Diabetic neuropathy: A narrative review of risk factors, classification, screening and current pathogenic treatment options (Review)

Polymorphic variants and risk of diabetic peripheral neuropathy in patients with type 2 diabetes mellitus: systematic review and meta-analysis

BACKGROUND

Neuropathy is a frequent complication of diabetes mellitus, a disease that is growing exponentially worldwide. Genetic research has emerged as an important tool for better understanding its predisposition, although a systematic synthesis of existing evidence is needed to better comprehend its association. The objective of this review was to determine the association between polymorphic variants identified through massive genomic testing and the risk of peripheral diabetic neuropathy in patients with type 2 diabetes mellitus.

METHODS

Inclusion criteria were case-control, cohort, and cross-sectional studies examining polymorphic variants and diabetic neuropathy (DNP) risk in type 2 diabetes, studies using GWAS, EWAS, or microarray for identifying genetic polymorphisms, studies involving adults, and articles in English or Spanish. Exclusion criteria included case reports, case series, ecological studies, editor letters, reviews, or secondary studies and conference abstracts. Exhaustive search in PubMed, Scopus, and Web of Science databases, using keywords. Risk of bias was determined through Newcastle-Ottawa scale. A qualitative synthesis of the results was performed (frequency), including meta-analysis where applicable (forest plot and funnel plot).

RESULTS

The searching strategy identified 370 studies, from which 7 were chosen for the systematic review, included 9478 participants. The quality of the studies was mostly good, but a significant heterogeneity in methods was found. We identify a significant association between peripheral neuropathy and plenty of single nucleotide variants (SNVs). Just the SNV rs10555080 in the gene THEG5 showed a higher likelihood of neuropathy (OR:1,34; IC 95%: 1,19 - 1,49).

DISCUSSION

This study faced limitations due to heterogeneity in DNP definitions, genotyping methods, and a focus on white and Arab populations, limiting generalization. Only English and Spanish articles were included, potentially excluding relevant research in other languages. Multiple SNVs were identified through genomic testing that were associated with peripheral diabetic neuropathy in patients with type 2 diabetes mellitus; however, the SNVs were not similar between studies.

TRIAL REGISTRATION

This research received no funding and was registered in PROSPERO (ID CRD42024505256).

Crumbling Pathogenesis and Biomarkers for Diabetic Peripheral Neuropathy

Background: Diabetic sensorimotor polyneuropathy (DSP) is a common chronic diabetic complication. Traditionally, DSP was once considered irreversible with a typical loss of axon. However, the superimpose of acquired demyelination on axonal loss in DSP patients has been observed, implying that DSP may be preventable or reversible, particularly within a subgroup of patients exhibiting early-stage acquired demyelination, underscoring the critical importance of identifying early prognostic markers. Methods: We systemically review the literature on the roles of biomarkers in predicting DSP and monitoring the progress. The underlying mechanisms of biomarkers were also discussed. Results: The pathogenesis of DSP is multifaceted, with various pathological mechanisms contributing to its development. Key mechanisms include aberrant glucose metabolism and induction of oxidative stress and inflammation. Several pathological processes, such as disrupted glucose metabolism, nerve damage, impaired microcirculation, genetic variants, and microRNA dysregulation, lead to molecular and protein changes that may be detectable in blood and other biological compartments, thus serving as potential biomarkers for DSP progression. However, the utility of a biomarker depends on its predictive accuracy, practicality, and ease of measurement. Conclusions: Most biomarkers for predicting DSP have demonstrated suboptimal predictive value, and many lack established accuracy in forecasting DSP progression. Consequently, the diagnostic utility of any single biomarker remains limited. A comprehensive combination of biomarkers from various categories may hold incredible promise for accurate detection. As artificial intelligence (AI) techniques, especially machine learning, rapidly advance, these technologies may offer significant potential for developing diagnostic platforms to integrate and interpret complex biomarker data for DSP.

Differences in splicing factors may predict type 2 diabetes remission in the CORDIOPREV study

Alternative splicing is a post-transcriptional process resulting in multiple protein isoforms from a single gene. Abnormal splicing may lead to metabolic diseases, including type 2 diabetes mellitus (T2DM). To identify the splicing factor expression that predicts T2DM remission in coronary heart disease (CHD) patients, we identified newly diagnosed T2DM at baseline (n = 190) from the CORDIOPREV study. Patients were classified as Responders (T2DM remission during 5 years without antidiabetic drugs) or non-Responders. Baseline dysregulation in 5 splicing factors (MBNL1, RBM5, hnRNP G/RBMX, CD44, NT5E) distinguished Responders from non-Responders. Adding these factors to clinical variables [AUC = 0.67], insulin resistance, and beta-cell indexes [AUC = 0.76], improved T2DM remission prediction [AUC = 0.80]. Cox regression analysis showed those with higher remission scores had a 2.63-fold increased remission probability. To conclude, a set of splicing factors that contribute to predicting T2DM remission in patients with CHD has been identified. Further research is needed to elucidate these findings' clinical relevance.

Neurotrophins in Peripheral Neuropathy: Exploring Pathophysiological Mechanisms and Emerging Therapeutic Opportunities

Neuropathies, which encompass a wide array of peripheral nervous system disorders, present significant challenges due to their varied causes, such as metabolic diseases, toxic exposures, and genetic mutations. This review article, focused on the critical role of neurotrophins in peripheral neuropathy, highlights the intricate balance of neurotrophins necessary for nerve health and the pathophysiological consequences when this balance is disturbed. Neurotrophins, including Nerve Growth Factor (NGF), Brain-Derived Neurotrophic Factor (BDNF), Neurotrophin-3 (NT- 3), and Neurotrophin-4 (NT-4), are essential for neuronal survival, axonal growth, and synaptic plasticity. Their signaling pathways are crucial for maintaining peripheral nervous system integrity, primarily via the Tropomyosin receptor kinase (Trk) receptors and the p75 neurotrophin receptor p75(NTR). Dysregulation of neurotrophins is implicated in various neuropathies, such as diabetic neuropathy and chemotherapy-induced peripheral neuropathy, leading to impaired nerve function and regeneration. Understanding neurotrophin signaling intricacies and their alterations in neuropathic conditions is crucial for identifying novel therapeutic targets. Recent advancements illuminate neurotrophins' potential as therapeutic agents, promising disease-modifying treatments by promoting neuronal survival, enhancing axonal regeneration, and improving functional recovery post-nerve injury. However, translating these molecular insights into effective clinical applications faces challenges, including delivery methods, target specificity, and the instability of protein- based therapies.

Effects of Short-Term Treatment with α-Lipoic Acid on Neuropathic Pain and Biomarkers of DNA Damage in Patients with Diabetes Mellitus

BACKGROUND/OBJECTIVES

Diabetes mellitus (DM) is a complex and heterogenous disease classified as a group of metabolic disorders characterized by chronic hyperglycemia resulting from defects in insulin secretion, insulin action, or both. It leads to various complications, some of which are macrovascular or microvascular complications, like diabetic polyneuropathy (DPN), having a profound impact on patients' quality of life. Oxidative stress (OS) is one of the significant mechanisms in the development and progression of DPN. Thus, targeting OS pathways by antioxidants, such as α-lipoic acid (ALA), could represent a promising therapeutic strategy for alleviating neuropathic symptoms. The aim of our study was to evaluate whether short-term (from 4 to 9 days) intravenous administration of ALA could cause any measurable improvement in subjects with DM.

METHODS

Sixteen subjects with DM (six type 1 and ten type 2) and sixteen nondiabetic subjects matched by sex and age were recruited to this study. Only subjects with DM received treatment with ALA (600 mg daily). Pain intensity and biomarkers of DNA damage including plasma concentration of 8-hydroxy-2'-deoxyguanosine (8-OHdG), frequency of micronucleated lymphocytes (MN), and frequency of sister-chromatid exchanges (SCEs), were measured before and after the treatment with ALA.

RESULTS

Pain intensity and 8-OHdG levels were significantly lower in DM subjects after the ALA treatment than before the treatment. However, no changes in the frequency of SCEs and MN were observed.

CONCLUSIONS

Our results show some evidence that even a short-term intravenous treatment with ALA could be beneficial for diabetic subjects, reducing pain intensity and concentration of 8-OHdG in blood plasma.

Regression equation analysis enhances detection of conduction slowing beyond axonal loss in diabetic neuropathy

Objectives

To evaluate the utility of regression analysis in the assessment of conduction slowing in diabetic distal symmetrical polyneuropathy (DSP) and in identifying superimposed demyelination beyond fiber loss.

Background

Causes of conduction slowing beyond pure axonal loss has been attributed to an additional demyelinating component. We therefore evaluated the utility of regression analysis in the assessment of conduction slowing in diabetic DSP and in identifying superimposed demyelination beyond fiber loss.

Methods

We previously established regression analysis to develop confidence intervals that assess the range of conduction slowing from primary demyelination in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). In this study, by using the regression equations, we analyzed conduction slowing in patients with diabetic DSP.

Results

Mean conduction velocity (CV) was significantly slower in diabetic DSP than in the non-diabetic DSP for all tested nerves. More patients were found to fulfill the regression equation criteria in the diabetic group compared to the non-diabetic group (47.0 % vs. 23.3 %). The estimated likelihood of having more than two motor nerves with CV slowing in the demyelination range by American Academy of Neurology or regression equations criteria was significantly higher in the diabetic DSP (0.73) compared to non-diabetic DSP (0.52).

Conclusions

Conduction slowing in diabetic DSP beyond what is expected exclusively from axonal loss could be identified by regression analysis.

Nanotechnology as a potential treatment for diabetes and its complications: A review

BACKGROUND AND AIM

Diabetes mellitus is a chronic metabolic disorder that causes multiple complications in various organs, such as the kidney, liver and cardiovascular system. These complications are the main causes of morbidity and mortality in patients with diabetes. Nanotechnology offers new opportunities for the therapy of diabetes and its multiple complications through site-specific and precise drug delivery. This review summarizes the various studies demonstrating the potential applications of different nanoparticles in diabetes-associated complications.

METHOD

A literature search was conducted using PubMed, Google Scholar and Scopus databases, focusing on the role of nanoparticles in the improved delivery of various hypoglycemic agents for the treatment of microvascular and macrovascular diabetic complications.

RESULTS

Numerous studies have shown that nanoparticles, such as nanoliposomes, polymeric micelles, dendrimers and metallic nanoparticles, improve the delivery of various hypoglycemic agents. Moreover, nanoparticles have been found to be safer, with improved pharmacokinetic and pharmacodynamic profiles.

CONCLUSION

This review outlines the significant role of nanotechnology in diabetes and related complications and its superiority over conventional drug delivery.

A Missing Puzzle in Preclinical Studies-Are CCR2, CCR5, and Their Ligands' Roles Similar in Obesity-Induced Hypersensitivity and Diabetic Neuropathy?-Evidence from Rodent Models and Clinical Studies

Research has shown that obesity is a low-grade inflammatory disease that is often associated with comorbidities, such as diabetes and chronic pain. Recent data have indicated that chemokines may play a role in these conditions due to their pronociceptive and chemotactic properties, which promote hypersensitivity and inflammation. Accumulating evidence suggests that CCR2, CCR5, and their ligands (CCL2, CCL3, CCL4, CCL5, CCL7, CCL8, CCL11 CCL12, and/or CCL13) play a role in rodent models of pain and obesity, as well as in patients with diabetes and obesity. It was proven that the blockade of CCR2 and CCR5, including the simultaneous blockade of both receptors by dual antagonists, effectively reduces hypersensitivity to thermal and mechanical stimuli in chronic pain states, including diabetic neuropathy. The present review discusses these chemokine receptors and the role of their ligands in diabetes and obesity, as well as their involvement in diabetic neuropathy and obesity-induced hypersensitivity.

Multifactorial inspiratory muscle training and its impact on respiratory and functional parameters of patients with diabetic polyneuropathy-A Randomized Controlled Trial

BACKGROUND AND PURPOSE

Diabetic polyneuropathy is a long-standing microvascular complication of diabetes that affects the postural control and functional mobility of patients. There are other microvascular complications, including pulmonary complications that reduce lung function. Multifactorial Inspiratory Muscle Training (IMT) can act as a home-based technique targeted to affect both these complications. This study aims to determine the effects of IMT on respiratory and functional parameters in diabetic polyneuropathy patients.

METHODS

This is a Pre-Test Post-Test Randomized Controlled Trial (NCT#04947163) with 62 diabetic polyneuropathy patients. Each was randomly assigned to the IMT or sham-IMT group. Both the groups performed OTAGO exercises , with the sham-IMT group performing IMT at 15% of baseline maximal inspiratory pressure (MIP), whereas IMT were trained at 50% of baseline MIP as an initial intensity, which was increased as per the tolerance of patients. Both groups performed training for 12 weeks. The study investigated diaphragmatic strength, pulmonary function, functional capacity through 6MWT, 30s sit to stand test and anterior trunk muscle endurance tested through sit up test as outcome variables. Data was analysed on SPSS v26 at the significance level of 0.0.5.

RESULTS

The IMT group significantly improved diaphragmatic strength, pulmonary function, 6MWT and anterior trunk muscle endurance when compared to the sham-IMT group.

CONCLUSION

The study concluded that home-based IMT can improve pulmonary parameters including diaphragmatic strength and lung function as well as functional parameters including functional capacity in patients with diabetic polyneuropathy. The study was registered at ClinicalTrials.gov, NCT#04947163.

Sexual function of overweight pregnant women with gestational diabetes mellitus: A cross-sectional study

Background and Aims

Overweight and obesity are on the rise worldwide and may affect female sexual function. The aim of this study was to investigate the relationship between sexual function in normal and overweight pregnant women with gestational diabetes mellitus (GDM).

Methods

This cross-sectional study was conducted in overweight and normal-weight pregnant women with GDM in Sari, Iran. Data were collected from 2018 to 2021. The demographic data collected from the participants included age, educational level, occupation, gestational age, duration of marriage, number of births, place of residence (city or village), private house, private bedroom, and insurance status. The General Health Questionnaire, Female Sexual Function Index (FSFI), and Enriched Marital Satisfaction questionnaires were used to assess mental health, sexual functioning, and marital satisfaction, respectively.

Results

The study included 200 women with GDM. The mean age of the participants was 29.75 (SD = 4.40) years. Among pregnant women with GDM, 56.50% of them had sexual dysfunction based on FSFI. The mean FSFI score in pregnant women with GDM was 25.60 (SD = 3.61). Among the participants, 50.00% had normal body mass index (BMI). There was no significant difference between BMI status and total sexual function score (p > 0.05). The multivariate analysis revealed that marital satisfaction (β = 0.41, p < 0.001) and BMI status (β = -0.15, p = 0.002) were the only factors significantly associated with overall sexual function, explaining 27% of the variance in the total FSFI score.

Conclusion

The results of this study showed that there was no significant relationship between sexual dysfunction and obesity in GDM. Considering that the research in this area is very limited and the negative effects of obesity and GDM have been confirmed in many areas, including sexual desire disorder, necessary planning should be done to control these factors.

Prevalence and factors associated with the correlation between malnutrition and pain in hemodialysis patients

Malnutrition and pain are common in patients with chronic kidney disease who undergo hemodialysis. Although both pain and malnutrition are associated with increased morbidity and mortality, few studies have explored the correlation between pain and nutritional status. This study aimed to investigate the factors associated with pain intensity in patients undergoing hemodialysis, focusing on the risk of malnutrition. This was a cross-sectional study conducted at a regional dialysis center in a large tertiary hospital. Convenience sampling was used to recruit adult patients who had undergone hemodialysis for more than three months. An interviewer-administered questionnaire was used to gather sociodemographic and clinical data related to dialysis status, comorbidities, and body mass index (BMI). Pain severity and pain interference with functioning domains of the Brief Pain Index (BPI) were used to assess pain, and the malnutrition inflammation score (MIS) was used to assess nutritional status. Descriptive and inferential statistics were used to report the findings. The data were analyzed using the 25th version of the Statistical Package for the Social Sciences (IBM-SPSS) software. Of the final sample of 230 patients, 63.0% were males and 37.0% were females, with an average age of 58.3 years. Almost one-third of the participants had a BMI within the normal range (33.9%), and nearly one-third had a BMI within the underweight range (33.9%). Slightly more than half had a normal nutritional status or mild malnutrition (54.8%), while just under half had moderate or severe malnutrition (45.2%). The prevalence of pain was 47.0%. At the multivariate level, the severity of pain was associated with malnutrition (p < 0.001). Pain interference with function was associated with marital status (p = 0.045), number of comorbidities (p = 0.012), and malnutrition (p < 0.001). The MIS was positively correlated with both the severity of pain and the interference score. Pain and malnutrition were found to be prevalent in patients undergoing hemodialysis. Pain severity was associated with malnutrition, and pain interference was associated with malnutrition, marital status, and the number of comorbidities. Hemodialysis treatment should follow a patient-tailored approach that addresses pain, nutritional status, and associated chronic conditions. In addition, pain assessment and management should be included in the curriculum of nephrology training programs.

Potential Role of Phytochemicals as Glucagon-like Peptide 1 Receptor (GLP-1R) Agonists in the Treatment of Diabetes Mellitus

Currently, there is no known cure for diabetes. Different pharmaceutical therapies have been approved for the management of type 2 diabetes mellitus (T2DM), some are in clinical trials and they have been classified according to their route or mechanism of action. Insulin types, sulfonylureas, biguanides, alpha-glucosidase inhibitors, thiazolidinediones, meglitinides, sodium-glucose cotransporter type 2 inhibitors, and incretin-dependent therapies (glucagon-like peptide-1 receptor agonists: GLP-1R, and dipeptidyl peptidase 4 inhibitors: DPP-4). Although some of the currently available drugs are effective in the management of T2DM, the side effects resulting from prolonged use of these drugs remain a serious challenge. GLP-1R agonists are currently the preferred medications to include when oral metformin alone is insufficient to manage T2DM. Medicinal plants now play prominent roles in the management of various diseases globally because they are readily available and affordable as well as having limited and transient side effects. Recently, studies have reported the ability of phytochemicals to activate glucagon-like peptide-1 receptor (GLP-1R), acting as an agonist just like the GLP-1R agonist with beneficial effects in the management of T2DM. Consequently, we propose that careful exploration of phytochemicals for the development of novel therapeutic candidates as GLP-1R agonists will be a welcome breakthrough in the management of T2DM and the co-morbidities associated with T2DM.

Novel strategy: Identifying new markers for demyelination in diabetic distal symmetrical polyneuropathy

Objective

To develop a novel strategy for identifying acquired demyelination in diabetic distal symmetrical polyneuropathy (DSP).

Background

Motor nerve conduction velocity (CV) slowing in diabetic DSP exceeds expectations for pure axonal loss thus implicating superimposed acquired demyelination.

Methods

After establishing demyelination confidence intervals by regression analysis of nerve conduction data from chronic inflammatory demyelinating polyneuropathy (CIDP), we prospectively studied CV slowing in 90 diabetic DSP patients with and without at least one motor nerve exhibiting CV slowing (groups A and B) into the demyelination range by American Academy of Neurology (AAN) criteria respectively and 95 amyotrophic lateral sclerosis (ALS) patients. Simultaneously, secretory phospholipase A2 (sPLA2) activity was assessed in both diabetic groups and 46 healthy controls.

Results

No ALS patient exhibited CV slowing in more than two motor nerves based on AAN criteria or the confidence intervals. Group A demonstrated a significantly higher percentage of patients as compared to group B fulfilling the above criteria, with an additional criterion of at least one motor nerve exhibiting CV slowing in the demyelinating range and a corresponding F response in the demyelinating range by AAN criteria (70.3 % vs. 1.9 %; p < 0.0001). Urine sPLA2 activity was increased significantly in diabetic groups as compared to healthy controls (942.9 ± 978.0 vs. 591.6 ± 390.2 pmol/min/ml, p < 0.05), and in group A compared to Group B (1328.3 ± 1274.2 vs. 673.8 ± 576.9 pmol/min/ml, p < 0.01). More patients with elevated sPLA2 activity and more than 2 motor nerves with CV slowing in the AAN or the confidence intervals were identified in group A as compared to group B (35.1 % vs. 5.7 %, p < 0.001). Furthermore, 13.5 % of patients in diabetic DSP Group A, and no patients in diabetic DSP Group B, fulfilled an additional criterion of more than one motor nerve with CV slowing into the demyelinating range with its corresponding F response into the demyelinating range by AAN criteria.

Conclusion

A combination of regression analysis of electrodiagnostic data and a urine biological marker of systemic inflammation identifies a subgroup of diabetic DSP with superimposed acquired demyelination that may respond favorably to immunomodulatory therapy.

A Bibliometric Analysis of Study of Associations of Certain Genotypes with the Cardiovascular Form of Diabetic Neuropathy

This bibliometric analysis explores the landscape of research on the associations between specific genotypes and the cardiovascular form of diabetic neuropathy. Diabetes mellitus (DM) is a major contributor to premature mortality, primarily due to increased susceptibility to cardiovascular diseases. The global prevalence of DM is rising, with projections indicating further increases. Diabetic neuropathy, a complication of DM, includes the cardiovascular subtype, posing challenges in diagnosis and management. Understanding the genetic basis of cardiovascular diabetic neuropathy is crucial for targeted therapeutic interventions. The study utilizes bibliometric analysis to synthesize existing literature, identify trends, and guide future research. The Scopus database was searched, applying inclusion criteria for English articles related to genotypes and cardiovascular diabetic neuropathy. The analysis reveals a dynamic field with a notable impact, collaborative efforts, and multidimensional aspects. Publication trends over 1997-2023 demonstrate fluctuating research intensity. Top journals, authors, and affiliations are highlighted, emphasizing global contributions. Keyword analysis reveals thematic trends, and citation analysis identifies influential documents. Limitations include database biases, incomplete metadata, and search query specificity. The urgent need to explore genetic factors in cardiovascular diabetic neuropathy aligns with the increasing global diabetes burden. This analysis provides a comprehensive overview, contributing to the broader discourse on diabetic neuropathy research.

Biomarkers and signaling pathways of diabetic nephropathy and peripheral neuropathy: possible therapeutic intervention of rutin and quercetin

Diabetic nephropathy and peripheral neuropathy are the two main complications of chronic diabetes that contribute to high morbidity and mortality. These conditions are characterized by the dysregulation of multiple molecular signaling pathways and the presence of specific biomarkers such as inflammatory cytokines, indicators of oxidative stress, and components of the renin-angiotensin system. In this review, we systematically collected and collated the relevant information from MEDLINE, EMBASE, ELSEVIER, PUBMED, GOOGLE, WEB OF SCIENCE, and SCOPUS databases. This review was conceived with primary objective of revealing the functions of these biomarkers and signaling pathways in the initiation and progression of diabetic nephropathy and peripheral neuropathy. We also highlighted the potential therapeutic effectiveness of rutin and quercetin, two plant-derived flavonoids known for their antioxidant and anti-inflammatory properties. The findings of our study demonstrated that both flavonoids can regulate important disease-promoting systems, such as inflammation, oxidative stress, and dysregulation of the renin-angiotensin system. Importantly, rutin and quercetin have shown protective benefits against nephropathy and neuropathy in diabetic animal models, suggesting them as potential therapeutic agents. These findings provide a solid foundation for further comprehensive investigations and clinical trials to evaluate the potential of rutin and quercetin in the management of diabetic nephropathy and peripheral neuropathy. This may contribute to the development of more efficient and comprehensive treatment approaches for diabetes-associated complications.

Bidirectional association between diabetic peripheral neuropathy and vitamin B12 deficiency: Two longitudinal 9-year follow-up studies using a national sample cohort

AIM

This study aims to investigate the association among metformin use, vit B12 deficiency, and DPN occurrence in diabetes.

METHODS

This retrospective, propensity-matched cohort study was performed using National Health Insurance Service database - National Sample Cohort in South Korea. Study 1 analyzed DPN incidence according to vit B12 deficiency and study 2 analyzed vit B12 deficiency incidence according to the presence/absence of DPN. Moreover, we compared the results with respect to metformin use.

RESULTS

In study 1, DPN incidence per 10000 person-year (PY) was 179.7 and 76.6 in the vit B12 and non-vit B12 deficiency groups, respectively. The adjusted HR was 1.32 (95% CI; 1.21-1.44, P < 0.05) and metformin use elicited a more significant effect of DPN occurrence in patient with vit B12 deficiency (HR: 5.76 (95% CI; 5.28-6.29). In study 2, vit B12 deficiency incidence per 10000 PY was 250.6 and 129.4 in the DPN and non-DPN groups, respectively. The adjusted HR was 2.44 (95% CI; 2.24-2.66, P < 0.05), however, metformin prescription was associated with the reduced incidence of vit B12 deficiency in DPN patients (HR 0.68 (95% CI; 0.62-0.74, P < 0.05).

CONCLUSION

DPN occurrence increased in diabetes with vit B12 deficiency and the incidence of vit B12 deficiency was also high in DPN patients. However, metformin showed opposite effects in both cohorts. Further studies clarifying the causal relationship among DPN occurrence, vit B12 deficiency, and metformin use are warranted.

The Relationship Between Diabetic Neuropathy and Uric Acid/High-Density Lipoprotein Ratio in Patients With Type-2 Diabetes Mellitus

BACKGROUND

We aimed to investigate whether there was a relationship between diabetic peripheral distal neuropathy (DPDN), one of the most common chronic complications in patients with type 2 diabetes mellitus (T2DM), and the uric acid/HDL ratio, which can be used as an indicator of poor metabolic status.

METHODOLOGY

The study consisted of a total of 150 subjects, including 50 patients with T2DM (group 1) who were determined to have diabetic peripheral distal neuropathy with electroneuromyography (ENMG), 50 patients with T2DM who were determined to not have DPDN in their ENMG (group 2), and 50 healthy individuals (group 3). Participants' serum fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), uric acid, total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride levels were analyzed. The uric acid/HDL-C ratio (UHR) was calculated. The relationship between UHR and other parameters was evaluated in all three groups.

RESULTS

Patients with T2DM who had diabetic neuropathy (group 1), did not have diabetic neuropathy (group 2), and healthy subjects (group 3) were similar in terms of age and gender (p=0.066, p=0.185). Groups 1 and 2 were similar in terms of the duration of diabetes and FBG values (p=0.825, p=0.572), but these values were lower in group 3 than in groups 1 and 2 (p<0.05). HbA1c did not differ significantly between groups 1 and 2 (p=0.607). Creatinine levels were similar in the three groups. Uric acid levels were significantly higher in group 1 than in group 2 (p=0.040), but there was no significant difference between groups 1 and 3 or between groups 2 and 3 (p>0.05). UHR was significantly lower in group 1 than in groups 2 and 3 (p<0.001), but no significant difference was found between groups 2 and 3.

CONCLUSION

In our study, we found that the UHR level of the group with diabetic neuropathy was statistically significant compared to the levels of the other two groups. However, no significant difference was found between the patients with diabetes who did not have neuropathy and the healthy group. Based on the findings of our study, we can say that the UHR level is a predictor of the microvascular complications of diabetes.

A scientometrics analysis and visualisation of diabetic foot research from 1955 to 2022

Diabetic foot (DF) has become a serious health problem in modern society, and it has been a hotspot of research for a long time. However, little scientometric analysis has been carried out on DF. In the present study, we analysed 8633 literature reports on DF in the Web of Science Core Collection from database inception until April 23, 2022. VOSviewer (Centre for Science and Technology Studies at Leiden University, Leiden, the Netherlands) and CiteSpace (College of Computing and Informatics, Drexel University, Philadelphia, United States) were employed to address high-impact countries and institutions, journals, references, research hotspots, and key research fields in DF research. Our analysis findings indicated that publications on DF have increased markedly since 2016 and were primarily published in the United States of America. The recent studies focus on the amniotic membrane, foot ulcers, osteomyelitis, and diabetic wound healing. The five keyword clusters, which included DF ulcer and wound healing therapies, management and guidelines, neuropathy and plantar pressure, amputation and ischemia, and DF infection and osteomyelitis, are helpful for enhancing prevention, standardising treatment, avoiding complications, and improving prognosis. These findings indicated a method for future therapies and research in DF.

Screening for diabetic peripheral neuropathy in resource-limited settings

BACKGROUND

Diabetic neuropathy is the most common microvascular complication of diabetes mellitus and a major risk factor for diabetes-related lower-extremity complications. Diffuse neuropathy is the most frequently encountered pattern of neurological dysfunction and presents clinically as distal symmetrical sensorimotor polyneuropathy. Due to the increasing public health significance of diabetes mellitus and its complications, screening for diabetic peripheral neuropathy is essential. Consequently, a review of the principles that guide screening practices, especially in resource-limited clinical settings, is urgently needed.

MAIN BODY

Numerous evidence-based assessments are used to detect diabetic peripheral neuropathy. In accordance with current guideline recommendations from the American Diabetes Association, International Diabetes Federation, International Working Group on the Diabetic Foot, and National Institute for Health and Care Excellence, a screening algorithm for diabetic peripheral neuropathy based on multiphasic clinical assessment, stratification according to risk of developing diabetic foot syndrome, individualized treatment, and scheduled follow-up is suggested for use in resource-limited settings.

CONCLUSIONS

Screening for diabetic peripheral neuropathy in resource-limited settings requires a practical and comprehensive approach in order to promptly identify affected individuals. The principles of screening for diabetic peripheral neuropathy are: multiphasic approach, risk stratification, individualized treatment, and scheduled follow-up. Regular screening for diabetes-related foot disease using simple clinical assessments may improve patient outcomes.

Nicotinamide Riboside Improves Enteric Neuropathy in Streptozocin-Induced Diabetic Rats Through Myenteric Plexus Neuroprotection

BACKGROUND

Diabetes Mellitus causes a systemic oxidative stress due in part to the hyperglycemia and the reactive oxygen species generated. Up to 75% of diabetic patients present with an autonomic neuropathy affecting the Enteric Nervous System. Deficits in the human population are chronic dysmotilities with either increased (i.e., constipation) or decreased (i.e., diarrhea) total gastrointestinal transit times. These are recapitulated in the streptozocin-induced diabetic rat, which is a model of Type I Diabetes Mellitus.

AIMS

Examine the effects that a precursor of nicotinamide adenosine dinucleotide (NAD), nicotinamide riboside (NR), had on the development of dysmotility in induced diabetic rats and if fecal microbiota transplant (FMT) could produce the same results.

MATERIALS AND METHODS

Utilizing a 6-week treatment paradigm, NR was administered intraperitoneally every 48 h. Total gastrointestinal transit time was assessed weekly utilizing the carmine red method. Three weeks following hyperglycemic induction, FMT was performed between NR-treated animals and untreated animals.

SIGNIFICANT RESULTS

There is improvement in overall gastrointestinal transit time with the use of NR. 16S microbiome sequencing demonstrated decreased alpha and beta diversity in induced diabetic rats without change in animals receiving FMT. Improvements in myenteric plexus ganglia density in small and large intestines in diabetic animals treated with NR were seen.

CONCLUSIONS

NR treatment led to functional improvement in total gastrointestinal transit time in induced diabetic animals. This was associated with neuroprotection in the myenteric plexuses of both small and large intestines of induced diabetic rats. This represents an important first step in showing NR's benefit as a treatment for diabetic enteric neuropathy. Streptozocin-induced diabetic rats have improved transit times and increased myenteric plexus ganglia density when treated with intraperitoneal nicotinamide riboside.

Diabetic neuropathy: Past, present, and future

BACKGROUND

A sedentary lifestyle and an unhealthy diet have considerably increased the incidence of diabetes mellitus worldwide in recent decades, which has generated a high rate of associated chronic complications.

METHODS

A narrative review was performed in MEDLINE, EMBASES and SciELO databases, including 162 articles.

RESULTS

Diabetic neuropathy (DN) is the most common of these complications, mainly producing two types of involvement: sensorimotor neuropathy, whose most common form is symmetric distal polyneuropathy, and autonomic neuropathies, affecting the cardiovascular, gastrointestinal, and urogenital system. Although hyperglycemia is the main metabolic alteration involved in its genesis, the presents of obesity, dyslipidemia, arterial hypertension, and smoking, play an additional role in its appearance. In the pathophysiology, three main phenomena stand out: oxidative stress, the formation of advanced glycosylation end-products, and microvasculature damage. Diagnosis is clinical, and it is recommended to use a 10 g monofilament and a 128 Hz tuning fork as screening tools. Glycemic control and non-pharmacological interventions constitute the mainstay of DN treatment, although there are currently investigations in antioxidant therapies, in addition to pain management.

CONCLUSIONS

Diabetes mellitus causes damage to peripheral nerves, being the most common form of this, distal symmetric polyneuropathy. Control of glycemia and comorbidities contribute to prevent, postpone, and reduce its severity. Pharmacological interventions are intended to relieve pain.

A novel approach to alpha-lipoic acid therapy in the treatment of diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is a heterogenic disorder prevalent amongst patients suffering from diabetes mellitus (DM), with symptoms comprising neuropathic pain, paresthesia, and numbness in distal lower limbs. Alpha-lipoic acid (ALA) is proposed as a pathogenesis-oriented treatment option, targeting underlying causes of neural lesions such as hyperglycemia, metabolic and microvascular dysfunctions, and cellular oxidative stress. We performed a comprehensive review of controlled clinical trials demonstrating the clinical usefulness of ALA in the treatment of DPN, published in the last 5 years to determine the benefits of ALA monotherapy and combined treatments with other known antioxidants. We also investigated the differential efficacy of oral versus intravenous ALA administration. Clinical trials show the efficacy of ALA treatment, attributed to its anti-inflammatory, anti-hyperglycemic, and antioxidant properties, as well as its function in the endothelial activation and lipid metabolism parameters. ALA supplementation is associated with amelioration in nerve conduction velocity scores, clinically significant reduction of reported neuropathic pain, burning and paresthesia, as well as a decrease in serum triglycerides, improved insulin sensitivity, and quality of life.

The Outcome of Surgical Treatment for the Neuropathic Diabetic Foot Lesions-A Single-Center Study

The prevalence of diabetic foot complications is continuously increasing as diabetes has become one of the most important "epidemics" of our time. The main objective of this study was to describe the appropriate surgical intervention for the complicated neuropathic diabetic foot; the secondary goal was to find the risk factors associated with minor/major amputation and good or adverse surgical outcomes. This is an observational, retrospective study conducted between 1 January 2018 and 31 December 2019, which included 251 patients from the General Surgery Department at the Dr I. Cantacuzino Clinical Hospital in Bucharest with type II diabetes mellitus and neuropathic diabetic foot complications. The surgical conditions identified at admission were the following: osteitis (38.6%), infected foot ulcer (27.5%), gangrene (20.7%), infected Charcot foot (3.6%), non-healing wound (3.6%), necrosis (3.2%), and granulated wound (2.8%). We found that a minor surgical procedure (transmetatarsal amputation of the toe and debridement) was performed in 85.8% of cases, and only 14.2% needed major amputations. Osteitis was mainly associated with minor surgery (p = 0.001), while the gangrene and the infected Charcot foot were predictable for major amputation, with OR = 2.230, 95% CI (1.024-4.857) and OR = 5.316, 95% CI (1.354-20.877), respectively. Admission anemia and diabetic nephropathy were predictive of a major therapeutical approach, with p = 0.011, OR = 2.975, 95% CI (1.244-8.116) and p = 0.001, OR = 3.565, 95% CI (1.623-7.832), respectively. All the major amputations had a good outcome, while only several minor surgeries were interpreted as the adverse outcome (n = 24). Osteitis (45.8%) and admission anemia (79.2%) were more frequently associated with adverse outcomes, with p = 0.447 and p = 0.054, respectively. The complicated neuropathic diabetic foot requires a surgical procedure mainly associated with a good outcome.

An overview of painful diabetic peripheral neuropathy: Diagnosis and treatment advancements

Diabetes mellitus remains a public health problem, affecting 422 million people worldwide. Currently, there is no consensus around treating painful diabetic peripheral neuropathy in a step-wise manner. Among the non-pharmacological interventions, neuromodulation has become a promising alternative. Over the past decade, significant clinical trials have paved the way for prompt inclusion of high-frequency spinal cord stimulation within the painful diabetic peripheral neuropathy treatment algorithm. This article aims to provide an updated evidence-based approach for the management of painful diabetic peripheral neuropathy.

Therapeutic potential of vitamin B1 derivative benfotiamine from diabetes to COVID-19

Benfotiamine (S-benzoylthiamine-O-monophosphate), a unique, lipid-soluble derivative of thiamine, is the most potent allithiamine found in roasted garlic, as well as in other herbs of the genus Allium. In addition to potent antioxidative properties, benfotiamine has also been shown to be a strong anti-inflammatory agent with therapeutic significance to several pathological complications. Specifically, over the past decade or so, benfotiamine has been shown to prevent not only various secondary diabetic complications but also several inflammatory complications such as uveitis and endotoxemia. Recent studies also demonstrate that this compound could be used to prevent the symptoms associated with various infectious diseases such as HIV and COVID-19. In this review article, the authors discuss the significance of benfotiamine in the prevention of various pathological complications.

The Emerging Role of Continuous Glucose Monitoring in the Management of Diabetic Peripheral Neuropathy: A Narrative Review

The aim of this narrative review is to present data on the role of continuous glucose monitoring (CGM) in the management of peripheral diabetic neuropathy (DPN) among individuals with type 1 and type 2 diabetes mellitus. Adequate glycaemic control is crucial to prevent the development or progression of DPN. CGM systems are valuable tools for improving glycaemic control and reducing glycaemic variability (GV). Chronic hyperglycaemia is known to be a risk factor for the development of diabetic microvascular complications, including DPN. In addition, there is now evidence that GV, evaluated by mean amplitude of glycaemic excursions, may be a novel factor in the pathogenesis of diabetic complications. Increased GV appears to be an independent risk factor for DPN and correlates with painful neuropathy. Similarly, time-in-range correlates positively with peripheral nerve function and negatively with sudomotor dysfunction. However, relevant studies are rather limited in scope, and the vast majority are cross-sectional and use different methodologies for the assessment of DPN. Therefore, the causal relationship between CGM-derived data and the development of DPN cannot be firmly established at the present time. It also remains to be elucidated whether CGM measures can be considered the new therapeutic targets for DPN management.

Does the SDMQ-9 Predict Changes in HbA1c Levels? An Ecuadorian Cohort

Background and Objectives: Diabetes mellitus affects 422 million people around the world, positioning it as a major health problem. According to the WHO(World Health Organization), 90% corresponds to type 2. The shared-decision making (SDM) is a method used to facilitate patient control, medication, maintenance, and assessment of health status according to their priorities and preferences. With the application of SDM in patients with diabetes, it is expected there will be an increase in treatment adherence and a reduction in HbA1c levels. The aim of this study is to determine the predictors of the change in HbA1c. Material and Methods: A sample of 76 participants attending as endocrinology outpatients was obtained. Data collected within the sample included: sex, age, educational level, body mass index, and the level of SDM using the SDMQ-9. In addition, HbA1c levels were measured twice: at baseline and three months after the first measurement. Results: The linear regression indicates that the level of SDM is a significant predictor of the change in HbA1c, specifically in men. However, the direction of the relationship was a somewhat opposite trend than we expected. Higher levels of SDM imply an increase in HbA1c rather than a reduction. Conclusions: Contrary to the literature, our results shows that elevated levels of perceived SDM may be associated with worse diabetic control. However, more investigation is needed as these results are not generalizable, due to the specific population used and the sample size. Furthermore, to better understand the effect of SDM on the change in HbA1c in patients with poorly controlled diabetes.

Oral Health among Elderly, Impact on Life Quality, Access of Elderly Patients to Oral Health Services and Methods to Improve Oral Health: A Narrative Review

Dental health is often neglected among the elderly because of the numerous comorbidities in this population, such as cardiovascular diseases. However, dental health influences general health and quality of life by impacting both the general health and the psychological state of the individual. The present review highlights the main dental comorbidities in the elderly population, their impact on the quality of life, the barriers towards access to dental care in the elderly and methods to improve their dental health. Information related to dental care and its importance must be provided both to older individuals and their caregivers in order to detect dental pathology and treat it adequately. Ensuring dental health involves the whole society of elders, caregivers, dental care providers, the public sector, health policymakers, and the private sector.

Enhanced Differentiation Capacity and Transplantation Efficacy of Insulin-Producing Cell Clusters from Human iPSCs Using Permeable Nanofibrous Microwell-Arrayed Membrane for Diabetes Treatment

Although pancreatic islet transplantation is a potentially curative treatment for insulin-dependent diabetes, a shortage of donor sources, low differentiation capacity, and transplantation efficacy are major hurdles to overcome before becoming a standard therapy. Stem cell-derived insulin-producing cells (IPCs) are a potential approach to overcoming these limitations. To improve the differentiation capacity of the IPCs, cell cluster formation is crucial to mimic the 3D structure of the islet. This study developed a biodegradable polycaprolactone (PCL) electrospun nanofibrous (NF) microwell-arrayed membrane permeable to soluble factors. Based on the numerical analysis and experimental diffusion test, the NF microwell could provide sufficient nutrients, unlike an impermeable PDMS (polydimethylsiloxane) microwell. The IPC clusters in the NF microwells showed higher gene expression of insulin and PDX1 and insulin secretion than the PDMS microwells. The IPC clusters in the NF microwell-arrayed membrane could be directly transplanted. Transplanted IPC clusters in the microwells survived well and expressed PDX1 and insulin. Additionally, human c-peptide was identified in the blood plasma at two months after transplantation of the membranes. The NF microwell-arrayed membrane can be a new platform promoting IPC differentiation capacity and realizing an in situ transplantation technique for diabetic patients.

Significance of the Modified NUTRIC Score for Predicting Clinical Outcomes in Patients with Severe Community-Acquired Pneumonia

Nutritional status could affect clinical outcomes in critical patients. We aimed to determine the prognostic accuracy of the modified Nutrition Risk in Critically Ill (mNUTRIC) score for hospital mortality and treatment outcomes in patients with severe community-acquired pneumonia (SCAP) compared to other clinical prediction rules. We enrolled SCAP patients in a multi-center setting retrospectively. The mNUTRIC score and clinical prediction rules for pneumonia, as well as clinical factors, were calculated and recorded. Clinical outcomes, including mortality status and treatment outcome, were assessed after the patient was discharged. We used the receiver operating characteristic (ROC) curve method and multivariate logistic regression analysis to determine the prognostic accuracy of the mNUTRIC score for predicting clinical outcomes compared to clinical prediction rules, while 815 SCAP patients were enrolled. ROC curve analysis showed that the mNUTRIC score was the most effective at predicting each clinical outcome and had the highest area under the ROC curve value. The cut-off value for predicting clinical outcomes was 5.5. By multivariate logistic regression analysis, the mNUTRIC score was also an independent predictor of both clinical outcomes in SCAP patients. We concluded that the mNUTRIC score is a better prognostic factor for predicting clinical outcomes in SCAP patients compared to other clinical prediction rules.

Notoginsenoside R1 attenuates oxidative stress-induced osteoblast dysfunction through JNK signalling pathway

Oxidative stress (OS)‐induced mitochondrial damage and the subsequent osteoblast dysfunction contributes to the initiation and progression of osteoporosis. Notoginsenoside R1 (NGR1), isolated from Panax notoginseng, has potent antioxidant effects and has been widely used in traditional Chinese medicine. This study aimed to investigate the protective property and mechanism of NGR1 on oxidative‐damaged osteoblast. Osteoblastic MC3T3‐E1 cells were pretreated with NGR1 24 h before hydrogen peroxide administration simulating OS attack. Cell viability, apoptosis rate, osteogenic activity and markers of mitochondrial function were examined. The role of C‐Jun N‐terminal kinase (JNK) signalling pathway on oxidative injured osteoblast and mitochondrial function was also detected. Our data indicate that NGR1 (25 μM) could reduce apoptosis as well as restore osteoblast viability and osteogenic differentiation. NGR1 also reduced OS‐induced mitochondrial ROS and restored mitochondrial membrane potential, adenosine triphosphate production and mitochondrial DNA copy number. NGR1 could block JNK pathway and antagonize the destructive effects of OS. JNK inhibitor (SP600125) mimicked the protective effects of NGR1while JNK agonist (Anisomycin) abolished it. These data indicated that NGR1 could significantly attenuate OS‐induced mitochondrial damage and restore osteogenic differentiation of osteoblast via suppressing JNK signalling pathway activation, thus becoming a promising agent in treating osteoporosis.

The Effects of Different Hormones on Supraventricular and Ventricular Premature Contractions in Healthy Premenopausal Women

Background and Objectives: The effects of gender differences on cardiac parameters have been well-established. In this study, we aimed to evaluate the possible associations of plasma levels of different sex hormones with premature atrial or ventricular contractions in premenopausal women. Materials and Methods: We conducted a prospective study which included women in late reproductive age who presented with palpitations during an eight-month period. A 12-lead electrocardiography, a transthoracic echocardiogram, blood samples, and 24-hour rhythm Holter were conducted on the third day of the menstrual cycle. Results Overall, 93 healthy premenopausal women with a median age of 42 years were enrolled. QTc interval was within normal limits in all patients. The 24 h range of premature atrial contractions (PACs) and premature ventricular contractions (PVCs) was 0–6450 and was 0–21,230, respectively. The median number of PVCs was 540 and the median number of PACs was 212, respectively. In total, 51 patients (54.8%) had a frequency of PVCs > 500/24 h and 37 patients (39.8%) had a frequency of PACs > 500/24 h, respectively. No statistically significant association was shown between any hormone and the frequency of PACs. Regarding PVCs, patients with a PVCs frequency > 500/24 h had higher estradiol levels compared to patients with PVCs less than 500/24 h (median 60 pg/mL versus 42 pg/mL, p = 0.02, OR: 1.01). No association was found between PVCs and other hormones. Conclusions: In premenopausal healthy women, higher estradiol levels are independently associated with increased PVCs. This suggests that estradiol in late reproductive stages may exert proarrhythmic effects.