Peripheral neuropathy in prediabetes and the metabolic syndrome

Incident Proteinuria by HIV Serostatus Among Men With Pre--Diabetes Mellitus: The Multicenter AIDS Cohort Study

BACKGROUND

Pre-diabetes mellitus (DM) is associated with proteinuria, a risk factor for chronic kidney disease. While people with human immunodeficiency virus (HIV; PWH) have a higher risk of proteinuria than people without HIV (PWOH), it is unknown whether incident proteinuria differs by HIV serostatus among prediabetic persons.

METHODS

The urine protein-to-creatinine ratio was measured at semiannual visits among men in the Multicenter AIDS Cohort Study since April 2006. Men with pre-DM on or after April 2006 and no prevalent proteinuria or use of antidiabetic medications were included. Pre-DM was defined as a fasting glucose level of 100-125 mg/dL confirmed within a year by a repeated fasting glucose or hemoglobin A1c measurement of 5.7%-6.4%. Incident proteinuria was defined as a urine protein-to-creatinine ratio (UPCR) >200 mg/g, confirmed within a year. We used Poisson regression models to determine whether incident proteinuria in participants with pre-DM differed by HIV serostatus and, among PWH, whether HIV-specific factors were related to incident proteinuria.

RESULTS

Between 2006 and 2019, among 1276 men with pre-DM, proteinuria developed in 128 of 613 PWH (21%) and 50 of 663 PWOH (8%) over a median 10-year follow-up. After multivariable adjustment, the incidence of proteinuria in PWH with pre-DM was 3.3 times (95% confidence interval, 2.3-4.8 times) greater than in PWOH (P < .01). Among PWH, current CD4 cell count <50/µL (P < .01) and current use of protease inhibitors (P = .03) were associated with incident proteinuria, while lamivudine and integrase inhibitor use were associated with a lower risk.

CONCLUSIONS

Among men with pre-DM, the risk of incident proteinuria was 3 times higher in PWH. Strategies to preserve renal function are needed in this population.

Systematic review of translational insights: Neuromodulation in animal models for Diabetic Peripheral Neuropathy

Diabetic Peripheral Neuropathy (DPN) is a prevalent and debilitating complication of diabetes, affecting a significant proportion of the diabetic population. Neuromodulation, an emerging therapeutic approach, has shown promise in the management of DPN symptoms. This systematic review aims to synthesize and analyze the current advancements in neuromodulation techniques for the treatment of DPN utilizing studies with preclinical animal models. A comprehensive search was conducted across multiple databases, including PubMed, Scopus, and Web of Science. Inclusion criteria were focused on studies utilizing preclinical animal models for DPN that investigated the efficacy of various neuromodulation techniques, such as spinal cord stimulation, transcranial magnetic stimulation, and peripheral nerve stimulation. The findings suggest that neuromodulation significantly alleviated pain symptoms associated with DPN. Moreover, some studies reported improvements in nerve conduction velocity and reduction in nerve damage. The mechanisms underlying these effects appeared to involve modulation of pain pathways and enhancement of neurotrophic factors. However, the review also highlights the variability in methodology and stimulation parameters across studies, highlighting the need for standardization in future research. Additionally, while the results are promising, the translation of these findings from animal models to human clinical practice requires careful consideration. This review concludes that neuromodulation presents a potentially effective therapeutic strategy for DPN, but further research is necessary to optimize protocols and understand the underlying molecular mechanisms. It also emphasizes the importance of bridging the gap between preclinical findings and clinical applications to improve the management of DPN in diabetic patients.

Predicting and comparing the long-term impact of lifestyle interventions on individuals with eating disorders in active population: a machine learning evaluation

Objective

This study aims to evaluate and predict the long-term effectiveness of five lifestyle interventions for individuals with eating disorders using machine learning techniques.

Methods

This study, conducted at Dr. Irandoust's Health Center at Qazvin from August 2021 to August 2023, aimed to evaluate the effects of five lifestyle interventions on individuals with eating disorders, initially diagnosed using The Eating Disorder Diagnostic Scale (EDDS). The interventions were: (1) Counseling, exercise, and dietary regime, (2) Aerobic exercises with dietary regime, (3) Walking and dietary regime, (4) Exercise with a flexible diet, and (5) Exercises through online programs and applications. Out of 955 enrolled participants, 706 completed the study, which measured Body Fat Percentage (BFP), Waist-Hip Ratio (WHR), Fasting Blood Sugar (FBS), Low-Density Lipoprotein (LDL) Cholesterol, Total Cholesterol (CHO), Weight, and Triglycerides (TG) at baseline, during, and at the end of the intervention. Random Forest and Gradient Boosting Regressors, following feature engineering, were used to analyze the data, focusing on the interventions' long-term effectiveness on health outcomes related to eating disorders.

Results

Feature engineering with Random Forest and Gradient Boosting Regressors, respectively, reached an accuracy of 85 and 89%, then 89 and 90% after dataset balancing. The interventions were ranked based on predicted effectiveness: counseling with exercise and dietary regime, aerobic exercises with dietary regime, walking with dietary regime, exercise with a flexible diet, and exercises through online programs.

Conclusion

The results show that Machine Learning (ML) models effectively predicted the long-term effectiveness of lifestyle interventions. The current study suggests a significant potential for tailored health strategies. This emphasizes the most effective interventions for individuals with eating disorders. According to the results, it can also be suggested to expand demographics and geographic locations of participants, longer study duration, exploring advanced machine learning techniques, and including psychological and social adherence factors. Ultimately, these results can guide healthcare providers and policymakers in creating targeted lifestyle intervention strategies, emphasizing personalized health plans, and leveraging machine learning for predictive healthcare solutions.

Efficacy and Safety of LX9211 for Relief of Diabetic Peripheral Neuropathic Pain (RELIEF-DPN 1): Results of a Double-Blind, Randomized, Placebo-Controlled, Proof-of-Concept Study

OBJECTIVE

To evaluate the efficacy of LX9211 in reducing pain related to diabetic peripheral neuropathy.

RESEARCH DESIGN AND METHODS

In this double-blind, multicenter, proof-of-concept trial, 319 individuals with diabetic peripheral neuropathic pain (DPNP) were randomized (1:1:1) to LX9211 10 mg (n = 106), LX9211 20 mg (n = 106), or matching placebo (n = 107), administered once daily for 6 weeks. DPNP was rated daily with an 11-point numerical rating scale. The primary end point was change from baseline to week 6 in the average daily pain score. The difference between each LX9211 group and placebo was evaluated with mixed-model repeated-measures analysis.

RESULTS

For those on low-dose LX9211 the primary efficacy end point was achieved: -1.39 vs. -0.72 points for placebo, least squares mean (SE) difference -0.67 (0.249), 95% CI -1.16 to -0.18, P = 0.007; results for high-dose LX9211 demonstrated improvement in pain severity versus placebo (-1.27 vs. -0.72 points, respectively), but the between-group LS mean difference did not reach the prespecified statistical significance (-0.55 [0.254], 95% CI -1.06 to -0.05, P = 0.030). Treatment benefit was observed beginning at week 1 and maintained thereafter. Results for LX9211 also demonstrated improvement in several patient-reported secondary outcomes. Most common adverse events (AEs) were dizziness, nausea, and headache. More participants treated with LX9211 (20 mg, n = 28 [26.4%]; 10 mg, 17 [16.0%]) than placebo (3 [2.8%]) discontinued study drug prematurely due to AEs; serious AEs were uncommon (2 [1.9%], 0, and 1 [0.9%], respectively).

CONCLUSIONS

These preliminary findings of improvement in DPNP with LX9211 support further investigation in larger trials.

Targeting neuroinflammation in distal symmetrical polyneuropathy in diabetes

Diabetic distal symmetric polyneuropathy is the most common type of peripheral neuropathy complication of diabetes mellitus. Neuroinflammation is emerging as an important contributor to diabetes-induced neuropathy. Long-term hyperglycemia results in increased production of advanced glycation end products (AGEs). AGEs interact with their receptors to activate intracellular signaling, leading to the release of various inflammatory cytokines. Increased release of inflammatory cytokines is associated with diabetes, diabetic neuropathy, and neuropathic pain. Thus, anti-inflammatory intervention is a potential therapy for diabetic distal symmetric polyneuropathy. Further characterization of inflammatory mechanisms might identify novel therapeutic targets to mitigate diabetic neuropathy.

Systematic investigation of Radix Salviae for treating diabetic peripheral neuropathy disease based on network Pharmacology

BACKGROUND

Diabetic peripheral neuropathy (DPN) is a debilitating complication of diabetes mellitus with limited available treatment options. Radix Salviae, a traditional Chinese herb, has shown promise in treating DPN, but its therapeutic mech-anisms have not been systematically investigated.

AIM

Radix Salviae (Danshen in pinin), a traditional Chinese medicine (TCM), is widely used to treat DPN in China. However, the mechanism through which Radix Salviae treats DPN remains unclear. Therefore, we aimed to explore the mechanism of action of Radix Salviae against DPN using network pharmacology.

METHODS

The active ingredients and target genes of Radix Salviae were screened using the TCM pharmacology database and analysis platform. The genes associated with DPN were obtained from the Gene Cards and OMIM databases, a drug-com-position-target-disease network was constructed, and a protein-protein inter-action network was subsequently constructed to screen the main targets. Gene Ontology (GO) functional annotation and pathway enrichment analysis were performed via the Kyoto Encyclopedia of Genes and Genomes (KEGG) using Bioconductor.

RESULTS

A total of 56 effective components, 108 targets and 4581 DPN-related target genes of Radix Salviae were screened. Intervention with Radix Salviae for DPN mainly involved 81 target genes. The top 30 major targets were selected for enrichment analysis of GO and KEGG pathways.

CONCLUSION

These results suggested that Radix Salviae could treat DPN by regulating the AGE-RAGE signaling pathway and the PI3K-Akt signaling pathway. Therefore, Danshen may affect DPN by regulating inflammation and apoptosis.

Tunable Hydrogel Electronics for Diagnosis of Peripheral Neuropathy

Peripheral neuropathy characterized by rapidly increasing numbers of patients is commonly diagnosed via analyzing electromyography signals obtained from stimulation-recording devices. However, existing commercial electrodes have difficulty in implementing conformal contact with skin and gentle detachment, dramatically impairing stimulation/recording performances. Here, this work develops on-skin patches with polyaspartic acid-modified dopamine/ethyl-based ionic liquid hydrogel (PDEH) as stimulation/recording devices to capture electromyography signals for the diagnosis of peripheral neuropathy. Triggered by a one-step electric field treatment, the hydrogel achieves rapid and wide-range regulation of adhesion and substantially strengthened mechanical performances. Moreover, hydrogel patches assembled with a silver-liquid metal (SLM) layer exhibit superior charge injection and low contact impedance, capable of capturing high-fidelity electromyography. This work further verifies the feasibility of hydrogel devices for accurate diagnoses of peripheral neuropathy in sensory, motor, and mixed nerves. For various body parts, such as fingers, the elderly's loose skin, hairy skin, and children's fragile skin, this work regulates the adhesion of PDEH-SLM devices to establish intimate device/skin interfaces or ensure benign removal. Noticeably, hydrogel patches achieve precise diagnoses of nerve injuries in these clinical cases while providing extra advantages of more effective stimulation/recording performances. These patches offer a promising alternative for the diagnosis and rehabilitation of neuropathy in future.

A multi-omics approach to investigate characteristics of gut microbiota and metabolites in hypertension and diabetic nephropathy SPF rat models

Background

Imbalance in intestinal microbiota caused by microbial species and proportions or metabolites derived from microbes are associated with hypertension, as well as diabetic nephropathy. However, the involvement of the intestinal microbiota and metabolites in hypertension and diabetic nephropathy comorbidities (HDN) remains to be elucidated.

Methods

We investigated the effects of intestinal microbiota on HDN in a rat model and determined the abundance of the intestinal microbiota using 16S rRNA sequencing. Changes in fecal and serum metabolites were analyzed using ultra-high-performance liquid chromatography-mass spectrometry.

Results

The results showed abundance of Proteobacteria and Verrucomicrobia was substantially higher, whereas that of Bacteroidetes was significant lower in the HDN group than in the sham group. Akkermansia, Bacteroides, Blautia, Turicibacter, Lactobacillus, Romboutsia, and Fusicatenibacter were the most abundant, and Prevotella, Lachnospiraceae_NK4A136_group, and Prevotella_9 were the least abundant in the HDN group. Further analysis with bile acid metabolites in serum showed that Blautia was negatively correlated with taurochenodeoxycholic acid, taurocholic acid, positively correlated with cholic acid and glycocholic acid in serum.

Conclusions

These findings suggest that the gut microbiota and metabolites in feces and serum substantially differed between the HDN and sham groups. The F/B ratio was higher in the HDN group than in the sham group. Blautia is potentially associated with HDN that correlated with differentially expressed bile acid metabolites, which might regulate the pathogenesis of HDN via the microorganism-gut-metabolite axis.

4. Painful diabetic polyneuropathy

INTRODUCTION

Pain as a symptom of diabetic polyneuropathy (DPN) significantly lowers quality of life, increases mortality and is the main reason for patients with diabetes to seek medical attention. The number of people suffering from painful diabetic polyneuropathy (PDPN) has increased significantly over the past decades.

METHODS

The literature on the diagnosis and treatment of diabetic polyneuropathy was retrieved and summarized.

RESULTS

The etiology of PDPN is complex, with primary damage to peripheral nociceptors and altered spinal and supra-spinal modulation. To achieve better patient outcomes, the mode of diagnosis and treatment of PDPN evolves toward more precise pain-phenotyping and genotyping based on patient-specific characteristics, new diagnostic tools, and prior response to pharmacological treatments. According to the Toronto Diabetic Neuropathy Expert Group, a presumptive diagnosis of "probable PDPN" is sufficient to initiate treatment. Proper control of plasma glucose levels, and prevention of risk factors are essential in the treatment of PDPN. Mechanism-based pharmacological treatment should be initiated as early as possible. If symptomatic pharmacologic treatment fails, spinal cord stimulation (SCS) should be considered. In isolated cases, where symptomatic pharmacologic treatment and SCS are unsuccessful or cannot be used, sympathetic lumbar chain neurolysis and/or radiofrequency ablation (SLCN/SLCRF), dorsal root ganglion stimulation (DRGs) or posterior tibial nerve stimulation (PTNS) may be considered. However, it is recommended that these treatments be applied only in a study setting in a center of expertise.

CONCLUSIONS

The diagnosis of PDPN evolves toward pheno-and genotyping and treatment should be mechanism-based.

Acid-sensing ion channel 3 mediates pain hypersensitivity associated with high-fat diet consumption in mice

ABSTRACT

Lipid-rich diet is the major cause of obesity, affecting 13% of the worldwide adult population. Obesity is a major risk factor for metabolic syndrome that includes hyperlipidemia and diabetes mellitus. The early phases of metabolic syndrome are often associated with hyperexcitability of peripheral small diameter sensory fibers and painful diabetic neuropathy. Here, we investigated the effect of high-fat diet-induced obesity on the activity of dorsal root ganglion (DRG) sensory neurons and pain perception. We deciphered the underlying cellular mechanisms involving the acid-sensing ion channel 3 (ASIC3). We show that mice made obese through consuming high-fat diet developed the metabolic syndrome and prediabetes that was associated with heat pain hypersensitivity, whereas mechanical sensitivity was not affected. Concurrently, the slow conducting C fibers in the skin of obese mice showed increased activity on heating, whereas their mechanosensitivity was not altered. Although ASIC3 knockout mice fed with high-fat diet became obese, and showed signs of metabolic syndrome and prediabetes, genetic deletion, and in vivo pharmacological inhibition of ASIC3, protected mice from obesity-induced thermal hypersensitivity. We then deciphered the mechanisms involved in the heat hypersensitivity of mice and found that serum from high-fat diet-fed mice was enriched in lysophosphatidylcholine (LPC16:0, LPC18:0, and LPC18:1). These enriched lipid species directly increased the activity of DRG neurons through activating the lipid sensitive ASIC3 channel. Our results identify ASIC3 channel in DRG neurons and circulating lipid species as a mechanism contributing to the hyperexcitability of nociceptive neurons that can cause pain associated with lipid-rich diet consumption and obesity.

Association of HbA1c Variability with Vibrating Perception Threshold in Middle-Aged and Elderly Patients with Type 2 Diabetes Mellitus: A Retrospective Cohort Study

Purpose

To investigate the relationship between HbA1c variability and vibrating perception threshold (VPT) in middle-aged and elderly patients with type 2 diabetes mellitus (T2DM).

Patients and Methods

A total of 367 middle-aged and elderly patients with T2DM were enrolled. All patients were categorized into the control and vibration sensation deficiency group (VSD) based on VPT. Clinical data were collected. The coefficient of variation of glycated hemoglobin A1c (HbA1c-CV) and the mean glycated hemoglobin A1c(HbA1c-Mean) are considered as indexes of HbA1c variability. Multivariate logistic regression analysis, the generalized linear model and ROC curve correlation analysis were used to analyze the correlation of various factors and VPT.

Results

The multivariate logistic regression analysis revealed that age, systolic blood pressure (SBP), and HbA1c-CV were identified as risk factors for vibration sensation deficiency in middle-aged and elderly patients with T2DM, while estimated glomerular filtration rate (eGFR), triiodothyronine (T3), and alanine aminotransferase (ALT) were considered as protective factors. In the unadjusted generalized linear model, a significant association was observed between HbA1c-CV and VPT values. After adjusting for age, diabetic duration, SBP, homeostatic model assessment for beta-cell function (HOMA-β), ALT, eGFR, T3, 24-hour urinary protein excretion levels, and HbA1c-Mean, HbA1c-CV remained significantly correlated with VPT values on both sides. (left side, B=2.560, 95% CI 1.298~3.823; P<0.001; right side, B=2.608, 95% CI 1.498~3.718, P<0.001). The area under the curve (AUC) for HbA1c-CV and VSD prevalence was 0.723, with a sensitivity of 79.85%, specificity of 56.22%.

Conclusion

The risk of developing VSD increases proportionally with higher HbA1c-CV levels in middle-aged and elderly patients with T2DM. Reaching and maintaining blood glucose stability is essential to the mitigation of diabetes peripheral neuropathy occurrence.

Applications of Cannabinoids in Neuropathic Pain: An Updated Review

Neuropathic pain is experienced due to injury to the nerves, underlying disease conditions or toxicity induced by chemotherapeutics. Multiple factors can contribute to neuropathic pain such as central nervous system (CNS)-related autoimmune and metabolic disorders, nerve injury, multiple sclerosis and diabetes. Hence, development of pharmacological interventions to reduce the drawbacks of existing chemotherapeutics and counter neuropathic pain is an urgent unmet clinical need. Cannabinoid treatment has been reported to be beneficial for several disease conditions including neuropathic pain. Cannabinoids act by inhibiting the release of neurotransmitters from presynaptic nerve endings, modulating the excitation of postsynaptic neurons, activating descending inhibitory pain pathways, reducing neural inflammation and oxidative stress and also correcting autophagy defects. This review provides insights on the various preclinical and clinical therapeutic applications of cannabidiol (CBD), cannabigerol (CBG), and cannabinol (CBN) in various diseases and the ongoing clinical trials for the treatment of chronic and acute pain with cannabinoids. Pharmacological and genetic experimental strategies have well demonstrated the potential neuroprotective effects of cannabinoids and also elaborated their mechanism of action for the therapy of neuropathic pain.

Assessment of Neuropathy by Temperature Threshold Testing in Type 2 Diabetes Mellitus

Introduction

Diagnosing diabetic neuropathy is a challenge at times as it is asymptomatic. Diagnosing diabetic neuropathy involves the use of quantitative sensory testing, nerve conduction study, and autonomic testing. Tempearture threshold testing (TTT) can aid in diagnosing small fiber neuropathy at early stages. This study aimed to assess the small fiber neuropathy using TTT in diabetes mellitus (DM) and correlate with age, duration of diabetes, and lipid profile.

Materials and Methods

The study was commenced after obtaining ethics approval from the institute ethics committee. The study participants included 100 patients with type 2 DM of both genders between the ages of 40 and 65 years. The glycemic status and lipid profile were noted along with physical examination. Neuropathy assessment was done using Michigan Neuropathy Screening Instrument (MNSI) and TTT.

Results

The prevalence of small fiber neuropathy based on TTT was 63%. The lipid profile was similar in both the groups. The MNSI B scale had significantly higher scores in the neuropathy group. In the neuropathy group, the thresholds for hot were significantly greater in all four limbs and cold were significantly lower. Age and years of DM were positively correlated with the neuropathy. Hot threshold in the lower limb had shown a strong positive correlation.

Conclusion

The age and duration of diabetes are independent risk factors for diabetic peripheral neuropathy. Small fiber neuropathy is a prequel to the motor neuropathy. Hot threshold testing in the lower limb is more sensitive than cold threshold testing for diagnosing small fiber neuropathy.

Higher obesity class is associated with more severe esophageal symptoms and reflux burden but not altered motor function or contractile reserve

BACKGROUND

Patients with obesity often report esophageal symptoms, with abnormal reflux and esophageal motility suggested as potential mechanisms. However, prior studies showed varying results, often limited by study design/size and esophageal function/symptom measures utilized. We aimed to examine the relationship between obesity and objective esophageal function testing and patient-reported outcomes, utilizing prospective symptom, manometric and reflux monitoring data with impedance.

METHODS

Adults referred for high-resolution impedance-manometry (HRiM) and multichannel intraluminal impedance-pH monitoring (MII-pH) to evaluate esophageal symptoms were enrolled. Validated symptom and health-related quality of life (HR-QOL) instruments were prospectively collected: GERDQ, reflux symptoms index (RSI), dominant symptom intensity (DSI, multiplied 5-point Likert scales for symptom frequency/severity), global symptom severity (GSS, 100-point visual analog scale), and Short Form-12 (SF-12) for HR-QOL. Esophageal function testing measures were compared across body mass index (BMI) categories and correlated with patient-reported outcomes.

KEY RESULTS

Seven hundred and fifty four patients were included (Normal:281/Overweight:253/Class I obesity:137/Class II/III obesity:83). Reflux burden measures on MII-pH (acid exposure time, total reflux episodes, bolus exposure time), conclusive pathologic reflux (Lyon), and hiatal hernia were increased in higher obesity classes compared to normal BMI. Class II/III obesity was associated with more normal/hypercontractile swallows, less ineffective swallows, and better bolus transit on HRiM. BMI correlated positively with GERDQ/RSI/DSI/GSS, and negatively with physical component score (SF-12). Esophageal symptom severity and HR-QOL correlated strongly with MII-pH findings, but not HRiM measures.

CONCLUSIONS/INFERENCES

Obesity is associated with increased esophageal symptom burden and worse physical HR-QOL, which correlate with higher acid/bolus reflux burden but not altered esophageal motility/transit/contractile reserve.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Correlation study of renal function indices with diabetic peripheral neuropathy and diabetic retinopathy in T2DM patients with normal renal function

Background

The anticipation of diabetes-related complications remains a challenge for numerous T2DM patients, as there is presently no effective method for early prediction of these complications. This study aims to investigate the association between renal function-related indicators and the occurrence of peripheral neuropathy and retinopathy in individuals diagnosed with type 2 diabetes mellitus (T2DM) who currently have normal renal function.

Methods

Patients with T2DM who met the criteria were selected from the MMC database and divided into diabetic peripheral neuropathy (DPN) and diabetic retinopathy (DR) groups, with a total of 859 and 487 patients included, respectively. Multivariate logistic regression was used to analyze the relationship between blood urea nitrogen (BUN), creatinine (Cr), uric acid (UA), urine albumin(ALB), albumin-to-creatinine ratio (ACR), estimated glomerular filtration rate (eGFR), and diabetic peripheral neuropathy and retinopathy. Spearman correlation analysis was used to determine the correlation between these indicators and peripheral neuropathy and retinopathy in diabetes.

Results

In a total of 221 patients diagnosed with DPN, we found positive correlation between the prevalence of DPN and eGFR (18.2, 23.3, 35.7%, p < 0.05). Specifically, as BUN (T1: references; T2:OR:0.598, 95%CI: 0.403, 0.886; T3:OR:1.017, 95%CI: 0.702, 1.473; p < 0.05) and eGFR (T1: references; T2:OR:1.294, 95%CI: 0.857, 1.953; T3:OR:2.142, 95%CI: 1.425, 3.222; p < 0.05) increased, the odds ratio of DPN also increased. Conversely, with an increase in Cr(T1: references; T2:OR:0.86, 95%CI: 0.56, 1.33; T3:OR:0.57, 95%CI: 0.36, 0.91; p < 0.05), the odds ratio of DPN decreased. Furthermore, when considering sensitivity and specificity, eGFR exhibited a sensitivity of 65.2% and specificity of 54.4%, with a 95% confidence interval of 0.568-0.656.

Conclusion

In this experimental sample, we found a clear positive correlation between eGFR and DPN prevalence.

Arginine Biosynthesis Pathway Found to Play a Key Role in the Neuroprotective Effect of Liu-Wei-Luo-Bi (LWLB) Granules in Diabetic db/db Mice with Peripheral Neuropathy Using an Untargeted Metabolomics Strategy

Aim

Liu-Wei-Luo-Bi (LWLB) granules was a Chinese compound prescription for treating diabetic peripheral neuropathy (DPN). The aim of this study was to investigate the effect of LWLB granules on diabetic mice with peripheral neuropathy and to elucidate the potential mechanism based on an untargeted metabolomics approach.

Methods

One hundred forty db/db mice were randomly divided into seven groups: the Control group, DPN group, Mudan (MD) granules group, Epalrestat (Epa) group, and the LWLB low, medium, or high dose (LW-l, LW-m, or LW-h) group. After 12 weeks of treatment, body weight, blood glucose, mechanical pain threshold, motor conduction velocity (MCV), sensory conduction velocity (SCV), and Pathological Organization of the Sciatic and Caudal Nerves in mice were measured. Serum samples were collected for untargeted metabolomics analysis using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) and multivariate statistics. Disease-related pathways were screened out with function enrichment analyses of candidate biomarkers.

Results

LWLB granules can improve the peripheral neuropathy of type 2 diabetic mice with peripheral nerve conduction disorders, mainly through significantly improving the nerve conduction velocity (P < 0.05) and lowering the mechanical pain threshold (P < 0.05). A total of 43 metabolites were identified as potential biomarkers related to the therapeutic effect of LWLB granules. Fifty, 4, and 26; 23, 4, and 22; and 24, 1, and 16 biomarkers were discovered in the LW-l, LW-m, and LW-h groups at the 4th, 6th, and 12th weeks, respectively. Five, three, seven, five, and four metabolic pathways were found in MD, Epa, LW-l, LW-m, and LW-h groups, respectively. The arginine biosynthesis pathway is the overlapping pathway in LW-l, LW-m, and LW-h groups.

Conclusion

LWLB granules have an obvious neuroprotective effect on diabetic peripheral neuropathy, and the metabolism mechanism of LWLB is mainly related to the arginine biosynthesis pathway on diabetic db/db mice with peripheral neuropathy.

Adverse health outcomes and global quality of life in long-term testicular cancer survivors: a longitudinal 30-year perspective

BACKGROUND

The aim of this study was to characterize the prevalence of self-reported adverse health outcomes (AHOs), track changes in AHOs, and examine their impact on health-related quality of life (HrQoL) in testicular cancer survivors (TCSs) who were diagnosed between 1980 and 1994. These assessments were conducted during two survey waves (SWs), with the first occurring ∼12 years after surgery-only or platinum-based chemotherapy (PBCT), and the second ∼28 years after initial treatment. The study primarily focused on 'typical AHOs', which included Peripheral Sensory Neuropathy (PSN), Raynaud's phenomenon, Tinnitus, and Hearing loss.

PATIENTS AND METHODS

A total of 427 TCSs were included in the evaluation, distributed as follows: surgery-only group (n = 155), PBCT-standard group with ≤850 mg cisplatin (n = 222), and PBCT-high group with >850 mg cisplatin (n = 50). For comparison of HrQoL, men from the general population served as a control group (referred to as 'Norms'). The statistical significance level was set at P < 0.05, and clinical importance, in terms of testing HrQoL differences, was defined as Δ ≥2.5 points.

RESULTS

A higher number of TCSs who underwent PBCT reported experiencing typical AHOs compared with those who had surgery only. The highest prevalence rates were observed among TCSs who had undergone PBCT-high. Further, the number of TCSs describing typical AHOs, except Raynaud's phenomenon, increased during the observation period of 16 years. At the last SW, a median of 4 AHOs (any type) were reported after PBCT-high compared with a median of 2 AHOs after Surgery-only or after PBCT-standard. With Surgery-only as reference, PBCT-high, but not PBCT-standard, was associated with decreasing physical HrQoL in the last SW (A2 Regression coefficient: -4.3; P = 0.008). When comparing all TCSs with Norms no clinically important difference in physical and mental HrQoL was observed at either SW. However, at the last SW, TCSs after PBCT-high therapy represented a subgroup of TCSs with clinically important impairment of HRQoL. Of the typical AHOs, only PSN reduced HrQoL. Chronic fatigue, pain, anxiety/depression, sexual dysfunction, unemployment, being single, and low education were additional covariates.

CONCLUSIONS

After a median of 28 years since their treatment, HrQoL in TCSs was found to be comparable to that of Norms. This similarity held true even though AHOs, especially after PBCT-high, were becoming more prevalent among TCSs. The study revealed that individuals with a history of PBCT-high are at a high risk of experiencing a significantly increased prevalence of long-term AHOs, which subsequently leads to diminished HrQoL. It is crucial to recognize and provide specialized attention to these TCSs during lifelong follow-up care.

Approach to diagnosis, evaluation, and treatment of generalized and nonlocal dysesthesia: A review

Dysesthesia is an abnormal sensation in the skin that occurs in the absence of any extraordinary stimulus or other primary cutaneous disorders, excluding any delusions or tactile hallucinations. Clinicians have characterized dysesthesias to include sensations such as burning, tingling, pruritus, allodynia, hyperesthesia, or anesthesia. The etiology and pathogenesis of various generalized dysesthesias is largely unknown, though many dysesthesias have been associated with systemic pathologies including malignancy, infection, autoimmune disorders, and neuropathies. Dermatologists are often the first-line clinicians for patients presenting with such cutaneous findings, thus it is crucial for these physicians to be able to methodically work-up generalized dysesthesias to build a working differential diagnosis, follow up with key labs and/or imaging, and offer patients evidence-based treatment to relieve their symptoms. This broad literature review is an attempt to centralize key studies, cases, and series to help guide dermatologists in their assessment and evaluation of complaints of abnormal cutaneous sensations.

Effect of tibial nerve mobilization on balance & gait functions in subjects with subclinical diabetic neuropathy: A randomized clinical trial

Introduction

With advancing age, balance control diminishes as a result of cognitive impairment, decreased muscle strength, and impairment in visual, vestibular, and somatosensory systems. Besides aforesaid factors, the addition of diabetes to all these leads to balance and gait-related issues such as falls and fall-related injuries. Impaired balance and gait performance in diabetics are primarily attributed to the diminished sensory function of the foot and ankle region owing to diabetic neuropathy. The purpose of this study was to explicitly examine the impact of neural mobilization on the balance & gait functions of subjects having subclinical diabetic neuropathy.

Methods

40 individuals with subclinical diabetic neuropathy, ranging in age from 50 to 75 years, were assigned to two groups at random: Group 1 received the concurrent application of Tibial nerve mobilization and Balance-Gait training whereas Group 2 received only Balance-Gait training. The therapy was administered five times each week, for four weeks. On the first and last day of treatment, measurements of VPT, BBS, TUG, and DGI were taken from each subject.

Results

The results of the study found that post neural mobilization and Balance-Gait training, scores of VPT, BBS, DGI, and TUG showed improvement but it was not significant. As it is evident that diabetic neuropathy is progressive in nature, even small changes can be helpful.

Conclusion

Neural mobilization integrated with balance-gait training of subclinical diabetic neuropathic individuals resulted in improved sensory functions along with enhanced balance-gait functions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01246-w.

Urinary acrolein protein conjugates-to-creatinine ratio is positively associated with diabetic peripheral neuropathy in patients with type 2 diabetes mellitus

Acrolein, an unsaturated aldehyde, plays a pathological role in neurodegenerative diseases. However, less is known about its effects on peripheral neuropathy. The aim of this study was to investigate the association of acrolein and diabetic peripheral neuropathy in patients with type 2 diabetes. We recruited 148 ambulatory patients with type 2 diabetes. Each participant underwent an assessment of the Michigan Neuropathy Screening Instrument Physical Examination. Diabetic peripheral neuropathy was defined as Michigan Neuropathy Screening Instrument Physical Examination score ≥ 2.5. Serum levels and urinary levels of acrolein protein conjugates were measured. Urinary acrolein protein conjugates-to-creatinine ratios were determined. Patients with diabetic peripheral neuropathy had significantly higher urinary acrolein protein conjugates-to-creatinine ratios than those without diabetic peripheral neuropathy (7.91, 95% CI: 5.96-10.50 vs 5.31, 95% CI: 4.21-6.68, P = 0.029). Logarithmic transformation of urinary acrolein protein conjugates-to-creatinine ratios was positively associated with diabetic peripheral neuropathy in univariate logistic analysis, and the association remained significant in multivariate analysis (OR = 2.45, 95% CI: 1.12-5.34, P = 0.025). In conclusion, urinary acrolein protein conjugates-to-creatinine ratio may act as a new biomarker for diabetic peripheral neuropathy in type 2 diabetes. The involvement of acrolein in the pathogenesis of diabetic peripheral neuropathy warrants further investigation.

Pharmacological and Nonpharmacological Treatments for Painful Diabetic Peripheral Neuropathy

Diabetic peripheral neuropathy (DPN) is one of the most prevalent chronic complications of diabetes. The lifetime prevalence of DPN is thought to be >50%, and 15%-25% of patients with diabetes experience neuropathic pain, referred to as "painful DPN." Appropriate treatment of painful DPN is important because this pain contributes to a poor quality of life by causing sleep disturbance, anxiety, and depression. The basic principle for the management of painful DPN is to control hyperglycemia and other modifiable risk factors, but these may be insufficient for preventing or improving DPN. Because there is no promising diseasemodifying medication for DPN, the pain itself needs to be managed when treating painful DPN. Drugs for neuropathic pain, such as gabapentinoids, serotonin-norepinephrine reuptake inhibitors, tricyclic antidepressants, alpha-lipoic acid, sodium channel blockers, and topical capsaicin, are used for the management of painful DPN. The U.S. Food and Drug Administration (FDA) has approved pregabalin, duloxetine, tapentadol, and the 8% capsaicin patch as drugs for the treatment of painful DPN. Recently, spinal cord stimulation using electrical stimulation is approved by the FDA for the treatment for painful DPN. This review describes the currently available pharmacological and nonpharmacological treatments for painful DPN.

Neuropathy in prediabetes

Diabetic neuropathies are the most frequent complications of diabetes, contributing to high morbidity, excess mortality, reduced quality of life, and increased healthcare costs. Prediabetes is characterised by glucose levels within an intermediate range above normoglycaemia yet below the diagnostic threshold for diabetes. In 2021, 10.6% and 6.2% of adults worldwide were estimated to have impaired glucose tolerance and impaired fasting glucose, respectively, the majority of whom are unaware of having prediabetes. Evidence has accumulated suggesting that prediabetes is a predictor of cardiovascular disease (CVD) and increased mortality. The past 2 decades have witnessed an extensive debate, particularly among diabetologists and neurologists, as to whether prediabetes is associated with peripheral neuropathy. In this review, we elaborate on the current evidence, particularly from population-based studies supporting an increased risk of distal sensorimotor polyneuropathy (DSPN) and cardiovascular autonomic neuropathy (CAN) in people with prediabetes. Moreover, we discuss whether lifestyle interventions showing efficacy in preventing or delaying the transition from prediabetes to diabetes in persons with prediabetes may also exert favourable effects on the development and progression of DSPN and CAN. This review should help in raising the awareness of and translating the current knowledge on neuropathies in people with prediabetes into clinical practice and public health. The current recommendation that adults who are overweight or obese should be screened for prediabetes and referred to or offered preventive interventions should ultimately culminate in preventing not only CVD but also prediabetic neuropathy.

Presence of Subclinical Polyneuropathy in Patients with Elevation of Hba1c

Introduction

It is aimed to investigate the relationship between the asymptomatic individiuals with elevated HbA1c and occurrence of polyneuropathy by way of comparison to normoglycemic condition.

Methods

The study includes 30 female patients diagnosed with subclinical elevation of HbA1c and 30 normoglycemic healthy female patients who applied to our hospital polyclinics with symptoms other than neuropathy between January-March 2017. Nerve conduction examination is done in these patients, parameters of both groups are compared.

Results

In regard to amplitude distribution; when compared to control group, tibial motor and ulnar sensory nerve amplitude is lower than the control group (p<0.05). In peroneal, median and ulnar motor nerves, distal latency values are extended compared to control group (p<0.05). Sural, median and ulnar sensory nerve latency is extended compared to control group. In terms of transmission rate distribution; in sural, median and ulnar sensory nerve, transmission speed is lower compared to the control group (p<0.05).

Conclusions

In asymptomatic cases with subclinical elevation of HbA1c, peripheral nervous system involvement is monitored, and early glycemic control should be provided in order to prevent development of neuropathy in patients.

Comparison of western diet-induced obesity and streptozotocin mouse models: insights into energy balance, somatosensory dysfunction, and cardiac autonomic neuropathy

Metabolic disorders such as obesity and type 2 diabetes (T2D) are increasingly prevalent worldwide, necessitating a deeper comprehension of their underlying mechanisms. However, translating findings from animal research to human patients remains challenging. This study aimed to investigate the long-term effects of Streptozotocin (STZ) on metabolic, cardiac, and somatosensory function in mice fed a Western diet (WD) of high fat, sucrose, and cholesterol with low doses of STZ administration compared to mice fed WD alone. In our research, we thoroughly characterized energy balance and glucose homeostasis, as well as allodynia and cardiac function, all of which have been previously shown to be altered by WD feeding. Notably, our findings revealed that the treatment of WD-fed mice with STZ exacerbated dysfunction in glucose homeostasis via reduced insulin secretion in addition to impaired peripheral insulin signaling. Furthermore, both WD and WD + STZ mice exhibited the same degree of cardiac autonomic neuropathy, such as reduced heart rate variability and decreased protein levels of cardiac autonomic markers. Furthermore, both groups developed the same symptoms of neuropathic pain, accompanied by elevated levels of activating transcription factor 3 (Atf3) in the dorsal root ganglia. These discoveries enhance our understanding of metabolic activity, insulin resistance, neuropathy, and cardiac dysfunction of diet-induced models of obesity and diabetes. The exacerbation of impaired insulin signaling pathways by STZ did not lead to or worsen cardiac and somatosensory dysfunction. Additionally, they offer valuable insights into suitable diet induced translational mouse models, thereby advancing the development of potential interventions for associated conditions.

Sildenafil Enhances the Therapeutic Effect of Islet Transplantation for Diabetic Peripheral Neuropathy via mTOR/S6K1 Pathway

Purpose

This study aimed to investigate the potential mechanism underlying the therapeutic effect of sildenafil in combination with islet transplantation for diabetic peripheral neuropathy.

Methods

A streptozotocin-induced diabetic mouse model was established to evaluate the effects of islet transplantation and sildenafil intervention. The mice were subjected to different interventions for 6 weeks, and histopathological staining and immunohistochemistry techniques were employed to examine the pathological changes and protein expressions of BDNF, MBP, and cleaved caspase-3 in the sciatic nerve tissue. Moreover, RSC96 cells were cocultured with islet cells and sildenafil under high glucose conditions to investigate the potential involvement of the mTOR/S6K1 pathway, BDNF, and MBP proteins. Western blotting was used to detect protein expression in each group.

Results

The results showed that islet transplantation can restore sciatic nerve injury in diabetic mice, and sildenafil can enhance the therapeutic effect of islet transplantation. In addition, the combination of sildenafil and islet cells significantly upregulated the expression levels of mTOR/S6K1, BDNF, and MBP in RSC96 cells under high glucose conditions.

Conclusions

Islet transplantation can reverse sciatic nerve injury in diabetic mice, and islet cells exhibit a protective effect on RSC96 cells under high glucose conditions via the activation of the mTOR/S6K1 pathway. Sildenafil enhances the therapeutic effect of islet transplantation, which may represent a potential treatment strategy for diabetic peripheral neuropathy.

THE PREVALENCE OF POLYNEUROPATHY IN THE PRE-DIABETES PERIOD

Objective

This study aims to determine the prevalence of neuropathy in the prediabetic period.

Design Subjects and Method

Informed consent was attained from the patients who volunteered to participate in the study after ethics committee approval was obtained. Patients under the age of 18, having vitamin B12 or folic acid deficiency, history of collagen tissue-rheumatological disease, chronic kidney failure, cirrhosis, ethylism, thyroid disease, autoimmune disease, malignancy, tuberculosis, type 1 or 2 diabetes mellitus and pregnant women were excluded from the study. Patients diagnosed with prediabetes were evaluated by the DN4 neuropathy complaint questionnaire. Neuropathy was diagnosed in patients having a score of four or more. For the statistical analyses Student t-test, Pearson chi-square test, and Fisher's exact test were performed using the NCSS program.

Results

A total of 224 volunteers, 167 women and 57 men, were included in the study. The mean age of the participants was 51 and the mean level of hemoglobin A1C was 5.9. Neuropathy was detected in 45% of the cases. Especially in women, there was a significant increase in the frequency of neuropathy compared to men. The most common complaints found in our study were burning sensation and numbness in the extremities.

Conclusions

Similar to diabetic patients, prediabetic patients also have a high rate of neuropathy. For the early diagnosis of neuropathy and to be treated promptly, screening tests such as DN4 should be performed for all prediabetic patients. According to the test results, advanced examinations such as EMG or biopsy should be performed earlier.

Diabetic Neuropathies

OBJECTIVE

This article provides an up-to-date review of the diagnosis and management of the most common neuropathies that occur in patients with diabetes.

LATEST DEVELOPMENTS

The prevalence of diabetes continues to grow worldwide and, as a result, the burden of diabetic neuropathies is also increasing. Most diabetic neuropathies are caused by hyperglycemic effects on small and large fiber nerves, and glycemic control in individuals with type 1 diabetes reduces neuropathy prevalence. However, among people with type 2 diabetes, additional factors, particularly metabolic syndrome components, play a role and should be addressed. Although length-dependent distal symmetric polyneuropathy is the most common form of neuropathy, autonomic syndromes, particularly cardiovascular autonomic neuropathy, are associated with increased mortality, whereas lumbosacral radiculoplexus neuropathy and treatment-induced neuropathy cause substantial morbidity. Recent evidence-based guidelines have updated the recommended treatment options to manage pain associated with distal symmetric polyneuropathy of diabetes.

ESSENTIAL POINTS

Identifying and appropriately diagnosing the neuropathies of diabetes is key to preventing progression. Until better disease-modifying therapies are identified, management remains focused on diabetes and metabolic risk factor control and pain management.

Peripheral Neuropathy in Diabetes: What Can MRI Do?

Diabetes peripheral neuropathy (DPN) is commonly asymptomatic in the early stage. However, once symptoms and obvious defects appear, recovery is not possible. Diagnosis of neuropathy is based on physical examinations, questionnaires, nerve conduction studies, skin biopsies, and so on. However, the diagnosis of DPN is still challenging, and early diagnosis and immediate intervention are very important for prevention of the development and progression of diabetic neuropathy. The advantages of MRI in the diagnosis of DPN are obvious: the peripheral nerve imaging is clear, the lesions can be found intuitively, and the quantitative evaluation of the lesions is the basis for the diagnosis, classification, and follow-up of DPN. With the development of magnetic resonance technology, more and more studies have been conducted on detection of DPN. This article reviews the research field of MRI in DPN.

Evidence of impaired H-reflex and H-reflex rate-dependent depression in diabetes, prediabetes and obesity: a mini-review

Diabetes Mellitus is a public health problem associated with complications such as neuropathy; however, it has been proposed that these may begin to develop during prediabetes and may also be present in persons with obesity. Diabetic peripheral neuropathy is the presence of signs and/or symptoms of peripheral nerve dysfunction in people living with diabetes, which increases the risk of developing complications and has a deleterious impact on quality of life. As part of the therapeutic protocol for diabetes, screening tests to identify peripheral neuropathy are suggested, however, there are no recommendations for people with prediabetes and obesity without symptoms such as pain, numbness, or paresthesias. Moreover, clinical screening tests that are usually used to recognize this alteration, such as tendon reflex, temperature sensation, and pressure and vibration perception, might be subjective as they depend on the evaluator's experience thus the incorrect application of these tests may not recognize the damage to small or large-nerve fibers. Recent evidence suggests that an objective study such as the impairment of the rate-dependent depression of the H-reflex could be used as a biomarker of spinal disinhibition and hence may provide more information on sensorimotor integration.

Longitudinal Movements and Stiffness of Lower Extremity Nerves Measured by Ultrasonography and Ultrasound Elastography in Symptomatic and Asymptomatic Populations: A Systematic Review With Meta-analysis

This study was aimed at analyzing the effectiveness of ultrasonography (US) and ultrasound elastography (UE) in evaluating longitudinal sliding and stiffness of nerves. In line with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, we analyzed 1112 publications (range: 2010-2021) extracted from MEDLINE, Scopus and Web of Science focusing on specific outcomes, including shear wave velocity (m/s), shear modulus (kPa), strain ratio (SR) and excursion (mm). Thirty-three papers were included and evaluated for overall quality and risk of bias. From the analysis of data concerning 1435 participants, mean shear wave velocity (SWV) in the sciatic nerve was 6.70 ± 1.26 m/s in controls and 7.51 ± 1.73 m/s in participants presenting with leg pain; in the tibial nerve, mean SWV was 3.83 ± 0.33 m/s in controls and 3.42 ± 3.53 m/s in participants presenting with diabetic peripheral neuropathy (DPN). The mean shear modulus (SM) was 20.9 ± 9.33 kPa for sciatic nerve, whereas it was an average of 23.3 ± 7.20 kPa for the tibial nerve. Considering 146 subjects (78 experimental, 68 controls) no significant difference was observed in SWV when comparing participants with DPN with controls (standard mean difference [SMD]: 1.26, 95% confidence interval [CI]: 0.54, 1.97), whereas a significant difference was observed in the SM (SMD: 1.78, 95% CI: 1.32, 2.25); furthermore, we found significant differences between left and right extremity nerves (SMD:1.14. 95% CI: 0.45, 1.83) among 458 participants (270 with DPN and 188 controls). No descriptive statistics are available for excursion because of the variability in participants and limb positions, whereas SR is considered only a semiquantitative outcome and therefore not comparable among different studies. Despite the presence of some limitations in study designs and methodological biases, on the basis of our findings, we can conclude that US and UE are effective methods in assessing longitudinal sliding and stiffness of lower extremity nerves in both symptomatic and asymptomatic subjects.

Association of reproductive factors and exogenous hormone use with distal sensory polyneuropathy among postmenopausal women in the United States: results from 1999 to 2004 NHANES

Postmenopausal status is a risk factor for distal sensory polyneuropathy-the most common type of peripheral neuropathy. We aimed to investigate associations between reproductive factors and history of exogenous hormone use with distal sensory polyneuropathy among postmenopausal women in the United States using data from the National Health and Nutrition Examination Survey 1999-2004, and to explore the modifying effects of ethnicity on these associations. We conducted a cross-sectional study among postmenopausal women aged ≥ 40 years. Women with a history of diabetes, stroke, cancer, cardiovascular disease, thyroid disease, liver disease, weak or failing kidneys, or amputation were excluded. Distal sensory polyneuropathy was measured using a 10-g monofilament test, and a questionnaire was used to collect data on reproductive history. Multivariable survey logistic regression was used to test the association between reproductive history variables and distal sensory polyneuropathy. In total, 1144 postmenopausal women aged ≥ 40 years were included. The adjusted odds ratios were 8.13 [95% confidence interval (CI) 1.24-53.28] and 3.18 (95% CI 1.32-7.68) for age at menarche < 11 years and time since menopause > 20 years, respectively, which were positively associated with distal sensory polyneuropathy; adjusted odds ratios were 0.45 for the history of breastfeeding (95% CI 0.21-0.99) and 0.41 for exogenous hormone use (95% CI 0.19-0.87) were negatively associated. Subgroup analysis revealed ethnicity-based heterogeneity in these associations. Age at menarche, time since menopause, breastfeeding, and exogenous hormone use were associated with distal sensory polyneuropathy. Ethnicity significantly modified these associations.

Excitatory and inhibitory neuronal signaling in inflammatory and diabetic neuropathic pain

Pain, although unpleasant, is an essential warning mechanism against injury and damage of the organism. An intricate network of specialised sensors and transmission systems contributes to reception, transmission and central sensitization of pain. Here, we briefly introduce some of the main aspects of pain signal transmission, including nociceptors and nociceptive signals, mechanisms of inflammatory and neuropathic pain, and the situation of diabetes-associated neuropathic pain. The role of glia-astrocytes, microglia, satellite glia cells-and their specific channels, transporters and signaling pathways is described. A focus is on the contribution of inhibitory synaptic signaling to nociception and a possible role of glycine receptors in glucose-mediated analgesia and treatment-induced diabetic neuropathy. Inhibitory receptors such as GABA_A- and glycine receptors are important contributors to nociceptive signaling; their contribution to altered pain sensation in diabetes may be of clinical relevance, and they could be promising therapeutic targets towards the development of novel analgesics.

Validity and reliability of the Polish version of the Michigan Neuropathy Screening Instrument

BACKGROUND

Diabetic sensorimotor polyneuropathy is an important risk factor for foot ulceration and amputation. Thus, patients with diabetes should be screened for this disorder according to local guidelines. An obstacle to the diagnosis of this disease may be the lack of unified diagnostic criteria due to the lack of properly validated scales used for assessment.

AIM

To validate both sections (A and B) of the Michigan Neuropathy Screening Instrument (MNSI) in Polish (PL) patients with diabetes.

METHODS

A cross-sectional study using a test (A1, B1) and re-test (A2, B2) formula was performed in 80 patients with diabetes. The gold standard used for neuropathy detection was a nerve conduction study (NCS) which was performed in all participants. Reliability of the MNSI-PL was assessed using the Cronbach’s alpha, Kuder-Richardson formula 20 (KR-20), split-half reliability, the Gottman split-half tests, and correlation between first and second half was accessed. Stability was assessed using an intraclass correlation coefficient (ICC). For external validation, we used simple linear correlation, binomial regression, and agreement between two different tools using a Bland-Altman plot analysis.

RESULTS

The scale was internally consistent (Cronbach’s alpha for the full scale: 0.81 for A and 0.87 for B). MNSI-PL scores in test/retest showed high stability (ICC = 0.73 for A and ICC = 0.97 for B). The statistically important correlations between MNSI-PL and NCS were found for B1, B2, and A1 (P < 0.005). The cut-off points of ≥ 3 for section A (sensitivity of 90%-100%; specificity of 33%-40%) and ≥ 2 for section B (sensitivity of 81%-84%; specificity of 60%-70%) were obtained during neuropathy detection.

CONCLUSION

The MNSI-PL is a reliable and valid instrument in screening for diabetic neuropathy.

Methods for evaluation of corneal nerve fibres in diabetes mellitus by in vivo confocal microscopy: a scoping review protocol

INTRODUCTION

Globally, 422 million people have diabetes. Late complications of diabetes are blindness, kidney failure, heart attack, stroke and lower limb amputation. The prevalence of diabetic peripheral neuropathy and diabetic retinopathy is 50% and 35%, respectively. In vivo confocal microscopy (IVCM) is a rapid, non-invasive method to evaluate subbasal corneal nerve fibres, which are small fibres of the peripheral nervous system. Corneal nerve fibre changes can be a marker of diabetic peripheral neuropathy. There is currently no gold-standard procedure for IVCM imaging, image processing or quantitative analysis of the corneal nerve fibres in the subbasal plexus. This protocol describes a scoping review to map, summarise and critically evaluate current methods used with IVCM evaluation in people with diabetes mellitus.

METHODS

The scoping review will follow Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for scoping review. A comprehensive search of the literature will be conducted in MEDLINE, Embase, Cochrane, Scopus and Web of Science. The search strategy will include terms related to IVCM, diabetes and corneal nerve fibres. We will set inclusion and exclusion criteria prior to the search, and two reviewers will screen titles and abstracts independently. One reviewer will full text read eligible articles and chart data from the studies. A descriptive summary of the methods used in imaging, image processing and quantitative analysis of peripheral corneal nerve fibres by IVCM will be written.

ETHICS AND DISSEMINATION

Ethical approval is not required since this is a scoping review based on previously published articles. The findings will be published in a scientific peer-reviewed journal.

Biomarkers in diabetic neuropathy

CONTEXT

The prevalence of diabetic neuropathy is drastically increasing in the world. To halt the progression of diabetic neuropathy, there is an unmet need to have potential biomarkers for the diagnosis and new drug discovery.

OBJECTIVE

To study various biomarkers involved in the pathogenesis of diabetic neuropathy.

METHODS

The literature was searched with the help of various scientific databases and resources like PubMed, ProQuest, Scopus, and Google scholar from the year 1976 to 2020.

RESULTS

Biomarkers of diabetic neuropathy are categorised as inflammatory biomarkers such as MCP-1, VEGF, TRPV1, NF-κB; oxidative biomarkers such as adiponectin, NFE2L2; enzyme biomarkers like NADPH, ceruloplasmin, HO-1, DPP-4, PARP α; miscellaneous biomarkers such as SIRT1, caveolin 1, MALAT1, and microRNA. All biomarkers have a significant role in the pathogenesis of diabetic neuropathy.

CONCLUSION

These biomarkers have a potential role in the progression of diabetic neuropathy and can be considered as potential targets for new drug discovery.

Does irisin has neuroprotective effect against diabetes induced neuropathy in male rats?

We aimed to investigate the contribution of irisin in the neuroprotective process of exercise training in diabetic rats. Serum irisin levels, thermal and mechanical pain thresholds and intracellular calcium ([Ca²⁺]_i) levels in sensory neurons were measured at different time intervals during the eight weeks of exercise sessions for the control, non-exercise diabetics (3 groups) and exercise performing (low and high intensity groups) diabetic rats (n = 7-10 for all groups). Non-exercise diabetic groups were treated with irisin in different doses (1, 10 and 20 µg/kg respectively). Recovered pain thresholds at the end of the exercise sessions (p < .05), higher serum irisin levels that compared to control and diabetics (p < .05) and insignificant mean [Ca2⁺]_i peak amplitudes in sensory neurons (p > .05) obtained from experiments. Furthermore, irisin injection decreased the thermal pain threshold of diabetics only at 60th minutes (p < .05). Irisin may have a role in the neuroprotective effect of exercise training.

The Association of Inflammatory Factors With Peripheral Neuropathy: The Study of Women's Health Across the Nation

PURPOSE

Previous work has focused on the role of diabetes in peripheral neuropathy (PN), but PN often occurs before, and independently from, diabetes. This study measures the association of cardiometabolic and inflammatory factor with PN, independent of diabetes.

METHODS

Study of Women's Health Across the Nation participants (n = 1910), ages 60 to 73 (mean 65.6) were assessed for PN by symptom questionnaire and monofilament testing at the 15th follow-up visit (V15). Anthropometric measures and biomarkers were measured at study baseline approximately 20 years prior, and C-reactive protein (CRP) and fibrinogen were measured longitudinally. Log-binomial regression was used to model the association between metabolic syndrome (MetS), obesity (≥35 body mass index), CRP, and fibrinogen with PN, adjusting for sociodemographic and health behavior measures.

RESULTS

Baseline MetS [prevalence ratio (PR) 1.79, 95% CI (1.45, 2.20)], obesity [PR 2.08 (1.65, 2.61)], median CRP [PR 1.32 per log(mg/dL), (1.20, 1.45)], and mean fibrinogen (PR 1.28 per 100 mg/dL, (1.09, 1.50)] were associated with PN symptoms at V15. After excluding participants with baseline diabetes or obesity, MetS [PR 1.59 (1.17, 2.14)] and CRP [PR 1.19 per log(mg/dL), (1.06, 1.35)] remained statistically significantly associated with PN. There was a negative interaction between MetS and obesity, and the association between these conditions and PN was mediated by CRP.

CONCLUSIONS

Cardiometabolic factors and inflammation are significantly associated with PN, independent of diabetes and obesity. CRP mediates the relationship of both obesity and MetS with PN, suggesting an etiological role of inflammation in PN in this sample.

Sympathetic System in Wound Healing: Multistage Control in Normal and Diabetic Skin

In this review, we discuss sympathetic regulation in normal and diabetic wound healing. Experimental denervation studies have confirmed that sympathetic nerve endings in skin have an important and complex role in wound healing. Vasoconstrictor neurons secrete norepinephrine (NE) and neuropeptide Y (NPY). Both mediators decrease blood flow and interact with inflammatory cells and keratinocytes. NE acts in an ambiguous way depending on receptor type. Beta2-adrenoceptors could be activated near sympathetic endings; they suppress inflammation and re-epithelialization. Alpha1- and alpha2-adrenoceptors induce inflammation and activate keratinocytes. Sudomotor neurons secrete acetylcholine (ACh) and vasoactive intestinal peptide (VIP). Both induce vasodilatation, angiogenesis, inflammation, keratinocytes proliferation and migration. In healthy skin, all effects are important for successful healing. In treatment of diabetic ulcers, mediator balance could be shifted in different ways. Beta2-adrenoceptors blockade and nicotinic ACh receptors activation are the most promising directions in treatment of diabetic ulcers with neuropathy, but they require further research.

Association Between Breastfeeding and Reduced Distal Sensory Polyneuropathy in Postmenopausal Women Aged 40-70 Years: Analysis of Data from the 1999-2004 National Health and Nutrition Examination Survey

Background: Distal sensory polyneuropathy (DSP) is a common peripheral neuropathy subtype. We aimed to determine the association between breastfeeding and DSP among postmenopausal women aged 40-70 years, and the effect modification of obesity on this association. Methods: A cross-sectional study was conducted using data from the National Health and Nutrition Examination Survey 1999-2004. Postmenopausal women aged 40-70 years were included. Women with diabetes, stroke, cancer, cardiovascular disease, thyroid disease, liver disease, weak/failing kidneys, or amputation were excluded. Binary logistic regression was used to analyze the association between breastfeeding and DSP. Results: Among 798 participants, 386 (44.30%) reported breastfeeding history and 51 (5.29%) were defined as having DSP using the monofilament test. A significant inverse association was observed between breastfeeding and DSP (odds ratio [OR] = 0.29; 95% confidence interval [CI]: 0.11-0.79; p = 0.017) after adjusting for other confounding variables. In subgroup analysis, this adjusted association was observed only in the obese group (OR = 0.21; 95% CI: 0.06-0.73, p = 0.013). Conclusions: Breastfeeding was found to have potential benefits in the presence of DSP in postmenopausal women aged 40-70 years, and obesity modified the association between breastfeeding and DSP. Promoting breastfeeding may reduce the burden of peripheral neuropathy in middle-aged postmenopausal women.

Neuropathy, its Profile and Experimental Nerve Injury Neuropathic Pain Models: A Review

Neuropathy is a terrible disorder that has a wide range of etiologies. Drug-induced neuropathy, which happens whenever a chemical agent damages the peripheral nerve system, has been linked here to the iatrogenic creation of some drugs. It is potentially permanent and causes sensory impairments and paresthesia that typically affects the hands, feet, and stockings; motor participation is uncommon. It might appear suddenly or over time, and the long-term outlook varies. The wide range of chronic pain conditions experienced by people has been one of the main obstacles to developing new, more effective medications for the treatment of neuropathic pain. Animal models can be used to examine various neuropathic pain etiologies and symptoms. Several models investigate the peripheral processes of neuropathic pain, whereas some even investigate the central mechanisms, such as drug induce models like vincristine, cisplatin, bortezomib, or thalidomide, etc., and surgical models like sciatic nerve chronic constriction injury (CCI), sciatic nerve ligation through spinal nerve ligation (SNL), sciatic nerve damage caused by a laser, SNI (spared nerve injury), etc. The more popular animal models relying on peripheral nerve ligatures are explained. In contrast to chronic sciatic nerve contraction, which results in behavioral symptoms of less reliable stressful neuropathies, (SNI) spared nerve injury generates behavioral irregularities that are more feasible over a longer period. This review summarizes the latest methods models as well as clinical ideas concerning this mechanism. Every strongest current information on neuropathy is discussed, along with several popular laboratory models for causing neuropathy.

Function and mechanism of mesenchymal stem cells in the healing of diabetic foot wounds

Diabetes has become a global public health problem. Diabetic foot is one of the most severe complications of diabetes, which often places a heavy economic burden on patients and seriously affects their quality of life. The current conventional treatment for the diabetic foot can only relieve the symptoms or delay the progression of the disease but cannot repair damaged blood vessels and nerves. An increasing number of studies have shown that mesenchymal stem cells (MSCs) can promote angiogenesis and re-epithelialization, participate in immune regulation, reduce inflammation, and finally repair diabetic foot ulcer (DFU), rendering it an effective means of treating diabetic foot disease. Currently, stem cells used in the treatment of diabetic foot are divided into two categories: autologous and allogeneic. They are mainly derived from the bone marrow, umbilical cord, adipose tissue, and placenta. MSCs from different sources have similar characteristics and subtle differences. Mastering their features to better select and use MSCs is the premise of improving the therapeutic effect of DFU. This article reviews the types and characteristics of MSCs and their molecular mechanisms and functions in treating DFU to provide innovative ideas for using MSCs to treat diabetic foot and promote wound healing.

Development and validation of a risk prediction model for early diabetic peripheral neuropathy based on a systematic review and meta-analysis

Background

Early identification and intervention of diabetic peripheral neuropathy is beneficial to improve clinical outcome.

Objective

To establish a risk prediction model for diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes mellitus (T2DM).

Methods

The derivation cohort was from a meta-analysis. Risk factors and the corresponding risk ratio (RR) were extracted. Only risk factors with statistical significance were included in the model and were scored by their weightings. An external cohort were used to validate this model. The outcome was the occurrence of DPN.

Results

A total of 95,604 patients with T2DM from 18 cohorts were included. Age, smoking, body mass index, duration of diabetes, hemoglobin A1c, low HDL-c, high triglyceride, hypertension, diabetic retinopathy, diabetic kidney disease, and cardiovascular disease were enrolled in the final model. The highest score was 52.0. The median follow-up of validation cohort was 4.29 years. The optimal cut-off point was 17.0, with a sensitivity of 0.846 and a specificity of 0.668, respectively. According to the total scores, patients from the validation cohort were divided into low-, moderate-, high- and very high-risk groups. The risk of developing DPN was significantly increased in moderate- (RR 3.3, 95% CI 1.5-7.2, P = 0.020), high- (RR 15.5, 95% CI 7.6-31.6, P < 0.001), and very high-risk groups (RR 45.0, 95% CI 20.5-98.8, P < 0.001) compared with the low-risk group.

Conclusion

A risk prediction model for DPN including 11 common clinical indicators were established. It is a simple and reliable tool for early prevention and intervention of DPN in patients with T2DM.

The curious case of SARM1: Dr. Jekyll and Mr. Hyde in cell death and immunity?

Sterile alpha and toll/interleukin-1 receptor motif-containing protein 1 (SARM1) was first identified as a novel ortholog of Drosophila protein CG7915 and was subsequently placed as the fifth member of the human TIR-containing adaptor protein. SARM1 holds a unique position in this family where, unlike other members, it downregulates NFκB activity in response to immunogenic stimulation, interacts with another member of the family, TRIF, to negatively regulate its function, and it also mediates cell death responses. Over the past decade, SARM1 has emerged as one of the primary mediators of programmed axonal degeneration and this robust regulation of axonal degeneration-especially in models of peripheral neuropathy and traumatic injury-makes it an attractive target for therapeutic intervention. The TIR domain of SARM1 possesses an intrinsic NADase activity resulting in cellular energy deficits within the axons, a striking deviation from its other family members of human TLR adaptors. Interestingly, the TIR NADase activity, as seen in SARM1, is also observed in several prokaryotic TIR-containing proteins where they are involved in immune evasion once within the host. Although the immune function of SARM1 is yet to be conclusively discerned, this closeness in function with the prokaryotic TIR-domain containing proteins, places it at an interesting juncture of evolution raising questions about its origin and function in cell death and immunity. In this review, we discuss how a conserved immune adaptor protein like SARM1 switches to a pro-neurodegenerative function and the evolutionarily significance of the process.

Clinical Utility of Boston-CTS and Six-Item CTS Questionnaires in Carpal Tunnel Syndrome Associated with Diabetic Polyneuropathy

Diabetic polyneuropathy (DPN) is the most frequent complication of diabetes. Carpal tunnel syndrome (CTS), one of the most common neuropathies, is a chronic compression of the median nerve at the wrist. In our prospective cross-sectional study, we enrolled patients with type 2 diabetes presenting with signs and symptoms suggestive of DPN (n = 53). We aimed to compare two clinical scales: the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) and the six-item CTS symptoms scale (CTS-6), with nerve conduction studies (NCS) for detecting CTS in patients with DPN. Carpal tunnel syndrome and DPN were clinically evaluated, and the diagnosis was confirmed by NCS. Depending on the NCS parameters, the study group was divided into patients with and without DPN. For each group, we selected patients with CTS confirmed through NCS, and the results were compared with the BCTQ and CTS-6 scales. The clinical evaluation of CTS performed through BCTQ and CTS-6 was statistically significantly different between patients with and without CTS. When comparing the BCTQ questionnaire with the NCS tests, we found area under the curve (AUC) = 0.76 (95% CI 0.65-0.86) in patients with neuropathy and AUC = 0.72 (95% CI 0.55-0.88) in patients without neuropathy. At the same time, the AUC values of the CTS-6 scale were 0.76 (95% CI 0.61-0.88) in patients with neuropathy and 0.70 (95% CI 0.51-0.86) in patients without neuropathy. Using multiple logistic regression, we demonstrated that DPN increased the chances of detecting CTS using the two questionnaires. The Boston Carpal Tunnel Syndrome and CTS-6 questionnaires can be used in the diagnosis of CTS in diabetic patients with and without DPN but with moderate AUC. The presence of DPN increased the chances of detecting CTS using the BCTQ questionnaire and the CTS-6 scale.

ABCA1 C69T Gene Polymorphism Association with Dysglycemia in Saudi Prediabetic Adults

Studies suggest that ATP-binding cassette transporter A1 (ABCA1 C69T) polymorphism is associated with a decreased incidence of type 2 diabetes mellitus (T2DM) and that there is an association between ABCA1 C69T polymorphism and the risk of dyslipidemia in diabetic individuals. However, other studies contradict these suggestions. Therefore, we aimed to investigate the prevalence of ABCA1 C69T (rs1800977) gene polymorphism in a representative sample of the Saudi population not previously diagnosed with diabetes and its possible association with dyslipidemia and dysglycemia. A cross-sectional design was used to recruit nondiabetic adults of both genders from the Saudi population in Jeddah by employing a stratified, two-stage cluster sampling method. A total of 650 people (337 men and 313 women) were recruited. Demographic, dietary, and lifestyle variables, as well as medical history and family history of chronic diseases, were collected using a predesigned questionnaire. Fasting blood samples were taken for the determination of fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), and lipids profile, which were followed by a 1-h oral glucose tolerance test (OGTT). Real-time PCR technology was used to determine the ABCA1 C69T gene SNP (rs1800977). The T allele of ABCA1 C69T (rs1800977) was very frequent (TT in 44.9% and CT in 43.7%). There was a trend toward significance for a higher dysglycemia percentage in people with CT and TT genotypes (25.7%, and 23.3%, respectively) compared with CC genotypes (16.2%). In addition, FPG and 1-h plasma glucose were significantly higher in people with both TT and CT genotypes compared to CC genotypes. However, T allele was not associated with any dysregulation of lipid parameters.

Patterns and Correlates of Physical Symptoms among People with Peripheral Neuropathy

Background

As the population ages and more people are affected by multiple chronic conditions, the prevalence of Peripheral Neuropathy (PN) has also rapidly increased. This swift rise in PN leaves clinicians and patients challenged by a lack of consistent diagnosis and treatment guidelines.

Purpose

To assist those affected by PN, it is imperative to understand the breadth of symptoms, experiences, and factors related to the quality of life. The primary aims of this study are to (1) characterize the symptoms of PN in a nationwide sample; (2) discern differences in symptom clusters, given perceived causes of PN; and (3) identify significant physiological symptoms related to the quality of life for people with PN.

Methods

An online survey of people in online PN support groups. Participants were recruited primarily via an open request sent to recipients of web-based communications from nationally recognized online PN support groups. Inclusion criteria were as follows: Self-reported diagnosis of PN, ability to read English or Spanish, residence in the U.S., and age ≥ 18 years.

Results

A total of 608 individuals with PN were included in the analysis. This sample represents 49 U.S. states and the District of Colombia; 221 were male and 387 female. Their disease severity and etiology were similar to previously reported information on this population, with 53.3% of respondents suffering from PN without a known cause. Among known causes, diabetes was the most common (19.6%), followed by chemotherapy (6.9%) and autoimmune diseases (3.6%). Factors affecting the quality of life among people with PN included lower extremity mobility, upper extremity mobility, sleep disturbance, depressive symptoms, and patient activation.

Fasting plasma glucose and HbA1c levels predict the risk of type 2 diabetes and diabetic retinopathy in a Thai high-risk population with prediabetes

Introduction: The incidences of diabetes and diabetic retinopathy (DR) in Thai high-risk individuals with prediabetes have not been identified. This study compared diabetes and DR incidences among people at risk with different glycemic levels, using fasting plasma glucose (FPG) and hemoglobin A1C (HbA1c).

Materials and methods: A historical cohort study estimating risk of type 2 diabetes and DR was conducted among outpatients, using FPG and HbA1c measurements at recruitment and monitored for ≥5 years. High-risk participants (defined as having metabolic syndrome or atherosclerotic cardiovascular disease) were categorized by glycemic level into 4 groups: 1) impaired fasting glucose (IFG)-/HbA1c- (FPG &lt;110 mg/dl; HbA1c &lt; 6.0%); 2) IFG+/HbA1c- (FPG 110–125 mg/dl; HbA1c &lt; 6.0%); 3) IFG-/HbA1c+ (FPG &lt;110 mg/dl; HbA1c 6.0%–6.4%); and 4) IFG+/HbA1c+ (FPG 110–125 mg/dl; HbA1c 6.0%–6.4%). The incidences of type 2 diabetes mellitus (T2DM) and DR were obtained and estimated using Kaplan-Meier analysis. Cox regression models explored hazard ratios (HRs).

Results: We recruited 8,977 people at risk (metabolic syndrome, 89.9%; atherosclerotic cardiovascular disease, 16.9%). The baseline cohort consisted of 1) IFG-/HbA1c- (n = 4,221; 47.0%); 2) IFG+/HbA1c- (n = 1,274; 14.2%); 3) IFG-/HbA1c+ (n = 2,151; 24.0%); and 4) IFG+/HbA1c+ (n = 1,331; 14.8%). Their 5-year T2DM incidences were 16.0%, 26.4%, 30.8%, and 48.5% (p &lt; 0.001). The median DR follow-up was 7.8 years (interquartile range, 7.0–8.4 years). The DR incidences were 0.50, 0.63, 1.44, and 2.68/1,000 person-years (p &lt; 0.001) for IFG-/HbA1c-, IFG+/HbA1c-, IFG-/HbA1c+, and IFG+/HbA1c+, respectively. Compared with IFG-/HbA1c-, the multivariable-adjusted HRs (95% CI) for incident diabetes were 1.94 (1.34–2.80), 2.45 (1.83–3.29), and 4.56 (3.39–6.15) for IFG+/HbA1c-, IFG-/HbA1c+, and IFG+/HbA1c+, respectively. As for incident DR, the corresponding HRs were 0.67 (0.08–5.76), 4.74 (1.69–13.31), and 5.46 (1.82–16.39), respectively.

Conclusion: The 5-year incidence of T2DM in Thai high-risk participants with prediabetes was very high. The incidences of diabetes and DR significantly increased with higher degrees of dysglycemia. High-risk people with FPG 110–125 mg/dl and HbA1c 6.0%–6.4% were more likely to develop T2DM and DR. Such individuals should receive priority lifestyle and pharmacological management.

Schwann cells-derived exosomal miR-21 participates in high glucose regulation of neurite outgrowth

As a common complication of diabetes, the pathogenesis of diabetic peripheral neuropathy (DPN) is closely related to high glucose but has not been clarified. Exosomes can mediate crosstalk between Schwann cells (SC) and neurons in the peripheral nerve. Herein, we found that miR-21 in serum exosomes from DPN rats was decreased. SC proliferation was inhibited, cell apoptosis was increased, and the expression of miR-21 in cells and exosomes was downregulated when cultured in high glucose. Increasing miR-21 expression reversed these changes, while knockdown of miR-21 led to the opposite results. When co-cultured with exosomes derived from SC exposed to high glucose, neurite outgrowth was inhibited. On the contrary, neurite outgrowth was accelerated when incubated with exosomes rich in miR-21. We further demonstrated that the SC-derived exosomal miR-21 participates in neurite outgrowth probably through the AKT signaling pathway. Thus, SC-derived exosomal miR-21 contributes to high glucose regulation of neurite outgrowth.

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The miR-21 was decreased in serum exosomes and sciatic nerve of DPN rats

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High glucose inhibited SC viability and downregulated the expression of miR-21

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Exosomes derived from SC cultured in high glucose inhibited the neurite outgrowth

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SC-derived exosomes rich in miR-21 accelerated the neurite outgrowth of neuron