Search Results (157)

Aim: To compare diabetic polyneuropathy (DPN) and cardiac autonomic neuropathy (CAN) between T1DM and T2DM patients. Methods: This study enrolled 66 T1DM and 79 T2DM patients. DPN was evaluated using three different methods: clinical examination, using neuropathy symptom score (NSS) and neuropathy disability score (NDS), current perception threshold (CPT) using Neurometer, and nerve conduction studies (NCSs). CAN was assessed by cardiovascular autonomic reflex tests (CARTs). Results: The prevalence of DPN did not differ between T1DM and T2DM (p > 0.05 for all), however, the proportion of DPN depended on the method used and was highest with CPT (53.0% vs. 46.8%), followed by NCSs (44.1% vs. 41.2%) and clinical examination (25.8% vs. 31.6%). T2DM vs. T1DM patients were more often diagnosed with painful DPN (51.9% vs. 27.3%, p = 0.004), reduced perception of vibration (72.2% vs. 48.5%, p = 0.006), and autonomic neuropathy (59.5% vs. 32.3%, p = 0.001), while NCSs revealed more prevalent motor nerve dysfunction in T1DM compared to T2DM (41.2% vs. 19.6%). Multivariate regression analysis showed increased DPN risk with age and CAN risk with worsening of eGFR in T1DM. No significant associations remained after multivariate adjustment for T2DM. Conclusions: The prevalence of DPN is highly varied and depends on the diagnostic method used. T2DM patients more often had symptoms and signs of diabetic neuropathy. However, stronger associations with risk factors were observed in T1DM. Full article

Diabetic sensorimotor polyneuropathy (DSPN) is the most prevalent complication of diabetes, affecting nearly half of all persons with diabetes. It is characterized by nerve degeneration, progressive sensory loss and pain, with increased risk of ulceration and amputation. Despite its high prevalence, disease-modifying treatments for DSPN do not exist. Mitochondrial dysfunction and Ca²⁺ dyshomeostasis are key contributors to the pathophysiology of DSPN, disrupting neuronal energy homeostasis and initiating axonal degeneration. Recent findings have demonstrated that antagonism of the muscarinic acetylcholine type 1 receptor (M₁R) promotes restoration of mitochondrial function and axon repair in various neuropathies, including DSPN, chemotherapy-induced peripheral neuropathy (CIPN) and HIV-associated neuropathy. Pirenzepine, a selective M₁R antagonist with a well-established safety profile, is currently under clinical investigation for its potential to reverse neuropathy. The transient receptor potential melastatin-3 (TRPM3) channel, a Ca²⁺-permeable ion channel, has recently emerged as a downstream effector of G protein-coupled receptor (GPCR) pathways, including M₁R. TRPM3 activation enhanced mitochondrial Ca²⁺ uptake and bioenergetics, promoting axonal sprouting. This review highlights mitochondrial and Ca²⁺ signaling imbalances in DSPN and presents M₁R antagonism and TRPM3 activation as promising neuro-regenerative strategies that shift treatment from symptom control to nerve restoration in diabetic and other peripheral neuropathies. Full article

Background and objectives: Duloxetine is widely used for the treatment of major depressive disorder (MDD), generalized anxiety disorder (GAD), and various types of neuropathic pain. While its efficacy is well documented in clinical trials, less is known about how it is perceived and utilized in routine psychiatric practice. To address this knowledge gap, we conducted a cross-sectional observational study involving 80 psychiatrists from Spain to assess real-world clinical attitudes toward duloxetine. Methods: Participants completed a 20-item multiple-choice questionnaire that examined familiarity, perceived efficacy in multiple conditions (MDD, GAD, neuropathic pain, somatization, and quality of life), and perspectives on tolerability, safety, adherence, and overall satisfaction. Results: Survey results indicated that a large majority of psychiatrists frequently prescribe duloxetine, particularly for patients with MDD and comorbid chronic pain. Notably, 94% rated it as either “more effective” or “much more effective” for diabetic peripheral neuropathic pain. Psychiatrists reported a high perceived efficacy of duloxetine: 94% rated it as “more effective” or “much more effective” for diabetic peripheral neuropathy, and 93% gave similarly positive ratings for general neuropathic pain. For somatization, 70% found it “effective” or “very effective”, and 83% observed improvements in quality of life for many of their patients. Psychiatrists generally reported favorable perceptions of duloxetine’s tolerability profile: 97.5% rated it as the antidepressant associated with the least weight gain, and 82.5% perceived fewer sexual side effects compared to other options. Sedation and gastrointestinal side effects were generally considered mild or less severe. In terms of treatment adherence, 69% rated it as “better” or “much better” than other antidepressants, and 80% found its combination with other antidepressants to be “favorable” or “very favorable”. Overall satisfaction was high, with 99% of psychiatrists reporting being either “satisfied” or “very satisfied” with its use. The side effect profile was generally viewed as manageable, with low perceived rates of weight gain, sedation, and sexual dysfunction. Furthermore, 96% of respondents expressed a willingness to recommend duloxetine to their colleagues. Conclusions: Psychiatrists reported highly favorable attitudes toward duloxetine, viewing it as a flexible treatment option in routine care. However, these findings reflect clinicians’ subjective perceptions rather than objective clinical outcomes and should be interpreted accordingly. Full article

Diabetic neuropathy (DN) remains a major clinical burden, characterized by progressive sensory dysfunction, pain, and impaired quality of life. Despite the available symptomatic treatments, there is a pressing need for disease-modifying therapies. In recent years, preclinical research has highlighted the potential of repurposed pharmacological agents, originally developed for other indications, to target key mechanisms of DN. This narrative review examines the main pathophysiological pathways involved in DN, including metabolic imbalance, oxidative stress, neuroinflammation, ion channel dysfunction, and mitochondrial impairment. A wide array of repurposed drugs—including antidiabetics (metformin, empagliflozin, gliclazide, semaglutide, and pioglitazone), antihypertensives (amlodipine, telmisartan, aliskiren, and rilmenidine), lipid-lowering agents (atorvastatin and alirocumab), anticonvulsants (topiramate and retigabine), antioxidant and neuroprotective agents (melatonin), and muscarinic receptor antagonists (pirenzepine, oxybutynin, and atropine)—have shown promising results in rodent models, reducing neuropathic pain behaviors and modulating underlying disease mechanisms. By bridging basic mechanistic insights with pharmacological interventions, this review aims to support translational progress toward mechanism-based therapies for DN. Full article

Background/Objectives: Painful diabetic peripheral neuropathy (pDPN) significantly impacts quality of life, yet its diagnosis remains challenging due to reliance on subjective pain reports and limited objective biomarkers. This meta-analysis evaluated corneal nerve morphology parameters; corneal nerve fibre length (CNFL), corneal nerve fibre density (CNFD), and corneal nerve branch density (CNBD), measured through in vivo confocal microscopy (IVCM), as potential tools for differentiating painful and painless forms of diabetic neuropathy. Methods: A systematic review was performed comparing corneal nerve morphology across four groups: painful diabetic neuropathy (pDPN), non-painful diabetic neuropathy (npDPN), diabetes without neuropathy (DPN-), and healthy controls. Literature search extended over MEDLINE, EMBASE, Web of Science, and Cochrane Library, focusing on studies published since 2000. Study quality was assessed using the Newcastle–Ottawa Scale, while evidence certainly followed GRADE guidelines. Random-effects meta-analyses calculated mean differences (MDs) with 95% confidence intervals (CIs) for CNFL, CNFD, and CNBD. Results: Seven observational studies comprising 803 participants (213 pDPN, 275 npDPN, 99 DPN-, and 216 controls) revealed no significant differences between pDPN and npDPN groups in CNFL (MD = 0.79, 95% CI −0.64 to 2.22), CNFD (MD = 1.67, 95% CI −0.14 to 3.47), or CNBD (MD = 1.84, 95% CI −4.31 to 7.98). However, all metrics were markedly reduced in pDPN compared to DPN- and healthy controls. Conclusions: While effective in identifying diabetic neuropathy, common corneal nerve morphology parameters cannot reliably distinguish pDPN from npDPN. This highlights the need for research into mechanisms like central sensitization, inflammation, and micro-neuromas, which could refine diagnostic and therapeutic approaches for pDPN. Full article

Background and Aim: Neuropathic pain leads to a significant deterioration in health-related quality of life (HRQOL). Treating neuromusculoskeletal pain is especially important to prevent and improve physical frailty and the locomotive syndrome. Varied pharmacotherapies could be applicable for neuropathic pain patients, but evidence has been limited for a wide range of neuropathic pain conditions with different etiologies. The aim of this review was to highlight mirogabalin, a novel calcium channel α2δ ligand which was first approved in Japan, and which is effective for various types of neuropathic pain diseases. Methods: We conducted a narrative review of the recent evidence that mirogabalin has significant analgesic potency for varied types of neuropathic pain conditions. Futher, this review highlighted specific advantages over other calcium channel ligands. Results: Analgesic potency of mirogabalin could cover peripheral neuropathic pain conditions including post-herpetic neuralgia, diabetic peripheral neuropathy, cauda equina syndrome caused by lumbar spinal stenosis, radiculopathy caused by cervical spondylosis, and also central neuropathic pain conditions like spinal cord injury. Mirogabalin consistently demonstrated daytime sleepiness and dizziness as adverse effects, but most of these were mild. Conclusions: Mirogabalin is recommended as the first-line drug against most molecular mechanisms that cause neuropathic pain regardless of whether they have a peripheral or central origin. Mirogabalin demonstrates relatively less daytime sleepiness, making it age-friendly in the current global situation where population aging is accelerated. Considering the epidemic of ‘opiophobia’ in Japan and other countries, pharmacotherapy using mirogabalin could treat neuropathic pain associated with cancer and its treatment (e.g., chemotherapy-induced peripheral neuropathy), as well as non-cancer etiologies worldwide. Full article

The study investigated the antinociceptive effects of four compounds (F1–F4) based on a 1H-isoindole-1,3(2H)-dione core, using various in vivo pain models—tonic (formalin test), neurogenic (capsaicin and glutamate tests), neuropathic (oxaliplatin-induced model of peripheral neuropathy as well as the streptozotocin-induced model of painful diabetic neuropathy), and inflammatory (carrageenan-induced). Pharmacokinetic parameters were also assessed. In the capsaicin test, F1, F2, and F4 (5–20 mg/kg) significantly reduced pain, while compound F3 was only active at 20 mg/kg. In the glutamate test, F1, F2, and F3 (5–20 mg/kg) demonstrated the most pronounced effect. In phase I of the formalin test, compounds F1 and F2 were active at doses of 5 and 10 mg/kg, respectively, while F3 and F4 exhibited activity only at the 20 mg/kg dose. In phase II, a dose-dependent reduction in pain was observed, with the weakest effect noted at F4. At a dose of 20 mg/kg, the compounds significantly reduced edema and carrageenan-induced pain, but to a lesser extent than ketoprofen. The compounds tested (10 mg/kg) showed significant anti-allodynic activity in the oxaliplatin- and streptozotocin-induced neuropathy pain models. All compounds demonstrated favorable pharmacokinetic results. The results of this study indicate that the compounds have a broad analgesic spectrum of activity. Full article

Background/Objectives. Diabetic peripheral neuropathy is a debilitating disease-related complication with a significant impact on quality of life. Its management represents a therapeutic challenge. Antioxidant agents such as α-lipoic acid, N-acetyl cysteine, and glutatione may be useful treatment strategies. Methods. A real-world, observational, retrospective, case–control study involving consecutive subjects with type 2 diabetes with diabetic peripheral neuropathy was performed. Participants who were supplemented with three different formulations for 12 weeks (high-dose α-lipoic acid (800 mg); low-dose α-lipoic acid (100 mg) plus glutathione (200 mg) plus Vitamin D (800 IU); N-acetyl cysteine (600 mg) plus glutathione (200 mg) plus Vitamin D (800 IU)) were compared with a non-treated control group. Questionnaires aimed at investigating the degree of disability and quality of life were administered. The primary endpoint was the change in neuropathic pain intensity measured by the Numerical Rating Scale (NRS). Results. Among 750 consecutive screened subjects with type 2 diabetes, 98 (13%) had diabetic neuropathy (mean age 66.7 ± 7.6 years, diabetes duration 11.3 ± 6.7 years, HbA1c 8.1 ± 1.5%, 43.8% insulin-treated). When comparing the differences between treatment groups in the changes in individual questionnaire scores between baseline and follow-up, all three supplements showed significant reductions compared to the control group in the NRS scale scores. No side effects have been reported during the study. Conclusions. As well as lipoic acid, other substances with specific activity on the genesis of neuropathic pain, such as N-acetyl cysteine and glutathione, have proved effective in reducing the intensity of pain. Full article

Neuropathic pain is a chronic disorder that arises from damaged or malfunctioning nerves. Hypersensitivity to stimuli, also known as hyperalgesia, can cause a person to experience pain from non-painful stimuli, termed allodynia. Cannabis-based medicines (CBMs) may provide new treatment options to manage neuropathic pain. A review of the relevant studies was conducted to evaluate the effectiveness of CBMs in treating neuropathic pain. Scientific literature was systematically searched from January 2003 to December 2024 using the Web of Science Core Collection, PubMed, and MEDLINE. A total of 22 randomized controlled trials (RCTs) were identified that considered the use of 1′,1′-dimethylheptyl-Δ⁸-tetrahydrocannabinol-11-oic acid (CT-3), Δ⁹-tetrahydrocannabinol (Δ⁹-THC), cannabidiol (CBD), combinations of Δ⁹-THC with CBD, and cannabidivarin for treatment of neuropathic pain. Significant reductions in pain were reported in 15 studies focused on the treatment of multiple sclerosis, spinal cord injuries, diabetic neuropathy, postherpetic neuralgia, HIV-associated sensory neuropathy, peripheral neuropathic pain, complex regional pain syndrome, chronic radicular neuropathic pain, and peripheral neuropathy of the lower extremities. These positive outcomes often adopted personalized and adjusted dosing strategies. By contrast, seven RCTs observed no significant pain relief compared to placebo, although some had minor improvements in secondary outcomes, such as mood and sleep. Collectively, CBM treatments may improve pain scores, but study limitations such as small sample sizes and study durations, high placebo response rates, and trial unblinding because of the psychoactive effects of cannabinoids all hinder data interpretation and the extrapolation to chronic pain conditions. Hence, future RCTs will need to have larger numbers and be more extended studies that explore optimal dosing and delivery methods and identify patient subgroups that are most likely to benefit. While CBMs show potential, their current use balances modest benefits against possible adverse effects and variable outcomes. Full article

Peripheral artery disease (PAD) is a chronic progressive accumulation of atherosclerotic lesions with varying degrees of arterial obstruction determining ischemic symptoms of the involved extremities. PAD is associated with decreased bioavailable nitric oxide due to endothelial cell dysfunction and the development and progression of vascular arterial stiffening (VAS). Atherosclerosis also plays an essential role in the development and progression of vascular arterial stiffening (VAS), which is associated with endothelial cell activation and dysfunction that results in a proinflammatory endothelium with a decreased ability to produce bioavailable nitric oxide (NO). NO is one of three gasotransmitters, along with carbon monoxide and hydrogen sulfide, that promotes vasodilation. NO plays a crucial role in the regulation of PAD, and a deficiency in its bioavailability is strongly linked to the development of atherosclerosis, VAS, and PAD. A decreased arterial patency may also occur due to a reduction in the elasticity or diameter of the vessel wall due to the progressive nature of VAS and atherosclerosis in PAD. Progressive atherosclerosis and VAS promote narrowing over time, which leads to impairment of vasorelaxation and extremity blood flow. This narrative review examines how atherosclerosis, aging and hypertension, metabolic syndrome and type 2 diabetes, tobacco smoking, and endothelial cell activation and dysfunction with decreased NO and VAS with its increased damaging pulsatile pulse pressure result in microvessel remodeling. Further, the role of ischemia and ischemia–reperfusion injury is discussed and how it contributes to ischemic skeletal muscle remodeling, ischemic neuropathy, and pain perception in PAD. Full article

Diabetic peripheral neuropathy (DPN) is a debilitating complication of diabetes, characterized by mechanical allodynia, neuroinflammation, and oxidative stress. Current treatments offer limited efficacy and are often associated with systemic side effects. Emerging evidence suggests that activation of cannabinoid receptor type 2 (CB₂) may represent a promising target for managing neuropathic pain and inflammation. This study investigates the therapeutic potential of intraplantar β-Caryophyllene (BCP), a selective CB₂ receptor agonist, administered as a topical intervention in a streptozotocin (STZ)-induced DPN mouse model. Hyperglycemia was induced by STZ injections, and diabetic mice received intraplantar BCP (9, 18, or 27 µg) daily for 21 days. Mechanical allodynia was assessed using von Frey filaments, and levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) and oxidative stress markers (MDA, SOD, CAT) were quantified in hind paw tissues. BCP dose-dependently alleviated STZ-induced mechanical allodynia, with the 27 µg dose producing the most pronounced effect (p < 0.001). The anti-allodynic effects of BCP were mediated through CB₂ receptor activation, confirmed by reversal with the CB₂ antagonist AM630 (p < 0.001), while the CB₁ antagonist AM251 had no significant impact. In addition, BCP significantly reduced pro-inflammatory cytokines (p < 0.01) and oxidative stress markers (p < 0.001) while restoring antioxidant enzyme activities (p < 0.05). A control group treated with a clinically available topical analgesic cream containing capsaicin 0.075% exhibited limited efficacy. These findings position topical BCP administration as a novel therapeutic strategy for DPN, offering sustained pain relief and modulation of neuroinflammatory and oxidative pathways with minimal systemic exposure. Further clinical studies are warranted to validate its potential for translation into therapeutic practice. Full article

Diabetes mellitus is characterized by a state of hyperglycemia, which can lead to severe complications if left untreated or poorly managed. Diabetic peripheral neuropathy (DPN) is one common complication. This condition is characterized by damage to the nerves that supply the legs and feet as well as problems with blood vessels, the heart, or urinary tract. To alleviate pain for patients, clinicians resort to long-term treatment regimens of nerve pain medications, which are usually either anticonvulsants or antidepressants. However, little is understood about the underlying mechanisms of DPN. Many pathogenic pathways have been proposed, one of which is mitochondrial dysfunction. Mitochondrial dysfunction includes a range of possible deficiencies given the number of functions controlled by or located in mitochondria, including their core function of bioenergetics. This review focuses on mitochondrial bioenergetics, including respiration/ATP synthesis and reactive oxygen species (ROS) production, as well as calcium homeostasis and apoptosis, and their potential as targets for the effective treatment of diabetic peripheral neuropathy. Full article

Peripheral neuropathy (PN) is a prevalent condition characterized by damage to peripheral nerves, often linked to risk factors such as diabetes. This condition results from various forms of neural damage, including injury to the cell body, axons, or demyelination, frequently beginning with small and thinly or unmyelinated fibers. Such nerve damage disrupts normal signaling, leading to symptoms like numbness, tingling, and pain. Effective nerve repair and regeneration, particularly through remyelination, are essential therapeutic objectives. While vitamin B12’s role in repair processes has been well established, emerging evidence suggests that other neurotropic vitamins, specifically B1 and B6, also contribute significantly to nerve health and symptom relief in PN. In this study, we demonstrate that a combination treatment of vitamins B1, B6, and B12 enhances repair and oxidative stress responses in co-cultures of neural and Schwann cells, leading to improved cell maturation and connectivity compared to vitamin B12 alone. Furthermore, proteomic analysis supports these observations at the molecular level, with enhanced cellular recycling processes like proteasome enhancement, as well as protein synthesis upregulation, needed to rebuild nerve connections and combatting oxidative stress. Our combined morphological and molecular results highlight the potential therapeutic advantage of the B1, B6, and B12 combination over vitamin B12 alone. Full article

Diabetic peripheral neuropathy (DPN) is a prevalent and disabling complication of diabetes, with painful diabetic peripheral neuropathy (PDPN) being its most severe subtype due to chronic pain and resistance to treatment. Satellite glial cells (SGCs), critical for maintaining dorsal root ganglion (DRG) homeostasis, undergo significant structural and functional changes under pathological conditions. This study investigated the role of galactosylceramide (GalCer), a key sphingolipid, in SGC dysfunction and neuron–glia interactions during DPN progression. Using a rat model of PDPN, we employed single-cell RNA sequencing (scRNA-seq), targeted mass spectrometry, and immunofluorescence analysis. The PDPN group exhibited transcriptional activation and structural reorganization of SGCs, characterized by increased SGC abundance and glial activation, evidenced by elevated Gfap expression. Functional enrichment analyses revealed disruptions in sphingolipid metabolism, including marked reductions in GalCer levels. Subclustering identified vulnerable SGC subsets, such as Cluster a, with dysregulated lipid metabolism. The depletion of GalCer impaired SGC-neuron communication, destabilizing DRG homeostasis and amplifying neurodegeneration and neuropathic pain. These findings demonstrate that GalCer depletion is a central mediator of SGC dysfunction in PDPN, disrupting neuron–glia interactions and exacerbating neuropathic pain. This study provides novel insights into the molecular mechanisms of DPN progression and identifies GalCer metabolism as a potential therapeutic target. Full article

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. Full article