Inflammation as a Therapeutic Target for Diabetic Neuropathies

Diabetic neuropathy: cutting-edge research and future directions

Diabetic neuropathy (DN) is a prevalent and debilitating complication of diabetes mellitus, significantly impacting patient quality of life and contributing to morbidity and mortality. Affecting approximately 50% of patients with diabetes, DN is predominantly characterized by distal symmetric polyneuropathy, leading to sensory loss, pain, and motor dysfunction, often resulting in diabetic foot ulcers and lower-limb amputations. The pathogenesis of DN is multifaceted, involving hyperglycemia, dyslipidemia, oxidative stress, mitochondrial dysfunction, and inflammation, which collectively damage peripheral nerves. Despite extensive research, disease-modifying treatments remain elusive, with current management primarily focusing on symptom control. This review explores the complex mechanisms underlying DN and highlights recent advances in diagnostic and therapeutic strategies. Emerging insights into the molecular and cellular pathways have unveiled potential targets for intervention, including neuroprotective agents, gene and stem cell therapies, and innovative pharmacological approaches. Additionally, novel diagnostic tools, such as corneal confocal microscopy and biomarker-based tests, have improved early detection and intervention. Lifestyle modifications and multidisciplinary care strategies can enhance patient outcomes. While significant progress has been made, further research is required to develop therapies that can effectively halt or reverse disease progression, ultimately improving the lives of individuals with DN. This review provides a comprehensive overview of current understanding and future directions in DN research and management.

Inflammation and autophagy in peripheral nerves of rodent models with metabolic syndrome and type 2 diabetes mellitus

Metabolic syndrome (MetS) and type 2 diabetes mellitus (T2D) are associated with inflammation and the accumulation of macrophages in peripheral nerves, which increases the risk of developing peripheral neuropathy (PN). We have previously investigated that macrophage infiltration in the peripheral nerves of animals with T2D (leptin-deficient ob/ob mice, leptin receptor-deficient db/db) correlated with PN, whereas this process in animals with MetS (Wistar Ottawa Karlsburg W (RT1u) WOKW rat) did not lead to neuropathic changes. Additional data presented in this study suggest an association between increased mRNA expression of the anti-inflammatory marker IL-10 and autophagy in the prevention of neuropathy.

Uncoupling protein 1-mediated protective effects of β3-adrenergic receptor agonist on kidney fibrosis via promoting adipose tissue browning in diabetic mice

BACKGROUND

Diabetes mellitus (DM) is a global health concern. Diabetic kidney disease (DKD) is a prevalent severe complication of DM and therapy is urgently needed. Adipose tissue (AT) plays a crucial role in the energy mediation through glucolipid metabolism. Mirabegron is a specific β3-adrenergic receptor agonist, which can activate thermogenesis in adipocytes, improve energy consumption, and increase insulin sensitivity and glucose tolerance. Therefore, mirabegron may play a role in DKD pathogenesis. However, its effects and precise mechanisms remain unclear.

METHODS

A DKD mouse model based on type 2 DM (T2DM) was constructed and treated with mirabegron. Mice with AT surgically removed and mice with uncoupling protein 1 (Ucp1) knockout were used to confirm whether thermogenesis induced by mirabegron was the key process.

RESULTS

Mirabegron promoted AT browning in DKD mice. Mirabegron increased insulin sensitivity, promoted glucolipid metabolism, reduced inflammatory factor levels in kidney tissue, and improved renal function and fibrosis in DKD mice. Notably, all of these benefits disappeared in AT-removed DKD mice or in Ucp1 knockout DKD mice.

CONCLUSIONS

Mirabegron protects against kidney fibrosis in DM mice by activating AT thermogenesis via the UCP1 pathway. Thus, mirabegron may provide a promising potential option for DKD therapy.

High-Resolution Whole-Genome DNA Methylation Revealed Unique Signatures of Painful Diabetic Neuropathy

ARTICLE HIGHLIGHTS

Approximately one out of two patients with diabetes develops diabetic neuropathy; of these, 20% experience neuropathic pain. Risk factors for neuropathic pain are largely unknown; however, DNA methylation was recently associated with neuropathies and degeneration of nerve fibers. The aim of this work was to describe the DNA methylation signature and identify genes associated with neuropathic pain in type 2 diabetes mellitus (T2DM). We discovered distinct DNA methylation signatures that differentiate painful and painless neuropathy phenotypes associated with T2DM and identified genes with potential as therapeutic targets for neuropathic pain, such as GCH1, MYT1L, and MED16. This work can serve as reference hallmark for future studies on painful diabetic neuropathy and other chronic pain conditions.

Exploring the role of exosomes in diabetic neuropathy: From molecular mechanisms to therapeutic potential

Diabetic neuropathy (DN) is a debilitating complication of diabetes mellitus (DM), characterized by progressive neuronal damage, sensory dysfunction, and impaired quality of life. Recent advances in exosome research have elucidated their crucial role in DN's pathogenesis, diagnosis, and treatment. Exosomes-nanoscale extracellular vesicles-function as vehicles for molecular cargo, including microRNAs (miRNAs), proteins, and lipids, which mediate intercellular communication and regulate key biological processes. Pathologically, hyperglycemia and hyperlipidemia induce the release of exosomes enriched with pathogenic miRNAs, such as miR-130a and miR-20b-3p, which disrupt neuronal function, axonal regeneration, and inflammatory pathways. Conversely, diagnostic studies highlight the utility of exosomal biomarkers like miR-7 and miR-221 in the early detection and monitoring of DN. Therapeutically, Schwann cell-derived and mesenchymal stromal cell (MSC)-derived exosomes demonstrate neuroprotective and reparative effects by enhancing mitochondrial function, modulating inflammation, and promoting axonal repair. Emerging approaches, including engineered exosomes and miRNA-enriched vesicles, further expand their therapeutic potential. Despite these advances, challenges such as standardization, large-scale production, and clinical validation remain in translating these findings into clinical practice. This review underscores the multifaceted roles of exosomes in DN and highlights their potential as innovative tools for precision diagnostics and targeted therapies, paving the way for future research and clinical applications.

The Impact of High Glycated Hemoglobin A1c on Prognosis in Patients with Bell's Palsy: A Propensity Score Matchingatched Analysis

Background

Glycated hemoglobin A1c (HbA1c) is an indicator of blood glucose levels, but the impact of hyperglycemia on Bell's palsy (BP) remains unclear. This study aims to assess the influence of high and low HbA1c levels on the prognosis of patients with BP.

Methods

This monocentric, retrospective study included 712 patients with BP, divided into 103 patients with HbA1c ≥ 6.5% and 609 patients with HbA1c < 6.5%. Receiver operating characteristic curve analysis was used to evaluate the main factors affecting HbA1c levels. Propensity score matching (PSM) was further utilized to avoid selection bias and disproportionate distributions of confounding factors between the 2 groups. The House-Brackmann (H-B) facial nerve grading system was employed to assess the severity of facial motor dysfunction.

Results

Analysis showed that high HbA1c patients were older, had higher body mass index, less frequently suffered from dysgeusia, and more often had hypertension (P < .05). According to the area under the curve, age had the greatest impact on HbA1c levels (95% CI=0.748-0.803, P <.001). After PSM 1 : 1 matching, there was no statistical difference in initial H-B grade between the 2 groups, but there was a statistical difference in final H-B grade (P = .023), indicating a worse prognosis for patients with BP in the high HbA1c group.

Conclusion

The study, after controlling for confounding factors, showed that patients with BP and high HbA1c have a worse prognosis, suggesting that controlling blood glucose levels has a positive significance for the recovery of patients with BP.

Mitigative effect of sodium alginate on streptozotocin (STZ)-induced diabetic neuropathy through regulation of redox status and miR-146a in the rat sciatic nerve

Diabetic peripheral neuropathy (DPN) is a significant complication of diabetes with limited effective therapeutic options. Sodium alginate (SA), a natural polysaccharide from brown algae, has demonstrated health benefits, however, whether it can treat streptozotocin (STZ)-induced DPN remains unclear. The present experiment aimed to test the preventive role of SA on STZ-induced DPN in rats and explored the possible mechanisms. The DPN rat model was established in rats by intraperitoneal injection of a single dose of 40 mg/kg b.w. STZ, and SA (200 mg/kg b.w./day) was orally administered for 28 days after type 2 diabetes mellitus (T2DM) induction. The obtained findings revealed that STZ significantly increased serum levels of FBG, HOMA-IR, TC, TG, VLDL-C, and LDL-C, while decreased serum insulin, incretin GLP-1, HDL-C, and lipase activity. In the sciatic nerves, STZ significantly increased proinflammatory cytokine levels (IL-1β, IL-6, and TNF-α), caspase-3 (a pro-apoptotic protein), markers of oxidative stress (MDA and NO), and AGEs. In parallel, STZ induced a significant decline in the activities of enzymatic antioxidants, viz., SOD, CAT, and GPx, and non-enzymatic GSH. These changes were accompanied by a low expression of miR-146a in the sciatic nerves of DPN rats. Except for HOMA-IR, SA treatment to STZ injected rats significantly improved these parameters and helped to rescue the neurological morphology of the sciatic nerve fibers. In conclusion, SA mitigated experimental DPN, and this might be due to its ability to suppress hyperglycemic-hyperlipidemic effects, counteract the overactivation of inflammatory molecules, increase miR-146a expression, modulate oxidative dysregulation, and reduce cell apoptosis.

siRNA targeting PARP-1 alleviates diabetic peripheral neuropathy in a streptozotocin-induced rat model

Diabetic peripheral neuropathy (DPN) is a debilitating complication of diabetes mellitus, affecting nearly 50% of diabetic patients and leading to chronic pain, numbness and progressive sensory and motor function loss. This study investigates the potential of siRNA-mediated silencing of poly(ADP-ribose) polymerase 1 (PARP1) to alleviate DPN in a rat model. PARP1 overactivation, driven by hyperglycaemia-induced oxidative stress, exacerbates neuronal damage in DPN. Using chitosan nanoparticles (ChNPs) to deliver PARP1-targeting siRNA intrathecally in diabetic rats induced with streptozotocin (STZ) 55 mg/kg intraperitoneally, we conducted behavioural and physiological assessments, including Sciatic Functional Index (SFI), motor nerve conduction velocity (MNCV), grip strength and pain sensitivity tests, alongside qRT-PCR analyses, to evaluate therapeutic outcomes. Our findings indicate statistically significant improvements, with siRNA ChNPs-mediated PARP1 silencing alleviating neuropathic symptoms in DPN rats (p < .001 for SFI and MNCV improvements). Biochemical analyses revealed reductions in oxidative stress markers, such as MDA, and increased antioxidant levels, including GSH, CAT and SOD (p < .001). Pro-inflammatory cytokines and apoptotic markers, including NF-κB, IL6, IL1β, TNFa, TGF-β, CAS3, CAS9, BAK and BAX, also showed significant reductions (p < .01), confirming the neuroprotective effects of PARP1 inhibition. These results highlight the potential of siRNA-based therapies targeting PARP1 as a promising therapeutic approach for DPN, paving the way for future research with clinical applications.

Cytokine Signaling in Diabetic Neuropathy: A Key Player in Peripheral Nerve Damage

Diabetic peripheral neuropathy (DPN) is a debilitating complication of diabetes mellitus, characterized by progressive nerve damage driven by chronic hyperglycemia and systemic inflammation. The pathophysiology of DPN is significantly influenced by pro-inflammatory cytokines, such as IL-1β, IL-6, and TNF-α. These cytokines promote oxidative stress, vascular dysfunction, and neuronal degeneration by activating important signaling pathways including NF-κB and MAPK. While IL-6 promotes a pro-inflammatory microenvironment, increasing neuronal damage and neuropathic pain, TNF-α and IL-1β worsen Schwann cell failure by compromising axonal support and causing demyelination. Immune cell infiltration and TLR activation increase the inflammatory cascade in DPN, resulting in a persistent neuroinflammatory state that sustains peripheral nerve injury. The main characteristics of DPN are axonal degeneration, decreased neurotrophic support, and Schwann cell dysfunction, which weaken nerve transmission and increase susceptibility to damage. Advanced glycation end-products, TNF-α, and CXCL10 are examples of biomarkers that may be used for early diagnosis and disease progression monitoring. Additionally, crucial molecular targets have been found using proteomic and transcriptome techniques, enabling precision medicine for the treatment of DPN. This review emphasizes the importance of cytokine signaling in the pathogenesis of DPN and how cytokine-targeted treatments might reduce inflammation, restore nerve function, and improve clinical outcomes for diabetic patients.

Phytochemical Analysis and Pharmaceutical Applications of Monoterpenoids Present in the Essential Oil of Boswellia sacra (Omani Luban)

Due to its intricacy and long-term usefulness, traditional medicine continues to be practiced in several nations. Among the many medicinal plants found in the Dhofar region of Oman, the aromatic oleo-gum resin generated by Boswellia sacra, commonly referred to as frankincense, stands out for its medical and commercial significance. Resin-carrying ducts are unique to members of the Boswellia family. Boswellia sacra Flueck is one of the 29 species in the genus Boswellia (Burseraceae) and has long been cultivated for its aromatic gums and resins for use as incense. In addition to the resins (60%-80% alcohol soluble), gums (15%-20% water soluble), and essential oil (5%-7%), other components, including polysaccharides and polymeric compounds, also exist in smaller amounts. Physiochemical analyses indicate that Boswellia resin oil is made up of 42.5% diterpenes, 13.1% monoterpenes, and 1% sesquiterpenes. Traditional medicine makes extensive use of frankincense for the treatment of stomach diseases, Alzheimer's disease, and hepatic illnesses. The bioactive chemicals present in frankincense, particularly boswellic acids, are plentiful. The current review examines various compounds present in different species of Boswellia, especially Boswellia sacra, along with their structure.

Using codesign workshops to develop a conceptual framework for a mobile health app targeting chronic low back pain self-management

OBJECTIVES

The aim of this study was to gather insights from a diverse group of stakeholders, identify existing challenges and explore associated solutions to develop a conceptual framework that assists in the development of a chronic low back pain (CLBP) self-management app.

DESIGN

Codesign workshop methodology.

SETTING

The study was conducted online, allowing for the participation of a diverse group of stakeholders.

PARTICIPANTS

Participants were recruited through social media platforms and professional networks, including individuals with LBP for at least 3 months, healthcare professionals experienced in CLBP management and app developers with a background in digital health applications.

INTERVENTIONS

The study used codesign workshops focused on brainstorming, communication and reflection exercises designed to foster collaboration and gather insights from stakeholders.

OUTCOME MEASURES

Identification of key challenges and potential solutions for mobile health (mHealth) apps targeting CLBP.

RESULTS

Nine stakeholders identified four primary challenges in current back pain apps: belief and trust, motivation, safety and usability. The group also collaboratively developed and proposed practical solutions to these challenges.

CONCLUSIONS

This study illustrated the utility of the codesign workshop approach in generating critical insights for the development of a mHealth solution for CLBP. The insights gathered from these workshops can be used to inform future app development, potentially improving user engagement.

Aspirin-triggered lipoxin A4 reduces neuropathic pain and anxiety-like behaviours in male diabetic rats: antinociceptive enhancement by cannabinoid receptor agonists

Neuropathy is the most common complication of diabetes, leading to painful symptoms like hyperalgesia. Current treatments for diabetic painful neuropathy often prove inadequate, necessitating the exploration of new pharmacological approaches. Therefore, this study aimed to investigate the potential antinociceptive effect of aspirin-triggered lipoxin A4 (ATL), a specialized pro-resolving lipid mediator, when administered alone or in combination with cannabinoid agonists, to alleviate diabetic neuropathic pain. Mechanical hyperalgesia in the hindpaws of streptozotocin (STZ)-induced diabetic (DBT) rats was assessed using the electronic Von Frey test (VFT), before diabetes induction and for up to 32 days after STZ administration and intraperitoneal ATL (0.3, 1, 3, 10, or 30 ng/rat) treatment, alone or in combination with intrathecal CB1 or CB2 receptor agonists (ACEA or JWH-133, respectively; 10 or 30 μg/rat). The effect of ATL treatment on locomotor activity and anxious or depressive-like behaviors was also evaluated. In comparison to control normoglycemic rats, control DBT rats developed: 1) mechanical hyperalgesia; 2) increase in anxious and depressive-like behaviors. ATL treatment attenuated mechanical hyperalgesia in DBT rats both acutely (at 30 ng) and cumulatively (at doses of 1, 3, 10, or 30 ng), without compromising locomotor activity. The antinociceptive effect of ATL (at 1 or 3 ng) was augmented when combined with ACEA or JWH-133 treatments (only at a dose of 30 μg/rat). While ATL treatment alone reduced anxious-like behavior in DBT rats, it did not affect depressive-like behavior. These findings underscore the therapeutic potential of ATL, in diabetic complications, suggesting a possible interaction with the endocannabinoid system.

Association between adiponectin single nucleotide polymorphisms and the risk of diabetic polyneuropathy

Genetic factors play a significant role in the occurrence and clinical course of diabetic peripheral neuropathy (DPN). This research aimed to search the influence of adiponectin single nucleotide polymorphisms (SNPs) on the risk of developing and the severity of DPN in Egyptian patients. Adiponectin SNPs were genotype in 360 participants comprising diabetic sufferers with and without peripheral neuropathy and healthy volunteers via the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach. Regarding the + 45 T/G SNP, the TG/ and GG genotypes and the G allele were linked to an rised risk of DPN by comparing the DPN group with both the control and diabetic patients without peripheral neuropathy (DWPN) groups, and when comparing the DWPN group with the control group. Concerning + 276 G/T SNP, the GT genotype and T allele were linked to a declined risk of occuring DPN when comparing the DPN group with both other groups. Patients with DPN had greater frequencies of the GA genotype of the - 11,391 G/A SNP than individuals in the control group, while patients with DPN had greater frequencies of the AA genotype than patients in the DWPN group. Regarding clinic-pathological features, a meaningful rise in the mean values of fasting blood glucose (FBG), duration of the disease, and Toronto Clinical Neuropathy Severity Score (TCSS) were noted in the + 45 GG genotype and G allele carriers. Contrariwise, the + 276 TT genotype carriers had lower mean values for the same clinic-pathological features. For the T allele carriers, the same results were observed in case of duration of the disease and TCSS value. Our results concluded that adiponectin + 45 T/G SNP could be a risk factor considering DPN and the severity of the disease. The - 11391G/A SNP might be associated with DPN. In addition, + 276 G/T SNP could be a protective factor regarding DPN and the severity of the disease.

Inflammatory Markers and Measures of Cardiovascular Autonomic Neuropathy in Type 1 Diabetes

BACKGROUND

Cardiovascular autonomic neuropathy (CAN) and inflammation predict more severe outcomes in type 1 diabetes (T1D). However, the link between CAN and inflammation in T1D remains unclear. We examined associations between CAN measures and inflammatory biomarkers in individuals with T1D.

METHODS AND RESULTS

In a cross-sectional study, we measured cardiovascular autonomic reflex tests and heart rate variability (established CAN measures) and a panel of 39 inflammatory biomarkers, including soluble urokinase plasminogen activator receptor (suPAR), in T1D participants of the TINSAL-T1DN (Targeting Inflammation with Salsalate in Individuals with T1D Neuropathy) trial (n=57, discovery), and the PERL (Preventing Early Renal Loss in Diabetes) trial (n=468, validation). Amongst 39 inflammatory biomarkers measured in TINSAL-T1DN, suPAR levels had the strongest negative correlations with CAN measures: expiration/inspiration (r=-0.48), Valsalva (r=-0.28), 30:15 (r=-0.37), SD of the normal RR interval (r=-0.37), and root mean square of differences of successive RR intervals (r=-0.31) (all P<0.05). Findings were validated in PERL. In unadjusted analyses, median suPAR levels significantly differed between the lowest and highest SD of the normal RR interval tertiles (3.79 versus 3.12 ng/mL, P<0.001) and root mean square of differences of successive RR intervals (3.76 versus 3.17 ng/mL, P<0.001). After adjusting for covariates (age, sex, hemoglobin A1c, and estimated glomerular filtration rate), median suPAR values remained significantly elevated in the lowest tertiles of SD of the normal RR interval (P=0.004) and root mean square of differences of successive RR intervals (P=0.006).

CONCLUSIONS

Amongst several inflammatory biomarkers, suPAR, an immune-mediated glycoprotein, has a singular association with CAN measures. The potential of targeting suPAR as a disease-modifying approach for CAN in T1D warrants further exploration.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT02936843, NCT02017171.

The impact of endogenous N/OFQ on DPN: Insights into lower limb blood flow regulation in rats

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes, often accompanied by impaired vascular endothelial function in the lower limbs. This dysfunction is characterized by a reduced vasodilatory response, leading to decreased blood flow in the lower limbs and ultimately contributing to the development of diabetic peripheral neuropathy. To delve deeper into this pathological process, the study employed bioinformatics to identify and analyze genes highly active in DPN. The investigation revealed that Membrane metallo-endopeptidase (MME) was effectively mitigated by its antagonist. Male Sprague-Dawley (SD) rats served as the model to systematically explore the intrinsic connection among the nociceptible/orphanin FQ-N/OFQ receptor (N/OFQ-NOP) system, femoral artery blood flow in the lower extremities, MME, and DPN. The rats were randomized into two groups: a control group and a DPN group induced by a single intraperitoneal injection of 55 mg/kg streptozotocin (STZ), with 6 rats in each group. The findings indicated that compared to the control group, the DPN group exhibited a significant reduction in femoral artery blood flow. This was accompanied by a notable increase in serum N/OFQ concentration, heightened expression of opioid-related nociceptive protein receptor 1 (OPRL1) and MME in femoral artery tissues of the lower limbs, and an elevated sciatic nerve stimulation threshold. These results suggest that the serum N/OFQ level in DPN rats is increased, which may promote the occurrence of peripheral neuropathy by up regulating MME and reducing peripheral flow distribution.

Interpretable multimodal machine learning (IMML) framework reveals pathological signatures of distal sensorimotor polyneuropathy

BACKGROUND

Distal sensorimotor polyneuropathy (DSPN) is a common neurological disorder in elderly adults and people with obesity, prediabetes and diabetes and is associated with high morbidity and premature mortality. DSPN is a multifactorial disease and not fully understood yet.

METHODS

Here, we developed the Interpretable Multimodal Machine Learning (IMML) framework for predicting DSPN prevalence and incidence based on sparse multimodal data. Exploiting IMMLs interpretability further empowered biomarker identification. We leveraged the population-based KORA F4/FF4 cohort including 1091 participants and their deep multimodal characterisation, i.e. clinical data, genomics, methylomics, transcriptomics, proteomics, inflammatory proteins and metabolomics.

RESULTS

Clinical data alone is sufficient to stratify individuals with and without DSPN (AUROC = 0.752), whilst predicting DSPN incidence 6.5 ± 0.2 years later strongly benefits from clinical data complemented with two or more molecular modalities (improved ΔAUROC > 0.1, achieved AUROC of 0.714). Important and interpretable features of incident DSPN prediction include up-regulation of proinflammatory cytokines, down-regulation of SUMOylation pathway and essential fatty acids, thus yielding novel insights in the disease pathophysiology.

CONCLUSIONS

These may become biomarkers for incident DSPN, guide prevention strategies and serve as proof of concept for the utility of IMML in studying complex diseases.

Astaxanthin has a beneficial influence on pain-related symptoms and opioid-induced hyperalgesia in mice with diabetic neuropathy-evidence from behavioral studies

BACKGROUND

The treatment of painful diabetic neuropathy is still a clinical problem. The aim of this study was to determine whether astaxanthin, a substance that inhibits mitogen-activated protein kinases, activates nuclear factor erythroid 2-related factor 2 and influences N-methyl-D-aspartate receptor, affects nociceptive transmission in mice with diabetic neuropathy.

METHODS

The studies were performed on streptozotocin-induced mouse diabetic neuropathic pain model. Single intrathecal and intraperitoneal administrations of astaxanthin at various doses were conducted in both males and females. Additionally, repeated twice-daily treatment with astaxanthin (25 mg/kg) and morphine (30 mg/kg) were performed. Hypersensitivity was evaluated with von Frey and cold plate tests.

RESULTS

This behavioral study provides the first evidence that in a mouse model of diabetic neuropathy, single injections of astaxanthin similarly reduce tactile and thermal hypersensitivity in both male and female mice, regardless of the route of administration. Moreover, repeated administration of astaxanthin slightly delays the development of morphine tolerance and significantly suppresses the occurrence of opioid-induced hyperalgesia, although it does not affect blood glucose levels, body weight, or motor coordination. Surprisingly, astaxanthin administered repeatedly produces a better analgesic effect when administered alone than in combination with morphine, and its potency becomes even more pronounced over time.

CONCLUSIONS

These behavioral results provide a basis for further evaluation of the potential use of astaxanthin in the clinical treatment of diabetic neuropathy and suggest that the multidirectional action of this substance may have positive effects on relieving neuropathic pain in diabetes.

Prevalence and clinical implications of diabetes mellitus in autoimmune nodopathies: A systematic review

BACKGROUND AND AIMS

Autoimmune nodopathies comprise a newly-established subtype of immune-mediated peripheral neuropathies, characterized by circulating autoantibodies that target nodal-paranodal proteins, including contactin-1 (CNTN1), contactin-associated protein-1 (Caspr1), neurofascin-155 (NF155) and neurofascin-isoforms (NF140 and NF186). Emerging evidence suggests that diabetes mellitus (DM) may confer increased risk for autoimmune nodopathies.

METHODS

A systematic search was performed including studies reporting on patients harboring nodal/paranodal antibodies (CNTN1, Caspr1, NF155, NF140 and NF186). We sought to evaluate: (1) the prevalence of DM among patients with autoimmune nodopathies; (2) the phenotype of DM-patients harboring different types of nodal/paranodal antibodies; (3) clinical features that allow distinction of autoimmune nodopathies from diabetic peripheral neuropathy (DPN).

RESULTS

Five cohort studies, 3 case-reports and one case-series study were identified comprising 114 patients with autoimmune nodopathies. DM prevalence was documented to range between 10.5 % and 60 %. DM-patients harbored mostly paranodal antibodies; CNTN1: 58.3 %, followed by pan-neurofascin: 33.3 %, and Caspr1: 25 % antibodies. No significant differences in clinical phenotype were uncovered between DM-patients and their non-DM counterparts. Overall, DM patients were refractory to intravenous-immunoglobulins (IVIG), but responded well to escalation immunotherapies. Compared to DPN, distinctive features of autoimmune nodopathy comprised: (i) severe ataxia, tremor, and cranial nerve involvement; (ii) neurophysiological findings indicative of nodal-paranodal pathology, including (reversible) conduction failure and conduction velocity slowing, often accompanied by reduced compound muscle and sensory nerve action potentials; and (iii) marked protein-elevation or albuminocytological dissociation in cerebrospinal fluid analysis.

CONCLUSIONS

DM patients fall under the typical clinical phenotype of autoimmune nodopathy, displaying predominantly paranodal antibodies. Early suspicion is crucial, as unlike DPN, diagnosis of autoimmune nodopathy unfolds therapeutic perspectives.

Bayesian Mendelian Randomization Analysis for Latent Exposures Leveraging GWAS Summary Statistics for Traits Co-Regulated by the Exposures

Mendelian Randomization analysis is a popular method to infer causal relationships between exposures and outcomes, utilizing data from genome-wide association studies (GWAS) to overcome limitations of observational research by treating genetic variants as instrumental variables. This study focuses on a specific problem setting, where causal signals may exist among a series of correlated traits, but the exposures of interest, such as biological functions or lower-dimensional latent factors that regulate the observable traits, are not directly observable. We propose a Bayesian Mendelian randomization analysis framework that allows joint analysis of the causal effects of multiple latent exposures on a disease outcome leveraging GWAS summary-level association statistics for traits co-regulated by the exposures. We conduct simulation studies to show the validity and superiority of the method in terms of type I error control and power due to a more flexible modeling framework and a more stable algorithm compared to an alternative approach and traditional single- and multi-exposure analysis approaches not specifically designed for the problem. We have also applied the method to reveal evidence of the causal effects of psychiatric factors, including compulsive, psychotic, neurodevelopmental, and internalizing factors, on neurodegenerative, autoimmune, digestive, and cardiometabolic diseases.

Bibliometric and visualized analysis of 2014-2024 publications on therapy for diabetic peripheral neuropathy

Background

This research aimed to examine the global developing patterns in the treatment of diabetic peripheral neuropathy (DPN) using a bibliometric analysis of published literature.

Methods

We extracted publication data from papers published between 2014 and 2024 using a specific topic search in the "Web of Science Core Collection" (WoSCC) database. Various metrics, such as the number of papers, citations, authors, countries, institutions, and references, were collected for analysis. To further explore the data, CiteSpace was employed to examine co-citation patterns among authors, identify collaborative efforts between countries and institutions, and uncover emerging trends using burst keywords and reference analysis.

Results

The study encompassed 2,488 publications that exhibited an increasing trend in annual output. Notably, the journal PAIN, the United States, the Pfizer institution, and the author Feldman, EvaL emerged as the most prolific contributors to this research domain. The term "placebo-controlled trial" was the most prominent burst keyword from 2014 to 2017, whereas "spinal cord stimulation" held this distinction in the recent 5-year span. Furthermore, the publication titled "Pharmacotherapy for neuropathic pain in adults: a systematic review and meta-analysis-2015" demonstrated the highest burst in terms of references.

Conclusion

This study is the first to objectively reveal the current hotspots and trends in DPN treatment. The results indicate that drug therapy remains the primary first-line treatment for DPN and that future research on DPN treatment will likely focus on "spinal cord stimulation" and "pain management." These findings provide valuable insights into DPN treatment.

Evaluation of the Impact of Advanced Glycation End-Products on Peripheral Neuropathy Outcomes in Type 2 Diabetes

Background: Type 2 diabetes (T2DM) affects over 500 million people worldwide, and over 50% of this group experience the most common complication, diabetic peripheral neuropathy (DPN). The presence of advanced glycation end-products (AGEs) has been linked with the development of DPN. The present study assessed AGE levels in participants with type 2 diabetes and explored the hypothesis that there may be increased AGE levels in more severe DPN. Methods: A total of 124 participants with T2DM were consecutively recruited, and they underwent skin autofluorescence, clinical assessment for peripheral neuropathy, peripheral nerve ultrasound, nerve conduction studies, and axonal excitability assessment. Results: AGE accumulation showed weak but significant correlations with neuropathy severity and reduced nerve conduction function. However, after adjusting for confounding variables, a linear regression analysis did not reveal significant associations between the AGE levels and neuropathy outcomes. Conclusions: The present study suggests that the accumulation of AGE is not associated with the clinical, electrophysiological, and morphological measures of neuropathy in T2DM.

Nerve decompression for diabetic peripheral neuropathy with nerve entrapment: a narrative review

Diabetic peripheral neuropathy (DPN) is one of the most common complications of diabetes which primarily affects the sensory nervous system. Pain is the most common complaint that prompts patients to seek medical advice. With various presentations and intricate pathological mechanisms, diabetic peripheral neuropathic pain is currently the most crucial and challenging aspect of managing diabetic complications. As a heterogeneous disorder, there is no medication or treatment modality that is effective for all types of DPN and its associated neuropathic pain. Peripheral nerve decompression provides a new option for treating patients with diabetic peripheral neuropathic pain in the lower extremities. However, the clinical applicability of nerve decompression has been debated since it was first proposed. This review discusses the theoretical basis of nerve decompression, the clinical indications, and the progress of basic research based on the pathological mechanisms and nerve impairment patterns of diabetic peripheral neuropathic pain. The heterogeneity of DPN patients is summarized in terms of three aspects: complex pathophysiological mechanisms, multilevel nervous system involvement, and various nerve impairment properties. Identifying the presence of nerve entrapment among complex pathophysiological mechanisms is the key to successful outcomes. Tinel signs, focal pain, mechanical allodynia, and two-point discrimination were reported to be prognostic factors for good surgical outcomes, and their predictive ability might stem from their association with the early stage of entrapment neuropathy.

Antiapoptotic and antinociceptive effects of Achillea millefolium L. aqueous extract in rats with experimental painful diabetic neuropathy

Background and purpose

Neuropathy is one of the common complications of diabetes mellitus. This study aimed to determine the analgesic and antiapoptotic effects of the aqueous extract of Achillea millefolium L. (Ach) in rats with experimental painful diabetic neuropathy by behavioral and molecular procedures.

Experimental approach

Thirty male Wistar rats were divided into 5 groups including control, diabetes + saline, and diabetes + Ach extract (doses of 150, 300, and 600 mg/kg/day for 3 weeks, orally). A tail-flick test was performed to assess the pain threshold in different groups. Western blotting test was used to evaluate the apoptotic (Bax, Bcl2, cleaved caspase-3, and cytochrome-c) and inflammatory (TNF-α and NF-kB) protein factors in the lumbar portion of the spinal cord tissue. Also, commercial assay kits were used to evaluate oxidative stress factors (MDA, GPx, and SOD enzyme activity) in the lumbar portion of the spinal cord tissue.

Findings/Results

Results showed that administering Ach extract at the doses of 300 and 600 mg/kg/day significantly increased the nociception threshold in treated diabetic animals compared to untreated diabetic animals. Moreover, the treatment of diabetic animals with Ach extract (300 and 600 mg/kg/day) significantly reduced the oxidative stress, inflammation, and apoptosis biochemical indicators in the lumbar spinal cord tissue compared to the untreated diabetic group.

Conclusion and implications

The findings showed that Ach extract has neuroprotective and anti-nociceptive effects in rats with diabetic neuropathy. The effects can be due to the inhibition of oxidative stress, inflammation, and apoptosis in the spinal cord tissue.

Exploring CCR5 + T regulatory cell subset dysfunction in type 1 diabetes patients: implications for immune regulation

T regulatory lymphocytes (Treg) expressing CCR5 exhibit strong suppression activity in various autoimmune disorders. However, there remains a lack of comprehensive understanding regarding their involvement in the development of type 1 diabetes (T1D). In this study, we examined the role of the CCR5/CCL5 axis in regulating inflammatory response and its impact on regulatory T cells in type 1 diabetes (T1D). We hypothesize that dysregulation of the CCR5/CCL5 axis contributes to the development and progression of T1D through modulation of Treg-dependent immune responses. We analyzed the expression levels of CCR5 on Tregs isolated from individuals with T1D, as well as the plasma concentration of its main ligands. We found that Tregs from T1D patients exhibited decreased expression of CCR5 compared to healthy controls. Additionally, we observed a correlation between the expression levels of CCR5 on Tregs and their immunosuppressive function in T1D patients. Our results indicate the impaired migratory capacity of CCR5 + Tregs, suggesting a possible link between the dysregulation of the CCR5/CCL5 axis and impaired immune regulation in T1D. In line with previous studies, our findings support the notion that dysregulation of the CCR5/CCL5 axis contributes to the development and progression of type 1 diabetes (T1D) by modulating Treg-dependent immune responses. The decreased expression of CCR5 on Tregs in T1D patients suggests a potential impairment in the migratory capacity of these cells, which could compromise their ability to suppress autoreactive T cells and maintain immune homeostasis. Furthermore, our study highlights the importance of CCR5 as a biomarker for identifying dysfunctional Tregs in T1D.

Differential associations between selenoprotein P and distal sensorimotor polyneuropathy in people with and without diabetes: KORA F4/FF4 study

BACKGROUND

Oxidative stress is a risk factor for distal sensorimotor polyneuropathy (DSPN). Selenoprotein P is a protein with antioxidant properties but has not been investigated in the context of DSPN. This study aimed to assess the associations between selenoprotein P and DSPN in people without and with type 2 diabetes (T2D).

METHODS

Cross-sectional and prospective analyses were based on 1053 (including 217 with T2D) and 513 participants (including 79 with T2D), respectively, aged 61-82 years from the population-based KORA F4 survey. DSPN at baseline (KORA F4) and in the follow-up survey KORA FF4 was defined based on the Michigan Neuropathy Screening Instrument. Serum levels of full-length selenoprotein P were quantified by ELISA. Associations between selenoprotein P and prevalent or incident DSPN were estimated using logistic regression analysis adjusting for multiple confounders.

RESULTS

Selenoprotein P levels were not associated with prevalent DSPN in the total sample. However, there was a significant interaction by diabetes status. Higher levels of selenoprotein P were associated with lower odds of prevalent DSPN in individuals without T2D (fully adjusted model: OR 0.825 [95 % CI 0.682, 0.998], p = 0.0476), but not in those with T2D (OR [95 % CI] 1.098 [0.829, 1.454], p = 0.5132; pinteraction = 0.0488). Selenoprotein P levels were not associated with incident DSPN over a follow-up of 6.5 years.

CONCLUSION

In individuals without T2D from the older general population, lower selenoprotein P levels were associated with a higher prevalence of DSPN. Whether the antioxidant properties of selenoprotein P are responsible for the observed associations remains to be elucidated in future research.

Therapeutic Effects of Metformin on Central Nervous System Diseases: A Focus on Protection of Neurovascular Unit

Metformin is one of the most commonly used oral hypoglycemic drugs in clinical practice, with unique roles in neurodegeneration and vascular lesions. Neurodegeneration and vasculopathy coexist in many diseases and typically affect the neurovascular unit (NVU), a minimal structural and functional unit in the central nervous system. Its components interact with one another and are indispensable for maintaining tissue homeostasis. This review focuses on retinal (diabetic retinopathy, retinitis pigmentosa) and cerebral (ischemic stroke, Alzheimer's disease) diseases to explore the effects of metformin on the NVU. Metformin has a preliminarily confirmed therapeutic effect on the retinal NUV, affecting many of its components, such as photoreceptors (cones and rods), microglia, ganglion, Müller, and vascular endothelial cells. Since it rapidly penetrates the blood-brain barrier (BBB) and accumulates in the brain, metformin also has an extensively studied neuronal protective effect in neuronal diseases. Its mechanism affects various NVU components, including pericytes, astrocytes, microglia, and vascular endothelial cells, mainly serving to protect the BBB. Regulating the inflammatory response in NVU (especially neurons and microglia) may be the main mechanism of metformin in improving central nervous system related diseases. Metformin may be a potential drug for treating diseases associated with NVU deterioration, however, more trials are needed to validate its timing, duration, dose, clinical effects, and side effects.

Update on Biomarkers of Chronic Inflammatory Processes Underlying Diabetic Neuropathy

There is an increasing prevalence of diabetes mellitus (DM), particularly type 2 DM (T2DM), and its associated complications. T2DM is linked to insulin resistance, chronic inflammation, and oxidative stress, which can lead to both macrovascular and microvascular complications, including peripheral diabetic neuropathy (PDN). Inflammatory processes play a key role in the development and progression of T2DM and its complications, with specific markers like C-reactive protein (CRP), interleukins (ILs), and tumor necrosis factor (TNF)-α being associated with increased risk. Other key inflammatory markers such as nuclear factor kappa B (NF-κB) are activated under hyperglycemic and oxidative stress conditions and contribute to the aggravation of PDN by regulating inflammatory gene expression and enhancing endothelial dysfunction. Other important roles in the inflammatory processes are played by Toll-like receptors (TLRs), caveolin 1 (CAV1), and monocyte chemoattractant protein 1 (MCP1). There is a relationship between vitamin D deficiency and PDN, highlighting the critical role of vitamin D in regulating inflammation and immune responses. The involvement of macrophages in PDN is also suspected, emphasizing their role in chronic inflammation and nerve damage in diabetic patients. Vitamin D supplementation has been found to reduce neuropathy severity, decrease inflammatory markers, and improve glycemic control. These findings suggest that addressing vitamin D deficiency could offer therapeutic benefits for PDN. These molecular pathways are critical in understanding the pathogenesis of DM complications and may offer potential biomarkers or therapeutic targets including anti-inflammatory treatments, vitamin D supplementation, macrophage phenotype modulation, and lifestyle modifications, aimed at reducing inflammation and preventing PDN. Ongoing and more extensive clinical trials with the aim of investigating anti-inflammatory agents, TNF-α inhibitors, and antioxidants are needed to advance deeper into the understanding and treatment of painful diabetic neuropathy.

Dietary phytochemical index and its relationship with diabetic sensorimotor polyneuropathy: a case-control study

Phytochemicals are compounds found in fruits, vegetables, whole grains, nuts and legumes that are non-nutritive but have bioactive properties. A high intake of these compounds is essential for optimal health and disease prevention. No study has investigated the association between Dietary Phytochemical Index (DPI) and polyneuropathy in patients with diabetes. This study aimed to examine the association between DPI and Diabetic Sensory-motor Polyneuropathy (DSPN) in a case-control study. In this case-control study, a total of 185 diabetic patients with DSPN (case group) and 185 sex- and age-matched diabetic patients without neuropathy (control group) were enrolled in this study. Participants were 30-60 years old. A validated food frequency questionnaire was used to measure the dietary intake of all participants. Daily energy derived from phytochemical-rich foods was used to calculate the DPI score. Toronto clinical neuropathy score was applied to define DSPN. Anthropometric data and fasting blood glucose levels were measured using standard methods. The Binary logistic regression was used to estimate Crude and multivariable-adjusted OR (95% CI) for DSPN across tertiles of DPI for the whole population. In the crude model, there was a significant trend across the tertile of DPI (OR highest vs. lowest tertile of DPI = 0.33; 95%CI 0.18, 0.52; P-trend < 0.001). After controlling for age, sex, and energy, a significant reverse association was observed between DPI and DSPN (OR highest vs. lowest tertile of DPI = 0.27; 95%CI 0.15, 0·48; P-trend < 0.001). Moreover, after adjusting for a wide range of confounding variables such as energy intake, physical activity, education, smoking status, and HbA1c, participants in the third tertile of DPI had 75% reduced odds for DSPN (95%CI 0.14, 0.45; P-trend < 0.001). Finally in the full adjusted model, after further adjustment for BMI, observed significant association was remained (OR highest vs. lowest tertile of DPI: 0.24; 95% CI 0.13, 0.14; P-trend < 0.001). Higher intakes of phytochemical-rich foods are associated with lower odds of DSPN.

Clinical Trials for Wolfram Syndrome Neurodegeneration: Novel Design, Endpoints, and Analysis Models

Objective

Wolfram syndrome, an ultra-rare condition, currently lacks effective treatment options. The rarity of this disease presents significant challenges in conducting clinical trials, particularly in achieving sufficient statistical power (e.g., 80%). The objective of this study is to propose a novel clinical trial design based on real-world data to reduce the sample size required for conducting clinical trials for Wolfram syndrome.

Methods

We propose a novel clinical trial design with three key features aimed at reducing sample size and improve efficiency: (i) Pooling historical/external controls from a longitudinal observational study conducted by the Washington University Wolfram Research Clinic. (ii) Utilizing run-in data to estimate model parameters. (iii) Simultaneously tracking treatment effects in two endpoints using a multivariate proportional linear mixed effects model.

Results

Comprehensive simulations were conducted based on real-world data obtained through the Wolfram syndrome longitudinal observational study. Our simulations demonstrate that this proposed design can substantially reduce sample size requirements. Specifically, with a bivariate endpoint and the inclusion of run-in data, a sample size of approximately 30 per group can achieve over 80% power, assuming the placebo progression rate remains consistent during both the run-in and randomized periods. In cases where the placebo progression rate varies, the sample size increases to approximately 50 per group.

Conclusions

For rare diseases like Wolfram syndrome, leveraging existing resources such as historical/external controls and run-in data, along with evaluating comprehensive treatment effects using bivariate/multivariate endpoints, can significantly expedite the development of new drugs.

Association of Symptoms and Collaborative Care Intervention with Systemic Inflammation Biomarkers in ESKD

Key Points

There were no associations between biomarkers and patient-reported pain, fatigue, and depression in a large ESKD cohort at baseline. Compared with control, the Technology-Assisted stepped Collaborative Care intervention had a short-term impact on reducing inflammatory burden. Treatment modified the association between changes in symptoms and in certain proinflammatory biomarkers (TNF-α and high sensitivity C-reactive protein) over time.

Background

Patient-reported symptoms are associated with inflammation biomarkers in many chronic diseases. We examined associations of inflammation biomarkers with pain, fatigue, and depression in patients with ESKD and the effects of a Technology-Assisted stepped Collaborative Care (TĀCcare) intervention on these biomarkers.

Methods

In the TĀCcare multisite randomized control trial, data on patient-reported symptoms were collected at baseline and 3 and 6 months. Anti-inflammatory (IL-1 receptor agonist, IL-10), proinflammatory (TNF-α , high sensitivity C-reactive protein, IL-6), and regulatory (IL-2) biomarkers were assayed. Linear mixed-effects modeling was used to examine within-group and between-group differences after adjusting for age, sex, race, and comorbidities.

Results

Among the 160 patients (mean age 58±14 years, 55% men, 52% white), there were no significant associations between inflammation biomarkers and pain, fatigue, or depression at baseline. Both intervention and control groups demonstrated reductions in IL-10 and IL-1 receptor agonist over 6 months (β range=−1.22 to −0.40, P range=<0.001–0.02) At 3 months, the treatment group exhibited decreases in TNF-α (β =−0.22, P < 0.001) and IL-2 (β =−0.71, P < 0.001), whereas the control group showed increases in IL-6/IL-10 ratio (β =0.33, P = 0.03). At 6 months, both groups exhibited decreases in IL-2 (β range=−0.66 to −0.57, P < 0.001); the control group showed significant increases in the ratio of IL-6/IL-10 (β =0.75, P < 0.001) and decrease in TNF-α (β =−0.16, P = 0.02). Compared with controls, the treatment group demonstrated significantly decreased IL-2 at 3 months (β =−0.53, P < 0.001). Significant interaction effects of treatment were observed on the association between changes in proinflammatory biomarkers (TNF-α and high sensitivity C-reactive protein) levels and changes in symptom scores from baseline to 6 months.

Conclusions

The TĀCcare intervention had a short-term impact on reducing inflammatory burden in patients with ESKD. More studies are needed to confirm our findings and to determine whether these biomarkers mediate the link between symptoms and disease progression.

Clinical Trial registration number:

ClinicalTrials.gov NCT03440853 .

Injectable, reversibly thermoresponsive captopril-laden hydrogel for the local treatment of sensory loss in diabetic neuropathy

A major and irreversible complication of diabetes is diabetic peripheral neuropathy (DPN), which can lead to significant disability and decreased quality of life. Prior work demonstrates the peptide hormone Angiotensin II (Ang II) is released locally in neuropathy and drives inflammation and impaired endoneurial blood flow. Therefore, we proposed that by utilizing a local thermoresponsive hydrogel injection, we could deliver inhibitors of angiotensin-converting enzyme (ACE) to suppress Ang II production and reduce nerve dysfunction in DPN through local drug release. The ACE inhibitor captopril was encapsulated into a micelle, which was then embedded into a reversibly thermoresponsive pluronics-based hydrogel matrix. Drug-free and captopril-loaded hydrogels demonstrated excellent product stability and sterility. Rheology testing confirmed sol properties with low viscosity at ambient temperature and increased viscosity and gelation at 37 °C. Captopril-loaded hydrogels significantly inhibited Ang II production in comparison to drug-free hydrogels. DPN mice treated with captopril-loaded hydrogels displayed normalized mechanical sensitivity and reduced inflammation, without side-effects associated with systemic exposure. Our data demonstrate the feasibility of repurposing ACE inhibitors as locally delivered anti-inflammatories for the treatment of sensory deficits in DPN. To the best of our knowledge, this is the first example of a locally delivered ACE inhibitor for the treatment of DPN.

Impact of streptozotocin-induced diabetes on experimental masseter pain in rats

This study aimed to assess the influence of streptozotocin (STZ)-induced diabetes on the nociceptive behavior evoked by the injection of hypertonic saline (HS) into the masseter muscle of rats. Forty male rats were equally divided into four groups: a) isotonic saline control, which received 0.9% isotonic saline (IS), (Ctrl-IS); b) hypertonic saline control, which received 5% HS (Ctrl-HS); c) STZ-induced diabetic, which received IS, (STZ-IS); d) STZ-induced diabetic, which received HS (STZ-HS). Experimental diabetes was induced by a single intraperitoneal injection of STZ at dose of 60 mg/kg dissolved in 0.1 M citrate buffer, and 100 μL of HS or IS were injected into the left masseter to measure the nociceptive behavior. Later on, muscle RNA was extracted to measure the relative expression of the following cytokines: cyclooxygenase-2 (COX-2), tumor necrosis factor (TNF-α), and interleukins (IL)-1β, -2, -6, and -10. One-way analysis of variance (ANOVA) was applied to the data (p < 0.050). We observed a main effect of group on the nociceptive response (ANOVA: F = 11.60, p < 0.001), where the Ctrl-HS group presented the highest response (p < 0.001). However, nociceptive response was similar among the Ctrl-IS, STZ-IS, and STZ-HS group (p > 0.050). In addition, the highest relative gene expression of TNF-α and IL-6 was found in the masseter of control rats following experimental muscle pain (p < 0.050). In conclusion, the loss of somatosensory function can be observed in deep orofacial tissues of STZ-induced diabetic rats.

Engineered exosomes as a prospective therapy for diabetic foot ulcers

Diabetic foot ulcer (DFU), characterized by high recurrence rate, amputations and mortality, poses a significant challenge in diabetes management. The complex pathology involves dysregulated glucose homeostasis leading to systemic and local microenvironmental complications, including peripheral neuropathy, micro- and macro-angiopathy, recurrent infection, persistent inflammation and dysregulated re-epithelialization. Novel approaches to accelerate DFU healing are actively pursued, with a focus on utilizing exosomes. Exosomes are natural nanovesicles mediating cellular communication and containing diverse functional molecular cargos, including DNA, mRNA, microRNA (miRNA), lncRNA, proteins, lipids and metabolites. While some exosomes show promise in modulating cellular function and promoting ulcer healing, their efficacy is limited by low yield, impurities, low loading content and inadequate targeting. Engineering exosomes to enhance their curative activity represents a potentially more efficient approach for DFUs. This could facilitate focused repair and regeneration of nerves, blood vessels and soft tissue after ulcer development. This review provides an overview of DFU pathogenesis, strategies for exosome engineering and the targeted therapeutic application of engineered exosomes in addressing critical pathological changes associated with DFUs.

Insights into the phytochemical profiling, antidiabetic and antioxidant potentials of Lepionurus sylvestris Blume extract in fructose/streptozotocin-induced diabetic rats

In this study, the antidiabetic activities of Lepionurus sylvestris Blume extract (LSB) in rats was investigated. The in vitro antidiabetic properties of LSB was evaluated using α-amylase, α-glucosidase and DPP-IV inhibitory assays, while the antioxidant assay was analysed using DPPH, ABTS and FRAP assays. Type 2 diabetes was with high-fructose/streptozotocin, and the diabetic animals were treated with LSB for 5 weeks. At the end of the experiment, the effects of LSB were evaluated via insulin level, lipid profile and hepatorenal function biomarkers. The level of oxido-inflammatory parameters, histopathology and insulin immunohistochemical staining in the pancreas was evaluated. Diabetic rats manifested significant increases in the blood glucose level, food/water intake, lipid profiles, hepatorenal function biomarkers, as well as a marked decreases in the body weight and serum insulin levels. Histopathological and insulin immunohistochemical examination also revealed decreased pancreatic beta cells and insulin positive cells, respectively. These alterations were associated with significant increases in malondialdehyde, TNF-α and IL-1β, in addition to significant declines in GSH, SOD and CAT activities. LSB significantly reduced blood glucose level, glucose intolerance, serum lipids, restored altered hepatorenal and pancreatic functions in the treated diabetic rats. Further, LSB showed antioxidant and anti-inflammatory activities by reducing malondialdehyde, TNF-α, IL-1β, and increasing antioxidant enzymes activities in the pancreatic tissues. A total of 77 secondary metabolites were tentatively identified in the UPLC-Q-TOF-MS analysis of LSB. Overall, these findings provides insight into the potentials of LSB as an antidiabetic agent which may be associated to the plethora bioactive compounds in the plant.

Cardiovascular Autonomic Neuropathy and Risk of Kidney Function Decline in Type 1 and Type 2 Diabetes: Findings From the PERL and ACCORD Cohorts

Results of previous studies have suggested that cardiovascular autonomic neuropathy (CAN) may predict rapid kidney function decline among people with diabetes. We analyzed the association between baseline CAN and subsequent glomerular filtration rate (GFR) decline among individuals with type 1 diabetes (T1D) from the Preventing Early Renal Loss in Diabetes (PERL) study (N = 469) and with type 2 diabetes (T2D) from Action to Control Cardiovascular Risk in Diabetes (ACCORD) (N = 7,973). Baseline CAN was ascertained with electrocardiogram-derived heart rate variability indices. Its association with GFR slopes, rapid kidney function decline (GFR loss of ≥5 mL/min/1.73 m2/year), and ≥40% GFR loss was evaluated by linear mixed-effects, logistic, and Cox regression, respectively. Participants with CAN experienced more rapid GFR decline, by an excess 1.15 mL/min/1.73 m2/year (95% CI -1.93 to -0.37; P = 4.0 × 10-3) in PERL and 0.34 mL/min/1.73 m2/year (95% CI -0.49 to -0.19; P = 6.3 × 10-6) in ACCORD. This translated to 2.11 (95% CI 1.23-3.63; P = 6.9 × 10-3) and 1.39 (95% CI 1.20-1.61; P = 1.1 × 10-5) odds ratios of rapid kidney function decline in PERL and ACCORD, respectively. Baseline CAN was also associated with a greater risk of ≥40% GFR loss events during follow-up (hazard ratio 2.60 [95% CI 1.15-5.45], P = 0.02, in PERL and hazard ratio 1.54 [95% CI 1.28-1.84], P = 3.8 × 10-6, in ACCORD). These associations remained significant after adjustment for potential confounders, including baseline GFR and albuminuria. Our findings indicate that CAN is a strong, independent predictor of rapid kidney function decline in both T1D and T2D. Further studies of the link between these two complications may help with development of new therapies to prevent kidney function decline in patients with diabetes.

ARTICLE HIGHLIGHTS

Advancing Tissue Damage Repair in Geriatric Diseases: Prospects of Combining Stem Cell-Derived Exosomes with Hydrogels

Geriatric diseases are a group of diseases with unique characteristics related to senility. With the rising trend of global aging, senile diseases now mainly include endocrine, cardiovascular, neurodegenerative, skeletal, and muscular diseases and cancer. Compared with younger populations, the structure and function of various cells, tissues and organs in the body of the elderly undergo a decline as they age, rendering them more susceptible to external factors and diseases, leading to serious tissue damage. Tissue damage presents a significant obstacle to the overall health and well-being of older adults, exerting a profound impact on their quality of life. Moreover, this phenomenon places an immense burden on families, society, and the healthcare system.In recent years, stem cell-derived exosomes have become a hot topic in tissue repair research. The combination of these exosomes with biomaterials allows for the preservation of their biological activity, leading to a significant improvement in their therapeutic efficacy. Among the numerous biomaterial options available, hydrogels stand out as promising candidates for loading exosomes, owing to their exceptional properties. Due to the lack of a comprehensive review on the subject matter, this review comprehensively summarizes the application and progress of combining stem cell-derived exosomes and hydrogels in promoting tissue damage repair in geriatric diseases. In addition, the challenges encountered in the field and potential prospects are presented for future advancements.

Inflammation in diabetes complications: molecular mechanisms and therapeutic interventions

At present, diabetes mellitus (DM) has been one of the most endangering healthy diseases. Current therapies contain controlling high blood sugar, reducing risk factors like obesity, hypertension, and so on; however, DM patients inevitably and eventually progress into different types of diabetes complications, resulting in poor quality of life. Unfortunately, the clear etiology and pathogenesis of diabetes complications have not been elucidated owing to intricate whole-body systems. The immune system was responsible to regulate homeostasis by triggering or resolving inflammatory response, indicating it may be necessary to diabetes complications. In fact, previous studies have been shown inflammation plays multifunctional roles in the pathogenesis of diabetes complications and is attracting attention to be the meaningful therapeutic strategy. To this end, this review systematically concluded the current studies over the relationships of susceptible diabetes complications (e.g., diabetic cardiomyopathy, diabetic retinopathy, diabetic peripheral neuropathy, and diabetic nephropathy) and inflammation, ranging from immune cell response, cytokines interaction to pathomechanism of organ injury. Besides, we also summarized various therapeutic strategies to improve diabetes complications by target inflammation from special remedies to conventional lifestyle changes. This review will offer a panoramic insight into the mechanisms of diabetes complications from an inflammatory perspective and also discuss contemporary clinical interventions.

Unveiling peripheral neuropathy and cognitive dysfunction in diabetes: an observational and proof-of-concept study with video games and sensor-equipped insoles

Background

Proactive screening for cognitive dysfunction (CD) and peripheral neuropathy (PNP) in elderly patients with diabetes mellitus is essential for early intervention, yet clinical examination is time-consuming and prone to bias.

Objective

We aimed to investigate PNP and CD in a diabetes cohort and explore the possibility of identifying key features linked with the respective conditions by machine learning algorithms applied to data sets obtained in playful games controlled by sensor-equipped insoles.

Methods

In a cohort of patients diagnosed with diabetes (n=261) aged over 50 years PNP and CD were diagnosed based on complete physical examination (neuropathy symptom and disability scores, and Montreal Cognitive Assessment). In an observational and proof-of-concept study patients performed a 15 min lasting gaming session encompassing tutorials and four video games with 5,244 predefined features. The steering of video games was solely achieved by modulating plantar pressure values, which were measured by sensor-equipped insoles in real-time. Data sets were used to identify key features indicating game performance with correlation regarding CD and PNP findings. Thereby, machine learning models (e.g. gradient boosting and lasso and elastic-net regularized generalized linear models) were set up to distinguish patients in the different groups.

Results

PNP was diagnosed in 59% (n=153), CD in 34% (n=89) of participants, and 23% (n=61) suffered from both conditions. Multivariable regression analyses suggested that PNP was positively associated with CD in patients with diabetes (adjusted odds ratio = 1.95; 95% confidence interval: 1.03-3.76; P=0.04). Predictive game features were identified that significantly correlated with CD (n=59), PNP (n=40), or both (n=59). These features allowed to set up classification models that were enriched by individual risk profiles (i.e. gender, age, weight, BMI, diabetes type, and diabetes duration). The obtained models yielded good predictive performance with the area under the receiver-operating-characteristic curves reaching 0.95 for CD without PNP, 0.83 for PNP without CD, and 0.84 for CD and PNP combined.

Conclusions

The video game-based assessment was able to categorize patients with CD and/or PNP with high accuracy. Future studies with larger cohorts are needed to validate these results and potentially enhance the discriminative power of video games.

Electroacupuncture efficacy in diabetic polyneuropathy: Study protocol for a double-blinded randomized controlled multicenter clinical trial

BACKGROUND

Diabetic peripheral neuropathy (DPN) is the most common complication of type 2 diabetes mellitus (T2DM); its diagnosis and treatment are based on symptomatic improvement. However, as pharmacological therapy causes multiple adverse effects, the implementation of acupunctural techniques, such as electroacupuncture (EA) has been suggested as an alternative treatment. Nonetheless, there is a lack of scientific evidence, and its mechanisms are still unclear. We present the design and methodology of a new clinical randomized trial, that investigates the effectiveness of EA for the treatment of DPN.

METHODS

This study is a four-armed, randomized, controlled, multicenter clinical trial (20-week intervention period, plus 12 weeks of follow-up after concluding intervention). A total of 48 T2DM patients with clinical signs and symptoms of DPN; and electrophysiological signs in the Nerve Conduction Study (NCS); will be treated by acupuncture specialists in outpatient units in Mexico City. Patients will be randomized in a 1:1 ratio to one of the following four groups: (a) short fibre DPN with EA, (b) short fibre DPN with sham EA, (c) axonal DPN with EA and (d) axonal DPN with sham EA treatment. The intervention will consist of 32 sessions, 20 min each, per patient over two cycles of intervention of 8 weeks each and a mid-term rest period of 4 weeks. The primary outcome will be NCS parameters, and secondary outcomes will include DPN-related symptoms and pain by Michigan Neuropathy Screening Instrument (MNSI), Michigan Diabetic Neuropathy Score (MDNS), Dolour Neuropatique Score (DN-4), Semmes-Westein monofilament, Numerical Rating Scale (NRS) for pain assessment, and the 36-item Short Form Health Survey (SF-36). To measure quality of life and improve oxidative stress, the inflammatory response; and genetic expression; will be analysed at the beginning and at the end of treatment.

DISCUSSION

This study will be conducted to compare the efficacy of EA versus sham EA combined with conventional diabetic and neuropathic treatments if needed. EA may improve NCS, neuropathic pain and symptoms, oxidative stress, inflammatory response, and genetic expression, and it could be considered a potential coadjutant treatment for the management of DPN with a possible remyelinating effect.

TRIAL REGISTRATION

ClinicalTrials.gov. NCT05521737 Registered on 30 August 2022. International Clinical Trials Registry Platform (ICTRP) ISRCTN97391213 Registered on 26 September 2022 [2b].

Hydrogel-mediated extracellular vesicles for enhanced wound healing: the latest progress, and their prospects for 3D bioprinting

Extracellular vesicles have shown promising tissue recovery-promoting effects, making them increasingly sought-after for their therapeutic potential in wound treatment. However, traditional extracellular vesicle applications suffer from limitations such as rapid degradation and short maintenance during wound administration. To address these challenges, a growing body of research highlights the role of hydrogels as effective carriers for sustained extracellular vesicle release, thereby facilitating wound healing. The combination of extracellular vesicles with hydrogels and the development of 3D bioprinting create composite hydrogel systems boasting excellent mechanical properties and biological activity, presenting a novel approach to wound healing and skin dressing. This comprehensive review explores the remarkable mechanical properties of hydrogels, specifically suited for loading extracellular vesicles. We delve into the diverse sources of extracellular vesicles and hydrogels, analyzing their integration within composite hydrogel formulations for wound treatment. Different composite methods as well as 3D bioprinting, adapted to varying conditions and construction strategies, are examined for their roles in promoting wound healing. The results highlight the potential of extracellular vesicle-laden hydrogels as advanced therapeutic tools in the field of wound treatment, offering both mechanical support and bioactive functions. By providing an in-depth examination of the various roles that these composite hydrogels can play in wound healing, this review sheds light on the promising directions for further research and development. Finally, we address the challenges associated with the application of composite hydrogels, along with emerging trends of 3D bioprinting in this domain. The discussion covers issues such as scalability, regulatory considerations, and the translation of this technology into practical clinical settings. In conclusion, this review underlines the significant contributions of hydrogel-mediated extracellular vesicle therapy to the field of 3D bioprinting and wound healing and tissue regeneration. It serves as a valuable resource for researchers and practitioners alike, fostering a deeper understanding of the potential benefits, applications, and challenges involved in utilizing composite hydrogels for wound treatment.

Spectrum of Diabetic Neuropathy: New Insights in Diagnosis and Treatment

Diabetic neuropathy is a highly prevalent complication of diabetes. It consists of a broad range of neuropathic conditions, such as distal symmetric polyneuropathy and various forms of autonomic neuropathies involving the cardiovascular, gastrointestinal, and urogenital systems. Prevention or diagnosis in early stages of disease is crucial to prevent symptomatic onset and progression, particularly in the absence of current disease-modifying therapies. In this review, we describe the four main types of diabetic neuropathy. We review current understanding with respect to diagnosis and treatment while highlighting knowledge gaps and future directions.

Serum levels of endocannabinoids and related lipids in painful vs painless diabetic neuropathy: results from the Pain in Neuropathy Study

ABSTRACT

N-arachidonoylethanolamine (also known as anandamide) and 2-arachidonoylglycerol are activators of the cannabinoid receptors. The endocannabinoid system also includes structurally and functionally related lipid mediators that do not target cannabinoid receptors, such as oleoylethanolamide, palmitoylethanolamide, and stearoylethanolamide. These bioactive lipids are involved in various physiological processes, including regulation of pain. The primary aim of the study was to analyze associations between serum levels of these lipids and pain in participants in the Pain in Neuropathy Study, an observational, cross-sectional, multicentre, research project in which diabetic patients with painless or painful neuropathy underwent deep phenotyping. Our hypothesis was that painful neuropathy would be associated with higher levels of the 5 lipids compared with painless neuropathy. Secondary aims were to analyze other patient-reported outcome measures and clinical data in relationship to lipid levels. The lipid mediators were analyzed in serum samples using liquid chromatography tandem mass spectrometry (LC-MS/MS). Serum levels of anandamide were significantly higher in the painful group, but the effect size was small (Cohen d = 0.31). Using cluster analysis of lipid data, patients were dichotomized into a "high-level" endocannabinoid group and a "low-level" group. In the high-level group, 61% of patients had painful neuropathy, compared with 45% in the low-level group ( P = 0.039). This work is of a correlative nature only, and the relevance of these findings to the search for analgesics targeting the endocannabinoid system needs to be determined in future studies.

Ocular surface changes in mice with streptozotocin-induced diabetes and diabetic polyneuropathy

PURPOSE

Diabetes mellitus (DM) is a leading risk factor for corneal neuropathy and dry eye disease (DED). Another common consequence of DM is diabetic peripheral polyneuropathy (DPN). Both complications affect around 50 % of the DM patients but the relationship between DM, DED and DPN remains unclear.

METHODS

In this study, we examined mice with early onset of DM and PN after streptozotocin (STZ)-induced diabetes (DPN). We compared the early morphological changes of the sciatic nerve, dorsal root and trigeminal ganglia with the changes in the ocular surface, including tear proteomic and we also investigated respective changes in the gene expressions and morphological alterations in the eye tissues involved in tear production.

RESULTS

The lacrimal gland, conjunctival goblet cells and cornea showed morphological changes along with alterations in tear proteins without any obvious signs of ocular surface inflammation. The gene expression for respectively altered tear proteins i.e., of Clusterin in cornea, Car6, Adh3a1, and Eef1a1 in eyelids, and Pigr in the lacrimal gland also showed significant changes compared to control mice. In the trigeminal ganglia like in the dorsal root ganglia neuronal cells showed swollen mitochondria and, in the latter, there was a significant increase of NADPH oxidases and MMP9 suggestive of oxidative and neuronal stress. In the dorsal root ganglia and the sciatic nerve, there was an upregulation of a number of pro-inflammatory cytokines and pain-mediating chemokines.

CONCLUSION

The early ocular changes in DM Mice only affect the lacrimal gland. Which, is reflected in the tear film composition of DPN mice. Due to the high protein concentration in tear fluid in humans, proteomic analysis in addition to noninvasive investigation of goblet cells and cornea can serve as a tools for the early diagnosis of DPN, DED in clinical practice. Early treatment could delay or even prevent the ocular complications of DM such as DED and PN.

Influence of Fibrinogen/Albumin Ratio and Fibrinogen/Pre-Albumin Ratio on Cardiac Autonomic Neuropathy in Type 2 Diabetes

Purpose

Subclinical inflammation may be involved in the pathogenesis of diabetic cardiac autonomic neuropathy (DCAN). The purpose of the study is to explore the relationship between novel inflammation biomarkers fibrinogen-albumin ratio (FAR), fibrinogen-prealbumin ratio (FPR), and DCAN in type 2 diabetes mellitus (T2DM).

Patients and Methods

A total of 715 T2DM patients were enrolled in this retrospective study, divided into non-DCAN (n=565) and DCAN (n=150) groups by Ewing's test. Serum fibrinogen, albumin, prealbumin, routine inflammatory and other biochemical markers were measured.

Results

Patients with versus without DCAN had higher FAR (10.29 ± 4.83 vs 7.22 ± 2.56 g/g, P < 0.001) and FPR (2.19 ± 1.85 vs 1.43 ± 0.93 g/mg, P < 0.001). As FAR and FPR quartiles increased, the incidence of DCAN increased (Quartile 1 vs Quartile 4: 8.4 vs 42.7%, 9.6 vs 39.2%, respectively, P < 0.001), heart rate variability parameters decreased (P < 0.001); the incidence of diabetic nephropathy, retinopathy and peripheral neuropathy tended to be higher and inflammation factors were more active (P < 0.01). FAR (OR, 95% CI: 1.16, 1.08-1.25, P < 0.001) and FPR (OR, 95% CI: 1.22, 1.03-1.44, P = 0.021) were independent determinants of DCAN; the risk of DCAN increased by approximately 65% and 27% with each increase in the standard deviation (SD) of FAR (OR per SD, 95% CI: 1.65, 1.29-2.11, P < 0.001) and FPR (OR per SD, 95% CI: 1.27, 1.04-1.56, P = 0.021).

Conclusion

FAR and FPR are independent risk factors and may influence DCAN development through inflammation.

Endotoxin of Porphyromonas gingivalis amplifies the inflammatory response in hyperglycemia-induced zebrafish through a mechanism involving chitinase-like protein YKL-40 analogs

Porphyromonas gingivalis (P. gingivalis), a key pathogen in periodontal diseases, is also associated with hyperglycemia-associated systemic diseases, including diabetes mellitus (DM). Gingipains are the most important endotoxins of P. gingivalis, and in vivo studies using gingipains are scarce. Zebrafish (Danio rerio) is a vertebrate with high physiological and genetic homology with humans that has multiple co-orthologs for human genes, including inflammation-related proteins. The aim of our study was to determine the effects of gingipain in a hyperglycemia-induced zebrafish model by evaluating inflammation, oxidant-antioxidant status, and the cholinergic system. Adult zebrafish were grouped into the control group (C), hyperglycemia-induced group subjected to 15 days of overfeeding (OF), gingipain-injected group (GP), and gingipain-injected hyperglycemic group (OF + GP). At the end of 15 days, an oral glucose tolerance test (OGTT) was performed, and fasting blood glucose (FBG) levels were measured. Lipid peroxidation (LPO), nitric oxide (NO), glutathione (GSH), glutathione S-transferase, catalase, acetylcholinesterase (AChE), alkaline phosphatase (ALP), and sialic acid (SA) levels were determined spectrophotometrically in the hepatopancreas. The expression levels of tnf-⍺, il-1β, ins, crp, and the acute phase protein YKL-40 analogs chia.5 and chia.6 were evaluated by RT‒PCR. After two weeks of overfeeding, significantly increased weight gain, FBG, and OGTT confirmed that the zebrafish were hyperglycemic. Increased oxidative stress, inflammation, and AChE and ALP activities were observed in both the overfeeding and GP groups. Amplification of inflammation and oxidative stress was evident in the OF + GP group through increased expression of crp, il-1β, chia.5, and chia.6 and increased LPO and NO levels. Our results support the role of gingipains in the increased inflammatory response in hyperglycemia-associated diseases.

Sulforaphane: A nutraceutical against diabetes-related complications

There is an increasing interest in the use of nutraceuticals and plant-derived bioactive compounds from foods for their potential health benefits. For example, as a major active ingredient found from cruciferous vegetables like broccoli, there has been growing interest in understanding the therapeutic effects of sulforaphane against diverse metabolic complications. The past decade has seen an extensive growth in literature reporting on the potential health benefits of sulforaphane to neutralize pathological consequences of oxidative stress and inflammation, which may be essential in protecting against diabetes-related complications. In fact, preclinical evidence summarized within this review supports an active role of sulforaphane in activating nuclear factor erythroid 2-related factor 2 or effectively modulating AMP-activated protein kinase to protect against diabetic complications, including diabetic cardiomyopathy, diabetic neuropathy, diabetic nephropathy, as well as other metabolic complications involving non-alcoholic fatty liver disease and skeletal muscle insulin resistance. With clinical evidence suggesting that foods rich in sulforaphane like broccoli can improve the metabolic status and lower cardiovascular disease risk by reducing biomarkers of oxidative stress and inflammation in patients with type 2 diabetes. This information remains essential in determining the therapeutic value of sulforaphane or its potential use as a nutraceutical to manage diabetes and its related complications. Finally, this review discusses essential information on the bioavailability profile of sulforaphane, while also covering information on the pathological consequences of oxidative stress and inflammation that drive the development and progression of diabetes.

Ocular motor nerve palsy in patients with diabetes: High-resolution MR imaging of nerve enhancement

OBJECTIVE

To evaluate the extent of signal abnormality in impaired ocular motor nerves using high signal and spatial resolution MRI sequences and to discuss the involvement of inflammatory or microvascular impairment in patients with diabetic ophthalmoplegia.

METHODS

We conducted a retrospective study of 10 patients referred for acute ocular motor nerve palsy in the context of diabetes mellitus from September 15th, 2021 to April 24th, 2022. 3T MRI evaluation included diffusion, 3D TOF, FLAIR, coronal STIR and post-injection 3D T1 SPACE DANTE sequences.

RESULTS

Ten patients were included: 9 males and 1 female aged from 46 to 79 years. Five patients presented with cranial nerve (CN) III palsy, and 5 presented with CN VI palsy. Third nerve palsy was pupil-sparing in 4 patients and pupil-involved in 1 patient. Pain was associated in all patients with CN III deficiencies and in 2 patients CN VI deficiencies. In all patients, MRI sequences ruled out mass effect and vascular pathology, such as acute stroke or aneurysm. Eight patients presented with STIR hypersignals, some with enlargement of the involved nerve. The diagnosis was confirmed through a post-injection 3D T1 SPACE DANTE sequence, which showed extended enhancement along the abnormal portion of the nerve.

CONCLUSION

High-resolution MRI evaluation of diplopia in diabetic patients is used to rule out a diagnosis of acute stroke and contributes to the positive diagnosis of ocular motor nerve impairment, possibly combining the influences of inflammatory and microvascular phenomena. Dedicated MR imaging should be included in the initial diagnosis and longitudinal follow-up of patients with diabetic ophthalmoplegia.

Corneal Confocal Microscopy Predicts Cardiovascular and Cerebrovascular Events and Demonstrates Greater Peripheral Neuropathy in Patients with Type 1 Diabetes and Foot Ulcers

OBJECTIVE

In this study, we evaluate small and large nerve fibre pathology in relation to diabetic foot ulceration (DFU) and incident cardiovascular and cerebrovascular events in type 1 diabetes (T1D).

METHODS

A prospective observational study was conducted on people with T1D without diabetic peripheral neuropathy (DPN) (n = 25), T1D with DPN (n = 28), T1D with DFU (n = 25) and 32 healthy volunteers. ROC analysis of parameters was conducted to diagnose DPN and DFU, and multivariate Cox regression analysis was performed to evaluate the predictive ability of corneal nerves for cardiac and cerebrovascular events over 3 years.

RESULTS

Corneal nerve fibre length (CNFL), fibre density (CNFD) and branch density (CNBD) were lower in T1D-DPN and T1D-DFU vs. T1D (all p < 0.001). In ROC analysis, CNFD (sensitivity 88%, specificity 87%; AUC 0.93; p < 0.001; optimal cut-off 7.35 no/mm2) and CNFL (sensitivity 76%, specificity 77%; AUC 0.90; p < 0.001; optimal cut-off 7.01 mm/mm2) had good ability to differentiate T1D with and without DFU. Incident cardiovascular events (p < 0.001) and cerebrovascular events (p < 0.001) were significantly higher in T1D-DPN and T1D-DFU. Corneal nerve loss, specifically CNFD predicted incident cardiovascular (HR 1.67, 95% CI 1.12 to 2.50, p = 0.01) and cerebrovascular (HR 1.55, 95% CI 1.06 to 2.26, p = 0.02) events.

CONCLUSIONS

Our study provides threshold values for corneal nerve fibre metrics for neuropathic foot at risk of DFU and further demonstrates that lower CNFD predicts incident cardiovascular and cerebrovascular events in T1D.

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

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

Evaluation of curcumin effect on Il6, Sirt1, TNFα and NFkB expression of liver tissues in diabetic mice with STZ

Background

Curcumin is active ingredient of turmeric The main purpose of this study is evaluating impact of curcumin on suger, hypoalgesia and inflammatory factors in diabetic mice.

Materials and methods

Male mice divided into six groups of 6. One group as a negative and the other five groups injected with Streptozotocin (STZ) (200 mg/kg). Diabetic mice in each group given different treatments for twenty-one days.After that, blood sugar and neuroathy studies have been done and tissue samples the liver were studied for gene expression.

Result

Curcumin reduced blood sugar, but the rate of hypoglycemia was significantly lower than metformin group P > 0.05, and the comparison of the synergistic effect of curcumin and metformin with metformin was not significant P > 0.05. Also, in neuropathy studies, the groups which recieved curcumin and metformin have shown a significant difference with diabetic group P < 0.01, Also, by evaluating inflammatory factors, there was a significant difference in the expression of TNF-a, IL-6 and NfkB, but there is no significant difference in the expression of Sirt1 P < 0.05.

Conclusions

The analgesic effect of curcumin was quite evident, probably due to the significant impact of this herbal drug in reducing the expression of inflammatory genes NF-kB, IL6, and TNF-α.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01090-4.