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Aims: Diabetic autonomic neuropathy is a severe complication of diabetes, estimated to affect up to 44% in type 1 diabetes (T1D) and 73% in type 2 diabetes (T2D) based on clinical studies. Currently, the assessment of diabetic autonomic neuropathy is not implemented in Denmark's clinical guidelines, complicating the estimation of the true prevalence. Thus, this study investigated the prevalence of self-reported symptoms of autonomic dysfunction in people living with diabetes in the North Denmark Region using the Composite Autonomic Symptoms Score (COMPASS)-31 questionnaire., Methods: In 2022, all adults with T1D or T2D in the North Denmark Region (n = 29,155) were identified using The National Health Insurance Service Registry and invited to an online survey including the Danish version of COMPASS-31. The prevalence and associated 95% confidence intervals (CI) for symptomatic autonomic dysfunction were determined using a cut-off value of 16., Results: In total, 7,377 completed COMPASS-31, of which 82.4% reported having T2D and 13.7% T1D. The prevalence of symptomatic autonomic dysfunction was 36.8% (95% CI: 34-40) after a median of 26 years with diabetes for T1D and 44.2% (95% CI: 43-45) after a median of 10 years for T2D. Pupillary and orthostatic intolerance were the most frequent moderate to severe symptoms, respectively (38.4% and 24.0% in T1D and 32.8% and 26.3% in T2D)., Conclusion: Symptoms of autonomic dysfunction are very common in individuals with diabetes living in the North Denmark Region, emphasizing the unmet need for regular testing to increase awareness and allow for adequate management, ultimately reducing the morbidity of diabetes., (© 2024. The Author(s).)

Aims: The aims were to quantify periventricular and deep white matter hyperintensities (WMHs) in adults with type 1 diabetes with different neuropathic phenotypes and to correlate WMH measurements to explanatory factors in diabetes., Methods: WMH measurements were obtained from brain magnetic resonance imaging of 56 adults with type 1 diabetes in subgroups including painful diabetic peripheral neuropathy (DPN), painless DPN, without DPN and 20 healthy controls using Fazekas scale and automatic segmentation analysis., Results: No differences in Fazekas assessed WMHs were found (individuals with periventricular lesions: diabetes 66 % vs. controls 40 %, p = 0.063, deep lesions: diabetes 52 % vs. controls 50 %, p = 1.0). Using automatic detection, there were no significant differences in count of periventricular (p = 0.30) or deep (p = 0.31) WMHs. Higher periventricular lesion burden was present in diabetes compared with controls (0.21 % vs. 0.06 %, p = 0.048), which was associated with more severe DPN, increased age, decreased cognitive function, and reduced volumetric and metabolic brain measures (all p < 0.05)., Conclusions: Our findings indicate increased burden of periventricular WMHs in diabetes which were associated to DPN severity and measurements reflecting neurodegeneration. Deep WMHs, often considered as chronic ischemic, were not significantly different. Mechanisms reflecting neurodegeneration and accelerated brain aging could be an overlooked aspect of peripheral and central neuropathy., (Copyright © 2024. Published by Elsevier B.V.)

Objectives: The study aimed to investigate brain metabolites in type 1 diabetes and the associations with disease characteristics. We explored the metabolic profiles predicting different neuropathic phenotypes using multiple linear regression analyses., Methods: We compared brain metabolites in 55 adults with type 1 diabetes (including painful diabetic peripheral neuropathy (DPN), painless DPN, without DPN) with 20 healthy controls. Proton magnetic resonance spectroscopy measurements (N-acetylaspartate (NAA), glutamate (glu), myo-inositol (mI), and glycerophosphocholine (GPC) were obtained in ratios to creatine (cre)) from the parietal region, anterior cingulate cortex and thalamus., Results: The overall diabetes group revealed decreased parietal NAA/cre compared to healthy controls (1.41 ± 0.12 vs. 1.55 ± 0.13,p < 0.001) and increased mI/cre (parietal: 0.62 ± 0.08 vs. 0.57 ± 0.07,p = 0.025, cingulate: 0.65 ± 0.08 vs. 0.60 ± 0.08,p = 0.033). Reduced NAA/cre was associated with more severe DPN (all p ≤ 0.04) whereas increased mI/cre was associated with higher hemoglobin A 1c (HbA 1c ) (p = 0.02). Diabetes was predicted from decreased parietal NAA/cre, increased parietal ml/cre, and decreased thalamic glu/cre. DPN was predicted from decreased parietal NAA/cre and increased GPC/cre. Painful DPN was predicted from increased parietal GPC/cre and thalamic glu/cre., Conclusions: Specific metabolic brain profiles were linked to the different phenotypes of diabetes, DPN and painful DPN., Significance: Assessment of metabolic profiles could be relevant for detailed understanding of central neuropathy in diabetes., Competing Interests: Declarations of interest None., (Copyright © 2024 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Aim: A diabetes-related foot ulcer (DFU) is a major risk factor for lower-extremity amputation (LEA). To help clinicians predict the risk of LEA in people with DFU, the Diabetic Foot Risk Assessment (DIAFORA) system was developed but has never been externally validated., Methods: In this study, 317 people presenting with a new DFU were included. At baseline, participants were grouped into three groups based on their DIAFORA score: low-risk (<15), medium-risk (15-25), and high-risk (>25). Participants were followed until healing, LEA, death, or at least 3 months. Discriminative accuracy was evaluated using sensitivity, specificity, likelihood ratios (LRs) and the area under the curve (AUC)., Results: All 317 participants completed at least 3 months of follow-up for a median duration of 146 days, during which 12.6% underwent minor amputation and 2.5% major amputation. People in the low- and medium-risk categories had major amputation rates of 0.9% and 2.1%, respectively, and negative LR of major LEA of 0.10 and 0.38, respectively, while the people in the high-risk category had an amputation rate of 25.0% and a positive LR of 12.9. The DIAFORA risk groups had a sensitivity of 75.0% and a specificity of 65.7%, with a corresponding AUC of 0.78 (95% CI 0.68-0.87) for the prediction of major LEA., Conclusion: The DIAFORA score is a useful tool for risk stratification of people presenting with a newly occurred DFU, with the external validation presenting results similar to those presented in the original study. The DIAFORA score may guide clinicians towards more individualized DFU treatment regimens., (© 2024 The Author(s). Diabetic Medicine published by John Wiley & Sons Ltd on behalf of Diabetes UK.)

Background: Diabetic peripheral neuropathy (DPN) is a prevalent and debilitating complication of diabetes, often leading to severe neuropathic pain. Although other diabetes-related complications have witnessed a surge of emerging treatments in recent years, DPN has seen minimal progression. This stagnation stems from various factors, including insensitive diagnostic methods and inadequate treatment options for neuropathic pain., Methods: In this comprehensive review, we highlight promising novel diagnostic techniques for assessing DPN, elucidating their development, strengths, and limitations, and assessing their potential as future reliable clinical biomarkers and endpoints. In addition, we delve into the most promising emerging pharmacological and mechanistic treatments for managing neuropathic pain, an area currently characterized by inadequate pain relief and a notable burden of side effects., Results: Skin biopsies, corneal confocal microscopy, transcutaneous electrical stimulation, blood-derived biomarkers, and multi-omics emerge as some of the most promising new techniques, while low-dose naltrexone, selective sodium-channel blockers, calcitonin gene-related peptide antibodies, and angiotensin type 2 receptor antagonists emerge as some of the most promising new drug candidates., Conclusion: Our review concludes that although several promising diagnostic modalities and emerging treatments exist, an ongoing need persists for the further development of sensitive diagnostic tools and mechanism-based, personalized treatment approaches., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Aim: An objective assessment of small nerve fibers is key to the early detection of diabetic peripheral neuropathy (DPN). This study investigates the diagnostic accuracy of a novel perception threshold tracking technique in detecting small nerve fiber damage., Methods: Participants with type 1 diabetes (T1DM) without DPN (n = 20), with DPN (n = 20), with painful DPN (n = 20) and 20 healthy controls (HCs) underwent perception threshold tracking on the foot and corneal confocal microscopy. Diagnostic accuracy of perception threshold tracking compared to corneal confocal microscopy was analyzed using logistic regression., Results: The rheobase, corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), and corneal nerve fiber length (CNFL) (all P < .001) differed between groups. The diagnostic accuracy of perception threshold tracking (rheobase) was excellent for identifying small nerve fiber damage, especially for CNFL with a sensitivity of 94%, specificity 94%, positive predictive value 97%, and negative predictive value 89%. There was a significant correlation between rheobase with CNFD, CNBD, CNFL, and Michigan Neuropathy Screening Instrument (all P < .001)., Conclusion: Perception threshold tracking had a very high diagnostic agreement with corneal confocal microscopy for detecting small nerve fiber loss and may have clinical utility for assessing small nerve fiber damage and hence early DPN., Clinical Trials: NCT04078516., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Preventing lower-extremity amputations (LEAs) is pivotal. In the present study, we aimed to examine the recent trends in nontraumatic LEAs seen in the Northern Danish Region., Methods: Using data from the regional Business Intelligence unit, we identified all nontraumatic LEAs (n = 689) performed in people above 50 years of age in the Northern Danish Region between January 2016 and December 2021 (approximately 600,000 inhabitants). Persons with diabetes (n = 26,025) were identified based on International Classification of Diseases-10 codes and data from the National Health Insurance Service Registry, while preventive vascular procedures (n = 1,097) were identified using surgical codes. Major LEA was defined as any amputation above the ankle. Incidence rates were expressed as events per 1,000 person-years. Trends were described as differences between the periods 2016-2018 and 2019-2021., Results: A total of 249 (36%) major LEAs were performed in people with diabetes. People with diabetes were younger (71 vs 77 years, P < 0.001) and more frequently male (70% versus 54%, P < 0.001). Between 2016-2018 and 2019-2021, the incidence of major LEA declined from 1.76 (95% CI: 1.75-1.76) to 1.39 (1.39-1.39) in people with diabetes and from 0.47 (0.47-0.47) to 0.20 (0.20-0.20) in people without diabetes (all P < 0.001). Simultaneously, the incidence of preventive vascular surgery increased from 2.26 (2.26-2.26) to 3.48 (3.48-3.48) in people with diabetes and declined slightly in people without 0.49 (0.49-0.49) to 0.47 (0.47-0.47) (all P < 0.001)., Conclusions: Despite significant declines in major LEA in both people with and without diabetes, most of the decline was driven by a large reduction in major LEAs in people without diabetes., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Diabetic peripheral neuropathy (DPN) is a common complication of diabetes, yet varying estimates of its prevalence exist. The present study aimed to estimate a questionnaire-centered prevalence of painful and painless DPN in the Northern Danish Region, examine its geographical distribution within the region, and investigate associations between DPN and potential risk factors., Methods: A questionnaire-based survey was sent to all persons living with diabetes in the Northern Danish Region using electronic mail. Persons with diabetes were identified using The National Health Insurance Service Registry. The survey included information on demographics, socioeconomics, municipality, diabetes type, duration, and treatment, as well as the validated questionnaires Michigan Neuropathy Screening Instrument-questionnaire (MNSIq) and the Douleur Neuropathique en 4 Questions (DN4)-interview. Possible DPN was defined as an MNSIq-score ≥ 4, while possible painful DPN was defined as pain in both feet and a DN4-interview score ≥ 3., Results: A total of 23,206 eligible people were identified as having diabetes and approximately 33 % answered all questionnaires. The prevalence of possible DPN was 23.3 % (95 % CI: 22.4-24.3 %), while the prevalence of possible painful DPN was 18.0 % (17.1-18.8 %). The prevalence of possible DPN ranged from 22.1 % to 35.0 % between municipalities, while the prevalence of possible painful DPN ranged from 15.6 % to 20.0 %. High body-mass index, long diabetes duration, insulin use, glucagon-like-peptide-1-analogue use, and low income were associated with increased risk of DPN., Conclusion: The high prevalence of possible painless and painful DPN emphasizes the need for better prevention and careful screening even in high-income countries., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest, (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Preventative foot self-care is vital for avoiding diabetic foot ulcer episodes and lowering the risk of amputations. Yet, it demands high levels of health literacy and cognitive function., Objective: To investigate health literacy and cognitive function in persons presenting with a diabetic foot ulcer., Methods: Participants with type 2 diabetes were recruited from the tertiary foot clinic at Steno Diabetes Center North Denmark. The European Health Literacy Survey Questionnaire and Addenbrooke's Cognitive Examination were applied. A semi-structured interview guide was developed to evaluate foot self-care knowledge, attitude, and practice. The qualitative data were analyzed with a deductive approach based on a qualitative thematic analysis model. Subsequently, an integrated analysis of the quantitative and qualitative results was conducted., Results: The participants ( n  = 12) had a mean age of 62.6 ± 8.4 years, and 11 were males. The mean diabetes duration was 15.9 ± 8.9 years. Eight participants had a recurrent diabetic foot ulcer. The health literacy level was sufficient in nine participants, and cognitive function was normal in five participants. Three different profiles related to foot self-care ( proactive , active , or passive , respectively) were constructed by the final integrated analysis: a proactive profile refers to taking preventative action in concordance with knowledge and attitude, an active profile to taking action in response to a situation, but challenged by conflicting levels of knowledge and attitude, and a passive profile to not taking action., Conclusion: The study suggests that people presenting with a diabetic foot ulcer have different foot self-care profiles based on person-specific health literacy, cognitive function, and knowledge, attitude, and practice element characteristics, highlighting the need for individualized education and intervention strategy instead of a one-size-fits-all approach., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2024.)

Purpose: Diabetic neuropathy can lead to decreased peripheral sensation and motor neuron dysfunction associated with impaired postural control and risk of falling. However, the relationship between decreased peripheral sensation and impaired vestibular function in diabetes mellitus is poorly investigated. Therefore, the aim of this study was to investigate the relationship between peripheral and autonomic measurements of diabetic neuropathy and measurements of vestibular function., Methods: A total of 114 participants with type 1 diabetes (n = 52), type 2 diabetes (n = 51) and controls (n = 11) were included. Vestibular function was evaluated by video head impulse testing. Peripheral neuropathy was assessed by quantitative sensory testing and nerve conduction. Autonomic neuropathy using the COMPASS 31 questionnaire. Data were analyzed according to data type and distribution., Results: Measurements of vestibular function did not differ between participants with type 1 diabetes, type 2 diabetes or controls (all p-values above 0.05). Subgrouping of participants according to the involvement of large-, small- or autonomic nerves did not change this outcome. Correlation analyses showed a significant difference between COMPASS 31 and right lateral gain value (ρ = 0.23, p = 0.02,), while no other significant correlations were found., Conclusion: Diabetic neuropathy does not appear to impair vestibular function in diabetes, by means of the VOR., Clinical Trials: NCT05389566, May 25th, 2022., (© 2023. The Author(s).)

Introduction/aims: Research has proven that epidermal and transcutaneous stimulation can identify the function of Aβ and Aδ fibers (i.e., in diabetes) individually using different electrodes. In this study we aimed to determine the stability of perception thresholds when using such electrodes., Methods: Twenty healthy volunteers participated in this study. The perception threshold of Aβ fibers (patch electrode) and Aδ fibers (pin electrode) was estimated 30 times during a period of 60 minutes. A threshold was established every other minute, alternating between the two electrodes. The stimulus duration was 1 millisecond and the interstimulus interval was 1.5 to 2.5 seconds. Linear regressions of the perception threshold as a function of time were performed. The slopes were used as an estimate of habituation and were compared between the electrodes., Results: The slope was significantly larger when assessed by the pin electrode (median: 0.020 [0.009 to 0.030] mA/trial) than when assessed by the patch electrode (median: 0.005 [0.001 to 0.018] mA/trial) (P = .017, paired t test). During the session, total increases in perception threshold of approximately 55% and 1% were seen for the pin and patch electrodes, respectively., Discussion: The two fiber types assessed showed significant perception threshold increases. The higher slope of the pin electrode indicated that the Aδ fibers were more prone to habituation than the Aβ fibers, and that habituation should be considered during prolonged experiments. This assessment is valuable for future research on nerve fiber function using the technique for long session experiments., (© 2023 The Authors. Muscle & Nerve published by Wiley Periodicals LLC.)

Introduction/aims: The axon-reflex flare response is a reliable method for functional assessment of small fibers in diabetic peripheral neuropathy (DPN), but broad adoption is limited by the time requirement. The aims of this study were to (1) assess diagnostic performance and optimize time required for assessing the histamine-induced flare response and (2) associate with established parameters., Methods: A total of 60 participants with type 1 diabetes with (n = 33) or without (n = 27) DPN participated. The participants underwent quantitative sensory testing (QST), corneal confocal microscopy (CCM), and flare intensity and area size assessments by laser-Doppler imaging (FLPI) following an epidermal skin-prick application of histamine. The flare parameters were evaluated each minute for 15 min, and the diagnostic performance compared to QST and CCM were assessed using area under the curve (AUC). Minimum time-requirements until differentiation and to achieve results comparable with a full examination were assessed., Results: Flare area size had better diagnostic performance compared with CCM (AUC 0.88 vs. 0.77, p < 0.01) and QST (AUC 0.91 vs. 0.81, p = 0.02) than mean flare intensity, and could distinguish people with and without DPN after 4 min compared to after 6 min (both p < 0.01). Flare area size achieved a diagnostic performance comparable to a full examination after 6 and 7 min (CCM and QST respectively, p > 0.05), while mean flare intensity achieved it after 5 and 8 min (CCM and QST respectively, p > 0.05)., Discussion: The flare area size can be evaluated 6-7 min after histamine-application, which increases diagnostic performance compared to mean flare intensity., (© 2023 The Authors. Muscle & Nerve published by Wiley Periodicals LLC.)

Introduction: Previous studies suggest that cognitive impairment is more prevalent in individuals with painful and painless diabetic peripheral neuropathy (DPN). However, the current evidence is not well described. This study investigated cognitive function in adults with type 1 diabetes mellitus (T1DM) and the association to painful/painless DPN and clinical parameters., Methods: This cross-sectional, observational, case-control study included 58 participants with T1DM, sub-grouped into 20 participants with T1DM and painful DPN, 19 participants with T1DM and painless DPN, 19 participants with T1DM without DPN, and 20 healthy controls were included. The groups were matched for sex and age. The participants performed Addenbrooke's examination III (ACE-III), which assesses attention, memory, verbal fluency, language and visuospatial skills. Working memory was evaluated using an N-back task. Cognitive scores were compared between the groups and correlated to age, diabetes duration, HbA1c and nerve conduction measurements., Results: Compared to healthy controls, T1DM participants showed lower total ACE-III (p = .028), memory (p = .013) and language scores (p = .028), together with longer reaction times in the N-back task (p = .041). Subgroup analyses demonstrated lower memory scores in those with painless DPN compared with healthy controls (p = .013). No differences were observed between the three T1DM subgroups. Cognitive scores and clinical parameters were not associated., Conclusions: This study supports the notion of cognitive alterations in T1DM and indicates that cognitive function is altered in T1DM regardless of underlying neuropathic complications. The memory domain appears altered in T1DM, particularly in those with painless DPN. Further studies are needed to verify the findings., (© 2023 The Authors. Endocrinology, Diabetes & Metabolism published by John Wiley & Sons Ltd.)

Aims: To investigate the co-existence of diabetic peripheral neuropathy (DPN), painful diabetic peripheral neuropathy (PDPN), and cardiac autonomic neuropathy (CAN) and to establish a model to predict CAN based on peripheral measurements., Methods: Eighty participants (20 type 1 diabetes (T1DM) + PDPN, 20 T1DM + DPN, 20 T1DM-DPN (without DPN), and 20 healthy controls (HC)) underwent quantitative sensory testing, cardiac autonomic reflex tests (CARTs), and conventional nerve conduction. CAN was defined as ≥ 2 abnormal CARTs. After the initial analysis, the participants with diabetes were re-grouped based on the presence or absence of small (SFN) and large fibre neuropathy (LFN), respectively. A prediction model for CAN was made using logistic regression with backward elimination., Results: CAN was most prevalent in T1DM + PDPN (50%), followed by T1DM + DPN (25%) and T1DM-DPN and HC (0%). The differences in prevalence of CAN between T1DM + PDPN and T1DM-DPN/HC were significant (p < 0.001). When re-grouping, 58% had CAN in the SFN group and 55% in the LFN group, while no participants without either SFN or LFN had CAN. The prediction model had a sensitivity of 64%, a specificity of 67%, a positive predictive value of 30%, and a negative predictive value of 90%., Conclusion: This study suggests that CAN predominantly co-exists with concomitant DPN., (© 2023. Springer-Verlag Italia S.r.l., part of Springer Nature.)

Abstract: It remains unknown why some people with diabetes develop painful neuropathies while others experience no pain. This study aimed to validate a novel method for assessing the function of small sensory nerves in diabetes to further elucidate this phenomenon. The function of large and small nerves was assessed using a novel perception threshold tracking technique in 3 well-characterized groups (n = 60) with type 1 diabetes, namely, (1) painful diabetic peripheral neuropathy (T1DM + PDPN), (2) painless diabetic peripheral neuropathy (T1DM + DPN), and (3) no neuropathy (T1DM - DPN), and healthy controls (n = 20). Electrical currents with different shapes, duration, and intensities were applied by 2 different skin electrodes activating large and small fibers, respectively. The minimal current needed to activate the fibers were analyzed as the rheobase of the stimulus-response function. Nerve fiber selectivity was measured by accommodation properties of stimulated nerves. The rheobase of both fiber types were highest for T1DM + PDPN, followed by T1DM + DPN, T1DM - DPN, and healthy controls, indicating that the nerve properties are specific in individuals with diabetes and pain. There was an overall significant difference between the groups ( P < 0.01). The accommodation properties of stimulated fibers were different between the 2 electrodes ( P < 0.05) apart from in the group with T1DM + PDPN, where both electrodes stimulated nerves displaying properties similar to large fibers. Perception threshold tracking reveals differences in large and small nerve fiber function between the groups with and without diabetes, DPN, and pain. This indicates that the methods have potential applications in screening DPN and explore further the features differentiating painful from nonpainful DPN., (Copyright © 2022 International Association for the Study of Pain.)

Objective: In this study we aimed to investigate the functional connectivity of brain regions involved in sensory processing in diabetes with and without painful and painless diabetic peripheral neuropathy (DPN) and the association with peripheral nerve function and pain intensity., Research Design and Methods: In this cross-sectional study we used resting-state functional MRI (fMRI) to investigate functional brain connectivity of 19 individuals with type 1 diabetes and painful DPN, 19 with type 1 diabetes and painless DPN, 18 with type 1 diabetes without DPN, and 20 healthy control subjects. Seed-based connectivity analyses were performed for thalamus, postcentral gyrus, and insula, and the connectivity z scores were correlated with peripheral nerve function measurements and pain scores., Results: Overall, compared with those with painful DPN and healthy control subjects, subjects with type 1 diabetes without DPN showed hyperconnectivity between thalamus and motor areas and between postcentral gyrus and motor areas (all P ≤ 0.029). Poorer peripheral nerve functions and higher pain scores were associated with lower connectivity of the thalamus and postcentral gyrus (all P ≤ 0.043). No connectivity differences were found in insula (all P ≥ 0.071)., Conclusions: Higher functional connectivity of thalamus and postcentral gyrus appeared only in diabetes without neuropathic complications. Thalamic/postcentral gyral connectivity measures demonstrated an association with peripheral nerve functions. Based on thalamic connectivity, it was possible to group the phenotypes of type 1 diabetes with painful/painless DPN and type 1 diabetes without DPN. The results of the current study support that fMRI can be used for phenotyping, and with validation, it may contribute to early detection and prevention of neuropathic complications., (© 2022 by the American Diabetes Association.)

Aims: This study investigated brain structure in patients of type 1 diabetes with diabetic peripheral neuropathy (DPN) and type 1 diabetes with neuropathic pain and the associations to clinical, peripheral, and cognitive measurements., Methods: Sixty individuals with type 1 diabetes and 20 healthy controls were included in the study. Nineteen individuals with type 1 diabetes and neuropathic pain, 19 with type 1 diabetes and DPN, 18 with type 1 diabetes without DPN, and 20 healthy controls were included in the brain analyses. We utilized structural brain magnetic resonance imaging to investigate total and regional gray matter volume., Results: Significant lower gray matter volume was found in type 1 diabetes with neuropathic pain and in type 1 diabetes without DPN compared to healthy controls ( p =0.024 and p =0.019, respectively). Lower insula volume was observed in all three diabetes groups (all p ≤0.050). Thalamus and hippocampus volume was lower in type 1 diabetes with neuropathic pain, cerebellum volume was lower in type 1 diabetes with DPN, and somatosensory cortex volume was lower in type 1 diabetes without DPN (all p ≤0.018). Attenuated memory was associated with lower gray matter volume in type 1 diabetes with DPN. No associations were found between gray matter volume and clinical/peripheral measurements., Conclusion: We demonstrated lower gray matter volume in individuals with type 1 diabetes regardless of the presence of DPN and neuropathic pain. Hence, central gray matter alteration was not associated with peripheral alterations., Competing Interests: None of the authors has potential conflicts of interest to be disclosed. All authors have approved the final version of the article., (Thieme. All rights reserved.)

Small nerve fibres are important when studying diabetic peripheral neuropathy (DPN) as they could be first affected. However, assessing their integrity and function adequately remains a major challenge. The aim of this study was to investigate the association between different degrees of DPN, the presence of neuropathic pain, and the intensity of the axon-reflex flare response provoked by epidermal histamine. Eighty adults were included and divided into 4 groups of 20 with type 1 diabetes and: painful DPN (T1DM+PDPN), non-painful DPN (T1DM+DPN), no DPN and no pain (T1DM-DPN), and 20 persons without diabetes or pain (HC). The vasomotor responses were captured by a Full-field Laser Speckle Perfusion Imager. The response was lowest in T1DM+DPN, followed by T1DM+PDPN, T1DM-DPN and HC. The response was significantly reduced in DPN (T1DM+DPN, T1DM+PDPN) compared with people without (T1DM-DPN, HC) (P < .001). The response was also attenuated in diabetes irrespective of the degree of DPN (T1DM+PDPN, T1DM+DPN, T1DM-DPN) (P < .001). There were no differences in the response between painful neuropathy (T1DM+PDPN) and painless DPN (T1DM+DPN) (P = .189). The method can distinguish between groups with and without diabetes and with and without DPN but cannot distinguish between groups with and without painful DPN. PERSPECTIVE: This study describes how diabetes attenuates the axon-reflex response, and how it is affected by neuropathy and pain clarifying previous findings. Furthermore, the study is the first to utilize histamine when evoking the response, thus providing a new and fast alternative for future studies into the pathophysiology of neuropathic pain., (Copyright © 2022 United States Association for the Study of Pain, Inc. Published by Elsevier Inc. All rights reserved.)

Aims: A diabetic foot ulcer (DFU) is a severe condition associated with morbidity and mortality. Population-based studies are rare and limited by access to reliable data. Without this data, efforts in primary prevention cannot be evaluated. Therefore, we examined the incidence and changes over time for the first DFU in people with diabetes. We also examined hospitalization and all-cause mortality and their changes over time., Methods: From the UK primary care CPRD GOLD database (2007-2017), we identified 129,624 people with diabetes by a prescription for insulin or a non-insulin anti-diabetic drug. DFUs were identified using Read codes and expressed as incidence rates (IRs). Changes over time were described using Poisson and logistic regression and expressed as incidence rate ratios (IRRs) and odds ratios (ORs) respectively., Results: The mean IR of first registered DFUs was 2.5 [95% CI: 2.1-2.9] per 1000 person-years for people with type 2 diabetes and 1.6 [1.3-1.9] per 1000 person-years for people with type 1. The IRs declined for people with type 2 diabetes (IRR per year: 0.97 [0.96-0.99]), while no changes were observed for people with type 1 diabetes (IRR per year: 0.96 [0.89-1.04]). Average hospitalization and 1-year mortality risk for people with type 2 diabetes were 8.2% [SD: 4.7] and 11.7% [SD: 2.2] respectively. Both declined over time (OR: 0.89 [0.84, 0.94] and 0.94 [0.89, 0.99])., Conclusion: The decline in all IRs, hospitalizations and mortality in people with type 2 diabetes suggests that prevention and care of the first DFU has improved for this group in primary care in the UK., (© 2021 Diabetes UK.)

Diabetic painless and painful peripheral neuropathy remains the most frequent complication of diabetes mellitus, but the pathophysiology remains undescribed, there are no robust clinical endpoints and no efficient treatment exists. This hampers good clinical practice, fruitful clinical research and successful pharmacological trials, necessary for the development of early detection, prevention and treatment. This chapter supplies an update on background and treatment of diabetic peripheral neuropathy. Goals and perspectives for future clinical and scientific approaches are also described., (© 2022. The Author(s), under exclusive license to Springer Nature Switzerland AG.)

Background: Treatment with sodium-glucose co-transporter-2-inhibitors (SGLT2-Is), such as canagliflozin, has been associated with an increased risk of lower limb amputations (LLAs) in type 2 diabetes mellitus (T2DM). However, conflicting results have been reported for different SGLT2-Is and the underlying mechanism is unclear., Objective: To investigate the risk of LLA and diabetic foot ulcer with SGLT2-I use compared to other anti-diabetic drugs and to explore hypovolemia as a potential underlying mechanism., Methods: A cohort study was conducted using data from the Clinical Practice Research Datalink GOLD (2013-2019). The study population (N=51,847) consisted of T2DM patients over 18 years of age with at least one prescription of a non-insulin anti-diabetic drug. Concomitant diuretic use and the presence of signs of hypovolemia were determined to assess the potential underlying mechanism. Cox proportional hazard models were used to estimate the hazard ratio (HR) for LLA in current SGLT2-I use versus current sulphonylurea (SU) use. Analyses were adjusted for lifestyle variables, comorbidities, and concomitant drug use., Results: Current SGLT2-I use was not associated with an increased risk of LLA compared to current SU use (fully adjusted HR 0.70; 95% confidence interval 0.38-1.29). Concomitant use of diuretics and the presence of signs of hypovolemia were not associated with an increased risk of LLA., Conclusion: Use of SGLT2-Is, with or without signs of hypovolemia, was not associated with an increased risk of LLA or DFU versus current SU use. Future studies powered to detect potential differences between individual SGLT2-Is are required to rule out a canagliflozin-specific effect., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Diabetic peripheral neuropathy (DPN) is traditionally divided into large and small fibre neuropathy (SFN). Damage to the large fibres can be detected using nerve conduction studies (NCS) and often results in a significant reduction in sensitivity and loss of protective sensation, while damage to the small fibres is hard to reliably detect and can be either asymptomatic, associated with insensitivity to noxious stimuli, or often manifests itself as intractable neuropathic pain., Objective: To describe the recent advances in both detection, grading, and treatment of DPN as well as the accompanying neuropathic pain., Methods: A review of relevant, peer-reviewed, English literature from MEDLINE, EMBASE and Cochrane Library between January 1st 1967 and January 1st 2020 was used., Results: We identified more than three hundred studies on methods for detecting and grading DPN, and more than eighty randomised-controlled trials for treating painful diabetic neuropathy., Conclusion: NCS remains the method of choice for detecting LFN in people with diabetes, while a gold standard for the detection of SFN is yet to be internationally accepted. In the recent years, several methods with huge potential for detecting and grading this condition have become available including skin biopsies and corneal confocal microscopy, which in the future could represent reliable endpoints for clinical studies. While several newer methods for detecting SFN have been developed, no new drugs have been accepted for treating neuropathic pain in people with diabetes. Tricyclic antidepressants, serotonin-norepinephrine reuptake inhibitors and anticonvulsants remain first line treatment, while newer agents targeting the proposed pathophysiology of DPN are being developed., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)