Diabetic neuropathy is a debilitating disorder characterized by spontaneous and mechanical allodynia. The role of skin mechanoreceptors in the development of mechanical allodynia is unclear. We discovered that mice with diabetic neuropathy had decreased sirtuin 1 (SIRT1) deacetylase activity in foot skin, leading to reduced expression of brain-derived neurotrophic factor (BDNF) and subsequent loss of innervation in Meissner corpuscles, a mechanoreceptor expressing the BDNF receptor TrkB.
View Article and Find Full Text PDFAbnormal NAD signaling has been implicated in axonal degeneration in diabetic peripheral neuropathy (DPN). We hypothesized that supplementing NAD precursors could alleviate DPN symptoms through increasing the NAD levels and activating the sirtuin-1 (SIRT1) protein. To test this, we exposed cultured Dorsal Root Ganglion neurons (DRGs) to Nicotinamide Riboside (NR) or Nicotinamide Mononucleotide (NMN), which increased the levels of NAD, the SIRT1 protein, and the deacetylation activity that is associated with increased neurite growth.
View Article and Find Full Text PDFDiabetic neuropathy is a debilitating disorder characterized by spontaneous and mechanical pain. The role of skin mechanoreceptors in the development of mechanical pain (allodynia) is unclear. We discovered that mice with diabetic neuropathy had decreased sirtuin 1 (SIRT1) deacetylase activity in foot skin, leading to reduced expression of brain-derived neurotrophic factor (BDNF) and subsequent loss of innervation in Meissner corpuscles, a mechanoreceptor expressing the BDNF receptor TrkB.
View Article and Find Full Text PDFAxon degeneration in diabetic peripheral neuropathy (DPN) is associated with impaired NAD metabolism. We tested whether the administration of NAD precursors, nicotinamide mononucleotide (NMN) or nicotinamide riboside (NR), prevents DPN in models of Type 1 and Type 2 diabetes. NMN was administered to streptozotocin (STZ)-induced diabetic rats and STZ-induced diabetic mice by intraperitoneal injection at 50 or 100 mg/kg on alternate days for 2 months.
View Article and Find Full Text PDFObjective: To present standardized diagnostic criteria for idiopathic distal sensory polyneuropathy (iDSP) and its subtypes: idiopathic mixed fiber sensory neuropathy (iMFN), idiopathic small fiber sensory neuropathy (iSFN), and idiopathic large fiber sensory neuropathy (iLFN) for use in research.
Methods: The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities and Networks (ACTTION) public-private partnership with the Food and Drug Administration convened a meeting to develop consensus diagnostic criteria for iMFN, iSFN, and iLFN. After background presentations, a collaborative, iterative approach was used to develop expert consensus for new criteria.
Although there is considerably more data showing an association between type 2 diabetes mellitus (T2DM) and autonomic neuropathy, accumulating evidence indicates that cardiovascular autonomic neuropathy (CAN) is common in persons with impaired glucose tolerance (IGT). Furthermore, CAN may occur early after a metabolic insult and obesity, especially among mean, and seems to play an important role in the early pathogenesis of CAN. Autonomic symptoms are common in subjects with IGT.
View Article and Find Full Text PDFDiabetes predisposes to cognitive decline leading to dementia and is associated with decreased brain NAD levels. This has triggered an intense interest in boosting nicotinamide adenine dinucleotide (NAD) levels to prevent dementia. We tested if the administration of the precursor of NAD, nicotinamide mononucleotide (NMN), can prevent diabetes-induced memory deficits.
View Article and Find Full Text PDFObjectives: The aim of this study was to determine the evaluation and management of dysphagia in amyotrophic lateral sclerosis (ALS) patients by speech-language pathologists (SLPs).
Methods: A 15-question web-based survey sent to SLPs in general clinical practice.
Results: Forty-nine SLPs responded.
In diabetic neuropathy, there is activation of axonal and sensory neuronal degeneration pathways leading to distal axonopathy. The nicotinamide-adenine dinucleotide (NAD+)-dependent deacetylase enzyme, Sirtuin 1 (SIRT1), can prevent activation of these pathways and promote axonal regeneration. In this study, we tested whether increased expression of SIRT1 protein in sensory neurons prevents and reverses experimental diabetic neuropathy induced by a high fat diet (HFD).
View Article and Find Full Text PDFDistal symmetrical axonal polyneuropathy (DSP) is due to injury to peripheral sensory, motor, and autonomic nerve fibers, resulting in distal predominant sensory loss, pain, and gait instability. DSP occurs as a complication of multiple medical conditions including diabetes or HIV, or following exposure to various toxins such as chemotherapy. It affects at least 10% of the United States population.
View Article and Find Full Text PDFWe present the case of a 44-year-old man with amyotrophic lateral sclerosis (ALS) intubated for hypercapnic respiratory failure and aspiration pneumonia. The patient was successfully extubated, transitioned to non-invasive ventilation and lived at home comfortably for 17 months, with good functional status for the first year. This case highlights the potential of prolonged survival post extubation in patients with advanced ALS and respiratory failure.
View Article and Find Full Text PDFSurvival of human peripheral nervous system neurons and associated distal axons is highly dependent on energy. Diabetes invokes a maladaptation in glucose and lipid energy metabolism in adult sensory neurons, axons and Schwann cells. Mitochondrial (Mt) dysfunction has been implicated as an etiological factor in failure of energy homeostasis that results in a low intrinsic aerobic capacity within the neuron.
View Article and Find Full Text PDFNat Rev Dis Primers
June 2019
The global epidemic of prediabetes and diabetes has led to a corresponding epidemic of complications of these disorders. The most prevalent complication is neuropathy, of which distal symmetric polyneuropathy (for the purpose of this Primer, referred to as diabetic neuropathy) is very common. Diabetic neuropathy is a loss of sensory function beginning distally in the lower extremities that is also characterized by pain and substantial morbidity.
View Article and Find Full Text PDFNat Rev Dis Primers
June 2019
The global epidemic of prediabetes and diabetes has led to a corresponding epidemic of complications of these disorders. The most prevalent complication is neuropathy, of which distal symmetric polyneuropathy (for the purpose of this Primer, referred to as diabetic neuropathy) is very common. Diabetic neuropathy is a loss of sensory function beginning distally in the lower extremities that is also characterized by pain and substantial morbidity.
View Article and Find Full Text PDFPurpose: Diabetic neuropathy is a common and disabling disorder, and there are currently no proven effective disease-modifying treatments. Physical activity and dietary interventions in patients with diabetes and diabetic neuropathy have multiple beneficial effects and are generally low risk, which makes lifestyle interventions an attractive treatment option. We reviewed the literature on the effects of physical activity and dietary interventions on length-dependent peripheral neuropathy and cardiac autonomic neuropathy in diabetes.
View Article and Find Full Text PDFObjectives: Patients with amyotrophic lateral sclerosis (ALS) have poor sleep quality, but little is known about which factors affect sleep at time of diagnosis.
Methods: Patients with newly diagnosed ALS were administered the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale, Beck Depression Inventory-Revised, and ALS Functional Rating Scale and were compared with controls.
Results: Forty-three patients, age 63.
Objective: Autonomic dysfunction is a known complication of systemic sclerosis (SSc) that can affect vascular tone, gastrointestinal (GI) motility, heart rate, and blood pressure control. We sought to quantify autonomic symptom burden in SSc, and to define the characteristics of patients with SSc and autonomic dysfunction.
Methods: Patients with SSc were consecutively recruited during routine clinical visits at the Johns Hopkins Scleroderma Center and asked to complete the Composite Autonomic Symptom Score (COMPASS)-31 questionnaire, a validated tool to assess symptoms of autonomic dysfunction.
Objectives: There is a critical need to develop effective treatments for diabetic neuropathy. This study determined if a selective mGluR2/3 receptor agonist prevented or treated experimental diabetic peripheral neuropathy (DPN) through glutamate recycling and improved mitochondrial function.
Methods: Adult male streptozotocin treated Sprague-Dawley rats with features of type 1 diabetes mellitus (T1DM) or Low Capacity Running (LCR) rats with insulin resistance or glucose intolerance were treated with 3 or 10 mg/kg/day LY379268.
Both type 1 (T1DM) and type 2 diabetes mellitus (T2DM) have been associated with reduced performance on multiple domains of cognitive function and with evidence of abnormal structural and functional brain magnetic resonance imaging (MRI). Cognitive deficits may occur at the very earliest stages of diabetes and are further exacerbated by the metabolic syndrome. The duration of diabetes and glycemic control may have an impact on the type and severity of cognitive impairment, but as yet we cannot predict who is at greatest risk of developing cognitive impairment.
View Article and Find Full Text PDFNeurodegeneration is an important determinant of disability in multiple sclerosis (MS) but while currently approved treatments reduce inflammation, they have not been shown to reduce neurodegeneration. SIRT1, a NAD dependent protein deacetylase, has been implicated in the pathogenesis of neurodegeneration in neurological diseases including MS. We have studied the role of SIRT1 in experimental autoimmune encephalomyelitis (EAE) and found evidence for a neuroprotective role.
View Article and Find Full Text PDFIntroduction: No treatments for axonal peripheral neuropathy are approved by the United States Food and Drug Administration (FDA). Although patient- and clinician-reported outcomes are central to evaluating neuropathy symptoms, they can be difficult to assess accurately. The inability to identify efficacious treatments for peripheral neuropathies could be due to invalid or inadequate outcome measures.
View Article and Find Full Text PDFPurpose: We reviewed the literature on chronic inflammatory demyelinating polyneuropathy (CIDP) in diabetes mellitus (DM) and explored real-world data on the prevalence and treatment of CIDP within DM.
Methods: A literature search of Scopus was performed for the terms chronic inflammatory demyelinating polyradiculoneuropathy, chronic inflammatory demyelinating polyneuropathy, CIDP, and prevalence, incidence, epidemiology, or diabetes; peripheral neuropathy and prevalence or diabetes. We also searched through the reference lists of the resulting publications for additional findings that may have been missed.