One-stop microvascular screening service: an effective model for the early detection of diabetic peripheral neuropathy and the high-risk foot

Sheffield One-Stop Service: A potential model to improve the screening uptake of diabetic peripheral neuropathy and other microvascular complications of diabetes

The world is experiencing an enormous rise in the prevalence of diabetes, which is associated with massive healthcare costs that threaten to overwhelm many healthcare systems. Most of the diabetes expenditure is attributed to the management of chronic diabetes complications, including diabetic peripheral neuropathy (DPN)/diabetic foot complications, chronic kidney disease, sight-threatening retinopathy and cardiovascular diseases. Of these complications, the most overlooked is DPN. Most consultations around the world do not even involve taking off shoes and socks to carry out a foot examination, and even when carried out, the peripheral neurological examination using the 10-g monofilament diagnoses DPN when it is already at an advanced stage. Thus, all too often diabetes complications are diagnosed late, resulting in devastating outcomes, particularly in low- to middle-income countries. There is, therefore, an urgent need to instigate new strategies to improve microvascular screening uptake using a holistic protocol for annual diabetes health checks outside the busy diabetes clinic. One such approach, the Sheffield One-Stop Microvascular Screening Service, which involves modern point of care devices to diagnose DPN, has been shown to be feasible and effective, resulting in high uptake and early management of diabetes complications. This article outlines the advantages of this One-Stop Microvascular Screening Service and a plan to trial an adapted version of this service to a resource-limited country, the Philippines. If successful, this model has the potential for implementation in other countries around the world.

Efficacy and Safety of the Combination of Palmitoylethanolamide, Superoxide Dismutase, Alpha Lipoic Acid, Vitamins B12, B1, B6, E, Mg, Zn and Nicotinamide for 6 Months in People with Diabetic Neuropathy

AIM

To investigate the efficacy of Palmitoylethanolamide (PEA, 300 mg), Superoxide Dismutase (SOD, 70 UI), Alpha Lipoic Acid (ALA, 300 mg), vitamins B6 (1.5 mg), B1 (1.1 mg), B12 (2.5 mcg), E (7.5 mg), nicotinamide (9 mg), and minerals (Mg 30 mg, Zn 2.5 mg) in one tablet in people with Diabetic Neuropathy (DN).

PATIENTS-METHODS

In the present pilot study, 73 people (age 63.0 ± 9.9 years, 37 women) with type 2 Diabetes Mellitus (DMT2) (duration 17.5 ± 7.3 years) and DN were randomly assigned to receive either the combination of ten elements (2 tablets/24 h) in the active group (n = 36) or the placebo (n = 37) for 6 months. We used the Michigan Neuropathy Screening Instrument Questionnaire and Examination (MNSIQ and MNSIE), measured vibration perception threshold (VPT) with biothesiometer, and Cardiovascular Autonomic Reflex Tests (CARTs). Nerve function was assessed by DPN Check [sural nerve conduction velocity (SNCV) and amplitude (SNAP)]. Sudomotor function was assessed with SUDOSCAN, which measures electrochemical skin conductance in hands and feet (ESCH and ESCF). Pain score (PS) was assessed with Pain DETECT questionnaire. Quality of life was assessed by questionnaire.

RESULTS

In the active group, there was a large improvement of pain (PS from 20.9 to 13.9, p < 0.001). There was also a significant improvement of vitamin B12 (B12) levels, MNSIQ, SNCV, VPT, and ESCF (222.1 vs. 576.3 pg/ mL, p < 0.001; 6.1 vs. 5.9, p = 0.017; 28.8 vs. 30.4, p = 0.001; 32.1 vs. 26.7, p = 0.001; and 72.2 vs. 74.8, p < 0.001 respectively). In the placebo group, neither pain (21.6 vs. 21.7, p = 0.870) or any other aforementioned parameters changed significantly, and MNSIE worsened (2.9 vs. 3.4, p < 0.001). As a result, changes from baseline to follow-up in pain, B12 levels, VPT, and MNSIQ differed significantly between the two groups (p < 0.001, 0.025, 0.009, and <0.001, respectively). CARTs, SNAP, ESCH did not significantly change in either of the two groups.

CONCLUSIONS

The combination of the ten elements in one tablet for 6 months at a daily dose of two tablets in people with DN significantly improves pain, vibration perception threshold, and B12 levels.

The Association between the Severity of Distal Sensorimotor Polyneuropathy and Increased Carotid Atherosclerosis in Individuals with Type 2 Diabetes

BACKGROUND

Diabetes contributes to a spectrum of complications encompassing microvascular and macrovascular disorders. This study aimed to explore the correlation between distal sensorimotor polyneuropathy (DSPN) severity and heightened carotid atherosclerosis among individuals with type 2 diabetes mellitus (T2DM). Method: Participants underwent comprehensive assessments including nerve conduction studies (NCS), Toronto Clinical Neuropathy Score (TCNS) evaluations, assessment of cardiometabolic risk factors, and carotid sonography studies covering dynamic and morphological parameters. The resistance index (RI), pulsatility index (PI), peak systolic velocity (PSV), and end-diastolic velocity (EDV) in both the common carotid artery (CCA) and internal carotid artery (ICA), carotid intima-media thickness (IMT), and carotid plaque score (CPS) were also measured. Peripheral nerve function severity was assessed using composite amplitude scores (CAS) derived from NCS.

RESULTS

Individuals with DSPN exhibited lower EDV in the CCA and ICA (p < 0.0001 and p = 0.002), higher PI and RI in both CCA and ICA (all p < 0.0001), and higher CPS (p = 0.002). They also demonstrated a higher prevalence of retinopathy as an underlying condition, higher index HbA1c, and reduced estimated glomerular filtration rate (eGFR) (all p < 0.0001). Multiple linear regression analysis revealed significant associations where eGFR, ICA-PI, index HbA1c, waist circumference, and age were correlated with CAS. Meanwhile, diabetes duration, waist circumference, age, and index HbA1c showed significant associations with TCNS.

CONCLUSIONS

Our study suggests that individuals with T2DM who exhibit more severe carotid atherosclerosis may not only be at increased risk of developing DSPN but also may experience greater severity of DSPN. PI in both the CCA and ICA, along with the CPS, serve as surrogate biomarkers for DSPN severity.

Indirect effects of the COVID-19 pandemic on diagnosing, monitoring, and prescribing in people with diabetes and strategies for diabetes service recovery internationally

The COVID-19 pandemic has caused major disruptions in clinical services for people with chronic long-term conditions. In this narrative review, we assess the indirect impacts of the COVID-19 pandemic on diabetes services globally and the resulting adverse effects on rates of diagnosing, monitoring, and prescribing in people with type 2 diabetes. We summarise potential practical approaches that could address these issues and improve clinical services and outcomes for people living with diabetes during the recovery phase of the pandemic.

Female sex is a risk factor for painful diabetic peripheral neuropathy: the EURODIAB prospective diabetes complications study

AIMS/HYPOTHESIS

While the risk factors for diabetic peripheral neuropathy (DPN) are now well recognised, the risk factors for painful DPN remain unknown. We performed analysis of the EURODIAB Prospective Complications Study data to elucidate the incidence and risk factors of painful DPN.

METHODS

The EURODIAB Prospective Complications Study recruited 3250 participants with type 1 diabetes who were followed up for 7.3±0.6 (mean ± SD) years. To evaluate DPN, a standardised protocol was used, including clinical assessment, quantitative sensory testing and autonomic function tests. Painful DPN (defined as painful neuropathic symptoms in the legs in participants with confirmed DPN) was assessed at baseline and follow-up.

RESULTS

At baseline, 234 (25.2%) out of 927 participants with DPN had painful DPN. At follow-up, incident DPN developed in 276 (23.5%) of 1172 participants. Of these, 41 (14.9%) had incident painful DPN. Most of the participants who developed incident painful DPN were female (73% vs 48% painless DPN p=0.003) and this remained significant after adjustment for duration of diabetes and HbA1c (OR 2.69 [95% CI 1.41, 6.23], p=0.004). The proportion of participants with macro- or microalbuminuria was lower in those with painful DPN compared with painless DPN (15% vs 34%, p=0.02), and this association remained after adjusting for HbA1c, diabetes duration and sex (p=0.03).

CONCLUSIONS/INTERPRETATION

In this first prospective study to investigate the risk factors for painful DPN, we definitively demonstrate that female sex is a risk factor for painful DPN. Additionally, there is less evidence of diabetic nephropathy in incident painful, compared with painless, DPN. Thus, painful DPN is not driven by cardiometabolic factors traditionally associated with microvascular disease. Sex differences may therefore play an important role in the pathophysiology of neuropathic pain in diabetes. Future studies need to look at psychosocial, genetic and other factors in the development of painful DPN.

Acupuncture in diabetic peripheral neuropathy-neurological outcomes of the randomized acupuncture in diabetic peripheral neuropathy trial

BACKGROUND

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus and can lead to serious complications. Therapeutic strategies for pain control are available but there are few approaches that influence neurological deficits such as numbness.

AIM

To investigate the effectiveness of acupuncture on improving neurological deficits in patients suffering from type 2 DPN.

METHODS

The acupuncture in DPN (ACUDPN) study was a two-armed, randomized, controlled, parallel group, open, multicenter clinical trial. Patients were randomized in a 1:1 ratio into two groups: The acupuncture group received 12 acupuncture treatments over 8 wk, and the control group was on a waiting list during the first 16 wk, before it received the same treatment as the other group. Both groups received routine care. Outcome parameters were evaluated after 8, 16 and 24 wk and included neurological scores, such as an 11-point numeric rating scale (NRS) 11 for hypesthesia, neuropathic pain symptom inventory (NPSI), neuropathy deficit score (NDS), neuropathy symptom score (NSS); nerve conduction studies (NCS) were assessed with a handheld point-of-care device.

RESULTS

Sixty-two participants were included. The NRS for numbness showed a difference of 2.3 (P < 0.001) in favor of the acupuncture group, the effect persisted until week 16 with a difference of 2.2 (P < 0.001) between groups and 1.8 points at week 24 compared to baseline. The NPSI was improved in the acupuncture group by 12.6 points (P < 0.001) at week 8, the NSS score at week 8 with a difference of 1.3 (P < 0.001); the NDS and the TNSc score improved for the acupuncture group in week 8, with a difference of 2.0 points (P < 0.001) compared to the control group. Effects were persistent in week 16 with a difference of 1.8 points (P < 0.05). The NCS showed no meaningful changes. In both groups only minor side effects were reported.

CONCLUSION

Study results suggest that acupuncture may be beneficial in type 2 diabetic DPN and seems to lead to a reduction in neurological deficits. No serious adverse events were recorded and the adherence to treatment was high. Confirmatory randomized sham-controlled clinical studies with adequate patient numbers are needed to confirm the results.

Sudoscan as substitute for quantitative sudomotor axon reflex test in composite autonomic scoring scale and its correlation with composite autonomic symptom scale 31 in type 2 diabetes

OBJECTIVE

This study aims to evaluate the feasibility of substituting electrochemical skin conductance measurement using SUDOSCAN for sudomotor function testing in the Composite Autonomic Scoring Scale (CASS) and to correlate the results with the Composite Autonomic Symptom Scale 31 (COMPASS 31) among patients with type 2 diabetes mellitus (T2DM).

METHODS

Fifty patients with T2DM underwent cardiovascular autonomic function testing and the SUDOSCAN test and completed the COMPASS 31 questionnaire. We developed a SUDOSCAN-based sudomotor subscore as a substitute for the original sudomotor subscore (based on the quantitative sudomotor axon reflex test [QSART]). The modified CASS score (SUDOSCAN-based sudomotor subscore combined with the adrenergic and cardiovagal subscores) and the original CASS score without suomotor assessment (sum of the adrenergic and cardiovagal subscores) were obtained according to the results of the cardiovascular autonomic function and SUDOSCAN tests.

RESULTS

The total COMPASS 31 score was significantly correlated with the modified CASS score (p = 0.019 and 0.037 for the raw and weighted scores, respectively) but not with the CASS score without sudomotor assessment. After adding the SUDOSCAN-based sudomotor subscore, the number of patients identified as having diabetic autonomic neuropathy (DAN) increased from 24 (48 %, based on the CASS score without sudomotor assessment) to 35 (70 %, based on the modified CASS score). The modified CASS score enhances the accuracy of assessing autonomic function and improves the diagnosis of diabetic autonomic neuropathy (DAN) among patients with T2DM. In medical settings where QSART is not accessible, SUDOSCAN testing offers a practical and efficient alternative.

Where does spinal cord stimulation fit into the international guidelines for refractory painful diabetic neuropathy? a consensus statement

BACKGROUND

Although pharmacotherapy with anticonvulsants and/or antidepressants can be effective for many people with painful diabetic neuropathy (PDN), albeit with frequent side-effects, a critical juncture occurs when neuropathic pain no longer responds to standard first- and second-step mono- and dual therapy and becomes refractory. Subsequent to these pharmacotherapeutic approaches, third-line treatment options for PDN may include opioids (short-term), capsaicin 8% patches, and spinal cord stimulation (SCS).

AIM

This document summarizes consensus recommendations regarding appropriate treatment for refractory peripheral diabetic neuropathy (PDN), based on outcomes from an expert panel convened on December 10, 2022, as part of the Worldwide Initiative for Diabetes Education Virtual Global Summit, "Advances in the Management of Painful Diabetic Neuropathy."

PARTICIPANTS

Nine attendees, eminent physicians and academics, comprising six diabetes specialists, two pain specialists, and one health services expert.

EVIDENCE

For individuals with refractory PDN, opioids are a high-risk option that do not provide a long-term solution and should not be used. For appropriately selected individuals, SCS is an effective, safe, and durable treatment option. In particular, high-frequency (HF) SCS (10 kHz) shows strong efficacy and improves quality of life. To ensure treatment success, strict screening criteria should be used to prioritize candidates for SCS.

CONSENSUS PROCESS

Each participant voiced their opinion after reviewing available data, and a verbal consensus was reached during the meeting.

CONCLUSION

Globally, the use of opioids should rarely be recommended for refractory, severe PDN. Based on increasing clinical evidence, SCS, especially HF-SCS, should be considered as a treatment for PDN that is not responsive to first- or second-line monotherapy/dual therapy.

Effect of 10.6 μm laser moxibustion on inflammation in diabetic peripheral neuropathy rats

Diabetic peripheral neuropathy (DPN) is the main cause of disability in diabetes patients but the efficacy of available drugs is poor. Moxibustion is an adjunctive treatment for DPN that can reduce symptoms. The peak value of the far infrared wavelength of 10.6 μm laser moxibustion is close to the infrared radiation spectrum of traditional moxibustion. Its effect is similar to that of moxibustion and does not cause pain, infection or produce irritating smoke. Twenty-four male SD rats were divided into control (Con), DPN, laser moxibustion (LM), and pyrrolidine dithiocarbamate (PDTC) groups (n=6/group). The DPN, LM and PDTC group rats were intraperitoneally injected with 1% streptozotocin (STZ) to induce a model of DPN. LM group rats were irradiated with a laser at bilateral ST36 acupoints for 15 min, once every other day, for 14 days. PDTC group rats were intraperitoneally injected with PDTC once a day. Body weight, blood glucose, and paw withdrawal mechanical threshold (PWMT) were measured and laser speckle imaging (LSI) performed before and after modeling and at 1 and 2 weeks after intervention. Two weeks after intervention, changes in serum interleukin 1β (IL1β), interleukin 6 (IL6), tumor necrosis factor α (TNFα) and nerve growth factor (NGF) were analyzed, and the abundance of NF-κB and IκB-α proteins and levels of NF-κB and IκB-α mRNAs in the sciatic nerve were observed. The results showed that 10.6 μm laser moxibustion can relieve pain, improve microcirculation, and alleviate inflammation in DPN rats, possibly via the NF-κB inflammatory pathway.

Bridging the "Know-Do" Gaps in Five Non-Communicable Diseases Using a Common Framework Driven by Implementation Science

According to the United Nations High-Level Meeting 2018, five non-communicable diseases (NCDs) including cardiovascular diseases, chronic respiratory diseases, diabetes mellitus, cancer, and mental health conditions accounted for two-thirds of global deaths. These five NCDs share five common risk factors including tobacco use, unhealthy diets, physical inactivity, alcohol use, and air pollution. Low- and middle-income countries (LMICs) face larger burden of NCDs than high-income countries (HICs), due to differences in ecological, technological, socioeconomic and health system development. Based on high-level evidence albeit mainly from HICs, the burden caused by NCDs can be reduced by affordable medicines and best practices. However, "know-do" gaps, ie, gaps between what we know in science and what we do in practice, has limited the impact of these strategies, especially in LMICs. Implementation science advocates the use of robust methodologies to evaluate sustainable solutions in health, education and social care aimed at informing practice and policies. In this article, physician researchers with expertise in NCDs reviewed the common challenges shared by these five NCDs with different clinical courses. They explained the principles of implementation science and advocated the use of an evidence-based framework to implement solutions focusing on early detection, prevention and empowerment, supplemented by best practices in HICs and LMICs. These successful stories can be used to motivate policymakers, payors, providers, patients and public to co-design frameworks and implement context-relevant, multi-component, evidence-based practices. In pursuit of this goal, we propose partnership, leadership, and access to continuing care as the three pillars in developing roadmaps for addressing the multiple needs during the journey of a person with or at risk of these five NCDs. By transforming the ecosystem, raising awareness and aligning context-relevant practices and policies with ongoing evaluation, it is possible to make healthcare accessible, affordable and sustainable to reduce the burden of these five NCDs.

Diagnosis, management and impact of painful diabetic peripheral neuropathy: A patient survey in four European countries

AIMS

The aim of this study was to assess patient perspectives and experiences of the impact of neuropathic pain, painful diabetic neuropathy (pDPN) diagnosis and treatment, and the patient-healthcare professional (HCP) relationship.

METHODS

We conducted a quantitative online survey in Germany, the Netherlands, Spain, and the UK among adults with diabetes who responded "yes" to at least four of ten questions of in the Douleur Neuropathique en 4 Questions (DN4) questionnaire.

RESULTS

Of 3626 respondents, 576 met the eligibility criteria. Daily pain was rated as moderate or severe by 79 % of respondents. Most participants reported a negative impact of their pain on sleep (74 %), mood (71 %), exercise (69 %), concentration (64 %) and daily activities (62 %), and 75 % of those in employment had missed work because of their pain in the past year. Overall, 22 % of respondents avoided discussing pain with their HCP, 50 % had not received formal pDPN diagnosis, and 56 % had not used prescribed pain medications. Although two-thirds (67 %) of respondents reported feeling satisfied or very satisfied with treatment, 82 % of these patients still experienced daily moderate or severe pain.

CONCLUSIONS

Neuropathic pain in people with diabetes affects daily life and remains underdiagnosed and undertreated in clinical practice.

Screening for diabetic peripheral neuropathy in resource-limited settings

BACKGROUND

Diabetic neuropathy is the most common microvascular complication of diabetes mellitus and a major risk factor for diabetes-related lower-extremity complications. Diffuse neuropathy is the most frequently encountered pattern of neurological dysfunction and presents clinically as distal symmetrical sensorimotor polyneuropathy. Due to the increasing public health significance of diabetes mellitus and its complications, screening for diabetic peripheral neuropathy is essential. Consequently, a review of the principles that guide screening practices, especially in resource-limited clinical settings, is urgently needed.

MAIN BODY

Numerous evidence-based assessments are used to detect diabetic peripheral neuropathy. In accordance with current guideline recommendations from the American Diabetes Association, International Diabetes Federation, International Working Group on the Diabetic Foot, and National Institute for Health and Care Excellence, a screening algorithm for diabetic peripheral neuropathy based on multiphasic clinical assessment, stratification according to risk of developing diabetic foot syndrome, individualized treatment, and scheduled follow-up is suggested for use in resource-limited settings.

CONCLUSIONS

Screening for diabetic peripheral neuropathy in resource-limited settings requires a practical and comprehensive approach in order to promptly identify affected individuals. The principles of screening for diabetic peripheral neuropathy are: multiphasic approach, risk stratification, individualized treatment, and scheduled follow-up. Regular screening for diabetes-related foot disease using simple clinical assessments may improve patient outcomes.

Multimodal testing reveals subclinical neurovascular dysfunction in prediabetes, challenging the diagnostic threshold of diabetes

AIM

To explore if novel non-invasive diagnostic technologies identify early small nerve fibre and retinal neurovascular pathology in prediabetes.

METHODS

Participants with normoglycaemia, prediabetes or type 2 diabetes underwent an exploratory cross-sectional analysis with optical coherence tomography angiography (OCT-A), handheld electroretinography (ERG), corneal confocal microscopy (CCM) and evaluation of electrochemical skin conductance (ESC).

RESULTS

Seventy-five participants with normoglycaemia (n = 20), prediabetes (n = 29) and type 2 diabetes (n = 26) were studied. Compared with normoglycaemia, mean peak ERG amplitudes of retinal responses at low (16-Td·s: 4.05 μV, 95% confidence interval [95% CI] 0.96-7.13) and high (32-Td·s: 5·20 μV, 95% CI 1.54-8.86) retinal illuminance were lower in prediabetes, as were OCT-A parafoveal vessel densities in superficial (0.051 pixels/mm² , 95% CI 0.005-0.095) and deep (0.048 pixels/mm² , 95% CI 0.003-0.093) retinal layers. There were no differences in CCM or ESC measurements between these two groups. Correlations between HbA_1c and peak ERG amplitude at 32-Td·s (r = -0.256, p = 0.028), implicit time at 32-Td·s (r = 0.422, p < 0.001) and 16-Td·s (r = 0.327, p = 0.005), OCT parafoveal vessel density in the superficial (r = -0.238, p = 0.049) and deep (r = -0.3, p = 0.017) retinal layers, corneal nerve fibre length (CNFL) (r = -0.293, p = 0.017), and ESC-hands (r = -0.244, p = 0.035) were observed. HOMA-IR was a predictor of CNFD (β = -0.94, 95% CI -1.66 to -0.21, p = 0.012) and CNBD (β = -5.02, 95% CI -10.01 to -0.05, p = 0.048).

CONCLUSIONS

The glucose threshold for the diagnosis of diabetes is based on emergent retinopathy on fundus examination. We show that both abnormal retinal neurovascular structure (OCT-A) and function (ERG) may precede retinopathy in prediabetes, which require confirmation in larger, adequately powered studies.

Assessing the Feasibility of Using Electrochemical Skin Conductance as a Substitute for the Quantitative Sudomotor Axon Reflex Test in the Composite Autonomic Scoring Scale and Its Correlation with Composite Autonomic Symptom Scale 31 in Parkinson's Disease

The Composite Autonomic Scoring Scale (CASS) is a quantitative scoring system that integrates the sudomotor, the cardiovagal, and the adrenergic subscores, and the Composite Autonomic Symptom Scale 31 (COMPASS 31) is based on a well-established comprehensive questionnaire designed to assess the autonomic symptoms across multiple domains. We tested the hypothesis that electrochemical skin conductance (Sudoscan) can be a substitute for the quantitative sudomotor axon reflex test (QSART) in the sudomotor domain and assessed its correlation with COMPASS 31 in patients with Parkinson's disease (PD). Fifty-five patients with PD underwent clinical assessment and cardiovascular autonomic function tests and completed the COMPASS 31 questionnaire. We compared the modified CASS (integrating the Sudoscan-based sudomotor, adrenergic, and cardiovagal subscores) and CASS subscores (the sum of the adrenergic and cardiovagal subscores). The total weighted score of COMPASS 31 was significantly correlated with both the modified CASS and the CASS subscore (p = 0.007 and p = 0.019). The correlation of the total weighted score of COMPASS 31 increased from 0.316 (CASS subscores) to 0.361 (modified CASS). When we added the Sudoscan-based sudomotor subscore, the case numbers for autonomic neuropathy (AN) increased from 22 (40%, CASS subscores) to 40 (72.7%, modified CASS). The modified CASS not only better reflects the exact autonomic function, but also improves the characterization and quantification of AN in patients with PD. In areas in which a QSART facility is not easily available, Sudoscan could be a time-saving substitution.

Distal symmetrical polyneuropathy is present in all individuals with diabetes and foot ulcers - and does not associate with healing time

We estimated the occurrence of diabetic neuropathy using six different diagnostic modalities in individuals with newly diagnosed diabetic foot ulcers (DFUs) and assessed the association with DFU healing time. All individuals with DFU had distal symmetrical polyneuropathy. Presence of neuropathy did not associate with ulcer healing time (p ≥ 0.12).

Diagnostic accuracy of nerve ultrasonography for the detection of peripheral neuropathy in type 2 diabetes

BACKGROUND AND PURPOSE

Nerve conduction studies (NCS) are the current objective measure for diagnosis of peripheral neuropathy in type 2 diabetes but do not assess nerve structure. This study investigated the utility of peripheral nerve ultrasound as a marker of the presence and severity of peripheral neuropathy in type 2 diabetes.

METHODS

A total of 156 patients were recruited, and nerve ultrasound was undertaken on distal tibial and distal median nerves. Neuropathy severity was graded using the modified Toronto Clinical Neuropathy Scale (mTCNS) and Total Neuropathy Score (TNS). Studies were undertaken by a single ultrasonographer blinded to nerve conduction results.

RESULTS

A stepwise increase in tibial nerve cross-sectional area (CSA) was noted with increasing TNS grade (p &lt; 0.001) and each mTCNS quartile (p &lt; 0.001). Regression analysis demonstrated a correlation between tibial nerve CSA and neuropathy severity (p &lt; 0.001). Using receiver operator curve analysis, tibial nerve CSA of &gt;12.88 mm yielded a sensitivity of 70.5% and specificity of 85.7% for neuropathy detection. Binary logistic regression revealed that tibial nerve CSA was a predictor of abnormal sural sensory nerve action potential amplitude (odds ratio = 1.239, 95% confidence interval [CI] = 1.142-1.345) and abnormal neuropathy score (odds ratio = 1.537, 95% confidence interval [CI] = 1.286-1.838).

CONCLUSIONS

Tibial nerve ultrasound has good specificity and sensitivity for neuropathy diagnosis in type 2 diabetes. The study demonstrates that tibial nerve CSA correlates with neuropathy severity. Future serial studies using both ultrasound and NCS may be useful in determining whether changes in ultrasound occur prior to development of nerve conduction abnormalities and neuropathic symptoms.

A scoping review protocol to map the evidence on the risks and benefits of population based diabetic foot screening

Background: Diabetic foot ulcers are one of the most common lower extremity complications of diabetes, with the lifetime risk of a person developing a DFU estimated to be as high as 34%. It is recommended that those with diabetes receive an annual review of their feet, by a trained healthcare professional, to identify risk factors for ulceration and allow for subsequent risk stratification, patient education and provision of appropriate care to prevent ulceration and amputation. Internationally, while many countries have a diabetic foot care pathway, it is not a structured population health screening programme unlike other areas of preventive care for people with diabetes such as retinopathy screening. A structured diabetic foot screening pathway could allow for earlier identification of the at-risk foot. However, the introduction of any population screening programme should meet the Wilson and Jungner principles of screening. This paper presents a protocol for a scoping review of existing evidence on screening for the at-risk-foot against the Wilson and Junger principles. Methods: The scoping review will be conducted in line with the six-stage methodological framework by Arksey & O'Mally and the Joanna Briggs Institute (JBI) scoping review methodology. Medline (EBSCO), Scopus, ScienceDirect and EMBASE databases will be searched. Studies relating to the burden of diabetic foot ulcers, their pathophysiology and screening tests for peripheral neuropathy and peripheral artery disease, and screening programmes will be included. A data extraction tool will be used to facilitate a chronological narrative synthesis of results. Results: These will be reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews (PRISMA-ScR). Conclusion: This scoping review will evaluate and map the evidence surrounding diabetic foot ulcers using the Wilson and Jungner principles of screening as a framework.

Screening, diagnosis and management of diabetic sensorimotor polyneuropathy in clinical practice: International expert consensus recommendations

Diabetic sensorimotor polyneuropathy (DSPN) affects around one third of people with diabetes and accounts for considerable morbidity, increased risk of mortality, reduced quality of life, and increased health care costs resulting particularly from neuropathic pain and foot ulcers. Painful DSPN is encountered in 13-26% of diabetes patients, while up to 50% of patients with DSPN may be asymptomatic. Unfortunately, DSPN still remains inadequately diagnosed and treated. Herein we provide international expert consensus recommendations and algorithms for screening, diagnosis, and treatment of DSPN in clinical practice derived from a Delphi process. Typical neuropathic symptoms include pain, paresthesias, and numbness particularly in the feet and calves. Clinical diagnosis of DSPN is based on neuropathic symptoms and signs (deficits). Management of DSPN includes three cornerstones: (1) lifestyle modification, optimal diabetes treatment aimed at near-normoglycemia, and multifactorial cardiovascular risk intervention, (2) pathogenetically oriented pharmacotherapy (e.g. α-lipoic acid and benfotiamine), and (3) symptomatic treatment of neuropathic pain including analgesic pharmacotherapy (antidepressants, anticonvulsants, opioids, capsaicin 8% patch and combinations, if required) and non-pharmacological options. Considering the individual risk profile, pain management should not only aim at pain relief, but also allow for improvement in quality of sleep, functionality, and general quality of life.

Early detection to prevent foot ulceration among type 2 diabetes mellitus patient: A multi-intervention review

Foot ulceration is one of the biggest complications experienced by type 2 diabetes patients. The severity and prevention of new wounds can be overcome through early detection interventions. This systematic review aims to explain and provide a comparison of various interventions that have been developed to prevent the occurrence of Diabetes Foot Ulcers (DFU). We searched Scopus, Science Direct, PubMed, CINAHL, SAGE, and ProQuest for English, experimental studies, published between 2016-2021 that tested early detection for preventing diabetic foot ulcers in diabetic patients. The Joanna Briggs Institute guidelines were used to assess eligibility, and PRISMA quality and a checklist to guide this review. 25 studies were obtained that matched the specified inclusion criteria. The entire article has an experimental study design. Majority of respondents were type 2 diabetes patients who have not experienced ulceration. Based on the results of the review, there were 3 main types of interventions used in the early detection of DFU. The types of intervention used are 1) conventional intervention/physical assessment, 2) 3D thermal camera assessment system, and 3) DFU screening instrument. The three types of interventions have advantages and disadvantages, so their use needs to be adjusted to the conditions and needs of the patient. the development of DFU risk early detection intervention needs to be developed. Integration with modern technology can also be done to increase the accuracy of the results and the ease of examination procedures.

SUDOSCAN in Combination with the Michigan Neuropathy Screening Instrument Is an Effective Tool for Screening Diabetic Peripheral Neuropathy

BACKGROUND

Screening for diabetic peripheral neuropathy (DPN) is important to prevent severe foot complication, but the detection rate of DPN is unsatisfactory. We investigated whether SUDOSCAN combined with Michigan Neuropathy Screening Instrument (MNSI) could be an effective tool for screening for DPN in people with type 2 diabetes mellitus (T2DM) in clinical practice.

METHODS

We analysed the data for 144 people with T2DM without other cause of neuropathy. The presence of DPN was confirmed according to the Toronto Consensus criteria. Electrochemical skin conductance (ESC) of the feet was assessed using SUDOSCAN. We compared the discrimination power of following methods, MNSI only vs. SUDOSCAN only vs. MNSI plus SUDOSCAN vs. MNSI plus 10-g monofilament test.

RESULTS

Confirmed DPN was detected in 27.8% of the participants. The optimal cut-off value of feet ESC to distinguish DPN was 56 μS. We made the DPN screening scores using the corresponding odds ratios for MNSI-Questionnaire, MNSI-Physical Examination, SUDOSCAN, and 10-g monofilament test. For distinguishing the presence of DPN, the MNSI plus SUDOSCAN model showed higher areas under the receiver operating characteristic curve (AUC) than MNSI only model (0.717 vs. 0.638, P=0.011), and SUDOSCAN only model or MNSI plus 10-g monofilament test showed comparable AUC with MNSI only model.

CONCLUSION

The screening model for DPN that includes both MNSI and SUDOSCAN can detect DPN with acceptable discrimination power and it may be useful in Korean patients with T2DM.

Diabetes Distal Peripheral Neuropathy: Subtypes and Diagnostic and Screening Technologies

Diabetes distal symmetrical peripheral neuropathy (DSPN) is the most prevalent form of neuropathy in industrialized countries, substantially increasing risk for morbidity and pre-mature mortality. DSPN may manifest with small-fiber disease, large-fiber disease, or a combination of both. This review summarizes: (1) DSPN subtypes (small- and large-fiber disease) with attention to clinical signs and patient symptoms; and (2) technological diagnosis and screening for large- and small-fiber disease with inclusion of a comprehensive literature review of published studies from 2015-present (N = 66). Review findings, informed by the most up-to-date research, advance critical understanding of DSPN large- and small-fiber screening technologies, including those designed for point-of-care use in primary care and endocrinology practices.

Individualised screening of diabetic foot: creation of a prediction model based on penalised regression and assessment of theoretical efficacy

AIMS/HYPOTHESIS

A large proportion of people with diabetes do not receive proper foot screening due to insufficiencies in healthcare systems. Introducing an effective risk prediction model into the screening protocol would potentially reduce the required screening frequency for those considered at low risk for diabetic foot complications. The main aim of the study was to investigate the value of individualised risk assignment for foot complications for optimisation of screening.

METHODS

From 2015 to 2020, 11,878 routine follow-up foot investigations were performed in the tertiary diabetes clinic. From these, 4282 screening investigations with complete data containing all of 18 designated variables collected at regular clinical and foot screening visits were selected for the study sample. Penalised logistic regression models for the prediction of loss of protective sensation (LOPS) and loss of peripheral pulses (LPP) were developed and evaluated.

RESULTS

Using leave-one-out cross validation (LOOCV), the penalised regression model showed an AUC of 0.84 (95% CI 0.82, 0.85) for prediction of LOPS and 0.80 (95% CI 0.78, 0.83) for prediction of LPP. Calibration analysis (based on LOOCV) presented consistent recall of probabilities, with a Brier score of 0.08 (intercept 0.01 [95% CI -0.09, 0.12], slope 1.00 [95% CI 0.92, 1.09]) for LOPS and a Brier score of 0.05 (intercept 0.01 [95% CI -0.12, 0.14], slope 1.09 [95% CI 0.95, 1.22]) for LPP. In a hypothetical follow-up period of 2 years, the regular screening interval was increased from 1 year to 2 years for individuals at low risk. In individuals with an International Working Group on the Diabetic Foot (IWGDF) risk 0, we could show a 40.5% reduction in the absolute number of screening examinations (3614 instead of 6074 screenings) when a 10% risk cut-off was used and a 26.5% reduction (4463 instead of 6074 screenings) when the risk cut-off was set to 5%.

CONCLUSIONS/INTERPRETATION

Enhancement of the protocol for diabetic foot screening by inclusion of a prediction model allows differentiation of individuals with diabetes based on the likelihood of complications. This could potentially reduce the number of screenings needed in those considered at low risk of diabetic foot complications. The proposed model requires further refinement and external validation, but it shows the potential for improving compliance with screening guidelines.

Assessment of diabetic small-fiber neuropathy by using short-wave infrared hyperspectral imaging

Among patients with type 2 diabetes mellitus (T2DM), the association between hyperspectral imaging (HSI) examination and diabetic neuropathy (DN) is ascertained using HSI of the feet using four types of spectral difference measurements. DN was evaluated by traditional Michigan Neuropathy Screening Instrument (MNSI), evaluation of painful neuropathy (ID-Pain, DN4) and sudomotor function by measuring electrochemical skin conductance (ESC). Of the 120 T2DM patients and 20 healthy adults enrolled, T2DM patients are categorized into normal sudomotor (ESC >60 μS) and sudomotor dysfunction (ESC ≤ 60 μS) groups. Spectral difference analyses reveal significant intergroup differences, whereas traditional examinations cannot distinguish between the two groups. HSI waveform reflectance gradually increases with disease severity, at 1400 to 1600 nm. The area under the curve (AUC) of receiver operating characteristic (ROC) analysis for abnormal ESC is ≥0.8 for all four HSI methods. HSI could be an objective, sensitive, rapid, noninvasive and remote approach to identify early small-fiber DN.

Supersonic shear wave imaging of the tibial nerve for diagnosis of diabetic peripheral neuropathy: A meta-analysis

BACKGROUND

Diabetic peripheral neuropathy (DPN) is the most common diabetes-associated complication and imposes a significant burden to healthcare systems. Thus, early diagnosis of DPN is extremely critical for management and outcome of diabetic patients. Supersonic Shear Wave Imaging (SSI) enables the noninvasive measurement of nerve stiffness. However, previous studies on SSI in the diagnosis of DPN were limited in sample sizes and reported various results. In this meta-analysis, we aimed to obtain comprehensive evidence on the value of tibial nerve stiffness measurement by SSI in the diagnosis of DPN.

METHODS

A comprehensive literature search in English and Chinese electronic database was conducted for studies (published until January 25, 2022) that investigated the diagnostic performance of tibial nerve stiffness measurement by SSI for detecting DPN. Summary receiver operating characteristics (SROC) modelling was constructed to conduct the meta-analysis of diagnostic accuracy of SSI for detecting DPN.

RESULTS

Finally, a total of 12 eligible studies with 1325 subjects were included for evaluation, and a meta-analysis was conducted to evaluate the diagnostic performance of tibial nerve stiffness measurement by SSI for detecting DPN. For tibial nerve stiffness measurement by SSI, the summary sensitivity and specificity for the diagnosis of DPN were 80% (95% confidence interval [CI]: 73%-86%) and 86% (95% CI: 82%-89%), respectively. The summary area under the ROC curve (AUROC) value of the SROC was 0.90 (95% CI: 0.87-0.92), for diagnosing DPN. A subgroup analysis of 11 SSI studies from China revealed similar diagnostic performance, with a summary sensitivity of 79% (95% CI: 72%-85%), specificity of 86% (95% CI: 82%-89%) and summary AUROC value of the SROC of 0.90 (95% CI: 0.87-0.92) for diagnosing DPN.

CONCLUSIONS

Our meta-analysis suggests that a tibial nerve stiffness measurement by SSI shows good performance in diagnosing DPN and has considerable potential as a noninvasive tool for detecting DPN.

The Treatment of Painful Diabetic Neuropathy

Painful diabetic peripheral neuropathy (painful-DPN) is a highly prevalent and disabling condition, affecting up to one-third of patients with diabetes. This condition can have a profound impact resulting in a poor quality of life, disruption of employment, impaired sleep, and poor mental health with an excess of depression and anxiety. The management of painful-DPN poses a great challenge. Unfortunately, currently there are no Food and Drug Administration (USA) approved disease-modifying treatments for diabetic peripheral neuropathy (DPN) as trials of putative pathogenetic treatments have failed at phase 3 clinical trial stage. Therefore, the focus of managing painful- DPN other than improving glycaemic control and cardiovascular risk factor modification is treating symptoms. The recommended treatments based on expert international consensus for painful- DPN have remained essentially unchanged for the last decade. Both the serotonin re-uptake inhibitor (SNRI) duloxetine and α2δ ligand pregabalin have the most robust evidence for treating painful-DPN. The weak opioids (e.g. tapentadol and tramadol, both of which have an SNRI effect), tricyclic antidepressants such as amitriptyline and α2δ ligand gabapentin are also widely recommended and prescribed agents. Opioids (except tramadol and tapentadol), should be prescribed with caution in view of the lack of definitive data surrounding efficacy, concerns surrounding addiction and adverse events. Recently, emerging therapies have gained local licenses, including the α2δ ligand mirogabalin (Japan) and the high dose 8% capsaicin patch (FDA and Europe). The management of refractory painful-DPN is difficult; specialist pain services may offer off-label therapies (e.g. botulinum toxin, intravenous lidocaine and spinal cord stimulation), although there is limited clinical trial evidence supporting their use. Additionally, despite combination therapy being commonly used clinically, there is little evidence supporting this practise. There is a need for further clinical trials to assess novel therapeutic agents, optimal combination therapy and existing agents to determine which are the most effective for the treatment of painful-DPN. This article reviews the evidence for the treatment of painful-DPN, including emerging treatment strategies such as novel compounds and stratification of patients according to individual characteristics (e.g. pain phenotype, neuroimaging and genotype) to improve treatment responses.

Implementation of corneal confocal microscopy for screening and early detection of diabetic neuropathy in primary care alongside retinopathy screening: Results from a feasibility study

OBJECTIVE

Screening for diabetic peripheral neuropathy (DPN) is essential for early detection and timely intervention. Quantitative assessment of small nerve fiber damage is key to the early diagnosis and assessment of its progression. Corneal confocal microscopy (CCM) is a non-invasive, in-vivo diagnostic technique that provides an accurate surrogate biomarker for small-fiber neuropathy. In this novel study for the first time, we introduced CCM to primary care as a screening tool for DPN alongside retinopathy screening to assess the level of neuropathy in this novel cohort.

RESEARCH DESIGN AND METHODS

450 consecutive subjects with type 1 or type 2 diabetes attending for annual eye screening in primary care optometry settings underwent assessment with CCM to establish the prevalence of sub-clinical diabetic peripheral neuropathy. Subjects underwent assessment for neurological and ocular symptoms of diabetes and a history of diabetic foot disease, neuropathy and diabetic retinopathy (DR).

RESULTS

CCM examination was completed successfully in 427 (94.9%) subjects, 22% of whom had neuropathy according to Diabetic Neuropathy Symptom (DNS) score. The prevalence of sub-clinical neuropathy as defined by abnormal corneal nerve fiber length (CNFL) was 12.9%. In the subjects with a short duration of type 2 diabetes, 9.2% had abnormal CNFL. CCM showed significant abnormalities in corneal nerve parameters in this cohort of subjects with reduction of corneal nerve fiber density (CNFD, p<0.001), CNFL (p<0.001) and corneal nerve branch density (CNBD, p<0.001) compared to healthy subjects. In subjects who had no evidence of DR (67% of all subjects), 12.0% had abnormal CNFL.

CONCLUSIONS

CCM may be a sensitive biomarker for early detection and screening of DPN in primary care alongside retinopathy screening.

Optical coherence tomography of the retina combined with color Doppler ultrasound of the tibial nerve in the diagnosis of diabetic peripheral neuropathy

OBJECTIVE

To investigate the value of the retinal nerve fiber layer (RNFL) thickness in the optic disc and the cross-sectional area (CSA) of lower limb nerves in the diagnosis of diabetic peripheral neuropathy (DPN) separately and in combination.

METHODS

A total of 140 patients with type 2 diabetes were enrolled, including 51 patients with DPN (DPN group) and 89 patients without DPN (NDPN group). Clinical data and biochemical parameters were collected. Electromyography/evoked potential instrument was performed for nerve conduction study. Optical coherence tomography was performed to measure the RNFL thickness of the optic disc. Color Doppler ultrasound was performed to measure CSA of lower limb nerves.

RESULTS

The RNFL thickness was lower and the CSA of the tibial nerve (TN) in the DPN group was larger than that in the NDPN group. The album/urine creatinine ratio, diabetic retinopathy, and CSA of TN at 3 cm were positively correlated with DPN. The RNFL thickness in the superior quadrant of the optic disc was negatively correlated with DPN. For RNFL thickness to diagnose DPN, the area under the curve (AUC) of the superior quadrant was the largest, which was 0.723 (95% confidence interval [CI]: 0.645-0.805), and the best cutoff value was 127.5 μm (70.5% sensitivity, 72.1% specificity). For CSA of TN to diagnose DPN, the AUC of the distance of 5 cm was the largest, which was 0.660 (95% CI: 0.575-0.739), and the best cutoff value was 13.50 mm² (82.0% sensitivity, 41.6% specificity). For the combined index, the AUC was greater than that of the above two indicators, which was 0.755 (95% CI: 0.664-0.846), and the best cutoff value was 0.376 (64.3% sensitivity, 83.0% specificity).

CONCLUSIONS

Patients with DPN have a reduction of the RNFL thickness and an increase in the CSA of TN, and these two changes are related to DPN. The RNFL thickness of the optic disc and the CSA of TN can be used as diagnostic indicators of DPN, and the combination of the two indicators has a higher diagnostic value.

Genomic DNA Methylation in Diabetic Chronic Complications in Patients With Type 2 Diabetes Mellitus

AIM

To explore the relationship between genomic DNA methylation and diabetic chronic complications.

METHODS

299 patients with type 2 diabetes mellitus (T2DM) hospitalized in the Second Affiliated Hospital of Soochow University were enrolled. We divided the patients into different complications groups and corresponding non-complication groups. Clinical and biochemical parameters were compared between the two groups. The level of genomic DNA methylation in leukocytes was determined by high-performance liquid chromatography-tandem mass spectrometry.

RESULTS

(1) Age, duration of diabetes, creatinine (Cr), blood urea nitrogen (BUN), genomic DNA methylation, 24- hour urine total protein (24-hUTP), and intima-media thickness (IMT) were significantly higher in the carotid plaque (CP) group. Waist-to-hip ratio (WHR), body mass index (BMI), estimated glomerular- filtration rate (eGFR), and albumin (Alb) were significantly lower in the CP group. Gender, age and BMI were the influencing factors of CP. (2) Age, duration, Cr, BUN, urinary microalbumin creatinine ratio (UACR), systolic blood pressure (SBP), TCSS, and 24- hUTP were significantly higher in the diabetic retinopathy (DR) group. eGFR, 2h postprandial C- peptide, and Alb were lower in the DR group. Age, duration, Cr, Alb, SBP, and the presence of DN were the influencing factors of DR. (3) Age, duration, HbA1c, BUN, TCSS, SBP, and IMT(R) were significantly higher in the diabetic nephropathy (DN) group. 2h postprandial C-peptide, and Alb were lower in the DN group. HbA1c, BUN, DR, and HBP were the influencing factors of DN. (4) Age, duration, total cholesterol (TC), low-density lipoprotein (LDL-C), triglyceride (TG), Cr, BUN, uric acid (UA), and SBP were significantly higher in the diabetic peripheral neuropathy (DPN) group. The level of genomic DNA methylation and eGFR were significantly lower in the DPN group. Age, duration, LDL-C, UA, the presence of DR, and the genomic DNA methylation level were the influencing factors for DPN. Incorporating the level of genomic DNA methylation into the prediction model could improve the ability to predict DPN on the basis of conventional risk factors.

CONCLUSION

Low level of genomic DNA methylation is a relatively specific risk factor for DPN in patients with T2DM and not a contributing factor to the other chronic complications.

Standard Clinical Screening Tests, Sural Radial Amplitude Ratio and F Wave Latency Compared to Conventional Nerve Conduction Studies in the Assessment of Sensorimotor Polyneuropathy in Patients with Type 2 Diabetes Mellitus

BACKGROUND AND AIMS

The measuring tools used for assessment of neuropathy include various questionnaires, monofilament testing, Biothesiometry and the gold standard test, nerve conduction studies (NCS). This study aims to evaluate the diagnostic accuracies of Michigan Neuropathy Screening Instrument (MNSI), Biothesiometry, Semmes Weinstein Monofilament (SWMF), Sural Radial Amplitude Ratio (SRAR) and minimal F wave latency as compared to conventional NCS and arrive at a simple diagnostic algorithm for early detection of Diabetic Peripheral Neuropathy (DPN).

METHODS

In a cross-sectional observational study on 48 Type 2 diabetes mellitus patients, MNSI, Biothesiometry, SWMF and NCS including F waves and SRAR were done and diagnostic accuracies (sensitivity, specificity, positive and negative predictive values) calculated taking NCS as gold standard.

RESULTS

MNSI, Biothesiometry, SWMF, SRAR and minimal F wave latency had a sensitivity of 64.3%, 78.6%, 14.3%, 100% and 78.6% and specificity of 67.7%, 52.9%, 94.1%, 23.53% and 76.47% respectively, with reference to NCS. Based on combined sensitivities and specificities, we arrived at a simple algorithm for early diagnosis of DPN, which showed that DPN could either be diagnosed or ruled out in 75% of the patients by a combination of the Biothesiometry, SRAR and left lower limb minimal F wave latency results.

CONCLUSIONS

In the setting of an outpatient, multidisciplinary diabetic clinic, simple tests such as questionnaires, monofilament testing and biosthesiometer could be performed with greater ease while considering NCS as the gold standard. This algorithm, combining Biothesiometry, SRAR and left lower limb minimal F wave latency would be less time consuming and help in early diagnosis of DPN.

Feasibility of combining heart rate variability and electrochemical skin conductance as screening and severity evaluation of cardiovascular autonomic neuropathy in type 2 diabetes

AIMS/INTRODUCTION

Clinical studies show that either heart rate variability (HRV) or electrochemical skin conductance (ESC) alone can serve as a simple and objective method for screening cardiovascular autonomic neuropathy (CAN). We tested the hypothesis that combining these two quantitative approaches can not only reinforce accuracy in CAN screening but also provide a better estimate of CAN severity in patients with type 2 diabetes (T2DM) who had already had CAN in outpatient clinics.

MATERIALS AND METHODS

Each patient received a complete battery of cardiovascular autonomic reflex tests (CARTs), with ESC measured by SUDOSCAN, time domain of HRV measured by standard deviation of all normal RR intervals (SDNN) and frequency domain of HRV (low frequency [LF], high frequency [HF], and LF/HF ratio), and peripheral blood studies for vascular risk factors. Severity of CAN was measured by CAN score.

RESULTS

The 90 T2DM patients included 50 males and 40 females. Those with more severe CAN had lower values in feet ESC (P = 0.023) and SDNN (P < 0.0001). Multiple linear regression analysis also showed that feet ESC and SDNN value (P = 0.003 and P < 0.0001) were significantly associated with CAN score. Combining SDNN and feet ESC also can increase the diagnostic accuracy of CAN with respective to sensitivity and specificity by using receiver operating characteristic analysis.

CONCLUSIONS

Combining the results of SDNN and feet ESC can not only assess, but also quantitatively reflect the progress or improvement of autonomic nerve function (including sympathetic and parasympathetic activity) in patients with T2DM.

Diagnostic value of optic disc retinal nerve fiber layer thickness for diabetic peripheral neuropathy

OBJECTIVE

To investigate the value of optic disc retinal nerve fiber layer (RNFL) thickness in the diagnosis of diabetic peripheral neuropathy (DPN).

METHODS

Ninety patients with type 2 diabetes, including 60 patients without DPN (NDPN group) and 30 patients with DPN (DPN group), and 30 healthy participants (normal group) were enrolled. Optical coherence tomography (OCT) was used to measure the four quadrants and the overall average RNFL thickness of the optic disc. The receiver operator characteristic curve was drawn and the area under the curve (AUC) was calculated to evaluate the diagnostic value of RNFL thickness in the optic disc area for DPN.

RESULTS

The RNFL thickness of the DPN group was thinner than those of the normal and NDPN groups in the overall average ((101.07± 12.40) µm vs. (111.07±6.99) µm and (109.25±6.90) µm), superior quadrant ((123.00±19.04) µm vs. (138.93±14.16) µm and (134.47±14.34) µm), and inferior quadrant ((129.37±17.50) µm vs. (143.60±12.22) µm and (144.48±14.10) µm), and the differences were statistically significant. The diagnostic efficiencies of the overall average, superior quadrant, and inferior quadrant RNFL thicknesses, and a combined index of superior and inferior quadrant RNFL thicknesses were similar, and the AUCs were 0.739 (95% confidence interval (CI) 0.635-0.826), 0.683 (95% CI 0.576-0.778), 0.755 (95% CI 0.652-0.840), and 0.773 (95% CI 0.672-0.854), respectively. The diagnostic sensitivity of RNFL thickness in the superior quadrant reached 93.33%.

CONCLUSIONS

The thickness of the RNFL in the optic disc can be used as a diagnostic method for DPN.

Impact of Plasma Xanthine Oxidoreductase Activity on the Mechanisms of Distal Symmetric Polyneuropathy Development in Patients with Type 2 Diabetes

To unravel associations between plasma xanthine oxidoreductase (XOR) and diabetic vascular complications, especially distal symmetric polyneuropathy (DSP), we investigated plasma XOR activities using a novel assay. Patients with type 2 diabetes mellitus (T2DM) with available nerve conduction study (NCS) data were analyzed. None were currently taking XOR inhibitors. XOR activity of fasting blood samples was assayed using a stable isotope-labeled substrate and LC-TQMS. JMP Clinical version 5.0. was used for analysis. We analyzed 54 patients. Mean age was 64.7 years, mean body mass index was 26.0 kg/m², and mean glycated hemoglobin was 9.4%. The logarithmically transformed plasma XOR activity (ln-XOR) correlated positively with hypoxanthine, xanthine, visceral fatty area, and liver dysfunction but negatively with HDL cholesterol. ln-XOR correlated negatively with diabetes duration and maximum intima-media thickness. Stepwise multiple regression analysis revealed ln-XOR to be among selected explanatory factors for various NCS parameters. Receiver operating characteristic curves showed the discriminatory power of ln-XOR. Principal component analysis revealed a negative relationship of ln-XOR with F-waves as well as positive relationships of ln-XOR with hepatic steatosis and obesity-related disorders. Taken together, our results show plasma XOR activity to be among potential disease status predictors in T2DM patients. Plasma XOR activity measurements might reliably detect pre-symptomatic DSP.

Pathogenesis, diagnosis and clinical management of diabetic sensorimotor peripheral neuropathy

Diabetic sensorimotor peripheral neuropathy (DSPN) is a serious complication of diabetes mellitus and is associated with increased mortality, lower-limb amputations and distressing painful neuropathic symptoms (painful DSPN). Our understanding of the pathophysiology of the disease has largely been derived from animal models, which have identified key potential mechanisms. However, effective therapies in preclinical models have not translated into clinical trials and we have no universally accepted disease-modifying treatments. Moreover, the condition is generally diagnosed late when irreversible nerve damage has already taken place. Innovative point-of-care devices have great potential to enable the early diagnosis of DSPN when the condition might be more amenable to treatment. The management of painful DSPN remains less than optimal; however, studies suggest that a mechanism-based approach might offer an enhanced benefit in certain pain phenotypes. The management of patients with DSPN involves the control of individualized cardiometabolic targets, a multidisciplinary approach aimed at the prevention and management of foot complications, and the timely diagnosis and management of neuropathic pain. Here, we discuss the latest advances in the mechanisms of DSPN and painful DSPN, originating both from the periphery and the central nervous system, as well as the emerging diagnostics and treatments.

Novel and Emerging Electrophysiological Biomarkers of Diabetic Neuropathy and Painful Diabetic Neuropathy

PURPOSE

Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes. Small and large peripheral nerve fibers can be involved in DPN. Large nerve fiber damage causes paresthesia, sensory loss, and muscle weakness, and small nerve fiber damage is associated with pain, anesthesia, foot ulcer, and autonomic symptoms. Treatments for DPN and painful DPN (pDPN) pose considerable challenges due to the lack of effective therapies. To meet these challenges, there is a major need to develop biomarkers that can reliably diagnose and monitor progression of nerve damage and, for pDPN, facilitate personalized treatment based on underlying pain mechanisms.

METHODS

This study involved a comprehensive literature review, incorporating article searches in electronic databases (Google Scholar, PubMed, and OVID) and reference lists of relevant articles with the authors' substantial expertise in DPN. This review considered seminal and novel research and summarizes emerging biomarkers of DPN and pDPN that are based on neurophysiological methods.

FINDINGS

From the evidence gathered from 145 papers, this submission describes emerging clinical neurophysiological methods with potential to act as biomarkers for the diagnosis and monitoring of DPN as well as putative future roles as predictors of response to antineuropathic pain medication in pDPN. Nerve conduction studies only detect large fiber damage and do not capture pathology or dysfunction of small fibers. Because small nerve fiber damage is prominent in DPN, additional biomarkers of small nerve fiber function are needed. Activation of peripheral nociceptor fibers using laser, heat, or targeted electrical stimuli can generate pain-related evoked potentials, which are an objective neurophysiological measure of damage along the small fiber pathways. Assessment of nerve excitability, which provides a surrogate of axonal properties, may detect alterations in function before abnormalities are detected by nerve conduction studies. Microneurography and rate-dependent depression of the Hoffmann-reflex can be used to dissect underlying pain-generating mechanisms arising from the periphery and spinal cord, respectively. Their role in informing mechanistic-based treatment of pDPN as well as facilitating clinical trials design is discussed.

IMPLICATIONS

The neurophysiological methods discussed, although currently not practical for use in busy outpatient settings, detect small fiber and early large fiber damage in DPN as well as disclosing dominant pain mechanisms in pDPN. They are suited as diagnostic and predictive biomarkers as well as end points in mechanistic clinical trials of DPN and pDPN.

Acupuncture for diabetic peripheral neuropathy: An overview of systematic reviews

BACKGROUND

Acupuncture has been widely used to treat diabetic peripheral neuropathy (DPN) in China as a complementary and alternative therapy. This study aims to summarize the characteristics and evaluate the methodology quality of the systematic reviews (SRs) regarding acupuncture for DPN.

METHODS

A comprehensive literature search was performed from inception to February 2020. We assessed the methodological quality of the included SRs with the Assessment of Multiple Systematic Reviews 2 (AMSTAR 2) tool, adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist to evaluate the reporting characteristics of included SRs, and utilized the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to evaluate the quality of evidence for outcomes including total effective rate, sensory nerve conduction velocity, motor nerve conduction velocity and adverse events. One-way analysis of variance and multiple linear regression were conducted to evaluate the associations between characteristics and two index scores (PRISMA and AMSTAR 2).

RESULTS

Eighteen SRs were included in this overview. The methodology quality of the included SRs ranged from very low to high. Only protocol registration and funding source reported were associated with the AMSTAR 2 index scores, while no variable showed significant difference in the PRISMA scores. The overall quality of evidence in included SRs ranged from "very low" to "moderate".

CONCLUSION

This overview suggested beneficial effects of acupuncture on DPN, whereas the results should be interpreted with cautious owing to methodology flaws, providing reference for further improvement of the study design.

Painful and non-painful diabetic neuropathy, diagnostic challenges and implications for future management

Peripheral neuropathy is one of the most common complications of both type 1 and type 2 diabetes. Up to half of patients with diabetes develop neuropathy during the course of their disease, which is accompanied by neuropathic pain in 30-40% of cases. Peripheral nerve injury in diabetes can manifest as progressive distal symmetric polyneuropathy, autonomic neuropathy, radiculo-plexopathies, and mononeuropathies. The most common diabetic neuropathy is distal symmetric polyneuropathy, which we will refer to as DN, with its characteristic glove and stocking like presentation of distal sensory or motor function loss. DN or its painful counterpart, painful DN, are associated with increased mortality and morbidity; thus, early recognition and preventive measures are essential. Nevertheless, it is not easy to diagnose DN or painful DN, particularly in patients with early and mild neuropathy, and there is currently no single established diagnostic gold standard. The most common diagnostic approach in research is a hierarchical system, which combines symptoms, signs, and a series of confirmatory tests. The general lack of long-term prospective studies has limited the evaluation of the sensitivity and specificity of new morphometric and neurophysiological techniques. Thus, the best paradigm for screening DN and painful DN both in research and in clinical practice remains uncertain. Herein, we review the diagnostic challenges from both clinical and research perspectives and their implications for managing patients with DN. There is no established DN treatment, apart from improved glycaemic control, which is more effective in type 1 than in type 2 diabetes, and only symptomatic management is available for painful DN. Currently, less than one-third of patients with painful DN derive sufficient pain relief with existing pharmacotherapies. A more precise and distinct sensory profile from patients with DN and painful DN may help identify responsive patients to one treatment versus another. Detailed sensory profiles will lead to tailored treatment for patient subgroups with painful DN by matching to novel or established DN pathomechanisms and also for improved clinical trials stratification. Large randomized clinical trials are needed to identify the interventions, i.e. pharmacological, physical, cognitive, educational, etc., which lead to the best therapeutic outcomes.

Acupuncture in diabetic peripheral neuropathy-protocol for the randomized, multicenter ACUDPN trial

BACKGROUND

Acupuncture is used to treat patients with diabetic peripheral neuropathy; however, the evidence is unclear. We present the design and methodology of the ACUDPN (ACUpuncture in Diabetic Peripheral Neuropathy) trial, which investigates the effectiveness of acupuncture for the treatment of diabetic peripheral neuropathy (DPN) symptoms. The aim of this study is to investigate whether acupuncture is effective for the treatment of DPN symptoms.

METHODS

This study is a two-armed, randomized, controlled, parallel group, open-label, confirmatory, multicenter trial (8-week intervention period plus 16 weeks of follow-up). Physicians in outpatient units in Germany who specialize in acupuncture treatment will treat 110 diabetes type II patients with clinical symptoms of peripheral neuropathy in the feet and legs with signs of neuropathy according to nerve conduction testing. The patients will be randomized in a 1:1 ratio to one of the following two groups: (a) semi-standardized acupuncture plus routine care or (b) routine care alone. Acupuncture will consist of 12 treatments per patient over 8 weeks. The primary outcome will be the overall DPN-related complaints in the extremities after 8 weeks as measured by the Visual Analog Scale (VAS). Further outcome measures will include DPN-related pain, the Neuropathic Pain Symptom Inventory (NPSI), Diabetic Peripheral Neuropathic Pain Impact (DPNPI) scores, and nerve conduction parameters of the sural nerve at weeks 8, 16, and 24.

DISCUSSION

The results of this trial will be available in 2021 and will help clarify whether acupuncture can be considered effective for the treatment of DPN with regard to the subdimensions of the neuropathic clinical picture.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03755960 . Registered on 11 August 2018.

Impairment of microvascular blood flow in patients with type 2 diabetes and cardiovascular autonomic neuropathy

BACKGROUND: Diabetic autonomic neuropathy is the reason for early morbidity and mortality on diabetic patients. The pathology not only cardiac innervation but microvascular is presented.

AIMS: We estimated the parameters of skin microvascular blood flow in accordance with cardiovascular autonomic neuropathy (CAN) staging in diabetic patients. We also assessed other risk factors of CAN in patients with diabetes.

MATERIALS AND METHODS: We included 76 patients with type 2 diabetes in the study (24 patients with resent-onset diabetes and/or diabetes without microvascular complications, 26 with diabetic sensorimotor neuropathy (SMN) and 26 with SMN and previous history of diabetic foot amputation). The SMN was diagnosed on the basis of patients complaints, anamnesis and data of clinical neurological examinations. CAN was detected using several cardiovascular autonomic reflex tests (CART) as a gold standard of diagnosis: the tilt-table test, a deepbreathing and Valsalva Maneuver, handgrip test, cold-stress vasoconstriction. According to the Toronto Diabetic Neuropathy Expert Group Recommendation all patients was separated on the groups: CAN 0 (all CARTs were normal), CAN 1 (possible/early CAN — one abnormal CART was presented), CAN 2 (definite/confirmed CAN –at least two abnormal CARTs were found), CAN 3 (severe/advanced CAN — in the cases of orthostatic hypotension in addition to CARTs abnormalities). Microvascular blood flow of skin at the nail roller of fingers skin was valuated at rest as well as in functional cold test by the method of High-frequency Ultrasonic Dopplerography using the “Minimax Doppler K” device (LLC JV “Minimax”, St. Petersburg, Russia).

RESULTS: CAN 1 was found in 8% diabetic patients without microvascular complications, 42 and 21% patients with SMN and diabetic foot amputations respectively. CAN 2 was diagnosed in 27% patients with SMN and 58% patients history of diabetic foot amputations. CAN 3 in 8% and 19% cases in patients with SMN and history of diabetic foot amputations respectively. The parameters of microvascular blood flow at rest were significantly decreased in patients with confirmed/severe CAN in comparison with early staging of CAN and patients without CAN (Vm=2.5±0.66 sm/sec vs. 4.4±0.54 sm/sec and 5.1±1.01 sm/sec respectively; p=0.0033). The abnormal result of cold test was detected in 94% patients with confirmed/ severe CAN and 26% patients with CAN 1.

CONCLUSIONS: This investigation has demonstrated in a cohort with type 2 diabetes patients with/without SMN and with/ without history of previously foot amputations that decrease the Vm (the variable of microvascular blood flow assessed by High-frequency Ultrasonic Dopplerography) lower than 2.4 sm/sec is associated with 6.4 times increased likelihood of confirmed/severe CAN as well as positive cold test result. That the patients with positive cold test results were 28.6 times more likely have confirmed/severe CAN.

Vitamin B12 Supplementation in Diabetic Neuropathy: A 1-Year, Randomized, Double-Blind, Placebo-Controlled Trial

AIM

To investigate the effect of normalizing vitamin B12 (B12) levels with oral B12 (methylcobalamin) 1000 μg/day for one year in patients with diabetic neuropathy (DN).

PATIENTS AND METHODS

In this prospective, double-blind, placebo-controlled trial, 90 patients with type 2 diabetes on metformin for at least four years and both peripheral and autonomic DN were randomized to an active treatment group (n = 44) receiving B12 and a control group (n = 46) receiving a placebo. All patients had B12 levels less than 400 pmol/L. Subjects underwent measurements of sural nerve conduction velocity (SNCV), sural nerve action potential (amplitude) (SNAP), and vibration perception threshold (VPT), and they performed cardiovascular autonomic reflex tests (CARTs: mean circular resultant (MCR), Valsalva test, postural index, and orthostatic hypotension). Sudomotor function was assessed with the SUDOSCAN that measures electrochemical skin conductance in hands and feet (ESCH and ESCF, respectively). We also used the Michigan Neuropathy Screening Instrument Questionnaire and Examination (MNSIQ and MNSIE, respectively) and questionnaires to evaluate quality of life (QoL) and level of pain (pain score).

RESULTS

B12 levels increased from 232.0 ± 71.8 at baseline to 776.7 ± 242.3 pmol/L at follow-up, p < 0.0001, in the active group but not in the control group. VPT, MNSIQ, QoL, pain score, SNCV, SNAP, and ESCF significantly improved in the active group (p < 0.001, p = 0.002, p < 0.0001, p < 0.000, p < 0.0001, p < 0.0001, and p = 0.014, respectively), whereas CARTS and MNSIE improved but not significantly. MCR, MNSIQ, SNCV, SNAP, and pain score significantly deteriorated in the control group (p = 0.025, p = 0.017, p = 0.045, p < 0.0001, and p < 0.0001, respectively).

CONCLUSIONS

The treatment of patients with DN with 1 mg of oral methylcobalamin for twelve months increased plasma B12 levels and improved all neurophysiological parameters, sudomotor function, pain score, and QoL, but it did not improve CARTS and MNSIE.

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.

Efficacy and Safety of the Combination of Superoxide Dismutase, Alpha Lipoic Acid, Vitamin B12, and Carnitine for 12 Months in Patients with Diabetic Neuropathy

Aim: To investigate the efficacy of Superoxide Dismutase, Alpha Lipoic Acid, Acetyl L-Carnitine, and Vitamin B12 (B12) in one tablet in Diabetic Neuropathy (DN). Patients–methods: In this prospective, double-blind, placebo-controlled study, 85 patients with Diabetes Mellitus Type 2 (DMT2) were randomly assigned, either to receive the combination of four elements (active group, n = 43), or placebo (n = 42) for 12 months. We used the Michigan Neuropathy Screening Instrument Questionnaire and Examination (MNSIQ and MNSIE), measured the vibration perception threshold (BIO), and Cardiovascular Autonomic Reflex Tests (CARTs). Nerve function was assessed by DPN Check [sural nerve conduction velocity (SNCV) and amplitude (SNAP)]. Pain (PS) and quality of life (QL) questionnaires were administered. Results: At follow-up, BIO, MNSIQ, QL, PAIN, and SNCV, SNAP, and B12 levels had significantly improved inactive group (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.027, p = 0.031, and p < 0.001 respectively), whereas the inplacebo group MCR (mean circular resultant) and PAIN deteriorated (p < 0.001, p < 0.001). The changes in MNSIQ, QL, SNCV, BIO, and PAIN differed significantly between groups (p < 0.001, p < 0.001, p = 0.031, p < 0.001, and p < 0.001 respectively). Conclusions: The combination of the four elements in one tablet for 12 months in patients with DMT2 improved all indices of peripheral neuropathy, including SNAP and SNCV, pain, and Quality of Life perception, except CARTs and MNSIE.

Corneal nerves in diabetes-The role of the in vivo corneal confocal microscopy of the subbasal nerve plexus in the assessment of peripheral small fiber neuropathy

The cornea's intense innervation is responsible for corneal trophism and ocular surface hemostasis maintenance. Corneal diabetic neuropathy affects subbasal nerve plexus, with progressive alteration of nerves' morphology and density. The quantitative analysis of nerve fibers can be performed with in vivo corneal confocal microscopy considering the main parameters such as corneal nerve fibers length, corneal nerve fibers density, corneal nerve branching density, tortuosity coefficient, and beadings frequency. As the nerve examination permits the detection of early changes occurring in diabetes, the invivo corneal confocal microscopy becomes, over time, an important tool for diabetic polyneuropathy assessment and follow-up. In this review, we summarize the actual evidence about corneal nerve changes in diabetes and the relationship between the grade of alterations and the duration and severity of the disease. We aim at understanding how diabetes impacts corneal nerves and how it correlates with sensorimotor peripheral polyneuropathy and retinal complications. We also attempt to analyze the safety of the most common surgical procedures such as cataract and refractive surgery in diabetic patients and to highlight the specific risk factors. We believe that information about the corneal nerve fibers' condition obtained from the in vivo subbasal nerve plexus investigation may be crucial in monitoring peripheral small fiber polyneuropathy and that it will help with decision-making in ophthalmic surgery in diabetic patients.

Point-of-care nerve conduction device predicts the severity of diabetic polyneuropathy: A quantitative, but easy-to-use, prediction model

Aims/Introduction

A gold standard in the diagnosis of diabetic polyneuropathy (DPN) is a nerve conduction study. However, as a nerve conduction study requires expensive equipment and well‐trained technicians, it is largely avoided when diagnosing DPN in clinical settings. Here, we validated a novel diagnostic method for DPN using a point‐of‐care nerve conduction device as an alternative way of diagnosis using a standard electromyography system.

Materials and Methods

We used a multiple regression analysis to examine associations of nerve conduction parameters obtained from the device, DPNCheck™, with the severity of DPN categorized by the Baba classification among 375 participants with type 2 diabetes. A nerve conduction study using a conventional electromyography system was implemented to differentiate the severity in the Baba classification. The diagnostic properties of the device were evaluated using a receiver operating characteristic curve.

Results

A multiple regression model to predict the severity of DPN was generated using sural nerve conduction data obtained from the device as follows: the severity of DPN = 2.046 + 0.509 × ln(age [years]) − 0.033 × (nerve conduction velocity [m/s]) − 0.622 × ln(amplitude of sensory nerve action potential [µV]), r = 0.649. Using a cut‐off value of 1.3065 in the model, moderate‐to‐severe DPN was effectively diagnosed (area under the receiver operating characteristic curve 0.871, sensitivity 70.1%, specificity 87.7%, positive predictive value 83.0%, negative predictive value 77.3%, positive likelihood ratio 5.67, negative likelihood ratio 0.34).

Conclusions

Nerve conduction parameters in the sural nerve acquired by the handheld device successfully predict the severity of DPN.

Diagnosing peripheral neuropathy in South-East Asia: A focus on diabetic neuropathy

Burning and stabbing pain in the feet and lower limbs can have a significant impact on the activities of daily living, including walking, climbing stairs and sleeping. Peripheral neuropathy in particular is often misdiagnosed or underdiagnosed because of a lack of awareness amongst both patients and physicians. Furthermore, crude screening tools, such as the 10-g monofilament, only detect advanced neuropathy and a normal test will lead to false reassurance of those with small fiber mediated painful neuropathy. The underestimation of peripheral neuropathy is highly prevalent in the South-East Asia region due to a lack of consensus guidance on routine screening and diagnostic pathways. Although neuropathy as a result of diabetes is the most common cause in the region, other causes due to infections (human immunodeficiency virus, hepatitis B or C virus), chronic inflammatory demyelinating polyneuropathy, drug-induced neuropathy (cancer chemotherapy, antiretrovirals and antituberculous drugs) and vitamin deficiencies (vitamin B1 , B6 , B12 , D) should be actively excluded.

Diabetic Distal Symmetrical Polyneuropathy: Correlation of Clinical, Laboratory, and Electrophysiologic Studies in Patients with Type 2 Diabetes Mellitus

This cross-sectional study is aimed at determining the prevalence of distal symmetrical polyneuropathy (DSPN) and diabetic peripheral neuropathic pain (DPNP) in participants with type 2 diabetes mellitus (T2DM); finding the risk factors for DSPN and DPNP via biochemical tests; and correlating DSPN and DPNP with the results of electrophysiologic studies, quantitative sensory tests, and neurologic examination. The 145 participants with T2DM enrolled were divided into the DSPN (abnormal nerve conduction studies (NCS) with signs of polyneuropathy), subclinical DSPN (abnormal NCS without signs of polyneuropathy), minimal DSPN (normal NCS with signs of polyneuropathy), and no DSPN groups. The biochemical risk factors of diabetic peripheral neuropathy were investigated. Neurologic examinations, laboratory tests, NCS, vibration threshold tests, and thermal threshold tests were conducted. The modified Michigan Neuropathy Screening Instrument (mMNSI) and Douleur Neuropathique 4 were used to evaluate the severity of DSPN and DPNP, respectively. In all, 30% of participants had DSPN and 11% had DPNP. DSPN correlated strongly with male gender and higher glycohaemoglobin levels; NCS abnormality correlated with higher glycohaemoglobin levels; DSPN severity correlated with NCS of each stimulating nerve. DPNP commonly occurred with clinical and electrophysiologic evidence of DSPN. Symptomatic diabetic polyneuropathy significantly correlated with longer disease duration, higher glycohaemoglobin levels, and abnormal vibration tests. The thermal threshold test combined with nerve conduction tests could detect most of the patients with DSPN, subclinical DSPN, and minimal DSPN. Poor diabetic control was independently associated with the development of DSPN. DPNP was associated with DSPN. The combination of thermal threshold tests with NCS can potentially provide the diagnosis of DSPN.

Diabetic Polyneuropathy - Advances in Diagnosis and Intervention Strategies

Over half of people with diabetes mellitus develop diabetic polyneuropathy (DPN), which is a major cause of reduced quality of life due to disabling neuropathic pain, sensory loss, gait instability, fall-related injury, and foot ulceration and amputation. The latter represents a major health and economic burden, with lower limb amputation rates related to diabetes increasing in the UK. There is a need for early diagnosis of DPN so that early management strategies may be instigated, such as achieving tight glucose control and management of cardiovascular risk factors, in an attempt to slow its progression. To this end, a one-stop microvascular assessment involving a combined eye, foot and renal screening clinic has proven feasible in the UK. Unfortunately, there are currently no approved disease-modifying therapies for DPN. Some disease-modifying agents have demonstrated efficacy, but further large trials using appropriate clinical endpoints are required before these treatments can be routinely recommended. There has been emerging evidence highlighting a reduction in vitamin D levels in cases of painful DPN and the potential for vitamin D supplementation in deficient individuals to improve neuropathic pain; however, this needs to be proved in randomised clinical trials. The use of established agents for neuropathic pain in DPN is limited by poor efficacy and adverse effects, but patient stratification using methods such as pain phenotyping are being tested to determine whether this improves the outcomes of such agents in clinical studies. In addition, innovative approaches such as the topical 8% capsaicin patch, new methods of electrical stimulation and novel therapeutic targets such as NaV1.7 offer promise for the future. This article aims to discuss the challenges of diagnosing and managing DPN and to review current and emerging lifestyle interventions and therapeutic options.

The diagnostic usefulness of the combined COMPASS 31 questionnaire and electrochemical skin conductance for diabetic cardiovascular autonomic neuropathy and diabetic polyneuropathy

The study investigated the diagnostic performance for diabetic cardiovascular autonomic neuropathy (CAN) and diabetic polyneuropathy (DPN) of the combined use of composite autonomic symptom score (COMPASS) 31, validated questionnaire for autonomic symptoms of CAN, and electrochemical skin conductance (ESC), proposed for detecting DPN and CAN. One-hundred and two participants with diabetes (age 57 ± 14 years, duration 17 ± 13 years) completed the COMPASS 31 before assessing cardiovascular reflex tests (CARTs), neuropathic symptoms, signs, vibratory perception threshold (VPT), thermal thresholds (TT), and ESC using Sudoscan. Two patterns were evaluated: (a) the combined abnormalities in both tests (COMPASS 31+ESC), and (b) the abnormality in COMPASS 31 and/or ESC (COMPASS 31 and/or ESC). CAN (≥1 abnormal CART) and confirmed CAN (≥2 abnormal CARTs) were present in 28.1% and 12.5%, DPN (two abnormalities among symptoms, signs, VPT, and TT) in 52%, abnormal COMPASS 31 (total weighted score >16.44) in 48% and abnormal ESC (hands ESC <50 μS and/or feet ESC <70 μS) in 47.4%. Both the patterns-COMPASS 31+ESC and COMPASS 31 and/or ESC-were associated with CAN and DPN (P < .01). COMPASS 31 and ESC reached a sensitivity of 75% and 83% for confirmed CAN, and a specificity of 65% and 67% for DPN. When combining the tests, the sensitivity for CAN rose by up to 100% for CAN and the specificity up to 89% for DPN. The combination of the tests can allow a stepwise screening strategy for CAN, by suggesting CAN absence with combined normality, and prompting to CARTs with combined abnormality.