The spectrum of diabetic neuropathies

Advancing the Diagnosis of Diabetic Neuropathies: Electrodiagnostic and Skin Autofluorescence Methods

INTRODUCTION

Diabetic neuropathy (DN) is a generic term for various neuropathies coexisting in a single patient. Clinical diagnosis alone can be misleading, yet routine electrodiagnostic studies in diabetes care are rare. Skin autofluorescence (SAF) is a recognized DN risk factor with potential screening value. This article highlights the diagnostic challenges and raises awareness of the often underdiagnosed neuropathic conditions in diabetes patients.

MATERIAL AND METHODS

We present common entrapment neuropathy cases from our diabetes clinic's electrodiagnosis laboratory in Iași, Romania. We selected seven type 2 diabetes patients with sensory or sensory-motor distal polyneuropathy and atypical DN presentations investigated through electroneurography (ENG) and electromyography (EMG) with the Neurosoft® EMG instrument and SAF measured by standard procedures. Subsequently, a narrative literature review was conducted.

RESULTS

Entrapment neuropathies were diagnosed in all the patients: three carpal tunnel syndromes, two ulnar neuropathies (one proximal, one distal), one peroneal neuropathy, and one case of meralgia paresthetica. The lower-limb cases showed radiculoplexopathy, and there was one case of superficial radial nerve neuropathy. The SAF values ranged from 2.5 AU to 3.4 AU.

CONCLUSIONS

Electrodiagnosis is essential for detecting focal neuropathies in patients with sensory-motor distal polyneuropathy. Elevated SAF levels may correlate with symptom severity, although further research, including large cohorts, is needed.

Incidence of Upper Extremity Neuropathies at a Single Tertiary Care Institution in the United States: Trends in Recent Years, Including the COVID-19 Pandemic

OBJECTIVE

This study examined trends in upper extremity (UE) neuropathies at a large urban tertiary care center in the Northeastern United States over the past five years, including the period of the COVID-19 pandemic.

METHOD

A retrospective medical record review was conducted from 2018 to 2022. We collected data from unique patient records identified using International Classification of Diseases, Tenth Revision (ICD-10) codes for UE neuropathies. We characterized subjects by age, demographics, and duration of symptoms.  Results: This study included 288 pediatric patients and 51,997 adult patients newly diagnosed with UE neuropathy. Most patients were aged 55+; 0.4% of all patients diagnosed with UE neuropathy were children. Across all ages, there was an overall increase in UE neuropathy diagnoses in the past five years, with the most noticeable increases from 2018 to 2019 (+5,761 diagnosed individuals, or +122%) and from 2020 to 2021 (+2,769 diagnosed individuals, or +28.8%).

CONCLUSION

Our institution's UE neuropathy diagnoses have increased in the past five years. Of note, there was a significantly increased rate of UE neuropathy diagnoses from 2020 to 2021. This increase coincides with the COVID-19 pandemic, which is leading to a changing environment for many Americans. These societal changes will likely become indelible after the pandemic; safety practices should be enacted to avoid these debilitating neuropathies.

Effective constituents and protective effect of Mudan granules against Schwann cell injury

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes. Mudan granules (MD) is a Chinese patent medicine for treating DPN, which is composed of nine Chinese medicinal herbs, including the radix of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao or Astragalus membranaceus (Fisch.) Bge. (Huangqi in Chinese), rhizome of Corydalis yanhusuo W.T. Wang (Yanhusuo), radix and rhizome of Panax notoginseng (Burk.) F. H. Chen (Sanqi), radix of Paeonia lactiflora Pall. or Paeonia veitchii Lynch (Chishao), radix and rhizome of Salvia miltiorrhiza Bge. (Danshen), rhizome of Ligusticum chuanxiong Hort. (Chuanxiong), flowers of Carthamus tinctorius L. (Honghua), lignum of Caesalpinia sappan L. (Sumu), and caulis of Spatholobus suberectus Dunn (Jixueteng). MD was reported to have a protective effect on Schwann cell (SC) that is considered as an important therapeutic target of DPN. However, the constituents of MD have not been reported, and the effective constituents and protective pathways for MD against SC injury remain unclear.

AIM OF THE STUDY

This study aimed to identify the constituents in MD, and to investigate the effective constituents and protective pathways of MD against high-glucose/lipid injury in SC.

MATERIALS AND METHODS

The chemical constituents of MD were identified using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). Protective effect and effective constituents screening were performed in an in vitro SC injury model induced by high glucose and lipid levels. The protective pathways of MD and its effective constituents were investigated by western blotting assay of related proteins.

RESULTS

A total of 136 constituents were identified in MD. MD downregulated the phosphorylation of extracellular-regulated protein kinases 1/2 (ERK1/2) and expression of cyclooxygenase-2 (COX-2) and upregulated the expression of sirtuin 2 (SIRT2). Seven effective constituents were screened out, including three from Sanqi [20(R)-ginsenoside Rh2, 20(S)-ginsenoside Rh2, and ginsenoside Rk3], one from Huangqi (astragaloside II), one from Danshen (danshensu), and two from Chuanxiong (chlorogenic and cryptochlorogenic acid). Six of the seven compounds, excluding danshensu, inhibited the phosphorylation of ERK1/2. Both astragaloside II and chlorogenic acid upregulated the expression of SIRT2, and cryptochlorogenic acid and danshensu downregulated the expression of COX-2.

CONCLUSIONS

The constituents of MD were firstly identified, and seven effective constituents were found. MD can protect SC against high-glucose and -lipid injury by downregulating ERK1/2 phosphorylation and COX-2 expression and upregulating SIRT2 expression. Seven effective constituents regulated the expression of these proteins. This study presented an important advance toward elucidating the chemical constituents, and the effective constituents and protective pathways of MD against high-glucose/lipid injury in SC, which is very helpful for investigating the action mechanism of MD on treating DPN, and could ultimately inform the development of effective quality control procedures for MD production.

Electroacupuncture alleviates streptozotocin-induced diabetic neuropathic pain via suppressing phosphorylated CaMKIIα in rats

Diabetic neuropathic pain (DNP) is a frequent complication of diabetes. Calcium/calmodulin-dependent protein kinase II α (CaMKIIα), a multi-functional serine/threonine kinase subunit, is mainly located in the surface layer of the spinal cord dorsal horn (SCDH) and the primary sensory neurons in dorsal root ganglion (DRG). Numerous studies have indicated electroacupuncture (EA) takes effect in various kinds of pain. In this research, we explored whether CaMKIIα on rats' SCDH and DRG participated in DNP and further explored the mechanisms underlying the analgesic effects of EA. The DNP model in rats was successfully established by intraperitoneal injection of streptozotocin. Certain DNP rats were treated with intrathecal injections of KN93, a CaMKII antagonist, and some of the DNP rats received EA intervention. The general conditions, behaviors, the expressions of CaMKIIα and phosphorylated CaMKIIα (p-CaMKIIα) were evaluated. DNP rats' paw withdrawal threshold was reduced and the expressions of p-CaMKIIα in SCDH and DRG were upregulated compared with the Normal group, while the level of CaMKIIα showed no significance. KN93 attenuated DNP rats' hyperalgesia and reduced the expressions of p-CaMKIIα. We also found EA attenuated the hyperalgesia of DNP rats and reduced the expressions of p-CaMKIIα. The above findings suggest that p-CaMKIIα in SCDH and DRG is involved in DNP. The analgesic effect of EA in DNP might be related to the downregulation of p-CaMKIIα expression level. Our study further supports that EA can be an effective clinical treatment for DNP.

Focal inflammatory neuropathies

This chapter focuses on neuropathies that present with focal involvement of nerve roots, plexus, and/or peripheral nerves associated with autoimmune and inflammatory mechanisms that present with focal involvement of nerve roots, plexus and/or peripheral nerves. The clinical presentation, diagnosis, and treatment of focal autoimmune demyelinating neuropathies, focal nonsystemic vasculitic disorders (diabetic and nondiabetic radiculoplexus neuropathies, postsurgical inflammatory neuropathy, and neuralgic amyotrophy), and focal neuropathies associated with sarcoidosis and bacterial and viral infections are reviewed.

The Functional Role of microRNAs and mRNAs in Diabetic Kidney Disease: A Review

Diabetes is a group of diseases marked by poor control of blood glucose levels. Diabetes mellitus (DM) occurs when pancreatic cells fail to make insulin, which is required to keep blood glucose levels stable, disorders, and so on. High glucose levels in the blood induce diabetic effects, which can cause catastrophic damage to bodily organs such as the eyes and lower extremities. Diabetes is classified into many forms, one of which is controlled by hyperglycemia or Diabetic Kidney Disease (DKD), and another that is not controlled by hyperglycemia (nondiabetic kidney disease or NDKD) and is caused by other factors such as hypertension, hereditary. DKD is associated with diabetic nephropathy (DN), a leading cause of chronic kidney disease (CKD) and end-stage renal failure. The disease is characterized by glomerular basement membrane thickening, glomerular sclerosis, and mesangial expansion, resulting in a progressive decrease in glomerular filtration rate, glomerular hypertension, and renal failure or nephrotic syndrome. It is also represented by some microvascular complications such as nerve ischemia produced by intracellular metabolic changes, microvascular illness, and the direct impact of excessive blood glucose on neuronal activity. Therefore, DKD-induced nephrotic failure is worse than NDKD. MicroRNAs (miRNAs) are important in the development and progression of several diseases, including diabetic kidney disease (DKD). These dysregulated miRNAs can impact various cellular processes, including inflammation, fibrosis, oxidative stress, and apoptosis, all of which are implicated during DKD. MiRNAs can alter the course of DKD by targeting several essential mechanisms. Understanding the miRNAs implicated in DKD and their involvement in disease development might lead to identifying possible therapeutic targets for DKD prevention and therapy. Therefore, this review focuses specifically on DKD-associated DN, as well as how in-silico approaches may aid in improving the management of the disease.

Ultrasound assessment of the brachial plexus nerve root cross-sectional areas in asymptomatic patients with type 2 diabetes

Type 2 diabetes mellitus (T2D) is one of the most common metabolic diseases and is often associated with cervical radiculoplexus neuropathies. Magnetic resonance imaging is the modality of choice for evaluating the brachial plexus, however, the use of ultrasound for its evaluation has increased and has been shown to be an additional reliable method. We aimed to compare the cross-sectional areas of the C5, C6, and C7 nerve roots of the brachial plexus, at the interscalene groove, in asymptomatic patients with T2D to that of an asymptomatic control cohort without T2D. A total of 25 asymptomatic patients with T2D were recruited from outpatient clinics. A total of 18 asymptomatic subjects without T2D were also recruited from hospital staff volunteers to form the control cohort. High-resolution ultrasound imaging of the bilateral C5, C6, and C7 nerve roots of the brachial plexus was performed in the short axis, at the level of the interscalene grooves. The nerve root cross-sectional areas were recorded and compared. In the patients with T2D, HbA1c and fasting blood glucose (FBG) levels were obtained as well as the duration of T2D in years and correlated with cross-sectional areas. The cross-sectional areas of C6 and C7 were significantly smaller in the T2D cohort. Additionally, HbA1c, and FBG levels as well as the duration of T2D were negatively correlated with the C5, C6, and C7 cross-sectional areas. Our study demonstrated smaller brachial plexus nerve root cross-sectional areas in asymptomatic patients with T2D which negatively correlated with HbA1c, and FBG levels as well as the duration of T2D.

Diabetes mellitus-related musculoskeletal disorders: Unveiling the cluster of diseases

The current study ushers in a comprehensive review in clinical research to demonstrate the prevalence of musculoskeletal (MSK) complications in diabetes mellitus and the most relevant clinical aspects. In particular, revealing the early symptoms of the disorders, the pathology lurking behind the complications and their optimal management. In diabetes mellitus, MSK complications are common and are largely due to similar pathogenetic factors responsible for the internal organ complications associated with diabetes leading to chronic low-intensity inflammatory processes. MSK disorders develop by vasculopathy, neuropathy, arthropathy or combinations of the above, which are not specific to diabetes. However, their prevalence is significantly increased in diabetes and contributes to the disability impairing patients' quality of life. Locomotor disease affects approximately 34.4-83.5 % of patients suffering from type-2 diabetes mellitus. Several musculoskeletal abnormalities (cheiroarthropathy, Dupuytren's contracture, trigger finger, ect.) can be diagnosed upon physical examination, although certain symptoms (frozen shoulder, neurogenic arthropathy, septic arthritis, etc.) require differential diagnostic considerations. Early identification regarding characteristic symptoms in the treatment reducing inflammation and pain, followed with increasingly strenuous exercise therapy, aligned with optimal management of carbohydrate metabolism, proves essential in alleviating MSK complications.

Cerebrolysin provides effective protection on high glucose-induced neuropathy in cultured rat dorsal root ganglion neurons

Cerebrolysin, an endogenous peptide with neuroprotective and neurotrophic properties, indicated to be beneficial on diabetic neuropathy by preliminary clinical and experimental studies but without evidence on central or peripheral action. Dorsal root ganglion (DRG) neurons, based on involvement of pain sensation in both health and disease as first relay centers for transmission and processing of peripheral nociceptive sensory signals, was used to investigate possible effects of Cerebrolysin on high glucose-induced neuropathy, as model. DRG's were obtained from adult rats and the isolated neurons were seeded on E-Plate®'s equipped with gold microelectrodes, and incubated in culture media in a CO2 incubator at 37 C. DRGs were exposed to high glucose (50 mM) in the absence and presence of different concentrations of Cerebrolysin ® (2-40 mg/ml). Cell index (derived from cell viability and neurite outgrowth) was recorded with Real-Time Cell Analyzer and was used as primary outcome measure. High glucose-induced cellular neuropathy and neuroprotective effects of Cerebrolysin was evaluated from area under the curve (AUC) of cell index-time graphs. Exposure of DRG neurons to high glucose caused a rapid and persistent decrease in the mean AUC values compared to normoglycemic controls. Co-treatment with Cerebrolysin (40 mg/ml) attenuated this high glucose-induced effect in a concentration-dependent manner. In normoglycemic conditions, treatment with Cerebrolysin caused a dose-dependent increase in the mean AUC values. Cerebrolysin treatment resulted in maintenance of the functional integrity, survival, and promotion of neurite outgrowth of the cultured DRG neurons exposed to high glucose, indicating involvement of peripheral sensory neurons.

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.

Diabetic neuropathy: Past, present, and future

Background

A sedentary lifestyle and an unhealthy diet have considerably increased the incidence of diabetes mellitus worldwide in recent decades, which has generated a high rate of associated chronic complications.

Methods

A narrative review was performed in MEDLINE, EMBASES and SciELO databases, including 162 articles.

Results

Diabetic neuropathy (DN) is the most common of these complications, mainly producing two types of involvement: sensorimotor neuropathy, whose most common form is symmetric distal polyneuropathy, and autonomic neuropathies, affecting the cardiovascular, gastrointestinal, and urogenital system. Although hyperglycemia is the main metabolic alteration involved in its genesis, the presents of obesity, dyslipidemia, arterial hypertension, and smoking, play an additional role in its appearance. In the pathophysiology, three main phenomena stand out: oxidative stress, the formation of advanced glycosylation end-products, and microvasculature damage. Diagnosis is clinical, and it is recommended to use a 10 g monofilament and a 128 Hz tuning fork as screening tools. Glycemic control and non-pharmacological interventions constitute the mainstay of DN treatment, although there are currently investigations in antioxidant therapies, in addition to pain management.

Conclusions

Diabetes mellitus causes damage to peripheral nerves, being the most common form of this, distal symmetric polyneuropathy. Control of glycemia and comorbidities contribute to prevent, postpone, and reduce its severity. Pharmacological interventions are intended to relieve pain.

Axonal transport deficits in the pathogenesis of diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is a chronic and prevalent metabolic disease that gravely endangers human health and seriously affects the quality of life of hyperglycemic patients. More seriously, it can lead to amputation and neuropathic pain, imposing a severe financial burden on patients and the healthcare system. Even with strict glycemic control or pancreas transplantation, peripheral nerve damage is difficult to reverse. Most current treatment options for DPN can only treat the symptoms but not the underlying mechanism. Patients with long-term diabetes mellitus (DM) develop axonal transport dysfunction, which could be an important factor in causing or exacerbating DPN. This review explores the underlying mechanisms that may be related to axonal transport impairment and cytoskeletal changes caused by DM, and the relevance of the latter with the occurrence and progression of DPN, including nerve fiber loss, diminished nerve conduction velocity, and impaired nerve regeneration, and also predicts possible therapeutic strategies. Understanding the mechanisms of diabetic neuronal injury is essential to prevent the deterioration of DPN and to develop new therapeutic strategies. Timely and effective improvement of axonal transport impairment is particularly critical for the treatment of peripheral neuropathies.

The relationship between vascular endothelial growth factor-A serum level and the severity of diabetic peripheral neuropathy

Background and aims

Diabetic peripheral neuropathy (DPN) is a common microvascular complication in type 2 diabetes mellitus (T2DM). The nerve fibers injury is caused by the interaction between metabolic and vascular factors. Vascular endothelial growth factor (VEGF) is an essential growth factor for vascular endothelial cells. We aimed to investigate the relation between VEGF-A serum level and the degree of DPN.

Results

This cross-sectional study was conducted on 81 patients with T2DM. Based on the combined clinical and electrophysiological assessment, 67 patients (82.7%) were diagnosed with peripheral neuropathy of which 32 patients (39.5%) had subclinical neuropathy, whereas 35 patients (43.2%) were confirmed cases of DPN. Patients with DPN had longer duration of DM and higher values of glycosylated hemoglobin (HbA1c). Although the mean serum VEGF-A level in diabetic patients without neuropathy was higher than that in diabetic patients with DPN, this difference did not reach statistical significance (P = 0.07). However, patients with subclinical DPN had significantly higher serum VEGF-A level compared to patients with confirmed DPN (P < 0.001).

Conclusion

DPN was found to be a common finding in the studied sample of T2DM patients. Longer duration of DM and poor glycemic control may be risk factors for development of severe DPN. Low VEGF-A serum levels may lead to more severe DPN in patients with T2DM.

Type 2 diabetes mellitus, physical activity, and neuromusculoskeletal complications

Objectives

The objectives of the study were to investigate the neuromusculoskeletal complications of Type 2 diabetes mellitus (T2DM) and their associated factors, including the level of physical activity (PA) and clinicodemographic characteristics.

Materials and Methods

In this cross-sectional analysis, we included 370 participants diagnosed with T2DM for no <1 year who satisfied the inclusion and exclusion criteria. Demographic and clinical characteristics were noted and a thorough clinical examination was performed on all the participants. International PA Questionnaire-Short Form was used to evaluate the level of PA of the participants. The continuous data is presented as mean ± SD and the categorical data is presented as the number of participants (n) and percentage (%). A logistic regression model was used to investigate the predictors for the prevalence of the complications.

Results

The mean duration of T2DM was 7.32 ± 5.53 years and the mean hemoglobin A1C (HbA1c) level (%) was 8.16±1.67. A majority of the participants were having uncontrolled diabetes with an HbA1c level ≥7.5% (n = 190; 51.35%). The level of PA was low in a substantial proportion of the participants (n = 276; 74.59%). A total of 162 (43.78%) participants were diagnosed with neuromusculoskeletal complications. Low back pain was the most common complication and degenerative disk disease was the most common diagnosis overall. Longer duration of diabetes, poor glycemic control, and low PA were associated with the prevalence of neuromusculoskeletal complications (P < 0.05).

Conclusion

Neuromusculoskeletal complications of T2DM are common and can result in significant disability in this population. Low PA is very common among T2DM patients and an important contributor to the development of complications. Health-care providers should consider PA an integral component of the management protocol for T2DM patients.

Neuronal Inflammation is Associated with Changes in Epidermal Innervation in High Fat Fed Mice

Peripheral neuropathy (PN), a debilitating complication of diabetes, is associated with obesity and the metabolic syndrome in nondiabetic individuals. Evidence indicates that a high fat diet can induce signs of diabetic peripheral PN in mice but the pathogenesis of high fat diet-induced PN remains unknown. PURPOSE: Determine if neuronal inflammation is associated with the development of mechanical hypersensitivity and nerve fiber changes in high fat fed mice. METHODS: Male C57Bl/6 mice were randomized to a standard (Std, 15% kcal from fat) or high fat diet (HF, 54% kcal from fat) for 2, 4, or 8 weeks (n = 11-12 per group). Lumbar dorsal root ganglia were harvested and inflammatory mediators (IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, IL-12p70, IL-17, MCP-1, IFN-γ, TNF-α, MIP-1α, GMCSF, RANTES) were quantified. Hindpaw mechanical sensitivity was assessed using the von Frey test. Intraepidermal nerve fiber density (IENFD) and TrkA nerve fiber density were quantified via immunohistochemistry. RESULTS: After 8 weeks, HF had greater body mass (33.3 ± 1.0 vs 26.7 ± 0.5 g, p < 0.001), fasting blood glucose (160.3 ± 9.4 vs 138.5 ± 3.4 mg/dl, p < 0.05) and insulin (3.58 ± 0.46 vs 0.82 ± 0.14 ng/ml, p < 0.001) compared to Std. IL-1α, RANTES and IL-5 were higher in HF compared to Std after 2 and 4 weeks, respectively (IL-1α: 4.8 ± 1.3 vs 2.9 ± 0.6 pg/mg, p < 0.05; RANTES: 19.6 ± 2.2 vs 13.3 ± 1.2 pg/mg p < 0.05; IL-5: 5.8 ± 0.7 vs 3.1 ± 0.5 pg/mg, p < 0.05). IENFD and TrkA fiber density were also higher in HF vs Std after 4 weeks (IENFD: 39.4 ± 1.2 vs 32.2 ± 1.3 fibers/mm, p < 0.001; TrkA: 30.4 ± 1.8 vs 22.4 ± 1.3 fibers/mm). There were no significant differences in hindpaw sensitivity for Std vs HF. CONCLUSION: Increased inflammatory mediators preceded and accompanied an increase in cutaneous pain sensing nerve fibers in high fat fed mice but was not accompanied by significant mechanical allodynia. Diets high in fat may increase neuronal inflammation and lead to increased nociceptive nerve fiber density.

Corneal confocal microscopy in patients with distal symmetric polyneuropathy compared to controls

BACKGROUND

Diabetic neuropathy (DN) is a very common clinical condition throughout the world. The diagnostic tests currently recommended have low sensitivity, such as electromyography, or are invasive, such as skin biopsy. New techniques have been developed to identify the early involvement of the peripheral nerve. With the advent of corneal confocal microscopy (CCM), a reduction in corneal innervation in patients with DN has been observed.

OBJECTIVE

To compare, through CCM, diabetic patients with symptomatic distal symmetric polyneuropathy (DSP) and controls.

METHODS

In the present study, through CCM, we compared the morphological changes in the sub-basal epithelial corneal plexus of 35 diabetic patients with symptomatic DSP with 55 controls. Moreover, we sought to determine a pattern of change regarding the severity stages of DSP, comparing the clinical, laboratory, and nerve-conduction (NC) variables.

RESULTS

Differences between the control and diabetic groups were observed for the following variables, respectively: age (44.9 ± 13.24 years versus 57.02 ± 10.4 years; p < 0.001); fiber density (29.7 ± 10.2 versus 16.6 ± 10.2; p < 0.001); number of fibers (4.76 ± 1.30 versus 3.14 ± 1.63; p < 0.001); number of Langerhans cells (4.64 ± 8.05 versus 7.49 ± 10.3; p = 0.035); tortuosity (p < 0.05); and thickness (p < 0.05). Furthermore, inverse relationships were found regarding fiber density and age (p < 0.01) and fiber density and the severity of the disease (p < 0.05). A positive relationship between the conduction velocity of the fibular nerve and fiber density (p < 0.05) was also observed.

CONCLUSION

Corneal confocal microscopy proved to be a fast, noninvasive and reproducible method for the diagnosis, staging, and monitoring of diabetic DSP.

Diabetic lumbosacral plexopathy: an unpredictable clinical entity

PURPOSE

Diabetic plexopathy is among the most unusual and disabling complication type 2 diabetic mellitus (T2DM) causing major suffering among affected individuals. The clinical presentation includes asymmetric muscle atrophy, weakness, and pain, typically associated with sudden weight loss. In part due to its rarity, this condition can be easily missed with serious consequences including potentially fatal complications.

METHODS AND RESULTS

A single case report of a 59-year-old woman with T2DM complicated by a lumbosacral plexopathy that presented with unusual clinical signs, symptoms and metabolic changes including (i) a life-threatening cardiac arrest due to a massive saddle pulmonary embolism (PE) secondary to a lower limb deep venous thrombosis ipsilateral to the plexopathy and (ii) an unexpected partial spontaneous remission of T2DM.

CONCLUSIONS

This case highlights the need for increased awareness and improved investigation and understanding of the pathogenesis and management of diabetic plexopathy, especially in rehabilitation settings for optimizing functional outcomes from rehabilitation input. Implications for rehabilitationDiabetic lumbosacral plexopathy (DLSP) is a distinct cause of neurological impairment requiring rehabilitation with a different natural history and prognosis. Its incidence almost three times higher than that of other common inflammatory neuropathies such as Guillain-Barré.Early recognition of DLSP in order to provide interventions, assessment, and therapeutic strategies in Rehabilitation.Diabetes plexopathy should remain an important consideration in the differential diagnoses when assessing any patient with diabetes presenting with acute pain and weakness in the extremities.

The Contribution of Wnt Signaling to Vascular Complications in Type 2 Diabetes Mellitus

Vascular complications are the leading cause of morbidity and mortality among patients with type 2 diabetes mellitus (T2DM). These vascular abnormalities result in a chronic hyperglycemic state, which influences many signaling molecular pathways that initially lead to increased oxidative stress, increased inflammation, and endothelial dysfunction, leading to both microvascular and macrovascular complications. Endothelial dysfunction represents the initial stage in both types of vascular complications; it represents "mandatory damage" in the development of microvascular complications and only "introductory damage" in the development of macrovascular complications. Increasing scientific evidence has revealed an important role of the Wnt pathway in the pathophysiology of the vascular wall. It is well known that the Wnt pathway is altered in patients with T2DM. This review aims to be an update of the current literature related to the Wnt pathway molecules that are altered in patients with T2DM, which may also be the cause of damage to the vasculature. Both microvascular complications (retinopathy, nephropathy, and neuropathy) and macrovascular complications (coronary artery disease, cerebrovascular disease, and peripheral arterial disease) are analyzed. This review aims to concisely concentrate all the evidence to facilitate the view on the vascular involvement of the Wnt pathway and its components by highlighting the importance of exploring possible therapeutic strategy for patients with T2DM who develop vascular pathologies.

Mechanistic approach towards diabetic neuropathy screening techniques and future challenges: A review

Diabetic neuropathy, also called peripheral diabetic neuropathy (PDN), is among the most significant diabetes health consequences, alongside diabetic nephropathy, diabetic cardiomyopathy and diabetic retinopathy. Diabetic neuropathy is the existence of signs and indications of peripheral nerve damage in patients with diabetes after other causes have been governed out. Diabetic neuropathy is a painful and severe complication of diabetes that affects roughly 20% of people. The development of diabetic neuropathy is regulated by blood arteries that nourish the peripheral nerves and metabolic problems such as increased stimulation of polyol pathway, loss of myo-inositol and enhanced non-enzymatic glycation. It's divided into four types based on where neurons are most affected: autonomic, peripheral, proximal, and focal, with each kind presenting different symptoms like numbing, gastrointestinal disorders, and heart concerns. Pharmacotherapy for neuropathic pain is complex and for many patients, effective treatment is lacking; as a result, scientific proof recommendations are crucial. As a result, the current demand is to give the most vital medications or combinations of drugs that work directly on the nerves to help diabetic neuropathy patients feel less pain without causing any adverse effects. In diabetic neuropathy research, animal models are ubiquitous, with rats and mice being the most typically chosen for various reasons. This review covers the epidemiology, clinical features, pathology, clinical symptom, mechanism of diabetic neuropathy development, diagnosis, screening models of animals, diabetic neuropathy pharmacotherapy.

Diabetic Neuropathic Cachexia: A Clinical Case and Review of Literature

A 46-year-old man was admitted to the surgical department because of abdominal pain and anemia, with the radiological finding of a perforated duodenal ulcer, and underwent laparoscopic surgical treatment. Type 2 diabetes mellitus (T2DM) had been diagnosed 5 years earlier and treated with diet. At clinical investigation, the patient was depressed and anorexic; moreover, he complained of lower extremity weakness and bilateral feet pain, burning in nature and accompanied by allodynia. This painful sensation had been preceded by an 8-month history of fatigue and anorexia with profound weight loss of 35 kg. After clinical evaluation and a nerve conduction study, diagnosis of diabetic cachectic neuropathy was made based on the rapid onset of severe neuropathic pain in the context of diabetic neuropathy, marked weight loss, and depressed mood. The therapy with pregabalin and duloxetine had scarce effect and was gradually discontinued. The patient, however, obtained progressive relief and amelioration of neuropathic lower-limb pain concomitant with weight gain. This clinical trend also confirmed the diagnosis of this rare form of diabetic neuropathy. A few cases of diabetic neuropathic cachexia have been reported in the literature and are briefly reviewed here.

Peripheral Neuropathies Derived from COVID-19: New Perspectives for Treatment

Peripheral neuropathies constitute a group of disorders affecting the peripheral nervous system. Neuropathies have multiple causes such as infections (i.e., COVID-19), diabetes, and nutritional (low vitamin levels), among others. Many micronutrients, such as vitamins (A, C, D, E, B6, B12, and folate), certain minerals (Fe, Mg, Zn, Se, and Cu), and ω-3 fatty acids have immunomodulatory effects. Therefore, they may play an instrumental role in the treatment of COVID-19 infection. However, many COVID-19 patients can undergo neuropathy. In this context, there is a wealth of information on a variety of first-, second-, and third-line treatment options. This review focuses on the application of nutraceutical strategies in order to improve the symptomatology of neuropathy and neuropathic pain in patients that suffered from COVID-19. Our aim is to provide an alternative vision to traditional medical-pharmacological treatment through nutraceuticals.

Fear of falling and functional mobility in Elders with Diabetic Peripheral Neuropathy in Coastal Karnataka, India: A Hospital-Based Study

BACKGROUND

Aging with diabetic neuropathy is likely to predispose people to falls. Despite being a high-risk population, estimates of falls and their associated factors are poorly documented in elderly diabetic neuropathy patients living in coastal Karnataka, India.

OBJECTIVE

To investigate fear of falling and functional mobility, as an approximate measure of clinical fall risk, and explore the associated risk factors in elderly diabetic neuropathy patients living in coastal Karnataka, India.

METHOD

A hospital-based cross-sectional study on 316 elders aged 60 to 80 with diabetic neuropathy was conducted. A detailed diabetic foot evaluation was done. Self-reported fear of fall and functional mobility was measured using the Falls Efficacy Scale- International and Timed Up and Go test, respectively with published cut-points. Additionally, a recall of 12 months of fall history was recorded.

RESULTS

Descriptive analysis showed that self-reported fear of fall and below-average functional mobility was present in 39% and 49% of the elders with diabetic neuropathy, respectively. Spearman's correlational analysis revealed that self-reported fall concerns and functional mobility are significantly interdependent. Regression analysis suggested female gender, the severity of neuropathy, and previous falls as significant modifiers for fear of fall and poor functional mobility.

CONCLUSION

Half of the elders (49%) with diabetic neuropathy have poor functional mobility and 39% have a fear of falling. Improving physical function and addressing fall concerns of elders with diabetic neuropathy can result in greater confidence to participate in everyday activities and contribute to their better health. Hence, early fall risk identification is recommended for providing better health care in these individuals.

Diabetes Ketoacidosis Complicating as Wrist Drop: A Case Report on Acute Motor Neuropathy

Diabetic ketoacidosis (DKA) is an acute and major complication of diabetes mellitus. Neurological complications can be seen at any time during the course of illness and range from decreased consciousness to ischemic or hemorrhagic stroke. Acute neuropathy is very rare in this milieu. Here, we report a case of a 40-year-old patient, who developed a left-sided wrist drop after being treated for DKA. The nerve conduction velocity studies demonstrated decreased action potential amplitude in only the motor component of the left radial nerve. Other possible causes of the complaint were ruled out and the patient was managed with cock-up splint, vitamin B1 and B6 supplementation, and physiotherapy. Despite all these measures, the patient had minimal improvement. Thus, close monitoring of patients is crucial to identify these infirmities, even after the acute condition has resolved.

A Review of Current Trends with Type 2 Diabetes Epidemiology, Aetiology, Pathogenesis, Treatments and Future Perspectives

Type 2 diabetes (T2D), which has currently become a global pandemic, is a metabolic disease largely characterised by impaired insulin secretion and action. Significant progress has been made in understanding T2D aetiology and pathogenesis, which is discussed in this review. Extrapancreatic pathology is also summarised, which demonstrates the highly multifactorial nature of T2D. Glucagon-like peptide (GLP)-1 is an incretin hormone responsible for augmenting insulin secretion from pancreatic beta-cells during the postprandial period. Given that native GLP-1 has a very short half-life, GLP-1 mimetics with a much longer half-life have been developed, which are currently an effective treatment option for T2D by enhancing insulin secretion in patients. Interestingly, there is continual emerging evidence that these therapies alleviate some of the post-diagnosis complications of T2D. Additionally, these therapies have been shown to induce weight loss in patients, suggesting they could be an alternative to bariatric surgery, a procedure associated with numerous complications. Current GLP-1-based therapies all act as orthosteric agonists for the GLP-1 receptor (GLP-1R). Interestingly, it has emerged that GLP-1R also has allosteric binding sites and agonists have been developed for these sites to test their therapeutic potential. Recent studies have also demonstrated the potential of bi- and tri-agonists, which target multiple hormonal receptors including GLP-1R, to more effectively treat T2D. Improved understanding of T2D aetiology/pathogenesis, coupled with the further elucidation of both GLP-1 activity/targets and GLP-1R mechanisms of activation via different agonists, will likely provide better insight into the therapeutic potential of GLP-1-based therapies to treat T2D.

Cardiovascular Pathology – a Factor of the Adverse Course of Diabetic Polyneuropathy

Diabetic polyneuropathy (DP) and angiopathy are interdependent processes, as disturbances in the microcirculatory system of peripheral nerves lead to increased axonal damage and is a kind of predictor of polyneuropathy progressing [6]. 80% of deaths from diabetes mellitus (DM) are associated with cardiovascular catastrophes, including coronary heart disease (CHD), stroke and peripheral artery disease [3]. The objective: to analyze the most common cardiovascular pathology (CVP) and show its impact on the course of DP in type I and II DM. Materials and methods. Was clinically examined 101 patient with DP. The examined patients were divided into groups: with DP on the background of type 1 DM (group I) (n=54) and with DP on the background of type II DM (group II) (n=47), and also were divided into subgroups: DP on the background of type I and II DM and existing CVP (including diabetic angiopathy) 82 (82%) (subgroup А) and with the DP on the background of DM type I and II without CVP – 19 (19%) (subgroup В). Patients were examined to determine the neurological status, were performed laboratory and instrumental methods of examination. Static calculation was performed in MS Excel 2003 and in the programme STATISTICA 10. Results. Regarding to the patients of subgroup А and В we noted the natural predominance of trophic disorders, changes in the reflex sphere and sensitivity in subgroup А. Patients of group II more often than in group I had pathology of the cardiovascular system. Hypertension (HT) and CHD in both cases were registered with a high frequency. In subgroup А there was a combination of several nosologies: from the respiratory, urinary, gastroenterological system (1%), urinary and gastroenterological (3%), gastroenterological and endocrine (2%), urinary and endocrine (1%). In subgroup В diseases of urinary and gastroenterological pathology were found in (5%), gastroenterological (5%), endocrine (11%). The examined patients from group I and with the concomitant CVP have lower linear velocity of blood flow (LVBF) on both tibial arteries, patients in group II – have marginally higher LVBF. Analysis of the results of duplex scanning of lower extremity arteries showed a high incidence of stenosis, in particular the anterior tibial arteries (ATA) up to 30–40%, posterior tibial arteries (PTA) up to 40–50% and occlusion (PTA and femoral, popliteal, tibial segment) in individuals of group I. Conclusions. In patients with DP on the background of type I and II DM and available CVP (subgroup А), the clinical manifestations of polyneuropathy were quite pronounced, especially in the field of trophic disorders, because CVP enhances the ischemia of the microsaceous channel of the peripheral nerves. In addition, persons with concomitant CVP have a wide range of another comorbid pathology, which accelerates the onset of DM complications.

Perspectives of Rehabilitation in Diabetic Neuropathy

Abstract Diabetic Neuropathy (DN) is a complication that affects at least half of the patients with Diabetes Mellitus. Unlike other symptoms and signs that may sooner alarm the patients, DN manifestations tend to be rather silent, and so usually neglected by the patient for a long period of time, which can last for years. Therefore it’s a “hidden complication of diabetes” label. Unfortunately, it is only when symptoms already affect the quality of life that the treatment becomes challenging when it comes to speaking of either etiological, symptomatic or rehabilitation strategies. Early diagnosis can also be tricky while aiming for lifestyle corrections and proper individualized treatment strategies. Rehabilitation methods for DN aim especially towards the improvement of articulation mobility and muscular strength amelioration, the suggested brief review of literature promoting this part of therapy essential for both prevention and amelioration of overall morbidity. Keywords: diabetic neuropathy, physical therapy, interdisciplinary approach, quality of life,

Zein-based nanocarriers for the oral delivery of insulin. In vivo evaluation in Caenorhabditis elegans

The aim was to evaluate the potential of nanocarriers, based on the coating of zein nanoparticles (ZNP) with a Gantrez® AN-PEG conjugate (GP), for the oral delivery of insulin. ZNP-GP displayed less negative surface charge and a 14-fold higher diffusion coefficient in pig intestinal mucus than ZNP. Both nanoparticles showed a spherical shape and an insulin load of 77.5 µg/mg. Under simulated gastric conditions, ZNP-GP released significantly lower amount of insulin than ZNP, while under simulated intestinal conditions, both types of nanoparticles displayed similar behaviour. In Caenorhabditis elegans wild-type N2, grown under high glucose conditions, insulin treatments reduced glucose and fat accumulation without altering the growth rate, the worm length, or the pumping rate. The effect was significantly greater (p < 0.001) when insulin was nanoencapsulated in ZNP-GP compared with that encapsulated in ZNP or formulated in solution. This would be related to the highest capability of ZNP-GP to diffuse in the dense peritrophic-like layer covering intestinal cells in worms. In daf-2 mutants, the effect on fat and glucose reduction by insulin treatment was suppressed, indicating a DAF-2 dependent mechanism. In summary, ZNP-GP is a promising platform that may offer new opportunities for the oral delivery of insulin and other therapeutic proteins.

The impact of diabetic neuropathy on the distal versus proximal comparison of weakness in lower and upper limb muscles of patients with type 2 diabetes mellitus: a cross-sectional study

OBJECTIVES

This study aimed to determine the impact of diabetic neuropathy (dNP) on the distal versus proximal comparison of weakness in lower and upper limb muscles of patients with type 2 Diabetes Mellitus (T2DM).

METHODS

19 healthy male controls without neuropathy (HC) and 35 male T2DM patients, without dNP (n=8), with sensory dNP (n=13) or with sensorimotor dNP (dNPsm; n=14), were enrolled in this study. Maximal isometric (IM) and isokinetic (IK) muscle strength and IK muscle endurance of the dominant knee, ankle and elbow, and maximal IM handgrip strength were measured by means of dynamometry.

RESULTS

Ankle muscle endurance was lower compared to the knee, independently of dNP (p<0.001). Maximal IK ankle muscle strength was also lower compared to the knee, albeit only in dNPsm (p=0.003). No differences were found between maximal IM handgrip and elbow strength.

CONCLUSIONS

Our results suggest an impact of T2DM -with or without dNP- on lower limb muscle strength more distally than proximally, while this was not observed in the upper limb. The gradient of dNP seemed to be a determining factor for the maximal muscle strength, and not for muscle endurance, in the lower limb.

Development of disulfide-derived fructose-1,6-bisphosphatase (FBPase) covalent inhibitors for the treatment of type 2 diabetes

Fructose-1,6-bisphosphatase (FBPase), as a key rate-limiting enzyme in the gluconeogenesis (GNG) pathway, represents a practical therapeutic strategy for type 2 diabetes (T2D). Our previous work first identified cysteine residue 128 (C128) was an important allosteric site in the structure of FBPase, while pharmacologically targeting C128 attenuated the catalytic ability of FBPase. Herein, ten approved cysteine covalent drugs were selected for exploring FBPase inhibitory activities, and the alcohol deterrent disulfiram displayed superior inhibitory efficacy among those drugs. Based on the structure of lead compound disulfiram, 58 disulfide-derived compounds were designed and synthesized for investigating FBPase inhibitory activities. Optimal compound 3a exhibited significant FBPase inhibition and glucose-lowering efficacy in vitro and in vivo. Furthermore, 3a covalently modified the C128 site, and then regulated the N125-S124-S123 allosteric pathway of FBPase in mechanism. In summary, 3a has the potential to be a novel FBPase inhibitor for T2D therapy.

Low brain-derived neurotrophic factor protein levels and single-nucleotide polymorphism Val66Met are associated with peripheral neuropathy in type II diabetic patients

BACKGROUND

Studies by our group demonstrated brain-derived neurotrophic factor (BDNF) levels in blood and BDNF-Val66met-SNP as potential biomarkers in chemotherapy-induced peripheral neuropathy. Here, we evaluate symptoms of peripheral neuropathy (PN) and depression in patients with type II diabetes mellitus in search of an association with serum BDNF levels and the Val66Met-SNP.

METHODS

In total, 90 patients enrolled in the study; 23 (25.6%) had known PN, as determined by nerve conduction studies (NCS-PN), and 67 (74.4%) were not diagnosed with PN (U-PN). PN symptoms were assessed and graded in these groups using the total neuropathy score (TNSr) and DN4 scales. Small nerve fiber testing of sensitivity thresholds to cold, warm and hot pain signals was performed using the Q-sense device. Depression was assessed using the PHQ9 questionnaire. BDNF protein levels and Val66Met-SNP were determined with ELISA and Sanger sequencing, respectively.

RESULTS

NCS-PN patients showed lower serum BDNF levels alongside significantly higher TNSr, DN4 and PHQ9 scores and lower hot pain sensitivity thresholds as compared to U-PN patients. Patients with Met-BDNF-SNP showed increased TNSr scores and lower hot pain sensitivity thresholds as compared to patients with Val-BDNF-SNP. Depression showed a weaker correlation with sensitivity thresholds to hot pain signals as compared to TNSr and DN4 scores.

CONCLUSIONS

Diminished peripheral BDNF resources and Met-BDNF-SNP genotype are associated with augmented symptoms of PN in patients with type II diabetes mellitus. Sensitivity thresholds to hot pain signals may be less influenced by depression and possibly more accurately detect PN symptoms in diabetic patients.

NADPH oxidase: A membrane-bound enzyme and its inhibitors in diabetic complications

The human body has a mechanism for balancing the generation and neutralization of reactive oxygen species. The body is exposed to many agents that are responsible for the generation of reactive oxygen/nitrogen species, which leads to disruption of the balance between generation of these species and oxidative stress defence mechanisms. Diabetes is a chronic pathological condition associated with prolonged hyperglycaemia. Prolonged elevation of level of glucose in the blood leads to the generation of reactive oxygen species. This generation of reactive oxygen species is responsible for the development of diabetic vasculopathy, which includes micro- and macrovascular diabetic complications. Nicotinamide adenine dinucleotide phosphate oxidase (NOX) is a membrane-bound enzyme responsible for the development of reactive oxygen species in hyperglycaemia. Phosphorylation of the cytosolic components of NOX, such as p47phox, p67phox, and RAC-1, in hyperglycaemia is one of the important causes of conversion of oxygen to reactive oxygen. Overexpression of NOX in pathological conditions is associated with activation of aldose reductase, advanced glycation end products, protein kinase C and the hexosamine pathway. In addition, NOX also promotes the activation of inflammatory cytokines, such as TGF-β, TNF-α, NF-kβ, IL-6, and IL-18, the activation of endothelial growth factors, such as VEGF and FGF, hyperlipidaemia, and the deposition of collagen. Thus, overexpression of NOX is linked to the development of diabetic complications. The present review focuses on the role of NOX, its associated pathways, and various NOX inhibitors in the management and treatment of diabetic complications, such as diabetic nephropathy, retinopathy, neuropathy and cardiomyopathy.

Spectrum of diabetic neuropathies

The diabetic state results in neuropathy. The main causative mechanism is hyperglycemia, although microvascular involvement, hypertriglyceridemia, as well as genetic and immune mechanisms may be contributory. There is a growing spectrum of types of diabetic neuropathies that differ based on the type of fibers involved (e.g. myelinated, unmyelinated, autonomic, somatic), distribution of nerves involved, and mechanisms of neuropathy. The most common type is distal sensory neuropathy (DSN), which affects the distal ends of large myelinated fibers, more often sensory than motor, and is often asymptomatic. The next-most common is distal small fiber neuropathy (DSFN), which largely affects the unmyelinated fibers and carries the phenotype of burning feet syndrome. Diabetic autonomic neuropathy (DAN) occurs when widespread involvement of autonomic unmyelinated fibers occurs, and patients can be incapacitated with orthostatic hypotension as well as neurogenic bladder and bowel involvement. Radiculoplexus diabetic neuropathy causes proximal weakness and pain, usually in the lower extremity, and has a combination of immune, inflammatory, and vascular mechanisms. The nerve roots and plexus are involved. These patients present with proximal weakness of a subacute onset, often with severe pain and some autonomic failure. Finally, rapid and sustained reduction of blood glucose can result in treatment-induced diabetic neuropathy (TIND), which largely affects the sensory and autonomic fibers. This occurs if HbA1c is rapidly reduced within 3 months, and the likelihood is proportional to the original A1c and the size of the reduction.

Challenges of neuropathic pain: focus on diabetic neuropathy

Neuropathic pain is a frequent condition caused by a lesion or disease of the central or peripheral somatosensory nervous system. A frequent cause of peripheral neuropathic pain is diabetic neuropathy. Its complex pathophysiology is not yet fully elucidated, which contributes to underassessment and undertreatment. A mechanism-based treatment of painful diabetic neuropathy is challenging but phenotype-based stratification might be a way to develop individualized therapeutic concepts. Our goal is to review current knowledge of the pathophysiology of peripheral neuropathic pain, particularly painful diabetic neuropathy. We discuss state-of-the-art clinical assessment, validity of diagnostic and screening tools, and recommendations for the management of diabetic neuropathic pain including approaches towards personalized pain management. We also propose a research agenda for translational research including patient stratification for clinical trials and improved preclinical models in relation to current knowledge of underlying mechanisms.

Diabetic amyotrophy, not your typical back pain

A 49-year-old man presented to the hospital for spinal cord decompression surgery with left buttock and left leg pain. The patient described an acute burning pain radiating down from his left buttock to left lateral leg. He also noted a 13.6 kg weight loss in recent months. Physical examination showed decreased muscle bulk of the left thigh, decreased strength of the left hip, left knee flexors and extensors. Recent MRI spine showed mild canal narrowing and cord flattening in the lower thoracic spine. Serologic testing showed an elevated glucose of 17.9 mmol/L and haemoglobin A1c of 9.8%. Electromyography showed denervation of scattered muscles of the left knee flexors, hip flexors and adductors. In the setting of newly diagnosed diabetes mellitus, he was diagnosed with diabetic amyotrophy, started on insulin therapy, and his surgery was cancelled.

High Mobility Group Box-1 and Diabetes Mellitus Complications: State of the Art and Future Perspectives

Diabetes mellitus (DM) is an endemic disease, with growing health and social costs. The complications of diabetes can affect potentially all parts of the human body, from the heart to the kidneys, peripheral and central nervous system, and the vascular bed. Although many mechanisms have been studied, not all players responsible for these complications have been defined yet. High Mobility Group Box-1 (HMGB1) is a non-histone nuclear protein that has been implicated in many pathological processes, from sepsis to ischemia. The purpose of this review is to take stock of all the most recent data available on the role of HMGB1 in the complications of DM.

Assessing pathological changes within the nucleus ambiguus of horses with recurrent laryngeal neuropathy: An extreme, length-dependent axonopathy

INTRODUCTION

Equine recurrent laryngeal neuropathy (RLN) is a naturally occurring model of length-dependent axonopathy characterized by asymmetrical degeneration of recurrent laryngeal nerve axons (RLn). Distal RLn degeneration is marked, but it is unclear whether degeneration extends to include cell bodies (consistent with a neuronopathy).

METHODS

With examiners blinded to RLN severity, brainstem location, and side, we examined correlations between RLN severity (assessed using left distal RLn myelinated axon count) and histopathological features (including chromatolysis and glial responses) in the nucleus ambiguus cell bodies, and myelinated axon count of the right distal RLn of 16 horses.

RESULTS

RLN severity was not associated with RLn cell body number (P > .05), or degeneration. A positive correlation between the left and right distal RLn myelinated axon counts was identified (R² = 0.57, P < .05).

DISCUSSION

We confirm that RLN, a length-dependent distal axonopathy, occurs in the absence of detectable neuronopathy.

Uremic neuropathy: an overview of the current literature

INTRODUCTION

Peripheral neuropathy is a disorder that affects the cell body, axon or myelin of motor or peripheral sensory neurons and occurs in 60-100% of patients who are submitted to dialysis due to chronic kidney disease. Uremic neuropathy (UN) is attributed to the accumulation of organic waste, evident in patients with reduced glomerular filtration rate.

OBJECTIVES

This review aims to make clinical characteristics of uremic neuropathy evident enabling early diagnosis and treatment.

METHODS

This is a literature review of articles published on PubMed over the last 10 years using "Uremic Neuropathy" as "Title/Abstract".

RESULTS

A total of nine articles that met the inclusion criteria were included. UN is a distal symmetric sensorimotor polyneuropathy that occurs due to the accumulation of uremic toxins associated with an oxidative stress-related free radical activity. Hyperkalemia is thought to play an important role in its pathophysiology. Diagnosis depends on nerve conduction studies, and treatment includes dialysis or renal transplant.

CONCLUSION

Clinical presentations of UN are broad and non-specific; nonetheless, it is important to detect early changes in order to avoid its progression. The earlier UN is diagnosed and treated, the more successful are the clinical outcomes.

Type 2 Diabetes Mellitus (T2DM) "Remission" in Non-bariatric Patients 65 Years and Older

Objective: To analyze the factors associated with type 2 diabetes mellitus (T2DM) “remission” in non-bariatric Medicare patients 65 years and older.

Research Design and Methods: A retrospective cohort analysis of a Medicare Advantage health plan was conducted using administrative data. An individual was identified as T2DM if the individual had: ≥ 2 medical claims for T2DM coded 250.xx excluding type 1 diabetes; or ≥ 2 pharmacy claims related to T2DM; or ≥ 2 combined medical claims, pharmacy claims for T2DM in 12 months. A T2DM individual was in “remission” if they had no T2DM related claims for more than 12 months continuously. This is different from the standard American Diabetes Association (ADA) definition of remission which includes HbA1c values and hence is represented in quotation (as “remission”). 10,059 T2DM individuals were evaluated over a period of 8 years from 2008 to 2015. Cox proportional hazards was used to identify significant variables associated with T2DM “remission.”

Results: 4.97% of patients studied met the definition of T2DM “remission” in the study cohort. After adjusting for covariates this study found a number of variables associated with T2DM “remission” that were not previously reported: no statin use; low diabetes complications severity index score; no hypertension; no neuropathy; no retinopathy; race (non-white and non-African American); presence of other chronic ischemic heart disease (IHD) and females (p < 0.05).

Conclusion: T2DM “remission” in Medicare patients 65 years and older is observed in a community setting in a small proportion of non-bariatric patients.

Uremic neuropathy: an overview of the current literature

INTRODUCTION

Peripheral neuropathy is a disorder that affects the cell body, axon or myelin of motor or peripheral sensory neurons and occurs in 60-100% of patients who are submitted to dialysis due to chronic kidney disease. Uremic neuropathy is attributed to the accumulation of organic waste, evident in patients with reduced glomerular filtration rate.

OBJECTIVES

This review aims to make clinical characteristics of uremic neuropathy evident enabling early diagnosis and treatment.

METHODS

This is a literature review of articles published on PubMed over the last 10 years using "Uremic Neuropathy" as "Title/Abstract".

RESULTS

A total of nine articles that met the inclusion criteria were included. UN is a distal symmetric sensorimotor polyneuropathy that occurs due to the accumulation of uremic toxins associated with an oxidative stress-related free radical activity. Hyperkalemia is thought to play an important role in its pathophysiology. Diagnosis depends on nerve conduction studies, and treatment includes dialysis or renal transplant.

CONCLUSION

Clinical presentations of UN are broad and non-specific; nonetheless, it is important to detect early changes in order to avoid its progression. The earlier UN is diagnosed and treated, the more successful are the clinical outcomes.

Diabetic neuropathy research: from mouse models to targets for treatment

Diabetic neuropathy is one of the most serious complications of diabetes, and its increase shows no sign of stopping. Furthermore, current clinical treatments do not yet approach the best effectiveness. Thus, the development of better strategies for treating diabetic neuropathy is an urgent matter. In this review, we first discuss the advantages and disadvantages of some major mouse models of diabetic neuropathy and then address the targets for mechanism-based treatment that have been studied. We also introduce our studies on each part. Using stem cells as a source of neurotrophic factors to target extrinsic factors of diabetic neuropathy, we found that they present a promising treatment.

Diabetic Neuropathic Cachexia in a Young Woman

Profound weight loss with painful symmetrical peripheral neuropathy in diabetic patients was first described as diabetic neuropathic cachexia more than 4 decades ago. It is a distinct type of diabetic peripheral neuropathy that occurs in the absence of other microvascular and autonomic complications of diabetes. The mechanism and precipitating cause are unknown. It was reported to have good prognosis with spontaneous recovery within months to 2 years. However, it was frequently missed by clinicians because the profound weight loss is the most outstanding complaint, rather than the pain, numbness, or weakness. This often leads to extensive investigation to exclude more sinister causes of weight loss, particularly malignancy. We report a case of a young woman with well-controlled diabetes who presented with profound unintentional weight loss (26 kg), symmetrical debilitating thigh pain, and clinical signs of peripheral neuropathy. As the disease entity may mimic an inflammatory demyelinating cause of neuropathy, she was treated with a trial of intravenous immunoglobulin, which failed to give any significant benefit. However, she recovered after 6 months without any specific treatment, other than an antidepressant for the neuropathic pain and ongoing rehabilitation.

Use of MRI in diabetic lumbosacral radiculoplexus neuropathy: case report and review of the literature

Diabetic lumbosacral radiculoplexus neuropathy is often confused with radiculopathy in the context of spinal degenerative disc disease including spinal stenosis. Accuracy in diagnosis may prevent unnecessary interventional procedures including selective nerve root blocks or epidural steroid injections or even surgery in selected cases. Our patient with known diabetes and lumbar disc disease presented with acute onset of pain in L5-S1 distribution of the left lower extremity. Initial MR imaging of the lumbar spine did not show sufficient structural changes to explain her symptomatology. An MR neurogram of the lumbosacral plexus revealed inflammation within the bilateral sciatic and femoral nerves; subsequent EMG demonstrated a generalized sensorimotor neuropathy but no evidence of plexopathy. To our knowledge, this is the first case report that utilized MR imaging of the pelvis to assist in the diagnosis of diabetic lumbosacral radiculoplexus neuropathy (DLRPN).

Peripheral Neuropathy as a Complication of Diabetic Ketoacidosis in a Child with Newly Diagnosed Diabetes Type 1: A Case Report

Neurological complications of diabetic ketoacidosis are considered to be a serious clinical problem. The most common complication is cerebral edema. However, these neurological complications also include less common entities such as ischemic or hemorrhagic stroke, cerebral venous and sinus thrombosis or peripheral neuropathy. We present a case of a 9-year old girl admitted to our intensive care unit with new onset type 1 diabetes, diabetic ketoacidosis, cerebral edema, multifocal vasogenic brain lesions and bilateral lower limb peripheral paresis. The patient developed polydipsia and polyuria one week before admission. The initial blood glucose level was 1136 mg/dL and severe acidosis was present (pH 7.1; BE-25.9). Computed tomography scan showed brain edema and a hypodense lesion in the left temporal region. Brain magnetic resonance imaging revealed more advanced multifocal brain lesions. Nerve conduction studies demonstrated damage of the motor neurons in both lower limbs with dysfunction in both peroneal nerves and the right tibial nerve. With treatment and physiotherapy, the patient’s health gradually improved. Acute neuropathy after ketoacidosis is a rare complication and its pathogenesis is not clear. Patients with diabetic ketoacidosis require careful monitoring of neurological function, even after normalization of their glycemic parameters.

Inflammatory Diabetic Neuropathy: Helpful Diagnostic Parameters

OBJECTIVES

Mild inflammatory diabetic neuropathies (IDNs) overlap with diabetic sensorimotor neuropathy (DPN) in clinical presentation and electrophysiological and laboratory tests. This study is to determine whether IDN can be differentiated from DPN by clinical features, electrophysiological, pathological, or laboratory tests.

METHODS

Suspected IDN cases were identified by a subacute onset and progressive sensory or motor neuropathy in patients with diabetes.

RESULTS

IDN occurred earlier in the course of diabetes mellitus and had higher prevalence of limb weakness, walking difficulty, and more severe electrophysiological abnormalities suggesting both demyelination and axonal loss. Sensory nerve biopsies in IDN showed perivascular inflammatory infiltrates, decreased fiber density, increased demyelination, and axonal degeneration. Most patients with IDN improved with immunotherapy.

CONCLUSIONS

Features that favor IDN over DPN are limb weakness, more severe nerve conduction abnormalities, inflammatory infiltrates on nerve biopsy, and a favorable response to immunotherapy. A nerve biopsy can help establish an inflammatory cause.