Neuropathy among the diabetes control and complications trial cohort 8 years after trial completion

Metabolic memory and diabetic retinopathy: Legacy of glycemia and possible steps into future

The response of retinal pathology to interventions in diabetic retinopathy (DR) is often independent of the glycated hemoglobin (HbA1c) values at the point of care. This is despite glucose control being one of the strongest risk factors for the development and progression of DR. Previous preclinical and clinical research has indicated metabolic memory, whereby past cumulative glucose exposure may continue to impact DR for a prolonged period. Preclinical studies have evaluated punitive metabolic memory through poor initial control of DM, whereas clinical studies have evaluated protective metabolic memory through good initial control of DM. In this narrative review, we evaluate the preclinical and clinical evidence regarding metabolic memory and discuss how this may form the basis of preventive care for DR by inducing "metabolic amnesia" in people with a history of uncontrolled diabetes in the past. While our review suggested mitochondrial biology may be one such target, research is still far from a possible clinical trial. We discuss the challenges in such research.

The impact of obstructive sleep apnea treatment on microvascular complications in patients with type 2 diabetes: a feasibility randomized controlled trial

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is associated with an increased risk of diabetes-related complications. Hence, it is plausible that continuous positive airway pressure (CPAP) could have a favorable impact on these complications. We assessed the feasibility of conducting a randomized control trial in patients with type 2 diabetes and OSA over 2 years.

METHODS

We conducted an open-label multicenter feasibility randomized control trial of CPAP vs no CPAP in patients with type 2 diabetes and OSA. Patients with resting oxygen saturation < 90%, central apnea index > 15 events/h, or Epworth Sleepiness Scale ≥ 11 were excluded. OSA was diagnosed using a multichannel portable device (ApneaLink Air, ResMed). The primary outcome measures were related to feasibility and the secondary outcomes were changes in various clinical and biochemical parameters related to diabetes outcomes.

RESULTS

Eighty-three (40 CPAP vs 43 no CPAP) patients were randomly assigned, with a median (interquartile range) follow-up of 645 (545, 861) days. CPAP compliance was inadequate, with a median usage of approximately 3.5 hours/night. Early CPAP use predicted longer-term compliance. The adjusted analysis showed a possible favorable association between being randomly assigned to CPAP and several diabetes-related end points (chronic kidney disease, neuropathy, and quality of life).

CONCLUSIONS

It was feasible to recruit, randomly assign, and achieve a high follow-up rate over 2 years in patients with OSA and type 2 diabetes. CPAP compliance might improve by a run-in period before randomization. A full randomized control trial is necessary to assess the observed favorable association between CPAP and chronic kidney disease , neuropathy, and quality of life in patients with type 2 diabetes.

CLINICAL TRIAL REGISTRATION

Registry: ISRCTN; Name: The impact of sleep disorders in patients with type 2 diabetes; URL: https://www.isrctn.com/ISRCTN12361838; Identifier: ISRCTN12361838.

CITATION

Makhdom EA, Maher A, Ottridge R, et al. The impact of obstructive sleep apnea treatment on microvascular complications in patients with type 2 diabetes: a feasibility randomized controlled trial. J Clin Sleep Med. 2024;20(6):947-957.

Advances in Exosome-Based Therapies for the Repair of Peripheral Nerve Injuries

Peripheral nerve injuries (PNIs) are the term used to describe injuries that occur to the nerve fibers of the peripheral nervous system (PNS). Such injuries may be caused by trauma, infection, or aberrant immunological response. Although the peripheral nervous system has a limited capacity for self-repair, in cases of severe damage, this process is either interrupted entirely or is only partially completed. The evaluation of variables that promote the repair of peripheral nerves has consistently been a focal point. Exosomes are a subtype of extracellular vesicles that originate from cellular sources and possess abundant proteins, lipids, and nucleic acids, play a critical role in facilitating intercellular communication. Due to their modifiable composition, they possess exceptional capabilities as carriers for therapeutic compounds, including but not limited to mRNAs or microRNAs. Exosome-based therapies have gained significant attention in the treatment of several nervous system diseases due to their advantageous properties, such as low toxicity, high stability, and limited immune system activation. The objective of this review article is to provide an overview of exosome-based treatments that have been developed in recent years for a range of PNIs, including nerve trauma, diabetic neuropathy, amyotrophic lateral sclerosis (ALS), glaucoma, and Guillain-Barre syndrome (GBS). It was concluded that exosomes could provide favorable results in the improvement of peripheral PNIs by facilitating the transfer of regenerative factors. The development of bioengineered exosome therapy for PNIs should be given more attention to enhance the efficacy of exosome treatment for PNIs.

Biomarkers and signaling pathways of diabetic nephropathy and peripheral neuropathy: possible therapeutic intervention of rutin and quercetin

Diabetic nephropathy and peripheral neuropathy are the two main complications of chronic diabetes that contribute to high morbidity and mortality. These conditions are characterized by the dysregulation of multiple molecular signaling pathways and the presence of specific biomarkers such as inflammatory cytokines, indicators of oxidative stress, and components of the renin-angiotensin system. In this review, we systematically collected and collated the relevant information from MEDLINE, EMBASE, ELSEVIER, PUBMED, GOOGLE, WEB OF SCIENCE, and SCOPUS databases. This review was conceived with primary objective of revealing the functions of these biomarkers and signaling pathways in the initiation and progression of diabetic nephropathy and peripheral neuropathy. We also highlighted the potential therapeutic effectiveness of rutin and quercetin, two plant-derived flavonoids known for their antioxidant and anti-inflammatory properties. The findings of our study demonstrated that both flavonoids can regulate important disease-promoting systems, such as inflammation, oxidative stress, and dysregulation of the renin-angiotensin system. Importantly, rutin and quercetin have shown protective benefits against nephropathy and neuropathy in diabetic animal models, suggesting them as potential therapeutic agents. These findings provide a solid foundation for further comprehensive investigations and clinical trials to evaluate the potential of rutin and quercetin in the management of diabetic nephropathy and peripheral neuropathy. This may contribute to the development of more efficient and comprehensive treatment approaches for diabetes-associated complications.

How inflammation dictates diabetic peripheral neuropathy: An enlightening review

BACKGROUND

Diabetic peripheral neuropathy (DPN) constitutes a debilitating complication associated with diabetes. Although, the past decade has seen rapid developments in understanding the complex etiology of DPN, there are no approved therapies that can halt the development of DPN, or target the damaged nerve. Therefore, clarifying the pathogenesis of DPN and finding effective treatment are the crucial issues for the clinical management of DPN.

AIMS

This review is aiming to summary the current knowledge on the pathogenesis of DPN, especially the mechanism and application of inflammatory response.

METHODS

We systematically summarized the latest studies on the pathogenesis and therapeutic strategies of diabetic neuropathy in PubMed.

RESULTS

In this seminal review, the underappreciated role of immune activation in the progression of DPN is scrutinized. Novel insights into the inflammatory regulatory mechanisms of DPN have been unearthed, illuminating potential therapeutic strategies of notable clinical significance. Additionally, a nuanced examination of DPN's complex etiology, including aberrations in glycemic control and insulin signaling pathways, is presented. Crucially, an emphasis has been placed on translating these novel understandings into tangible clinical interventions to ameliorate patient outcomes.

CONCLUSIONS

This review is distinguished by synthesizing cutting-edge mechanisms linking inflammation to DPN and identifying innovative, inflammation-targeted therapeutic approaches.

Multimodal Approaches in the Treatment of Chronic Peripheral Neuropathy-Evidence from Germany

Patients with chronic peripheral neuropathy suffer greatly and their quality of life is often restricted. Drug therapy can be accompanied by undesirable side effects and intolerances, or the hoped-for effect does not materialize. Therefore, in addition to drug therapy, attempts are also made to treat the physical symptoms with complementary procedures. In the case of severe forms, the search for a suitable form of therapy is difficult. Complex treatments can be an innovative way to treat peripheral neuropathy. At the same time, several different therapy methods are carried out at high frequency by a specialized treatment team. This study aimed to provide an overview of possible complementary forms of therapy. The focus was on a comparison of two interdisciplinary complex therapies that are used in severe cases in an acute inpatient care setting in Germany. The six dimensions (energy, sleep, pain, physicality, emotional response and social isolation) of the Nottingham Health Profile (NHP) were used to assess quality of life. Both complex treatments (naturopathic complex therapy/multimodal pain therapy) showed a significant reduction in impairment in all dimensions of the NHP. In addition, a multivariate analysis was carried out to take into account several influencing variables at the same time. At the time of admission to the hospital, the degree of chronicity was recorded for each patient. This allowed statements to be made about the effect of the respective therapy depending on the chronification stage of the patient. It has been shown that patients with acutely exacerbated pain with the highest degree of chronicity also benefit from both complex treatments. The naturopathic complex treatment gives the treatment team more options. Aspects such as nutrition, methods from phytotherapy and traditional Chinese medicine can be integrated into inpatient care. Thus, a patient-centered, holistic therapy can take place. However, an interdisciplinary holistic therapy requires more time for both the practitioner and the patient. This should be taken into account in the health systems in the context of the diagnosis related groups.

Assessment of Triglyceride-Glucose Index and Ratio in Patients with Type 2 Diabetes and Their Relation to Microvascular Complications

OBJECTIVE

Triglyceride-based indices have gained much attention over the past few years. Relation of triglyceride - glucose (TyG) index with insulin resistance and diabetic macrovascular complications was thoroughly studied; nevertheless its relation to microvascular complications is still unclear. This provoked us to carry out the present study.

METHODS

This cross-sectional study included 500 patients with type 2 diabetes (T2DM), who were enrolled from the outpatient clinic of the Diabetes and Metabolism Unit at Alexandria Main University Hospital. The equations utilized to calculate triglycerides-related indices were: TyG ratio = fasting triglycerides (mg/dL)/fasting glucose (mg/dL), and TyG index = logarithm of [fasting triglyceride (mg/dl) x fasting glucose (mg/dl)/2]. The diagnostic criteria set by the American Diabetes Association were followed to diagnose diabetic microvascular complications.

RESULTS

In patients with T2DM, TyG index was significantly higher in patients with diabetic retinopathy, diabetic kidney disease, and diabetic peripheral neuropathy compared to those without complications (p < 0.001). TyG index was significantly positively correlated to diabetes duration, as well as triglyceride/high density lipoprotein ratio in the total sample (p < 0.001).

CONCLUSION

TyG index is an easy, cheap, and available marker for detection of microvascular complications in patients with T2DM.

Frontiers in diagnostic and therapeutic approaches in diabetic sensorimotor neuropathy (DSPN)

Diabetes sensory polyneuropathy (DSPN) is a significant complication of diabetes affecting up to 50% of patients in their lifetime and approximately 20% of patients suffer from painful diabetes neuropathic pain. DSPN - both painless and painful - leads to considerable morbidity including reduction of quality of life, increased lower limb amputations and is associated with worsening mortality. Significant progress has been made in the understanding of pathogenesis of DSPN and the last decade has seen newer techniques aimed at its earlier diagnosis. The management of painful DSPN remains a challenge despite advances made in the unravelling the pathogenesis of pain and its transmission. This article discusses the heterogenous clinical presentation of DSPN and the need to exclude key differential diagnoses. Furthermore, it reviews in detail the current diagnostic techniques involving both large and small neural fibres, their limitations and advantages and current place in the diagnosis of DSPN. Finally, the management of DSPN including newer pharmacotherapies are also discussed.

Neurological Features and Their Association With Gender in Diabetes Mellitus Patients

Introduction Understanding the wide range of clinical signs and symptoms associated with diabetes mellitus (DM) is crucial because people with DM are frequently misdiagnosed, given incorrect care, or poorly controlled. Therefore, the purpose of this study was to evaluate the neurological symptoms associated with type 1 and type 2 DM patients with respect to patient gender. Methods This was a cross-sectional multicenter study that was conducted at different hospitals using a non-probability sampling method. The duration of the study was eight months, from January 2022 to August 2022. The study involved 525 type 1 and type 2 DM patients with an age range from 35 to 70 years. Demographic details such as age, gender, socioeconomic status, past medical history, presence of comorbidities, type, and duration of DM, and neurological features were recorded as frequencies and percentages. A Chi-square test was used to determine the association between neurological symptoms associated with type 1 and type 2 DM and gender. Results The study findings showed that of 525 diabetic patients, 210 (40.0%) were females and 315 (60.0%) were males. The mean male and female mean ages were 57.36±14.99 and 50.52±14.8 years, respectively, with a significant difference with respect to gender (p<0.001). The prevalence of neurological manifestations showed that irritability or mood swings were reported by most of the male 216 (68.6%) and 163 (77.6%) female diabetic patients, with a significant association noticed (p=0.022). Moreover, a significant association was observed between both genders in terms of swelling of feet, ankles, hands, and eyes (p=0.042), confusion or difficulty in concentration (p=0.040), burning pain in feet or legs (p=0.012), and muscular pain or cramps in legs or feet (p=0.016).  Conclusion This study concluded that the prevalence of neurological manifestations was high among diabetic patients. Most of the neurological symptoms were significantly more pronounced in female diabetic patients. Moreover, most of the neurological symptoms were associated with the type (type 2 DM) and duration of DM. The presence of hypertension, dyslipidemia, and smoking also influenced some neurological manifestations.

Precision of Michigan Neuropathy Screening Instrument (MNSI) Tool for the Diagnosis of Diabetic Peripheral Neuropathy Among People with Type 2 Diabetes-A Study from South India

Diabetic peripheral neuropathy (DPN) is one of the risk factors for foot-related complications among people with type 2 diabetes mellitus (T2DM). Hence, we aimed to validate the Michigan Neuropathy Screening Instrument (MNSI) tool against biothesiometer with a cut-off value of ≥25 V and also to determine the cut-off point of MNSI score for the diagnosis of diabetic neuropathy among people with T2DM in India. A cross-sectional study was conducted among 357 people with T2DM in a tertiary care centre for diabetes in Chennai, South India. The eligible study participants underwent testing with a biothesiometer and the MNSI tool was administered. The patient version tool of MNSI was translated to the local language, Tamil. The MNSI scores (1, 1.5, 2, and 2.5) were compared with biothesiometer value. For the MNSI scores of less than 1, 1.5, 2, and 2.5, sensitivities were 97.6%, 97.6%, 96.8%, and 77.8% and specificities were 76.6%, 77.9%, 85.7%, and 88.3% respectively. The cut-off value of MNSI score was derived as two with AUC of 0.934. The sensitivity was 96.8% and the specificity was 85.7% with 89.6% accuracy. The high sensitivity indicates the positive cases are diagnosed correctly. There is no validated tool available for detection of DPN in Indian population. The Indian version of MNSI tool was found to be effective for screening diabetic neuropathy among people with T2DM. The MNSI tool was found to be reliable, convenient, and non-invasive for diagnosis of DPN and can be used in routine clinical settings.

Intensive insulin therapy in sepsis patients: Better data enables better intervention

In clinics, sepsis is a critical disease that often develops into shock and multiple organ dysfunction, leading to a serious threat of death. Patients with sepsis are often accompanied by stress hyperglycemia which is an independent risk factor for poor prognosis in sepsis. Thus, the treatment for stress hyperglycemia has attracted more and more attention, among which intensive insulin therapy is widely concerned. However, the benefits and harms of intensive insulin therapy for sepsis patients remain controversial. What the existing literature discusses mostly are the clinical benefit and hypoglycemia risk of intensive insulin therapy, but there is no conclusion on the target range of blood glucose control, the applicable patients, the timing of treatment initiation, and how to avoid the risk. In this study, we have analyzed and summarized the existing literature, hoping to determine the adverse and clinical benefit of intensive insulin therapy in sepsis. And we attempt to assemble better evidence to propose a better recommendation on hyperglycemia intervention for sepsis patients.

Composite nerve conduction scores and signs for diagnosis and somatic staging of diabetic polyneuropathy: Mid North American ethnic cohort survey

INTRODUCTION/AIMS

In the Diabetes Control and Complications Trial (DCCT), the minimal nerve conduction (NC) criterion for diabetic sensorimotor polyneuropathy (DSPN) was abnormality of NC in more than one peripheral nerve without specifying the attributes of NCs to be evaluated. In the present study, we assess individual and composite scores of NCs meeting the DCCT criterion and signs for improved diagnosis and assessment of DSPN severity.

METHODS

Evaluated were 13 attributes and 6 composite NC scores and signs and symptoms in 395 healthy subjects (HS) and 388 persons with diabetes (DM).

RESULTS

Percent abnormality between subjects with DM and HS was remarkably different among individual attributes and the six composite NC scores. For diagnosis of DSPN using the DCCT criterion, assessment of conduction velocities (CVs) and distal latencies (DLs) provided sensitive diagnoses of DSPN. NC amplitudes provided stronger measures of severity. In studied cohorts, DSPN was staged: N0, no NC abnormality using NC score 2 (CVs and DLs), 60.0%; N1, NC abnormality only, 18.4%; N2, NC abnormality and signs of feet or legs, 16.3%; and N3, NC abnormality and signs of thighs, 5.3%.

DISCUSSION

For sensitive and standard diagnosis of DSPN using the DCCT NC criterion, specifically defined composite scores of CVs and DLs, e.g., score 2, is recommended. A composite score of amplitudes, e.g., score 4, provides a stronger measure of neuropathy severity. Also, provided are HS reference values of evaluated attributes of NCs and estimates of staged severity of DSPN of mid North American DM cohorts.

Stem Cell Therapy in Diabetic Polyneuropathy: Recent Advancements and Future Directions

Diabetic polyneuropathy (DPN) is the most frequent, although neglected, complication of long-term diabetes. Nearly 30% of hospitalized and 20% of community-dwelling patients with diabetes suffer from DPN; the incidence rate is approximately 2% annually. To date, there has been no curable therapy for DPN. Under these circumstances, cell therapy may be a vital candidate for the treatment of DPN. The epidemiology, classification, and treatment options for DPN are disclosed in the current review. Cell-based therapies using bone marrow-derived cells, embryonic stem cells, pluripotent stem cells, endothelial progenitor cells, mesenchymal stem cells, or dental pulp stem cells are our primary concern, which may be a useful treatment option to ease or to stop the progression of DPN. The importance of cryotherapies for treating DPN has been observed in several studies. These findings may help for the future researchers to establish more focused, accurate, effective, alternative, and safe therapy to reduce DPN. Cell-based therapy might be a permanent solution in the treatment and management of diabetes-induced neuropathy.

A Machine Learning-Based Severity Prediction Tool for the Michigan Neuropathy Screening Instrument

Diabetic sensorimotor polyneuropathy (DSPN) is a serious long-term complication of diabetes, which may lead to foot ulceration and amputation. Among the screening tools for DSPN, the Michigan neuropathy screening instrument (MNSI) is frequently deployed, but it lacks a straightforward rating of severity. A DSPN severity grading system has been built and simulated for the MNSI, utilizing longitudinal data captured over 19 years from the Epidemiology of Diabetes Interventions and Complications (EDIC) trial. Machine learning algorithms were used to establish the MNSI factors and patient outcomes to characterise the features with the best ability to detect DSPN severity. A nomogram based on multivariable logistic regression was designed, developed and validated. The extra tree model was applied to identify the top seven ranked MNSI features that identified DSPN, namely vibration perception (R), 10-gm filament, previous diabetic neuropathy, vibration perception (L), presence of callus, deformities and fissure. The nomogram's area under the curve (AUC) was 0.9421 and 0.946 for the internal and external datasets, respectively. The probability of DSPN was predicted from the nomogram and a DSPN severity grading system for MNSI was created using the probability score. An independent dataset was used to validate the model's performance. The patients were divided into four different severity levels, i.e., absent, mild, moderate, and severe, with cut-off values of 10.50, 12.70 and 15.00 for a DSPN probability of less than 50, 75 and 100%, respectively. We provide an easy-to-use, straightforward and reproducible approach to determine prognosis in patients with DSPN.

Effects of 1-methyl-1, 2, 3, 4-tetrahydroisoquinoline on a diabetic neuropathic pain model

Background: Neuropathy is a prevalent and debilitating complication of poorly managed diabetes, contributing towards poor quality of life, amputation risk, and increased mortality. The available therapies for diabetic neuropathic pain (DPN) have limitations in terms of efficacy, tolerability and patient compliance. Dysfunction in the peripheral and central monoaminergic system has been evidenced in various types of neuropathic and acute pain. The objective of the present study was to investigate 1-methyl 1, 2, 3, 4-tetrahydroisoquinoline (1MeTIQ), an endogenous amine found in human brain with a known neuroprotective profile, in a model of streptozotocin (STZ) induced neuropathic pain. Methods: Diabetic neuropathy in male BALB/c mice was induced by intraperitoneal injection of a single dose of STZ (200 mg/kg). Upon development of DPN after 4 weeks, mice were investigated for mechanical allodynia (von Frey filament pressure test) and thermal hyperalgesia (tail immersion test). Ondansetron (1.0 mg/kg i.p.), naloxone (3.0 mg/kg i.p.) and yohimbine (2.0 mg/kg i.p.) were used to elucidate the possible mechanism involved. Postmortem frontal cortical, striatal and hippocampal tissues were dissected and evaluated for changes in levels of dopamine, noradrenaline and serotonin using High-Performance Liquid Chromatography (HPLC) with UV detection. Results: Acute administration of 1MeTIQ (15-45 mg/kg i.p.) reversed streptozotocin-induced diabetic neuropathic static mechanical allodynia (von Frey filament pressure test) and thermal hyperalgesia (tail immersion test), these outcomes being comparable to standard gabapentin. Furthermore, HPLC analysis revealed that STZ-diabetic mice expressed lower concentrations of serotonin in all three brain regions examined, while dopamine was diminished in the striatum and 1MeTIQ reversed all these neurotransmitter modifications. These findings suggest that the antihyperalgesic/antiallodynic activity of 1MeTIQ may be mediated in part via supraspinal opioidergic and monoaminergic modulation since they were naloxone, yohimbine and ondansetron reversible. Conclusion: It was also concluded that acute treatment with 1MeTIQ ameliorated STZ-induced mechanical allodynia and thermal hyperalgesia and restored brain regionally altered serotonin and dopamine concentrations which signify a potential for 1MeTIQ in the management of DPN.

Protective effects of CHIP overexpression and Wharton's jelly mesenchymal-derived stem cell treatment against streptozotocin-induced neurotoxicity in rats

Diabetic neuropathy is a common complication of diabetes mellitus, posing a challenge in treatment. Previous studies have indicated the protective role of mesenchymal stem cells against several disorders. Although they can repair nerve injury, their key limitation is that they reduce viability under stress conditions. We recently observed that overactivation of the carboxyl terminus of heat shock protein 70 (Hsp70) interacting protein (CHIP) considerably rescued cell viability under hyperglycemic stress and played an essential role in promoting the beneficial effects of Wharton's jelly-derived mesenchymal stem cells (WJMSCs). Thus, the present study was designed to unveil the protective effects of CHIP-overexpressing WJMSCs against neurodegeneration using in vivo animal model based study. In this study, western blotting observed that CHIP-overexpressing WJMSCs could rescue nerve damage observed in streptozotocin-induced diabetic rats by activating the AMPKα/AKT and PGC1α/SIRT1 signaling pathway. In contrast, these signaling pathways were downregulated upon silencing CHIP. Furthermore, CHIP-overexpressing WJMSCs inhibited inflammation induced in the brains of diabetic rats by suppressing the NF-κB, its downstream iNOS and cytokines signaling nexus and enhancing the antioxidant enzyme system. Moreover, TUNEL assay demonstrated that CHIP carrying WJMSCs suppressed the apoptotic cell death induced in STZ-induced diabetic group. Collectively, our findings suggests that CHIP-overexpressing WJMSCs might exerts beneficial effects, which may be considered as a therapeutic strategy against diabetic neuropathy complications.

The Role of Angiotensin Receptor Blockers in the Personalized Management of Diabetic Neuropathy

Neuropathy is a frequent complication of diabetes mellitus (DM) and is associated with the increased risk ofamputation and vascular events. Tight glycemic control is an important component inthe prevention of diabetic neuropathy. However, accumulating data suggest that angiotensin receptor blockers (ARBs) might also be useful in this setting. We discuss the findings of both experimental and clinical studies that evaluated the effects of ARBs on indices of diabetic neuropathy. We also review the implicated mechanisms of the neuroprotective actions of these agents. Overall, it appears that ARBs might be a helpful tool for preventing and delaying the progression of diabetic neuropathy, but more data are needed to clarify their role in the management of this overlooked complication of DM.

Performance Analysis of Conventional Machine Learning Algorithms for Diabetic Sensorimotor Polyneuropathy Severity Classification Using Nerve Conduction Studies

Background

Diabetic sensorimotor polyneuropathy (DSPN) is a major form of complication that arises in long-term diabetic patients. Even though the application of machine learning (ML) in disease diagnosis is very common and well-established in the field of research, its application in DSPN diagnosis using nerve conduction studies (NCS), is very limited in the existing literature.

Method

In this study, the NCS data were collected from the Diabetes Control and Complications Trial (DCCT) and its follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) clinical trials. The NCS variables are median motor velocity (m/sec), median motor amplitude (mV), median motor F-wave (msec), median sensory velocity (m/sec), median sensory amplitude (μV), Peroneal Motor Velocity (m/sec), peroneal motor amplitude (mv), peroneal motor F-wave (msec), sural sensory velocity (m/sec), and sural sensory amplitude (μV). Three different feature ranking techniques were used to analyze the performance of eight different conventional classifiers.

Results

The ensemble classifier outperformed other classifiers for the NCS data ranked when all the NCS features were used and provided an accuracy of 93.40%, sensitivity of 91.77%, and specificity of 98.44%. The random forest model exhibited the second-best performance using all the ten features with an accuracy of 93.26%, sensitivity of 91.95%, and specificity of 98.95%. Both ensemble and random forest showed the kappa value 0.82, which indicates that the models are in good agreement with the data and the variables used and are accurate to identify DSPN using these ML models.

Conclusion

This study suggests that the ensemble classifier using all the ten NCS variables can predict the DSPN severity which can enhance the management of DSPN patients.

Bilirubin is inversely related to diabetic peripheral neuropathy assessed by sural nerve conduction study

AIMS/INTRODUCTION

Diagnosis of diabetic peripheral neuropathy (DPN) depends on subjective findings, certain investigations for DPN risks have not been performed enough. Bilirubin protects against vascular complications by reducing oxidative stress in diabetes, but is not fully tested for DPN. This study aimed to evaluate sural nerve conduction impairments (SNCI) as an objective DPN marker and the contribution of bilirubin to SNCI.

MATERIALS AND METHODS

Using DPN-Check® , SNCI was defined as a decline of amplitude potential or conduction velocity below the normal limit in 150 inpatients with diabetes. The correlations between SNCI and conventional DPN diagnosis criteria, the incidence of diabetic retinopathy/nephropathy, biomarkers for atherosclerosis, cardiac function by ultrasonic cardiogram, and bilirubin were statistically tested, followed by the comparison of logistic regression models for SNCI to find confounders with bilirubin.

RESULTS

The incidence of SNCI was 72.0%. The sensitivity and specificity of SNCI for DPN prediagnosis by simplified criteria were 54.6 and 90.5%, respectively, and similarly corresponded with diabetic retinopathy and nephropathy (sensitivity 57.4 and 50.0%, respectively). SNCI significantly related to diabetes duration, declined estimated glomerular filtration rate, albuminuria and total bilirubin. SNCI incidence was attenuated in the higher bilirubin tertiles (89.8/65.3/54.8%, P < 0.001). Bilirubin was an independent inverse risk factor for SNCI, even after adjustment by known risk factors for DPN and markers for microvascular complications.

CONCLUSIONS

SNCI is a comprehensive marker for diabetic complications. We first showed the independent inverse relationship between bilirubin and SNCI through the independent pathway with other complications, provably reducing oxidative stress, as previously reported.

A nomogram-based diabetic sensorimotor polyneuropathy severity prediction using Michigan neuropathy screening instrumentations

BACKGROUND

Diabetic Sensorimotor polyneuropathy (DSPN) is one of the major indelible complications in diabetic patients. Michigan neuropathy screening instrumentation (MNSI) is one of the most common screening techniques used for DSPN, however, it does not provide any direct severity grading system.

METHOD

For designing and modeling the DSPN severity grading systems for MNSI, 19 years of data from Epidemiology of Diabetes Interventions and Complications (EDIC) clinical trials were used. Different Machine learning-based feature ranking techniques were investigated to identify the important MNSI features associated with DSPN diagnosis. A multivariable logistic regression-based nomogram was generated and validated for DSPN severity grading using the best performing top-ranked MNSI features.

RESULTS

Top-10 ranked features from MNSI features: Appearance of Feet (R), Ankle Reflexes (R), Vibration perception (L), Vibration perception (R), Appearance of Feet (L), 10-gm filament (L), Ankle Reflexes (L), 10-gm filament (R), Bed Cover Touch, and Ulceration (R) were identified as important features for identifying DSPN by Multi-Tree Extreme Gradient Boost model. The nomogram-based prediction model exhibited an accuracy of 97.95% and 98.84% for the EDIC test set and an independent test set, respectively. A DSPN severity score technique was generated for MNSI from the DSPN severity prediction model. DSPN patients were stratified into four severity levels: absent, mild, moderate, and severe using the cut-off values of 17.6, 19.1, 20.5 for the DSPN probability less than 50%, 75%-90%, and above 90%, respectively.

CONCLUSIONS

The findings of this work provide a machine learning-based MNSI severity grading system which has the potential to be used as a secondary decision support system by health professionals in clinical applications and large clinical trials to identify high-risk DSPN patients.

Frequency of Neuropathic Sensory Symptoms Among Patients With Uncontrolled Diabetes Mellitus in Security Forces Hospital, Riyadh, Saudi Arabia

Background

Diabetic peripheral neuropathy (DPN) is a chronic sensorimotor length-dependent and symmetrical polyneuropathy. Some peripheral neuropathies have painful presentations, and some are painless. DPN can have a potential impact on the patient's life.

Objectives

This study was conducted in order to investigate the frequency of neuropathic sensory symptoms among patients with uncontrolled diabetes mellitus.

Methods

This is a cross-sectional study conducted in the Security Forces hospital using the Neuropathy Total Symptom Score-6 (NTSS-6) questionnaire. The questionnaire was administered by contacting patients through the phone. Patients with uncontrolled diabetes (HbA1C >9) were included in the study.

Results

This study included 285 participants; 58.9% had type II diabetes and 41.1% had type I diabetes, 156 (54.7%) were females, and 129 (45.3%) were males. Most of the patients (51.1%) were 45-64 years old and the majority were non-smokers (77.9%). Patients with neuropathic pain were 182 (63.9%); 79 (43.4%) of them were males and 103 (56.6%) were females. The prevalence of neuropathic symptoms was much higher in females than in males.

Conclusion

The prevalence of painful DPN is high among patients with long-term uncontrolled diabetes mellitus. Older, unemployed, and low-educated patients are at higher risk of developing painful DPN. Proper glycemic control and lifestyle modifications are essential in preventing the progression of this condition.

Painful diabetic neuropathy is associated with increased nerve regeneration in patients with type 2 diabetes undergoing intensive glycemic control

AIMS/INTRODUCTION

Painful diabetic peripheral neuropathy (pDPN) is associated with small nerve fiber degeneration and regeneration. This study investigated whether the presence of pDPN might influence nerve regeneration in patients with type 2 diabetes undergoing intensive glycemic control.

MATERIALS AND METHODS

This exploratory substudy of an open-label randomized controlled trial undertook the Douleur Neuropathique en 4 questionnaire and assessment of electrochemical skin conductance, vibration perception threshold and corneal nerve morphology using corneal confocal microscopy in participants with and without pDPN treated with exenatide and pioglitazone or basal-bolus insulin at baseline and 1-year follow up, and 18 controls at baseline only.

RESULTS

Participants with type 2 diabetes, with (n = 13) and without (n = 28) pDPN had comparable corneal nerve fiber measures, electrochemical skin conductance and vibration perception threshold at baseline, and pDPN was not associated with the severity of DPN. There was a significant glycated hemoglobin reduction (P < 0.0001) and weight gain (P < 0.005), irrespective of therapy. Participants with pDPN showed a significant increase in corneal nerve fiber density (P < 0.05), length (P < 0.0001) and branch density (P < 0.005), and a decrease in the Douleur Neuropathique en 4 score (P < 0.01), but no change in electrochemical skin conductance or vibration perception threshold. Participants without pDPN showed a significant increase in corneal nerve branch density (P < 0.01) and no change in any other neuropathy measures. A change in the severity of painful symptoms was not associated with corneal nerve regeneration and medication for pain.

CONCLUSIONS

This study showed that intensive glycemic control is associated with greater corneal nerve regeneration and an improvement in the severity of pain in patients with painful diabetic neuropathy.

Diabetic neuropathy in children and youth: New and emerging risk factors

Pediatric neuropathy attributed to metabolic dysfunction is a well-known complication in children and youth with type 1 diabetes. Moreover, the rise of obesity and in particular of type 2 diabetes may cause an uptick in pediatric neuropathy incidence. However, despite the anticipated increase in neuropathy incidence, pathogenic insights and strategies to prevent or manage neuropathy in the setting of diabetes and obesity in children and youth remain unknown. Data from adult studies and available youth cohort studies are providing an initial understanding of potential diagnostic, management, and preventative measures in early life. This review discusses the current state of knowledge emanating from these efforts, with particular emphasis on the prevalence, clinical presentation, diagnostic approaches and considerations, and risk factors of neuropathy in type 1 and type 2 diabetes in children and youth. Also highlighted are current management strategies and recommendations for neuropathy in children and youth with diabetes. This knowledge, along with continued and sustained emphasis on identifying and eliminating modifiable risk factors, completing randomized controlled trials to assess effectiveness of strategies like weight loss and exercise, and enhancing awareness to support early detection and prevention, are pertinent to addressing the rising incidence of neuropathy associated with diabetes and obesity in children and youth.

Recent Advances in Biomarkers and Regenerative Medicine for Diabetic Neuropathy

Diabetic neuropathy is one of the most common complications of diabetes. This complication is peripheral neuropathy with predominant sensory impairment, and its symptoms begin with hyperesthesia and pain and gradually become hypoesthesia with the loss of nerve fibers. In some cases, lower limb amputation occurs when hypoalgesia makes it impossible to be aware of trauma or mechanical stimuli. On the other hand, up to 50% of these complications are asymptomatic and tend to delay early detection. Therefore, sensitive and reliable biomarkers for diabetic neuropathy are needed for an early diagnosis of this condition. This review focuses on systemic biomarkers that may be useful at this time. It also describes research on the relationship between target gene polymorphisms and pathological conditions. Finally, we also introduce current information on regenerative therapy, which is expected to be a therapeutic approach when the pathological condition has progressed and nerve degeneration has been completed.

The time to develop treatments for diabetic neuropathy

BACKGROUND

Diabetic neuropathy is a multifaceted condition affecting up to 50% of individuals with long standing diabetes. The most common presentation is peripheral diabetic sensory neuropathy (DPN).

METHODS

We carried out a systematic review of papers dealing with diabetic neuropathy on Pubmed in addition to a targeted Google search.Search terms included small fiber neuropathy,diffuse peripheral neuropathy, quantitative sensory testing, nerve conduction testing, intra-epidermal nerve fiber density, corneal confocal reflectance microscopy, aldose reductase inhbitors, nerve growth factor, alpha-lipoic acid, ruboxistaurin, nerve growth factor antibody, and cibinetide.

RESULTS

Over the past half century, there have been a number of agents undergoing unsuccessful trials for treatment of DPN.There are several approved agents for relief of pain caused by diabetic neuropathy, but these do not affect the pathologic process.

EXPERT OPINION

The failure to find treatments for diabetic neuropathy can be ascribed to (1) the complexity of design of studies and (2) the slow progression of the condition, necessitating long duration trials to prove efficacy.We propose a modification of the regulatory process to permit early introduction of agents with demonstrated safety and suggestion of benefit as well as prolongation of marketing exclusivity while long term trials are in progress to prove efficacy.

Electrodiagnostic assessment of the autonomic nervous system: A consensus statement endorsed by the American Autonomic Society, American Academy of Neurology, and the International Federation of Clinical Neurophysiology

Evaluation of disorders of the autonomic nervous system is both an art and a science, calling upon the physician's most astute clinical skills as well as knowledge of autonomic neurology and physiology. Over the last three decades, the development of noninvasive clinical tests that assess the function of autonomic nerves, the validation and standardization of these tests, and the growth of a large body of literature characterizing test results in patients with autonomic disorders have equipped clinical practice further with a valuable set of objective tools to assist diagnosis and prognosis. This review, based on current evidence, outlines an international expert consensus set of recommendations to guide clinical electrodiagnostic autonomic testing. Grading and localization of autonomic deficits incorporates scores from sympathetic cardiovascular adrenergic, parasympathetic cardiovagal, and sudomotor testing, as no single test alone is sufficient to diagnose the degree or distribution of autonomic failure. The composite autonomic severity score (CASS) is a useful score of autonomic failure that is normalized for age and gender. Valid indications for autonomic testing include generalized autonomic failure, regional or selective system syndromes of autonomic impairment, peripheral autonomic neuropathy and ganglionopathy, small fiber neuropathy, orthostatic hypotension, orthostatic intolerance, syncope, neurodegenerative disorders, autonomic hyperactivity, and anhidrosis.

Neuropathy of the elderly

There is an aging of the peripheral nervous system characterized by a decrease in sensory and motor nerve conduction, amplitudes of motor and above all sensory potentials, an abolition of the ankle jerk reflexes and an alteration of proprioceptive sensitivity in almost two-thirds of individuals over 65 years old. These anomalies tend to increase beyond 80 years. However, these signs of aging do not affect the quality of life of the subjects. The causes of peripheral neuropathies in the elderly differ little from those observed before age 65. Of course, hereditary causes are much less frequent, except cases with a late onset, now easily detectable, such as familial amyloidosis. In our climates and in the most developed countries, diabetes remains the most common cause, the prevalence of neuropathy increasing with age. The so-called idiopathic causes are also frequent and despite extensive investigations, nearly 20% of cases remain without etiological diagnosis, but this type of neuropathy is generally mild and not very progressive. The presence of peripheral neuropathy in the elderly can cause real problems in daily life, including the frequency of falls that can be responsible for deleterious bone damage.

Cost and Cost-effectiveness of Large-scale Screening for Type 1 Diabetes in Colorado

OBJECTIVE

To assess the costs and project the potential lifetime cost-effectiveness of the ongoing Autoimmunity Screening for Kids (ASK) program, a large-scale, presymptomatic type 1 diabetes screening program for children and adolescents in the metropolitan Denver region.

RESEARCH DESIGN AND METHODS

We report the resource utilization, costs, and effectiveness measures from the ongoing ASK program compared with usual care (i.e., no screening). Additionally, we report a practical screening scenario by including utilization and costs relevant to routine screening in clinical practice. Finally, we project the potential cost-effectiveness of ASK and routine screening by identifying clinical benchmarks (i.e., diabetic ketoacidosis [DKA] events avoided, HbA_1c improvements vs. no screening) needed to meet value thresholds of $50,000-$150,000 per quality-adjusted life-year (QALY) gained over a lifetime horizon.

RESULTS

Cost per case detected was $4,700 for ASK screening and $14,000 for routine screening. To achieve value thresholds of $50,000-$150,000 per QALY gained, screening costs would need to be offset by cost savings through 20% reductions in DKA events at diagnosis in addition to 0.1% (1.1 mmol/mol) improvements in HbA_1c over a lifetime compared with no screening for patients who develop type 1 diabetes. Value thresholds were not met from avoiding DKA events alone in either scenario.

CONCLUSIONS

Presymptomatic type 1 diabetes screening may be cost-effective in areas with a high prevalence of DKA and an infrastructure facilitating screening and monitoring if the benefits of avoiding DKA events and improved HbA_1c persist over long-run time horizons. As more data are collected from ASK, the model will be updated with direct evidence on screening effects.

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.

Treatment of diabetic peripheral neuropathy: a review

OBJECTIVES

This review surveys current pharmacotherapies available for the treatment of diabetic peripheral neuropathy (DPN), emphasising their mechanisms of action.

METHODS

A comprehensive literature review focusing on the 'pharmacotherapy and treatment of diabetic peripheral neuropathy' was conducted. The Database of International Pharmaceutical Abstracts, EMBASE, PubMed, OVID, Scopus, Google and Google Scholar were searched, and reference lists of relevant articles were also included.

KEY FINDINGS

Diabetic peripheral neuropathy is often inadequately treated, and the role of improving glycaemic control specifically in type-2 diabetes remains unclear. It is crucial to explore the mechanisms of action and effectiveness of available therapies. Major international clinical guidelines for the management of DPN recommend several symptomatic treatments. First-line therapies include tricyclic antidepressants, serotonin-noradrenaline reuptake inhibitors, and anticonvulsants that act on calcium channels. Other therapies include opioids and topical agents such as capsaicin and lidocaine. The objectives of this paper are to review current guidelines for the pharmacological management of DPN and to discuss research relevant to the further development of pharmacological recommendations for the treatment of diabetic neuropathy.

SUMMARY

Diabetic neuropathy is a highly prevalent, disabling condition, the management of which is associated with significant costs. Evidence supports the use of specific anticonvulsants and antidepressants for pain management in patients with diabetic peripheral neuropathy. All current guidelines advise a personalised approach with a low-dose start that is tailored to the maximum response having the least side effects or adverse events.

Diabetic neuropathy in children and adolescents with type 1 diabetes mellitus: Diagnosis, pathogenesis, and associated genetic markers

Diabetic neuropathy (DN) is a common long-term complication of type 1 (T1D) and type 2 (T2D) diabetes mellitus, with significant morbidity and mortality. DN is defined as impaired function of the autonomic and/or peripheral nervous system, often subclinical, particularly in children and adolescents with T1D. Nerve conduction studies (NCS) and skin biopsies are considered gold-standard methods in the assessment of DN. Multiple environmental and genetic factors are involved in the pathogenesis of DN. Specifically, the role of metabolic control and glycemic variability is of paramount importance. A number of recently identified genes, including the AKR1B1, VEGF, MTHFR, APOE, and ACE genes, contribute significantly in the pathogenesis of DN. These genes may serve as biomarkers to predict future DN development or treatment response. In addition, they may serve as the basis for the development of new medications or gene therapy. In this review, the diagnostic evaluation, pathogenesis, and associated genetic markers of DN in children and adolescents with T1D are presented and discussed.

Infiltration of Blood-Derived Macrophages Contributes to the Development of Diabetic Neuropathy

Background and Objective

Diabetic neuropathic pain (DNP) is a common complication associated with diabetes. Currently, its underlying pathomechanism remains unknown. Studies have revealed that the recruitment of blood monocyte-derived macrophages (MDMs) to the spinal cord plays a pivotal role in different models of central nervous system injury. Therefore, the present study aimed at exploring the infiltration and function of MDMs in DNP using a mice model.

Methods

Diabetes was induced using streptozotocin in male A/J mice. Mechanical withdrawal thresholds were measured weekly to characterize neuropathy phenotype. Quantitative analysis of CD11b was performed and visualized by immunofluorescence. Spinal cord cells were isolated from myelin and debris by Percoll gradient. Flow cytometry was used to label CD11b and CD45 antibodies to differentiate MDMs (CD45^highCD11b⁺) from resident microglia (CD45^lowCD11b⁺). Mice were injected with clodronate liposomes to investigate the role of MDMs in DNP. The successful depletion of monocytes was determined by flow cytometry.

Results

The DNP mice model was successfully established. Compared with nondiabetic mice, diabetic mice displayed a markedly higher level of CD11b immunofluorescence in the spinal cord. The number of CD11b-positive microglia/macrophages gradually increased over the 28 days of testing after STZ injection, and a significant increase was observed on Day 14 (P < 0.01) and 28 (P < 0.01). Further analysis by flow cytometry showed that the infiltration of peripheral macrophages began to increase in 2 weeks (P < 0.001) and reached a maximum at 4 weeks (P < 0.001) post-STZ injection compared to the control. The depletion of MDMs by clodronate liposomes alleviated diabetes-induced tactile allodynia (P < 0.05) and reduced the infiltration of MDMs (P < 0.001) as well as the expression of IL-1β and TNF-α in the spinal cord (P < 0.05).

Conclusions

The infiltration of blood MDMs in the spinal cord may promote the development of painful neuropathy in diabetes.

A modelling study of the budget impact of improved glycaemic control in adults with Type 1 diabetes in the UK

AIMS

To develop a novel interactive budget impact model that assesses affordability of diabetes treatments in specific populations, and to test the model in a hypothetical scenario by estimating cost savings resulting from reduction in HbA_1c from ≥69 mmol/mol (8.5%) to a target of 53 mmol/mol (7.0%) in adults with Type 1 diabetes in the UK.

METHODS

A dynamic, interactive model was created using the projected incidence and progression over a 5-year horizon of diabetes-related complications (micro- and macrovascular disease, severe hypoglycaemia and diabetic ketoacidosis) for different HbA_1c levels, with flexible input of population size, complications and therapy costs, HbA_1c distribution and other variables. The model took a National Health Service and societal perspective.

RESULTS

The model was developed, and in the proposed hypothetical situation, reductions in complications and expected costs evaluated. Achievement of target HbA_1c in individuals with HbA_1c ≥69 mmol/mol (8.5%) would reduce expected chronic complications from 6.8 to 1.2 events per 100 person-years, and diabetic ketoacidosis from 14.5 to 1.0 events per 100 person-years. Potential cumulative direct cost savings achievable in the modelled population were estimated at £687 m over 5 years (£5,585/person), with total (direct and indirect) savings of £1,034 m (£8,400/person).

CONCLUSIONS

Implementation of strategies aimed at achieving target glucose levels in people with Type 1 diabetes in the UK has the potential to drive a significant reduction in complication costs. This estimate may provide insights into the potential for investment in achieving savings through improved diabetes care in the UK.

Plantar pressure distribution in diverse stages of diabetic neuropathy

Background

Diabetic Foot Ulceration in patients with diabetes could be associated with high plantar pressure caused by diabetes neuropathy. Therefore, it seems that one of the ways of identifying high-risk legs in diabetic patients with neuropathy would be characterization of elevated plantar pressure distributions.

Objective

Comparing the plantar pressure distribution in diabetic patients who suffered neuropathy with those without neuropathy.

Methods and materials

Plantar pressure distribution was recorded in the following categories: 38 diabetic patients without neuropathy, 30, 40 and 34 patients with mild neuropathy, moderate and severe neuropathy respectively.

Results

Patients suffered from severe neuropathy suggested higher maximum peak plantar pressure at midfoot, heel, and medial forefoot. The peak pressure of midfoot was significantly different in the following categories as well: patient without neuropathy (32.3 ± 17.9 kPa), mild neuropathic (24.0 ± 17.9 kPa), moderate neuropathic (21.5 ± 12.6 kPa), and severe neuropathic (22.9 ± 10.7 kPa) groups (p = 0.02).

Conclusion

The progression of diabetic neuropathy would have been increased followed by the peak plantar pressure.

[Diabetic neuropathy and diabetic foot syndrome (Update 2019)]

These are the guidelines for diagnosis and treatment of diabetic neuropathy and diabetic foot. Diabetic neuropathy comprises a number of mono- and polyneuropathies, plexopathies, radiculopathies and autonomic neuropathy.The position statement summarizes characteristic clinical symptoms and techniques for diagnostic assessment of diabetic neuropathy, including the complex situation of the diabetic foot syndrome. Recommendations for the therapeutic management of diabetic neuropathy, especially for the control of pain in sensorimotor neuropathy, are provided. The needs to prevent and treat diabetic foot syndrome are summarized.

Randomized Controlled Trial of Physical Exercise in Diabetic Veterans With Length-Dependent Distal Symmetric Polyneuropathy

Rationale: Physical exercise is an essential adjunct to the management of patients with type 2 diabetes mellitus. Therapeutic interventions that improve blood flow to peripheral nerves, such as exercise, may slow the progression of neuropathy in the diabetic patient.

Aims: This randomized clinical trial was conducted to determine whether a structured program of aerobic, isokinetic strength, or the combination of aerobic–isokinetic strength exercise intervention alters peripheral nerve function in glycemic-controlled diabetic patients with advanced length-dependent distal symmetric polyneuropathy.

Methods: Forty-five patients with type 2 diabetes mellitus exhibiting tight glycemic control (HbA_1c intergroup range 7.2–8.0%) were randomized by block design across four experimental groups: sedentary controls (n = 12), aerobic exercise (n = 11), isokinetic strength (n = 11), or the combination of aerobic–isokinetic strength training (n = 11). Patients randomized to training groups exercised 3× per week for 12 weeks, whereas patients randomized to the sedentary control group received standard of care. To minimize attention and educational bias, all patients attended a 12-session health promotion educational series. At baseline, immediately following intervention, and again at 12-week post-intervention, detailed nerve conduction studies were conducted as a primary outcome measure. At these same intervals, all patients completed as secondary measures quantitative sensory testing, symptom-limited treadmill stress tests, and a Short-Form 36-Veterans Questionnaire (SF-36V).

Results: Of the 45 patients randomized into this study, 37 (82%) had absent sural nerve responses, 19 (42%) had absent median sensory nerve responses, and 17 (38%) had absent ulnar sensory nerve responses. By comparison, responses from tibial nerves were absent in only three (7%) subjects while responses from peroneal nerves were absent in five (11%) subjects. Eleven (92%) of 12 patients that had volunteered to be biopsied exhibited abnormal levels of epidermal nerve fiber densities. Exercise, regardless of type, did not alter sensory or motor nerve electrodiagnostic findings among those patients exhibiting measurable responses (ANOVA). There was, however, a modest (p = 0.01) beneficial effect of exercise on sensory nerve function (Fisher’s Exact Test). Importantly, the beneficial effect of exercise on sensory nerve function was enhanced (p = 0.03) during the post-intervention interval. In addition, three of six patients that had undergone exercise intervention exhibited a marked 1.9 ± 0.3-fold improvement in epidermal nerve fiber density. By comparison, none of three sedentary patients whom agreed to be biopsied a second time showed improvement in epidermal nerve fiber density. Compared to baseline values within groups, and compared with sedentary values across groups, neither aerobic, isokinetic strength, or the combination of aerobic–isokinetic strength exercise intervention altered peak oxygen uptake. Patients that underwent aerobic or the combined aerobic–isokinetic strength exercise intervention, however, demonstrated an increase in treadmill test duration that was sustained over the 12-week post-intervention period.

Conclusion: A 12-week course of physical exercise, regardless of type, does not alter sensory or motor nerve electrodiagnostic findings. In a subset of patients, a short-term structured program of aerobic exercise may selectively improve sensory nerve fiber function. Large-scale exercise lifestyle intervention trials are warranted to further evaluate the impact of aerobic exercise on sensory nerve fiber function in diabetic neuropathic patients.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier NCT00955201.

Patterns of Nerve Conduction Abnormalities in Patients with Type 2 Diabetes Mellitus According to the Clinical Phenotype Determined by the Current Perception Threshold

BACKGROUND

Clinical manifestations of diabetic peripheral neuropathy (DPN) vary along the course of nerve damage. Nerve conduction studies (NCS) have been suggested as a way to confirm diagnoses of DPN, but the results have limited utility for evaluating clinical phenotypes. The current perception threshold (CPT) is a complementary method for diagnosing DPN and assessing DPN symptoms. We compared NCS variables according to clinical phenotypes determined by CPT measurements.

METHODS

We retrospectively enrolled patients with type 2 diabetes mellitus who underwent both NCS and CPT tests using a neurometer. CPT grades were used to determine the clinical phenotypes of DPN: normoesthesia (0 to 1.66), hyperesthesia (1.67 to 6.62), and hypoesthesia/anesthesia (6.63 to 12.0). The Michigan Neuropathy Screening Instrument (MNSI) was used to determine a subjective symptom score. DPN was diagnosed based on both patient symptoms (MNSI score ≥3) and abnormal NCS results.

RESULTS

A total of 202 patients (117 men and 85 women) were included in the final analysis. The average age was 62.6 years, and 71 patients (35.1%) were diagnosed with DPN. The CPT variables correlated with MNSI scores and NCS variables in patients with diabetes. Linear regression analyses indicated that hypoesthesia was associated with significantly lower summed velocities and sural amplitudes and velocities, and higher summed latencies, than normoesthesia. Sural amplitude was significantly lower in patients with hyperesthesia than in patients with normoesthesia.

CONCLUSION

NCS variables differed among patients with diabetes according to clinical phenotypes based on CPT and decreased sural nerve velocities was associated with hyperesthesia.

Convergence of non-communicable diseases and tuberculosis: a two-way street?

The intersection of tuberculosis (TB) with non-communicable diseases (NCDs), including diabetes mellitus (DM), chronic lung disease (CLD), and cardiovascular disease (CVD), has emerged as a critical clinical and public health challenge. Rapidly expanding NCD epidemics threaten TB control in low- and middle-income countries, where the prevention and treatment of TB disease remain a great burden. However, to date, the notion that TB may adversely impact NCD risk and severity has not been well explored. This review summarizes biomedical hypotheses, findings from animal models, and emerging epidemiologic data related to the progression of DM, CLD and CVD during and after active TB disease. We conclude that there is sufficient empirical evidence to justify a greater research emphasis on the syndemic interaction between TB and NCD.

Update on the Management of Diabetic Neuropathy

IN BRIEF Distal symmetric polyneuropathy (DSPN) and diabetic autonomic neuropathies, particularly cardiovascular autonomic neuropathy (CAN), are prevalent diabetes complications with high morbidity, mortality, and amputation risks. The diagnosis of DSPN is principally a clinical one based on the presence of typical symptoms combined with symmetrical, distal-to-proximal stocking-glove sensory loss. CAN is an independent risk factor for cardiovascular mortality, arrhythmia, silent ischemia, major cardiovascular events, and myocardial dysfunction. Screening for CAN in high-risk patients is recommended. Symptoms of gastroparesis are nonspecific and do not correspond with its severity. Diagnosis of gastroparesis should exclude other factors well documented to affect gastric emptying such as hyperglycemia, hypoglycemia, and certain medications. There is a lack of treatment options targeting the neuropathic disease state. Managing neuropathic pain also remains a challenge. Given the high risk of addiction, abuse, psychosocial issues, and mortality, opioids are not recommended as first-, second-, or third-line agents for treating painful DSPN.

Usefulness of the vibration perception thresholds measurement as a diagnostic method for diabetic peripheral neuropathy: Results from the Rio de Janeiro type 2 diabetes cohort study

AIMS

To investigate the associated factors with the vibration threshold perception (VPT) in patients with type 2 diabetes and to assess whether it is useful for detection of diabetic peripheral neuropathy (DPN).

METHODS

VPTs were measured with Vibration Sensory Analyzer (VSA-3000) in 426 diabetic patients. The diagnosis of DPN was based on Neuropathy Symptom Score and Neuropathy Disability Score (NDS). ROC curve analysis and multiple linear and logistic regressions were performed to investigate the associations between VPT and DPN.

RESULTS

Values of VPT were progressively higher according to NDS stages. Age, height, diabetes duration, and mean cumulative HbA_1c exposure (partial correlation coefficients: 0.34; 0.27; 0.10; and 0.13; respectively) were the variables independently associated with VPT. Area under ROC curve of VPT for detection of DPN was 0.71 (95% CI: 0.66-0.75) and >8.9 μm was its best cut-off value. VPT, age, female sex, height, diabetes duration and mean HbA_1c levels were the independent correlates of the presence of DPN. An increased VPT triplicate the likelihood of having DPN (OR: 3.24; 95% CI: 2.05-5.11).

CONCLUSIONS

VPT, measured by an automatic device, shares common correlates with DPN and is strongly associated with its presence. VPT testing may be useful as a screening tool for DPN assessment.

Diagnosing Diabetic Neuropathy: Something Old, Something New

There are potentially many ways of assessing diabetic peripheral neuropathy (DPN). However, they do not fulfill U.S. Food and Drug Administration (FDA) requirements in relation to their capacity to assess therapeutic benefit in clinical trials of DPN. Over the past several decades symptoms and signs, quantitative sensory and electrodiagnostic testing have been strongly endorsed, but have consistently failed as surrogate end points in clinical trials. Therefore, there is an unmet need for reliable biomarkers to capture the onset and progression and to facilitate drug discovery in DPN. Corneal confocal microscopy (CCM) is a non-invasive ophthalmic imaging modality for in vivo evaluation of sensory C-fibers. An increasing body of evidence from multiple centers worldwide suggests that CCM fulfills the FDA criteria as a surrogate endpoint of DPN.

A curcumin derivative J147 ameliorates diabetic peripheral neuropathy in streptozotocin (STZ)-induced DPN rat models through negative regulation AMPK on TRPA1

PURPOSE

To investigate the specific molecular mechanisms and effects of curcumin derivative J147 on diabetic peripheral neuropathy (DPN).

METHODS

We constructed streptozotocin (STZ)-induced DPN rat models to detected mechanical withdrawal threshold (MWT) in vivo using Von Frey filaments. In vitro, we measured cell viability and apoptosis, adenosine 5'-monophosphate-activated protein kinase (AMPK) and transient receptor potential A1 (TRPA1) expression using MTT, flow cytometry, qRT-PCR and western blot. Then, TRPA1 expression level and calcium reaction level were assessed in agonist AICAR treated RSC96cells.

RESULTS

The results showed that J147reduced MWT in vivo, increased the mRNA and protein level of AMPK, reduced TRPA1 expression and calcium reaction level in AITCR treated RSC96 cells, and had no obvious effect on cell viability and apoptosis. Besides, AMPK negative regulated TRPA1 expression in RSC96 cells.

CONCLUSIONS

J147 could ameliorate DPN via negative regulation AMPK on TRPA1 in vivo and in vitro. A curcumin derivative J147might be a new therapeutic potential for the treatment of DPN.

Diabetes and obesity are the main metabolic drivers of peripheral neuropathy

Objective

To determine the associations between individual metabolic syndrome (MetS) components and peripheral neuropathy in a large population‐based cohort from Pinggu, China.

Methods

A cross‐sectional, randomly selected, population‐based survey of participants from Pinggu, China was performed. Metabolic phenotyping and neuropathy outcomes were performed by trained personnel. Glycemic status was defined according to the American Diabetes Association criteria, and the MetS using modified consensus criteria (body mass index instead of waist circumference). The primary peripheral neuropathy outcome was the Michigan Neuropathy Screening Instrument (MNSI) examination. Secondary outcomes were the MNSI questionnaire and monofilament testing. Multivariable models were used to assess for associations between individual MetS components and peripheral neuropathy. Tree‐based methods were used to construct a classifier for peripheral neuropathy using demographics and MetS components.

Results

The mean (SD) age of the 4002 participants was 51.6 (11.8) and 51.0% were male; 37.2% of the population had normoglycemia, 44.0% prediabetes, and 18.9% diabetes. The prevalence of peripheral neuropathy increased with worsening glycemic status (3.25% in normoglycemia, 6.29% in prediabetes, and 15.12% in diabetes, P < 0.0001). Diabetes (odds ratio [OR] 2.60, 95% CI 1.77–3.80) and weight (OR 1.09, 95% CI 1.02–1.18) were significantly associated with peripheral neuropathy. Age, diabetes, and weight were the primary splitters in the classification tree for peripheral neuropathy.

Interpretation

Similar to previous studies, diabetes and obesity are the main metabolic drivers of peripheral neuropathy. The consistency of these results reinforces the urgent need for effective interventions that target these metabolic factors to prevent and/or treat peripheral neuropathy.

Hearing Loss in Type 2 Diabetes in Association with Diabetic Neuropathy

BACKGROUND

Reports assessing hearing abnormalities in diabetes are debated. We aimed to evaluated auditory alterations and their possible associations with vascular and neurological dysfunction in 160 Type 2 diabetes mellitus individuals and 100 age and sex-matched healthy controls.

METHODS

Participants underwent pure tone audiometry (PTA). Associations with demographic, metabolic and neuropathic variables were assessed.

RESULTS

Compared with healthy controls, diabetic patients had higher mean hearing thresholds at each frequency, with statistical significance at 2-8 kHz (p <0.05). Prevalence of hearing loss in diabetics was 67.5% (108/160), including high-frequency (72.22%, 78/108), and low/mid- and high-frequency (27.78%, 30/108). The mild hearing loss was predominant in diabetics with high-frequency impairment (52.56%), while the moderate/severe hearing loss was high in individuals with both low-and high-frequency hearing loss (80.00%). Multiple logistic regression analysis of PTA parameters showed that higher Semmes Weinstein Monofilament (OR 1.24, 95% CI 1.02-1.52), Michigan Neuropathy Screening Instrument score (OR 1.38, 95% CI 1.14-1.68), and vibration perception threshold (OR 1.19, 95% CI 1.05-1.34) were independent risk factors for hearing impairment in diabetics after adjusting for potential covariates.

CONCLUSIONS

These findings suggest that hearing loss is common in T2DM subjects, with predominantly high frequency involved. Diabetic neuropathic factors may explain the underlying mechanism of the association between diabetes and hearing loss.

IVIg for apparently autoimmune small-fiber polyneuropathy: first analysis of efficacy and safety

OBJECTIVES

Small-fiber polyneuropathy (SFPN) has various underlying causes, including associations with systemic autoimmune conditions. We have proposed a new cause; small-fiber-targeting autoimmune diseases akin to Guillain-Barré and chronic inflammatory demyelinating polyneuropathy (CIDP). There are no treatment studies yet for this 'apparently autoimmune SFPN' (aaSFPN), but intravenous immunoglobulin (IVIg), first-line for Guillain-Barré and CIDP, is prescribed off-label for aaSFPN despite very high cost. This project aimed to conduct the first systematic evaluation of IVIg's effectiveness for aaSFPN.

METHODS

With IRB approval, we extracted all available paper and electronic medical records of qualifying patients. Inclusion required having objectively confirmed SFPN, autoimmune attribution and other potential causes excluded. IVIg needed to have been dosed at ⩾1 g/kg/4 weeks for ⩾3 months. We chose two primary outcomes - changes in composite autonomic function testing (AFT) reports of SFPN and in ratings of pain severity - to capture objective as well as patient-prioritized outcomes.

RESULTS

Among all 55 eligible patients, SFPN had been confirmed by 3/3 nerve biopsies, 62% of skin biopsies, and 89% of composite AFT. Evidence of autoimmunity included 27% of patients having systemic autoimmune disorders, 20% having prior organ-specific autoimmune illnesses and 80% having ⩾1/5 abnormal blood-test markers associated with autoimmunity. A total of 73% had apparent small-fiber-restricted autoimmunity. IVIg treatment duration averaged 28 ± 25 months. The proportion of AFTs interpreted as indicating SFPN dropped from 89% at baseline to 55% (p ⩽ 0.001). Sweat production normalized (p = 0.039) and the other four domains all trended toward improvement. Among patients with pre-treatment pain ⩾3/10, severity averaging 6.3 ± 1.7 dropped to 5.2 ± 2.1 (p = 0.007). Overall, 74% of patients rated themselves 'improved' and their neurologists labeled 77% as 'IVIg responders'; 16% entered remissions that were sustained after IVIg withdrawal. All adverse events were expected; most were typical infusion reactions. The two moderate complications (3.6%) were vein thromboses not requiring discontinuation. The one severe event (1.8%), hemolytic anemia, remitted after IVIg discontinuation.

CONCLUSION

These results provide Class IV, real-world, proof-of-concept evidence suggesting that IVIg is safe and effective for rigorously selected SFPN patients with apparent autoimmune causality. They provide rationale for prospective trials, inform trial design and indirectly support the discovery of small-fiber-targeting autoimmune/inflammatory illnesses.