automated quantification of CCM with AI has enabled enhanced unbiased quantification of small nerve fibres and potentially early diagnosis of DPN. Improved screening tools will prevent and reduce the burden of foot ulceration and amputations with the primary aim of reducing the prevalence of this common microvascular complication.

Optical coherence tomography: a novel imaging approach to visualize and quantify cutaneous microvascular structure and function in patients with diabetes

INTRODUCTION

The pathophysiology of microvascular disease is poorly understood, partly due to the lack of tools to directly image microvessels in vivo.

RESEARCH DESIGN AND METHODS

In this study, we deployed a novel optical coherence tomography (OCT) technique during local skin heating to assess microvascular structure and function in diabetics with (DFU group, n=13) and without (DNU group, n=10) foot ulceration, and healthy controls (CON group, n=13). OCT images were obtained from the dorsal foot, at baseline (33°C) and 30 min following skin heating.

RESULTS

At baseline, microvascular density was higher in DFU compared with CON (21.9%±11.5% vs 14.3%±5.6%, p=0.048). Local heating induced significant increases in diameter, speed, flow rate and density in all groups (all p<0.001), with smaller changes in diameter for the DFU group (94.3±13.4 µm), compared with CON group (115.5±11.7 µm, p<0.001) and DNU group (106.7±12.1 µm, p=0.014). Heating-induced flow rate was lower in the DFU group (584.3±217.0 pL/s) compared with the CON group (908.8±228.2 pL/s, p<0.001) and DNU group (768.8±198.4 pL/s, p=0.014), with changes in density also lower in the DFU group than CON group (44.7%±15.0% vs 56.5%±9.1%, p=0.005).

CONCLUSIONS

This proof of principle study indicates that it is feasible to directly visualize and quantify microvascular function in people with diabetes; and distinguish microvascular disease severity between patients.

Altered pain processing in patients with type 1 and 2 diabetes: systematic review and meta-analysis of pain detection thresholds and pain modulation mechanisms

The first signs of diabetic neuropathy typically result from small-diameter nerve fiber dysfunction. This review synthesized the evidence for small-diameter nerve fiber neuropathy measured via quantitative sensory testing (QST) in patients with diabetes with and without painful and non-painful neuropathies. Electronic databases were searched to identify studies in patients with diabetes with at least one QST measure reflecting small-diameter nerve fiber function (thermal or electrical pain detection threshold, contact heat-evoked potentials, temporal summation or conditioned pain modulation). Four groups were compared: patients with diabetes (1) without neuropathy, (2) with non-painful diabetic neuropathy, (3) with painful diabetic neuropathy and (4) healthy individuals. Recommended methods were used for article identification, selection, risk of bias assessment, data extraction and analysis. For the meta-analyses, data were pooled using random-effect models. Twenty-seven studies with 2422 participants met selection criteria; 18 studies were included in the meta-analysis. Patients with diabetes without symptoms of neuropathy already showed loss of nerve function for heat (standardized mean difference (SMD): 0.52, p<0.001), cold (SMD: -0.71, p=0.01) and electrical pain thresholds (SMD: 1.26, p=0.01). Patients with non-painful neuropathy had greater loss of function in heat pain threshold (SMD: 0.75, p=0.01) and electrical stimuli (SMD: 0.55, p=0.03) compared with patients with diabetes without neuropathy. Patients with painful diabetic neuropathy exhibited a greater loss of function in heat pain threshold (SMD: 0.55, p=0.005) compared with patients with non-painful diabetic neuropathy. Small-diameter nerve fiber function deteriorates progressively in patients with diabetes. Because the dysfunction is already present before symptoms occur, early detection is possible, which may assist in prevention and effective management of diabetic neuropathy.

Microangiopathy: Is it relevant to wound healing in diabetic foot disease?

Chronic diabetic complications - both microvascular and macrovascular - have become serious health issues with their increasing prevalence paralleling the dramatic rise of the diabetic population worldwide. Of these complications, foot disease is a major cause of morbidity and mortality, consuming more health care resource than all other complications combined. Diabetic polyneuropathy and peripheral vascular disease constitute the two main risk factors, with trauma and foot infection being the most important initiating factors and contributors to delayed healing. Intracellular oxidative stress mediated by hyperglycaemia along with hypertension, dyslipidaemia and smoking constitute the main pathological processes in the aetiology of both macrovascular and microvascular disease. Whilst the former remains the major cause of overall mortality in diabetes, the role of microangiopathy in the pathogenesis of diabetes foot disease and its contribution to delayed wound healing in diabetes has yet to be fully understood and indeed continues to be debated. This article will review the key findings to date on structural and functional microvascular abnormalities in the diabetic foot skin and consider their contribution to impaired would healing.

A Synoptic Overview of Neurovascular Interactions in the Foot

Diabetes is a worldwide public health concern as it is associated with various complications. One of the major complications of diabetes is diabetic foot syndrome that results in catastrophic events such as ulceration and amputation. Therefore, the main four strategies of diabetic foot care involve risk prediction, prevention, and early diagnosis and prompt intervention. The drivers of ulceration are multifactorial, and importantly, include microcirculatory changes in the diabetic skin. Cutaneous microcirculation on the foot is greatly influenced by the small fibers which mediate thermal sensation and pain perception in addition to sympathetic activities such as thermoregulation and vasodilation. The interdependence between the neurovascular elements means with the loss of small fiber functions, the corresponding microcirculatory responses may be compromised. Thus, it can be hypothesized that the impairment of the microcirculation may follow the order of the corresponding small fiber nerve dysfunction or vice versa. In this review, select neurovascular investigations that inform the cutaneous microcirculatory and small fiber nerve function in response to pain, cold, and heat and pressure stimuli are reviewed and discussed in this order of sensory loss: the loss of pain, cold, warmth, touch and deep pressure sensation. We also discuss the neurological and vascular characteristics of each of these neurovascular responses. This review highlights the influence of small fibers on cutaneous microcirculation and the need for prospective studies that can determine the course of microcirculatory impairment over time. This, in turn, may help clarify the exact role of microcirculatory changes in the pathway of ulceration. The insights from this review can be pertinent to understand key microcirculatory disturbances and given that the microcirculatory impairment develops at an early stage, relevant interventions can be implemented to possibly reverse or regress the course of the disease. Therefore, knowledge of the neurovascular interactions aids to map the disease progression for early diagnosis and prevention of adverse complications.

New Concepts in the Management of Charcot Neuroarthropathy in Diabetes

Charcot Neuroarthropathy (CN) is an uncommon, debilitating and often underdiagnosed complication of chronic diabetes mellitus though, it can also occur in other medical conditions resulting from nerve injury. Till date, the etiology of CN remains unknown, but enhanced osteoclastogenesis is believed to play a central role in the pathogenesis of CN, in the presence of neuropathy. CN compromises the overall health and quality of life. Delayed diagnosis can result in a severe deformity that can act as a gateway to ulceration, infection and in the worst case, can lead to limb loss. In an early stage of CN, immobilization with offloading plays a key role to a successful treatment. Medical therapies seem to have limited role in the treatment of CN.In case of severe deformity, proper footwear or bracing may help prevent further deterioration and development of an ulcer. In individuals with a concomitant ulcer with osteomyelitis, soft tissue infection and severe deformity, where conservative measures fall short, surgical intervention becomes the only choice of treatment. Early diagnosis and proper management at an early stage can help prevent the occurrence of CN and amputation.

The continuums of impairment in vascular reactivity across the spectrum of cardiometabolic health: A systematic review and network meta-analysis

This study aimed to assess, for the first time, the change in vascular reactivity across the full spectrum of cardiometabolic health. Systematic searches were conducted in MEDLINE and EMBASE databases from their inception to March 13, 2017, including studies that assessed basal vascular reactivity in two or more of the following health groups (aged ≥18 years old): healthy, overweight, obesity, impaired glucose tolerance, metabolic syndrome, or type 2 diabetes with or without complications. Direct and indirect comparisons of vascular reactivity were combined using a network meta-analysis. Comparing data from 193 articles (7226 healthy subjects and 19344 patients), the network meta-analyses revealed a progressive impairment in vascular reactivity (flow-mediated dilation data) from the clinical onset of an overweight status (-0.41%, 95% CI, -0.98 to 0.15) through to the development of vascular complications in those with type 2 diabetes (-4.26%, 95% CI, -4.97 to -3.54). Meta-regressions revealed that for every 1 mmol/l increase in fasting blood glucose concentration, flow-mediated dilation decreased by 0.52%. Acknowledging that the time course of disease may vary between patients, this study demonstrates multiple continuums of vascular dysfunction where the severity of impairment in vascular reactivity progressively increases throughout the pathogenesis of obesity and/or insulin resistance, providing information that is important to enhancing the timing and effectiveness of strategies that aim to improve cardiovascular outcomes.

Neurovascular Response to Pressure in Patients With Diabetic Foot Ulcer

Diabetic foot ulcer (DFU) is a problem worldwide, and prevention is crucial. We hypothesized that the inability of the skin to respond to pressure is involved in DFU pathogenesis and could be an important predictive factor to take into account. We included 29 patients with DFU and 30 patients with type 2 diabetes without DFU. Neuropathy and skin blood flow at rest were assessed in response to acetylcholine, sodium nitroprusside, local heating (42°C), and to nonnoxious locally applied pressure. Results were compared with those obtained from 10 healthy age-matched control subjects. Vasodilatation in response to pressure was significantly impaired in both groups with diabetes compared with healthy subjects. The vasodilator capacity to pressure was significantly lower in patients with DFU compared with those without DFU, despite the absence of significant difference in cutaneous pressure perception threshold and vascular reactivity to acetylcholine, sodium nitroprusside, and heat. This pronounced alteration of neurovascular response to pressure in patients with DFU is a good marker of skin vulnerability and could be used to better predict individuals at risk.

Role of the Microcirculation in Diabetic Foot Ulceration

The concept of microcirculation being implicated in the pathogenesis of diabetic foot disease is being challenged by evidence that fails to confirm it. However, there is evidence of structural changes with capillary and in the basement membrane that do not permit the concept to be denied either. The lack of evidence should not be a reason to argue against surgery in the diabetic foot.

Nociception at the diabetic foot, an uncharted territory

The diabetic foot is characterised by painless foot ulceration and/or arthropathy; it is a typical complication of painless diabetic neuropathy. Neuropathy depletes the foot skin of intraepidermal nerve fibre endings of the afferent A-delta and C-fibres, which are mostly nociceptors and excitable by noxious stimuli only. However, some of them are cold or warm receptors whose functions in diabetic neuropathy have frequently been reported. Hence, it is well established by quantitative sensory testing that thermal detection thresholds at the foot skin increase during the course of painless diabetic neuropathy. Pain perception (nociception), by contrast, has rarely been studied. Recent pilot studies of pinprick pain at plantar digital skinfolds showed that the perception threshold was always above the upper limit of measurement of 512 mN (equivalent to 51.2 g) at the diabetic foot. However, deep pressure pain perception threshold at musculus abductor hallucis was beyond 1400 kPa (equivalent to 14 kg; limit of measurement) only in every fifth case. These discrepancies of pain perception between forefoot and hindfoot, and between skin and muscle, demand further study. Measuring nociception at the feet in diabetes opens promising clinical perspectives. A critical nociception threshold may be quantified (probably corresponding to a critical number of intraepidermal nerve fibre endings), beyond which the individual risk of a diabetic foot rises appreciably. Staging of diabetic neuropathy according to nociception thresholds at the feet is highly desirable as guidance to an individualised injury prevention strategy.

Retrogression of Nervous Fibers According to the Age of Patients with Diabetes Mellitus (DM)

[Purpose] This study was performed to discover the possible onset time of diabetic neuropathy by age of diabetic patients, and to provide the knowledge necessary for preventing or managing diabetic neuropathy. [Subjects] The subjects of this study were outpatients who visited D Hospital Department of Neurology with complaints of significant neuropathic symptoms including dullness, numbness and paraesthesia. [Methods] Stimulations of 5 Hz, 250 Hz and 2,000 Hz were generated with a Neurometer CPT (Neurotron Inc., Baltimore, MD, USA) and delivered selectively to C fibers, A-delta fibers and A-beta fibers. The intensity of the stimulations of 5 Hz, 250 Hz and 2,000 Hz was incrementally increased as much as 0.01 mA. [Result] The results of this experiment show that the period of retrogression of nervous fibers was different significantly according to the age of patients with diabetes mellitus. Especially, in the case of individuals in their 50's, Aβ, Aδ, and C fibers in both the right and left lower limbs significantly changed within a period of 2 months. In the case of individuals in their 60's, Aβ and C fibers of the right lower limb meaningfully changed 2 months after the onset of the disease, and Aβ, Aδ, and C fibers of the left lower limb also significantly changed within a period of 2 months. [Conclusion] We discovered that patients suffering from DM especially in their 50's or 60's should be thoroughly followed for their condition, right from the onset of DM, in order to prevent the retrogression of nervous fibers.

Microcirculatory vasomotor changes are associated with severity of peripheral neuropathy in patients with type 2 diabetes

Systemic microvascular complications are related to the presence of diabetic neuropathy. This study investigated the associations of blood flow oscillations with peripheral neuropathy in 25 controls and 3 diabetic groups including clinical (24), subclinical (27) and without neuropathy (26). Laser Doppler skin perfusion was transformed into three low-frequency subintervals corresponding to endothelial, neurogenic and myogenic vasomotor controls. The average vasomotion was significantly reduced in clinical neuropathy group and characterized by endothelial and neural but not smooth muscle-related changes. The normalized spectrums revealed a relative increase of myogenic and decrease of neurogenic activity in subclinical neuropathy group. The myogenic component showed a statistically inverse correlation with postural fall in systolic blood pressure (r = -0.32, p < 0.01). The diabetic patients with decreased low-frequency vasomotor responses were associated with increased odds ratio of peripheral neuropathy [odds ratio = 3.51 (95% confidence interval = 1.19-10.31), p = 0.02]. This study elucidated possible interaction between impaired microvascular flow motion and diabetic peripheral neuropathy. The vasomotor changes of skin microcirculation could be detected even in the absence of overt cardiovascular dysfunction.

Increased Transcutaneous Oxygen Tension in the Skin Dorsum Over the Foot in Patients With Diabetic Foot Disease in Response to the Topical Use of an Emulsion of Hyperoxygenated Fatty Acids

The aim of this study was to examine changes in the skin over the feet of patients with diabetic foot syndrome after local application of a product containing hyperoxygenated fatty acids (HOFAs) by measuring transcutaneous oxygen. In 64 patients, transcutaneous oxygen pressure (TcPo2) was measured on days 0, 7, 30, 60, and 90 of the study. Foot skin dryness, shedding, and skin color were also assessed using a clinical score. The patients were grouped on the basis of initial levels of transcutaneous oxygen; group 1 comprised patients with TcPo 2 >30 mm Hg and group 2 comprised patients with TcPo2 <30 mm Hg on the skin over the dorsum of the feet. Increases in local oxygenation values were observed at a local level in group 2 patients after 30 days of treatment. Skin trophism showed clinical improvement in all patients and these observations may be attributed to improved local microcirculation.

Large-fiber dysfunction in diabetic peripheral neuropathy is predicted by cardiovascular risk factors

OBJECTIVE

Diabetic large-nerve fiber dysfunction, as measured by vibration perception threshold (VPT), predicts foot ulceration, amputation, and mortality. Thus, determination of modifiable risk factors is of great clinical importance.

RESEARCH DESIGN AND METHODS

We assessed 1,407 patients with type 1 diabetes and a normal VPT participating in the EURODIAB Prospective Complications Study, at baseline mean +/- SD age of 32.7 +/- 10.2 years with diabetes duration of 14.7 +/- 9.3 years and follow-up of 7.3 +/- 0.6 years. VPT was measured using biothesiometry on the right big toe and medial malleolus. An abnormal result was defined as >2 SD from the predicted mean for the patient s age.

RESULTS

An abnormal VPT was associated with an increased incidence of gangrene, amputation, foot ulceration, leg bypass or angioplasty, and mortality (P < OR = 0.02). The incidence of abnormal VPT was 24% over the 7.3-year follow-up. Duration of diabetes and A1C significantly influenced the incidence of abnormal VPT (P < 0.0001). After correction for these, established risk factors for cardiovascular disease (CVD), including male sex (P = 0.0004), hypertension (P < 0.0001), total cholesterol (P = 0.002), LDL cholesterol (P = 0.01), smoking (P < 0.0001), weight (P < 0.0001), and diabetes complications (retinopathy [P = 0.0001], nephropathy [P = 0.01], and autonomic neuropathy [P = 0.001]), were all found to be significant risk factors. A previous history of CVD doubled the incidence of abnormal VPT.

CONCLUSIONS

This prospective study indicates that cardiovascular risk factors predict development of large-fiber dysfunction, which may account for the high mortality rate in patients with an abnormal VPT, and emphasizes the importance of early determination of VPT to detect subclinical neuropathy and to address cardiovascular risk factors.

New finger-occlusion plethysmograph for estimating peripheral blood flow and vascular resistance

BACKGROUND

The aim of the present study was to measure peripheral blood flow (BF) with a new finger-occlusion plethysmograph (FOP) and to compare this to BF measured with a laser Doppler flowmeter (LDF). An additional objective was to investigate the relationship between hypertension-related clinical parameters and peripheral vascular resistance (PVR) estimated from BF and mean blood pressure (BP) (PVR=mean BP/BF) in young subjects.

METHODS AND RESULTS

The present study employed 101 young volunteers (61 males, 40 females, mean age 23.2+/-2.5 years). The FOP was attached to the third finger and an LDF to the fourth fingertip of each subject. BF was measured simultaneously by the 2 devices. A multi-biomedical recorder (TM2425) measured 24-h BP. A high correlation was observed between BF measured by the FOP and LDF (r=0.79, p<0.001). In multiple linear regression analysis, PVR was independently correlated with a family history of hypertension (p<0.01) and with base diastolic BP during sleep (p<0.01), which is a sensitive predictor of severity of hypertension.

CONCLUSIONS

Our newly developed FOP can estimate peripheral absolute BF easily. Furthermore, BF determined by the FOP can be used to calculate PVR, and an elevated PVR may be a useful predictor of hypertension.

The LDIflare: a novel test of C-fiber function demonstrates early neuropathy in type 2 diabetes

OBJECTIVE

The aim of this study was to evaluate a novel method for assessing the axon reflex and to determine its value in detecting neuropathy in type 2 diabetes.

RESEARCH DESIGN AND METHODS

The neurogenic flare response to nociceptive stimuli is mediated by an axon reflex involving small unmyelinated C-fibers. We developed a method to assess this reflex involving skin heating to 44 degrees C to evoke the flare followed by scanning the site using a laser Doppler imager (LDI) to measure the area; we termed this method LDIflare. To confirm its neurogenic nature, we examined the LDIflare in eight healthy subjects before and after topical administration of anesthesia. We used this technique to detect C-fiber neuropathy in people with type 2 diabetes. A total of 36 subjects were studied: 12 subjects with neuropathy (group DN), 12 subjects without neuropathy (group DC), and 12 age- and sex-matched control subjects (group NC). For comparison, small-fiber function was also assessed using the Computer Aided Sensory Evaluator-IV (CASE IV) (WR Medical Electronics, Stillwater, MN).

RESULTS

In the eight healthy control subjects, LDIflare was markedly reduced after topical administration of anesthesia (1.62 [1.45-1.72] vs. 5.2 cm2 [3.9-5.9], P <0.0001), confirming its neurogenic nature. Similarly, in neuropathic subjects, LDIflare was significantly smaller compared with normal and diabetic control subjects (LDIflare area: DN 1.3 cm2 [0.9-1.8], NC 5.5 cm2 [3.9-5.8], and DC 2.8 cm2 [2.5-3.8]; P <0.0001 and P=0.01, respectively). The group without neuropathy (DC) also demonstrated a reduced flare compared with the NC group (P=0.01). In contrast, C-fiber function assessed by evaluating the quantitative thermal thresholds (CASE IV) did not detect a difference between the latter two groups.

CONCLUSIONS

This study confirms the neurogenic nature of the LDIflare and clearly demonstrates loss of C-fiber function in neuropathic subjects with type 2 diabetes. Moreover, it demonstrates C-fiber dysfunction before its detection by other currently available methods, including CASE IV. The LDIflare seems to be a simple objective method to detect early neuropathy and may be of value in assessing therapeutic interventions aimed at preventing or reversing C-fiber dysfunction.