Diabetic neuropathies: a statement by the American Diabetes Association

Relationships within and between lower and upper extremity dysfunction in people with diabetes

INTRODUCTION

Diabetes mellitus (DM) is associated with systemic musculoskeletal system impairments suggesting concurrent development of lower and upper extremity musculoskeletal problems. This study aims to examine relationships between lower and upper extremity function in people with DM.

METHODS

Sixty people with type 2 DM and peripheral neuropathy [mean (standard deviation); 67(6) years old, DM duration 14(10) yrs] completed the following measures: 1) Self-reports of function: Foot and Ankle Ability Measure (FAAM; higher = better function) and Shoulder Pain and Disability Index (SPADI; lower = better function), 2) Range of motion (goniometry): ankle dorsiflexion and shoulder flexion, and 3) Strength: unilateral heel rise power (UHR, 3D kinetics) and hand grip dynamometry. Pearson correlations examined associations between lower and upper extremity measures, p < .05.

RESULTS

Forty of 60 (67%) reported pain/disability in both the foot/ankle and shoulder and 95% of study participants had some limitation in foot or shoulder function. Significant between extremity correlations: FAAM and SPADI (r = -0.39), ankle dorsiflexion and shoulder flexion range of motion (r = 0.35), and UHR and hand grip strength (r = 0.40). Significant within extremity correlations: FAAM and UHR (r = .47) and SPADI with shoulder flexion (r = -0.44).

CONCLUSION

Upper and lower extremity inter- and intra-relationships indicate systemic musculoskeletal impairments in people with DM. Healthcare practitioners should consider the potential for concurrent and disabling musculoskeletal problems in people with DM.

Gongronema latifolium Benth. leaf extract attenuates diabetes-induced neuropathy via inhibition of cognitive, oxidative stress and inflammatory response

BACKGROUND

Gongronema latifolium (G. latifolium) Benth. leaves are traditionally used to treat diabetes mellitus (DM) and other diseases in Nigeria and West Africa. This study was performed to evaluate the neuroprotective effect of aqueous extract of G. latifolium leaf against DM. Antidiabetic activity of G. latifolium extracts (6.36, 12.72 and 25.44 mg kg^-1 , i.p.) was determined in alloxan-induced diabetic rats. Fasting blood glucose level and oxidative stress markers catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA), and nitric oxide (NO) levels were measured. Cognitive biomarkers acetylcholinesterase (AChE), butyrylcholinesterase (BChE), dopamine (DOPA), serotonin, epinephrine and norepinephrine and cyclooxygenase (COX-2) were measured in the brain of controls and of G. latifolium-treated diabetic rats.

RESULTS

Administration of G. latifolium leaf extract to diabetic rats significantly restored the alterations in the levels of fasting blood glucose (FBG). The MDA and NO levels were significantly reduced with an improvement in CAT, SOD, and GPx activity in the kidneys and brains of diabetic rats treated with G. latifolium. Gongronema latifolium also significantly decreased the levels of AChE, BChE, DOPA, serotonin, epinephrine, and nor-epinephrine in diabetic rats. G. latifolium effectively ameliorated COX-2 in diabetic rats.

CONCLUSION

This study showed that leaf extract of G. latifolium improved antioxidant defense against oxidative stress. It displays a neuroprotective effect resulting in the modulation of brain neurotransmitters, which could be considered as a promising treatment therapy. © 2020 Society of Chemical Industry.

State-of-the-art pharmacotherapy for diabetic neuropathy

INTRODUCTION

The global epidemic of diabetes has led to an epidemic of diabetes complications. Diabetic neuropathy is the most common microvascular complication, of which diabetic peripheral neuropathy (DPN) and autonomic neuropathy (AN) are the most prevalent, affecting ~50% of patients. DPN results in pain with a poor quality of life and a loss of sensation with an increased risk of foot ulceration. Autonomic neuropathy can cause significant morbidity in a minority and is associated with increased mortality. The cornerstone of treatment to prevent or limit the progression of DPN/AN is multifactorial risk factor modification including treatment of glycemia, lipids and blood pressure. Whilst, there are no FDA-approved disease-modifying therapies, there are a number of therapies to relieve symptoms in DPN and AN.

AREAS COVERED

The authors discuss current approved therapies for painful diabetic neuropathy and autonomic neuropathy. They also address the potential role of improving risk factors to limit the development and progression of diabetic neuropathy and new pathogenetic and pain-relieving treatments.

EXPERT OPINION

The FDA-approved Pregabalin and Duloxetine over 25 years ago and Tapentadol, 6 years ago for painful diabetic neuropathy. There are currently no FDA-approved disease-modifying treatments for diabetic neuropathy which has been attributed to inappropriate models of the disease with limited translational capacity and major limitations of trial designs and endpoints in clinical trials.

Turkish version of the Michigan Neuropathy Screening Instrument in the assessment of diabetic peripheral neuropathy: a validity and reliability study

Background/aim

Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes mellitus (DM). The Michigan Neuropathy Screening Instrument (MNSI) is a simple, brief, and useful screening tool that was designed to assess DPN. The aim of this study was to develop a Turkish version of the MNSI and assess its reliability and validity.

Materials and methods

Eighty-three patients with DM who were divided into two groups according the results of nerve conduction studies (NCS) as having DPN or without DPN were enrolled in this cross-sectional study. The Toronto clinical scoring system, pain detect questionnaire, and NCS were assessed along with the MNSI.

Results

Each section of the MNSI was internally consistent (Cronbach's alpha > 0.70), and the scores of both sections were positively correlated with total MNSI score (r = 0.938; r = 0.908, respectively, p < 0.001). The test-retest reliability of the Turkish version of the MNSI was determined as 0.99 for the total score (intraclass correlation coefficient = 0.996). Using the agreement between MNSI scores and DPN diagnosis by NCS as a gold standard, receiver-operating characteristic (ROC) curve values for section A and section B were estimated as 0.973 and 1.00, respectively. When a cut-off value ≥ 3.0 in section A and a cut-off value ≥ 2.0 in section B were used, we obtained a sensitivity of 97.6% and 100%; a specificity of 63.4% and 97.6%; a positive predictive value of 72.7% and 97.6%; and a negative predictive value of 96.3% and 100%, respectively.

Conclusion

The Turkish version of MNSI is a reliable and valid tool for screening DPN in Turkish patients.

Effects of Diabetes Mellitus on Functional Outcomes and Complications After Torsional Ankle Fracture

INTRODUCTION

It is well known that patients with diabetes mellitus experience higher complication rates after torsional ankle fracture; however, the functional consequences remain less clear. The goal of this study was to determine the effects of diabetes on complications, secondary operations, and functional outcomes after torsional ankle fracture.

METHODS

Nine hundred seventy-nine adult patients treated surgically for a torsional ankle injury (Orthopaedic Trauma Association 44B, 44C) over 13 years were retrospectively reviewed. Demographic information, comorbidities, injury characteristics, complications, and secondary procedures were recorded. Patient-reported outcome surveys: Foot Function Index (FFI) and Short Musculoskeletal Function Assessment were obtained after minimum of 12 months. Multivariable analysis was done to account for confounding variables.

RESULTS

One hundred thirty-one patients (13.4%) had diabetes. Diabetic patients were older (56.4 versus 43.0 years, P < 0.001), with no difference in sex or race. Body mass index was higher among diabetics (36.0 versus 30.4, P < 0.001) as were most medical comorbidities, including stroke, neuropathy, pulmonary disease, and renal disease (all P < 0.03). There were no differences in rates of dislocations or open injuries. Diabetics experienced more complications (26.0% versus 14.6%, P = 0.001), specifically deep infections (6.9% versus 1.3%, P = 0.001), and had more secondary procedures (18.3% versus 9.1%, P = 0.001), including débridement, arthrodesis, and amputation (all P < 0.02). Diabetes was a significant independent predictor of worse FFI activity limitation scores (P = 0.032), but was not predictive of worse outcomes on any other subscore of the FFI or Short Musculoskeletal Function Assessment.

CONCLUSIONS

Diabetes was associated with more complications and secondary operations. However, functional outcomes including pain and dysfunction were not markedly affected by these clinical outcomes, potentially due to diminished sensory function and less baseline physical activity among diabetic patients.

LEVEL OF EVIDENCE

Prognostic level III.

Efficacy and tolerability of DPP4 inhibitor, teneligliptin, on autonomic and peripheral neuropathy in type 2 diabetes: an open label, pilot study

BACKGROUND

Diabetic neuropathy increases risk of cardiovascular disease, peripheral artery disease, foot amputation and overall mortality. Not only hyperglycaemia induced nerve damage is harder to repair using currently approved medications, but also, the use of these agents is often limited by the extent of pain relief provided and side effects.

METHODOLOGY

In this prospective, open-label, pilot study, 20 type-2 diabetes mellitus patients (male/female=13/7, mean age- 56.1±8.04 years), meeting inclusion/exclusion criteria, were treated with dipeptidyl peptidase-4 (DPP-4) inhibitor, Teneligliptin, 20mg once a day for three months. Efficacy parameters: Sudomotor function (Sudoscan score); parasympathetic dysfunction assessed using Ewing's criteria i.e. heart rate response to -standing (HRS), -valsalva (HRV) and -deep breath (HRD); sympathetic dysfunction assessed as blood pressure response to -standing (BPS) and -handgrip (BPH); ankle brachial index (ABI), vibration perception threshold (VPT), C-reactive protein, glycemic profile and health related quality of life (HRQoL); and, tolerability parameters: complete blood count, liver function tests, serum creatinine, thyroid stimulating hormone, QT- interval and serum vitamin B12 levels, were measured.

RESULTS

There was no statistical difference in BMI, SBP, DBP, HRD, BPH and all safety parameters. After 12 weeks treatment, there was improvement in HRS (p<0.01) and HRV (p<0.01), but not in HRD (p=0.12). BPS was significantly lowered (p <0.01), but not the BPH (p =0.06). Sudoscan score was increased, while VPT was significantly decreased (both p<0.01).

CONCLUSION

Teneligliptin not only improves the glycemic status but also improves sudomotor function, peripheral and autonomic neuropathy, and reduces vascular inflammation in type 2 diabetes.

Association between diabetic neuropathy and osteoporosis in patients: a systematic review and meta-analysis

OBJECTIVES

Many studies have explored the association between neuropathy and osteoporosis in patients with diabetes mellitus. However, the results still remain inconsistent and controversial. We aimed to estimate the association between diabetic neuropathy and osteoporosis.

METHODS

Databases, including PubMed, Embase, Web of Science, the Cochrane library, Chinese Biomedical Literature Database (CBM), and Wanfang, were screened from inception to 30 March 2020. Studies were selected and data were extracted by two independent reviewers. Study characteristics and quality sections were reviewed independently. Pooled ORs and 95% CIs were calculated using random effects model when evidence of heterogeneity was present; otherwise, fixed effects model was used. Meta-regression and subgroup analyses were performed to explore the source of heterogeneity. Sensitivity analysis and publication bias were also tested.

RESULTS

A total of 11 studies with 27,585 participants were included in this analysis which indicated that there was an increased odd between diabetic neuropathy and osteoporosis (overall OR 2.20, 95% CI 1.71-2.83). In the subgroup analyses and meta-regression, diabetic neuropathy has no significant difference in osteoporosis or fracture (p = 0.532). And osteoporosis also has no significant difference in type 1 or type 2 diabetic neuropathy (p = 0.668).

CONCLUSIONS

This meta-analysis suggests that patients with diabetic neuropathy have a significantly increased chance of developing osteoporosis, even fragility fracture. The clinicians should pay more attention to the patients with diabetic neuropathy. Further studies were still needed to explore the confounding factors among studies and to elucidate the underlying biological mechanisms.

γ-Linolenic Acid versus α-Lipoic Acid for Treating Painful Diabetic Neuropathy in Adults: A 12-Week, Double-Placebo, Randomized, Noninferiority Trial

BACKGROUND

This study was a multicenter, parallel-group, double-blind, double-dummy, randomized, noninferiority trial to evaluate the efficacy and safety of γ-linolenic acid (GLA) relative to α-lipoic acid (ALA) over a 12-week treatment period in type 2 diabetes mellitus (T2DM) patients with painful diabetic peripheral neuropathy (DPN).

METHODS

This study included 100 T2DM patients between 20 and 75 years of age who had painful DPN and received either GLA (320 mg/day) and placebo or ALA (600 mg/day) and placebo for 12 weeks. The primary outcome measures were mean changes in pain intensities as measured by the visual analogue scale (VAS) and the total symptom scores (TSS).

RESULTS

Of the 100 subjects who initially participated in the study, 73 completed the 12-week treatment period. Per-protocol analyses revealed significant decreases in the mean VAS and TSS scores compared to baseline in both groups, but there were no significant differences between the groups. The treatment difference for the VAS (95% confidence interval [CI]) between the two groups was -0.65 (-1.526 to 0.213) and the upper bound of the 95% CI did not exceed the predefined noninferiority margin (δ₁=0.51). For the TSS, the treatment difference was -0.05 (-1.211 to 1.101) but the upper bound of the 95% CI crossed the noninferiority margin (δ₂=0.054). There were no serious adverse events associated with the treatments.

CONCLUSION

GLA treatment in patients with painful DPN was noninferior to ALA in terms of reducing pain intensity measured by the VAS over 12 weeks.

Understanding Diabetic Neuropathy: Focus on Oxidative Stress

Diabetic neuropathy is one of the clinical syndromes characterized by pain and substantial morbidity primarily due to a lesion of the somatosensory nervous system. The burden of diabetic neuropathy is related not only to the complexity of diabetes but also to the poor outcomes and difficult treatment options. There is no specific treatment for diabetic neuropathy other than glycemic control and diligent foot care. Although various metabolic pathways are impaired in diabetic neuropathy, enhanced cellular oxidative stress is proposed as a common initiator. A mechanism-based treatment of diabetic neuropathy is challenging; a better understanding of the pathophysiology of diabetic neuropathy will help to develop strategies for the new and correct diagnostic procedures and personalized interventions. Thus, we review the current knowledge of the pathophysiology in diabetic neuropathy. We focus on discussing how the defects in metabolic and vascular pathways converge to enhance oxidative stress and how they produce the onset and progression of nerve injury present in diabetic neuropathy. We discuss if the mechanisms underlying neuropathy are similarly operated in type I and type II diabetes and the progression of antioxidants in treating diabetic neuropathy.

Treatment with Tang-luo-ning altered the microRNA expression profile in rats with diabetic peripheral neuropathy

Tang-luo-ning (TLN) is a traditional Chinese herbal recipe that has been used to treat diabetic peripheral neuropathy (DPN); nevertheless, the underlying mechanism remains unclear. This study was aimed to investigate the microRNA (miRNA) expression profile in diabetic rats treated with TLN, and the target genes were predicted. Male Sprague-Dawley rats were randomly divided into control, diabetes, and TLN-treated diabetes groups. Diabetes was induced with streptozotocin, and TLN (5 g/kg/day) was orally given for eight weeks. Then, the sciatic nerves were harvested for miRNA microarray analyses. The differentially expressed miRNAs and their target genes were analyzed. Compared with the control rats, 24 miRNAs were significantly upregulated, and 59 were downregulated in the sciatic nerves of the diabetic rats by more than two folds (all P < 0.05). In TLN-treated diabetes rats, 26 miRNAs were upregulated, and 14 were downregulated compared with diabetic rats without TLN treatment (all P < 0.05). DPN-induced alterations of the miRNA profile were reversed by the TLN treatment. A total of 1402 target genes were screened. In GO analysis, genes in localization, cytoplasm, and protein binding processes were enriched, and the most significantly enriched pathways included the neurotrophin, Fc epsilon RI, and Wnt signaling pathways. Further analyses revealed that DVL1 and NTF3 genes were involved in these pathways. Our findings indicate that TLN may affect the Wnt and neurotrophin pathways by acting on DVL1 and NTF3 genes.

Clinical Features and Rules of Chinese Herbal Medicine in Diabetic Peripheral Neuropathy Patients

OBJECTIVE

To analyse the clinical features of diabetic peripheral neuropathy (DPN) and employ data mining technology to explore the rules of Chinese herbal medicine (CHM) therapy.

METHODS

The clinical data of 216 patients with DPN and qi-yin deficiency syndrome were obtained, and the clinical features of the patients were assessed by cluster analysis. Relevant information was entered into the clinical diagnosis and treatment collection system, and data mining techniques were used to analyse the drug frequency, core CHM, CHM pair, and so on.

RESULTS

In this study, glycated haemoglobin (HbA1c) and homocysteine (HCY) were closely related to the pathogenesis of DPN. Overall, 162 patients had typical DPN syndrome characteristics, and we analysed 216 prescriptions, including 182 CHM. The frequencies of prescription of Astragalus membranaceus, Ligusticum wallichii, Poria cocos, and Radix Rehmanniae were greater than 45%. A Bayesian network analysis diagram showed that the 9 most common core CHM included Astragalus membranaceus, Ligusticum wallichii, Poria cocos, atractylodes rhizome, and Salvia miltiorrhiza Bge. According to the association rules of CHM, Radix Ophiopogon is used for Codonopsis pilosula; Astragalus membranaceus and atractylodes rhizome for Rehmannia are also frequently used. Astragalus membranaceus and Cinnamomi Ramulus or Ligusticum wallichii and Moutan bark were highly related to a decreased Michigan Diabetic Neuropathy Score.

CONCLUSION

HbA1c and HCY are related risk factors for DPN. Numbness is a typical syndrome characteristic. Astragalus membranaceus is a monarch CHM and is used most frequently.

Clinical diagnosis and management of small fiber neuropathy: an update on best practice

INTRODUCTION

Small fiber neuropathy (SFN) is a heterogeneous group of disorders affecting thin myelinated Aδ and unmyelinated C fibers. Common symptoms include neuropathic pain and autonomic disturbances, and the typical clinical presentation is that of a length-dependent polyneuropathy, although other distributions could be present.

AREA COVERED

This review focuses on several aspects of SFN including etiology, clinical presentation, diagnostic criteria and tests, management, and future perspectives. Diagnostic challenges are discussed, encompassing the role of accurate and standardized assessment of symptoms and signs and providing clues for the clinical practice. The authors discuss the evidence in support of skin biopsy and quantitative sensory testing as diagnostic tests and present an overview of other diagnostic techniques to assess sensory and autonomic fibers dysfunction. The authors also suggest a systematic approach to the etiology including a set of laboratory tests and genetic examinations of sodium channelopathies and other rare conditions that might drive the therapeutic approach based on underlying cause or symptoms treatment.

EXPERT OPINION

SFN provides a useful model for neuropathic pain whose known mechanisms and cause could pave the way toward personalized treatments.

Role of Magnesium in Type 2 Diabetes Mellitus

Magnesium (in its ionized and biologically active form, Mg²⁺) is an essential trace element that participates in numerous physiologic processes. Abnormal Mg²⁺ homeostasis can lead to many metabolic disorders, including diabetes mellitus (DM) and its complications. Mg²⁺ participates in energy generation and is required for DNA and RNA synthesis, reproduction, and protein synthesis. Additionally, Mg²⁺ acts as a calcium antagonist and protects vascular endothelial cells from oxidative stress. Imbalances in Mg²⁺ status, more frequently hypomagnesemia, inhibit glucose transporter type 4 translocation, increase insulin resistance, affect lipid metabolism, induce oxidative stress, and impair the antioxidant system of endothelial cells, In these ways, hypomagnesemia contributes to the initiation and progression of DM and its macrovascular and microvascular complications. In this review, we summarize recent advances in knowledge of the mechanisms whereby Mg²⁺ regulates insulin secretion and sensitivity. In addition, we discuss the future prospects for research regarding the mechanisms whereby Mg²⁺ status impacts DM and its complications.

Diabetic neuropathy is associated with increased pain perception, low serum beta-endorphin and increase insulin resistance among Nigerian cohorts in Ekiti State

INTRODUCTION

There has been an increase in the global prevalence of diabetic polyneuropathy and research evidence suggests that insulin resistance plays an important role in its development and prognosis. However, there seem to be a dearth of information in understanding the likely interplay between beta endorphin, insulin resistance and pain perception especially in the setting of painful diabetic neuropathy.

METHOD

This study recruited 120 volunteers divided into four groups (30 per group): group 1 healthy volunteer (control); group 2 DM type 2 without neuropathy (DM group); group 3 DM type 2 with painful neuropathy (DPN group); group 4 DM type 2 without painful neuropathy (DN). All subjects were evaluated for pain threshold and neuropathy using an ischemia-induced pain model and biothesiometer respectively. Their beta-endorphin, glycated hemoglobin, fasting plasma insulin, and HOMA values were determined and means compared using ANOVA.

RESULT

Serum beta-endorphin is significantly reduced in DN and DPN (∗p < 0.001) compared with the control and DM group. Also, DPN and DN patients have significantly increased insulin resistance compared to those without neuropathy (∗p < 0.001; ∗p < 0.0001 respectively). There is a significant positive correlation between the pain threshold and beta-endorphin in all the groups except DN group. The correlation between beta-endorphin and insulin resistance was negative and significant in control and DM groups only. Suggestive that the fact that insulin resistance plays an important role in diabetes polyneuropathy, does not alone explain the chronic pain perception noticed in the DPN patients.

CONCLUSION

The present study demonstrates that diabetic neuropathy patients have a poor endogenous opioid peptide system which is associated with increased pain perception and high insulin resistance. However, insulin resistance alone does not explain the chronic pain perception noticed in the DPN patients. Thus, further study is required.

Prevalence and Determinants of Peripheral Neuropathy among Type 2 Adult Diabetes Patients Attending Jimma University Medical Center, Southwest Ethiopia, 2019, an Institutional-Based Cross-Sectional Study

BACKGROUND

Diabetes chronic complications are major causes of morbidity and mortality, among which diabetic peripheral neuropathy (DPN) stands out. One of the tools to screen DPN is the Michigan neuropathy screening instrument. However, there is no data compiled using this tool to assess the prevalence and its determinants in Jimma. So, the aim of this study was to assess the prevalence of DPN and its determinants among patients with diabetes mellitus at Jimma University Medical Center. Methods. A hospital-based cross-sectional study was conducted at Jimma University Medical Center on 366 type 2diabetic patients. Data were collected using pretested structured questionnaire and entered into EpiData 3.1 and exported to SPSS version 20 for analysis. Both bivariate and multivariate binary logistic regressions were employed to identify factors associated with DPN. A variable having a p value of < 0.25 in the bivariate model was subjected to multivariate analysis to avoid confounding variable's effect. Adjusted odds ratios were calculated at 95% confidence interval and considered significant with a p value of ≤ 0.05.

RESULTS

The mean age of participants was 50.1 ± 14.28 years. The study finding showed that the prevalence of DPN was 53.6% among study participants. According to the multivariate logistic regression age above 40 years (AOR = 4.57; 95% CI: 1.50, 13.9), above 50 years (AOR = 6.5; 95% CI: 2.24, 18.79), duration of diabetes above 5 years (AOR = 3.06; 95% CI: 1.63, 5.77), duration above 10 years (AOR = 7.1; 95% CI: 2.99, 17.28), physical inactivity (AOR = 2.02; 95% CI: 1.14, 3.55), and smoking (current smoker AOR = 7.96, 95% CI: 3.22, 19.64; former smoker (AOR = 2.65; 95% CI: 1.22, 5.77) were independent predictors of DPN among study participants.

CONCLUSION

Almost half of the study participants had DPN. Age above 40 years, diabetes duration of above 5 years, physical inactivity, and smoking were significantly associated with DPN. Early detection and appropriate interventions are important among patients with age above 40 years, physically inactive, smokers, and diabetes duration of above 5 years.

Insulin resistance is associated with an exaggerated blood pressure response to ischemic rhythmic handgrip exercise in nondiabetic older adults

Patients with type 2 diabetes display an exaggerated pressor response to exercise. However, evidence supporting the association between the magnitude of the pressor response to exercise and insulin resistance-related factors including hemoglobin A1c (HbA1c) or homeostatic model assessment of insulin resistance (HOMA-IR) in nondiabetic subjects has remained sparse and inconclusive. Thus we investigated the relationship between cardiovascular responses to exercise and insulin resistance-related factors in nondiabetic healthy men (n = 23) and women (n = 22) above 60 yr old. We measured heart rate (HR) and blood pressure (BP) responses during: isometric handgrip (IHG) exercise of 30% maximal voluntary contraction, a period of skeletal muscle ischemia (SMI) induced by tourniqueting the arm after IHG, and rhythmic dynamic handgrip (DHG) exercise during SMI. Greater diastolic BP (DBP) responses to DHG with SMI was associated with male sex (r = 0.44, P = 0.02) and higher HbA1c (r = 0.33, P = 0.03), heart-ankle pulse wave velocity (haPWV) (r = 0.45, P < 0.01), and resting systolic BP (SBP) (r = 0.36, P = 0.02). HbA1c persisted as a significant determinant explaining the variance in the DBP response to DHG with SMI in multivariate models despite adjustment for sex, haPWV, and resting SBP. It was also determined that the DBP response to DHG with SMI in a group in which HOMA-IR was abnormal (Δ33 ± 3 mmHg) was significantly higher than that of groups in which HOMA-IR was at intermediate (Δ20 ± 4 mmHg) and normal (Δ23 ± 2 mmHg) levels. These data suggest that even in nondiabetic older adults, insulin resistance is related to an exaggerated pressor response to exercise especially when performed under ischemic conditions.NEW & NOTEWORTHY The diastolic blood pressure response to rhythmic dynamic handgrip exercise under ischemic conditions was demonstrated to be correlated with insulin resistance-related factors in nondiabetic older adults. This finding provides important insight to the prescription of exercise in this particular patient population as the blood pressure response to exercise, especially under ischemic conditions, could be exaggerated to nonsafe levels.

Management of a Difficult-to-Treat Diabetic Foot Wound Complicated by Osteomyelitis: A Case Study

Introduction

Diabetic ulcers are a major health issue worldwide, causing significant economic burdens and affecting both the patient and the society as a whole. Predisposing factors in diabetic patients, known as the pathogenic triad, comprise trauma, ischemia, and neuropathy. Regardless of the cause, correct diagnosis and prompt treatment are essential in the management of leg ulcers. Case History. We report a case of a 51-year-old male patient, with a known history of type 2 diabetes mellitus who presented to our hospital with a history of two ulcers, one that he was mainly complaining of, which was actively infected and located at the posterior part of the distal left leg, and the second, dry ulcer caused by unrecognized trauma, located on the heel of the same limb. Magnetic resonance imaging showed osteomyelitis and degenerative changes in the calcaneonavicular and tarsal joints. The patient underwent multiple sessions of excisional debridement. He was started on negative pressure wound therapy with some improvements. However, after skin graft failure, Nanoflex powder was used, leading to complete wound closure within one month of treatment.

Conclusion

A multidisciplinary holistic approach must be used when treating diabetic foot ulcers. Different modalities and sessions of debridement should be performed after optimizing the general condition of the patient.

Measurement properties and factor analysis of the Diabetic Foot Ulcer Scale-short form (DFS-SF)

The purpose of this paper is to provide measurement properties evaluation and factor analysis of the Brazilian version of the diabetic foot ulcer scale-short form (DFS-SF). This methodological study evaluated the measurement properties of the DFS-SF by ceiling and floor effect reliability, responsiveness, and structural construct validity. The study included 290 people with diabetic foot under regular follow-up in a specialised outpatient clinic in inland São Paulo. Reliability was assessed by internal consistency using Cronbach's alpha and composite reliability. Ceiling and floor effects were assessed by the percentage of participants who scored the 15% worst (floor) and 15% best (ceiling) possible scale results. Validity was tested by correlating the instrument values with the domains of the Brazilian version of the Short Form Health Survey (SF-36). Responsiveness (n = 34) was accessed through the wound area obtained by photography and evaluated by the Image J Features program and the DFS-SF score at two moments, with a 4-week interval between them. The instrument had good evidence of reliability, shown by adequate internal consistency (Cronbach's alpha in domains >0.70) and compound reliability (0.84 > CC > 0.92); and of convergent validity, by significant positive correlations of moderate to strong magnitude with SF-36. Structural construct validity was examined by applying the DFS-SF confirmatory factor analysis, which indicated that the Brazilian version of the instrument is properly fitted to the original dimensional structure. The ceiling and floor effect analysis showed no ceiling or floor effects. Responsiveness was observed in the wound area, but not in the DFS-SF scores in the times. The Brazilian version of the DFS-SF presented evidence of validity and reliability, suggesting that this instrument is a valid tool for assessing the quality of life of people with diabetic foot in the Brazilian population.

Human adipose-derived mesenchymal stem cell-conditioned medium ameliorates polyneuropathy and foot ulceration in diabetic BKS db/db mice

BACKGROUND

Diabetic polyneuropathy (DPN) is the most common and early developing complication of diabetes mellitus, and the key contributor for foot ulcers development, with no specific therapies available. Different studies have shown that mesenchymal stem cell (MSC) administration is able to ameliorate DPN; however, limited cell survival and safety reasons hinder its transfer from bench to bedside. MSCs secrete a broad range of antioxidant, neuroprotective, angiogenic, and immunomodulatory factors (known as conditioned medium), which are all decreased in the peripheral nerves of diabetic patients. Furthermore, the abundance of these factors can be boosted in vitro by incubating MSCs with a preconditioning stimulus, enhancing their therapeutic efficacy. We hypothesize that systemic administration of conditioned medium derived from preconditioned MSCs could reverse DPN and prevent foot ulcer formation in a mouse model of type II diabetes mellitus.

METHODS

Diabetic BKS db/db mice were treated with systemic administration of conditioned medium derived from preconditioned human MSCs; conditioned medium derived from non-preconditioned MSCs or vehicle after behavioral signs of DPN was already present. Conditioned medium or vehicle administration was repeated every 2 weeks for a total of four administrations, and several functional and structural parameters characteristic of DPN were evaluated. Finally, a wound was made in the dorsal surface of both feet, and the kinetics of wound closure, re-epithelialization, angiogenesis, and cell proliferation were evaluated.

RESULTS

Our molecular, electrophysiological, and histological analysis demonstrated that the administration of conditioned medium derived from non-preconditioned MSCs or from preconditioned MSCs to diabetic BKS db/db mice strongly reverts the established DPN, improving thermal and mechanical sensitivity, restoring intraepidermal nerve fiber density, reducing neuron and Schwann cell apoptosis, improving angiogenesis, and reducing chronic inflammation of peripheral nerves. Furthermore, DPN reversion induced by conditioned medium administration enhances the wound healing process by accelerating wound closure, improving the re-epithelialization of the injured skin and increasing blood vessels in the wound bed in a skin injury model that mimics a foot ulcer.

CONCLUSIONS

Studies conducted indicate that MSC-conditioned medium administration could be a novel cell-free therapeutic approach to reverse the initial stages of DPN, avoiding the risk of lower limb amputation triggered by foot ulcer formation and accelerating the wound healing process in case it occurs.

The association between cardiac autonomic neuropathy and heart function in type 2 diabetic patients

Aim: Cardiac autonomic neuropathy (CAN) is a common and important chronic complication in diabetic patients. Heart failure resulting from cardiomyopathy is also a lethal complication in diabetic patients. However, data showing the exact association between CAN and heart failure in diabetic patients are relatively scarce. Therefore, our study aimed to determine the association between the parameters assessing CAN and heart function in diabetic patients.Method: The medical records of type 2 diabetic patients who underwent an autonomic function test with heart rate variability (HRV) and echocardiography were reviewed from January 2018 to December 2018. A total of 100 type 2 diabetic patients were included, and the association between the parameters assessing CAN and heart function was analysed.Results: Among the 100 analysed patients, 65 were diagnosed with CAN and 26 showed diastolic dysfunction. Moreover, 19 (73.1%) diabetic patients with diastolic dysfunction were complicated with CAN. The occurrence of diastolic dysfunction was higher in diabetic patients with CAN than in diabetic patients without CAN (29.2% vs 20.0%, p < 0.05), and the occurrence of CAN was higher in diabetic patients with diastolic dysfunction than in patients without diastolic dysfunction (73.1% vs 62.2%, p < 0.05). However, there were no significant associations between HRV parameters and heart function.Conclusion: We demonstrated that diastolic dysfunction is more common in diabetic patients complicated with CAN than in diabetic patients without CAN, although several diabetic patients without diastolic dysfunction are also diagnosed with CAN. Moreover, further studies about the long-term serial monitoring of heart function according to the progression of CAN are required to confirm the exact association between CAN and heart function.

A Study on the Relationship between Type 2 Diabetes and Taste Function in Patients with Good Glycemic Control

Type 2 diabetes mellitus (T2DM) has a very high impact on quality of life as it is characterized by disabling complications. There is little evidence about taste alterations in diabetes. Since many individual factors are involved in the onset of diabetes, the purpose of our study is to search a possible link between diabetes and individual taste function. Thirty-two participants with T2DM and 32 volunteers without T2DM (healthy controls) were recruited. Four concentrations of each of the four basic tastes (sweet, sour, salty, bitter), and pure rapeseed oil and water, were applied with cotton pads to the protruded tongue, immediately posterior to its first third, either to the left or right side. The results showed significant differences between groups in the ability to recognize sour, bitter, sweet, and water. Taste scores were lower in subjects with T2DM than in healthy controls, and an age-related decline in taste function was found. The taste function reduction associated with T2DM was not related to gender, disease duration, and glycemic control. In conclusion, it can be hypothesized that a general alteration of taste function can lead patients with type 2 diabetes to search for foods richer in sugars, as in a vicious circle, thus decreasing the likelihood of remission of diabetes mellitus.

Association of sarcopenia and muscle mass with both peripheral neuropathy and nerve function in patients with type 2 diabetes

AIM

This study aimed to investigate the association of sarcopenia and muscle mass with both peripheral neuropathy and nerve function in type 2 diabetes mellitus.

METHODS

A total of 1794 patients (937 men and 857 women) with type 2 diabetes, with a mean age of 60.22 years, were enrolled for a cross-sectional study; of these, 183 patients were enrolled for a follow-up study with a median follow-up of 2.7 years. All participants underwent nerve conduction studies and muscle mass index (ASM/HT²) measurements. The composite Z scores for the sensory nerve conduction velocity (SCV) and the motor nerve conduction velocity (MCV) were calculated. The changes in ASM/HT², SCV, and MCV were calculated from the measurements nearly 2 years apart and classified into three groups: a decrease in ASM/HT² of >3%, a minor change within ±3%, and an increase in ASM/HT² of >3%.

RESULTS

The ASM/HT² of men was positively associated with the composite Z scores of MCV and SCV, and sarcopenia highly correlated with DPN after adjusting for confounding factors. The optimal cutoff point for ASM/HT² that indicated DPN was 7.09 kg/m². Furthermore, increases in ASM/HT² independently predicted a greater benefit of MCV and SCV increment outcomes, whereas a minor change in ASM/HT² only significantly associated with lower benefit in terms of SCV increment. However, this phenomenon was not observed in women.

CONCLUSIONS

Sarcopenia and DPN exhibited a close association. The increased muscle mass improved the partial MCVs and SCVs. However, a sex-related discrepancy was observed in this phenomenon.

Altered morphology and function of the peripheral nociceptive system in the offspring of diabetic rats

The aim of this study was to determine whether maternal diabetes induced by alloxan injection in the first gestational day of female Wistar rats interferes with the development of the nociceptive peripheral system of the offspring. Behavioral and histologic analysis was performed using the adult offspring of diabetic and control rats. It was found that the offspring of diabetic rats were more sensitive to thermal stimulation and showed an altered response to carrageenan-induced inflammatory hyperalgesia. The histological analysis showed an increased proportion of nociceptive neurons, while the population of non-nociceptive myelinated neurons was reduced. Therefore, exposition to hyperglycemia and/or hyperinsulinemia in uterus, caused by a diabetic mother, might result in altered nociceptive sensations in the offspring throughout life.

Attenuation of Cortically Evoked Motor-Neuron Potential in Streptozotocin-Induced Diabetic Rats: A Study about the Effect of Diabetes upon Cortical-Initiated Movement

Aims/Hypothesis. The complications affecting the peripheral nervous system, associated with diabetes mellitus, have been the focus of considerable research. Comparably less research has focused upon the effect of diabetes upon the central nervous system. In this study, we investigate the effect of diabetes upon motor-neuron potentials evoked in the motor cortex of streptozotocin diabetic rats.

Methods

In this study, we investigated the cortical-evoked motor-neuron potentials in streptozotocin-induced diabetic rats. Cortical potentials were evoked using direct current stimulation to the motor cortex, and the resulting evoked potentials were recorded in the sciatic nerve. As voluntary movement consists of repeated activation of muscles, repeated stimulation trials were used to determine the effect of diabetes upon the animals' ability to recuperate between stimulations.

Results

Our findings showed that diabetes severely decreased the amplitude of cortical-evoked potentials and compromised the recuperation of motor neurons between activation. Conclusion/Interpretation. The reduced amplitude and weakened recuperation of diabetic motor neurons potentially may contribute to impaired transmission in motor pathways and thereby motor dysfunction.

Prevalence and Correlates of Cardiovascular Autonomic Neuropathy Among Patients with Diabetes in Uganda: A Hospital-Based Cross-sectional Study

Background

Cardiovascular autonomic neuropathy (CAN) is a common complication in individuals with diabetes mellitus (DM) but often overlooked in clinical practice. The burden and correlates of CAN have not been extensively studied in low-income countries, particularly in sub-Saharan Africa.

Objectives

To determine the prevalence and correlates of CAN among adults in ambulatory diabetes care in southwestern Uganda.

Method

We conducted a cross-sectional study among adults with diabetes from November 2018 to April 2019. CAN was assessed using the five autonomic function tests: deep breathing, Valsalva maneuver, postural index on standing, change in blood pressure during standing and diastolic blood pressure response to isometric exercise. We estimated the prevalence of CAN and fit regression models to identify its demographic and clinical correlates.

Results

We enrolled 299 individuals. The mean age was 50.1 years (SD ± 9.8), mean HbA1c was 9.7 (SD ± 2.6) and 69.6% were female. CAN was detected in 156/299 (52.2%) of the participants on the basis of one or more abnormal cardiovascular autonomic reflex tests. Out of 299 participants, 88 (29.4%) were classified as early CAN while 61/299 (20.4%) and 7/299 (2.3%) were classified as definite and severe (advanced) CAN respectively. In multivariable regression models, age over 50 years (aOR 3.48, 95%CI 1.35 -8.99, p = 0.010), duration of diabetes over 10 years (aOR 4.09, 95%CI 1.78 -9.38, p = 0.001), and presence of diabetic retinopathy (aOR 2.25, 95%CI 1.16 -4.34, p = 0.016) were correlated with CAN.

Conclusions

Our findings reveal a high prevalence of CAN among individuals in routine outpatient care for diabetes mellitus in Uganda. Older age, longer duration of diabetes and coexistence of retinopathy are associated with CAN. Future work should explore the clinical significance and long term outcomes associated with CAN in this region.

The haptoglobin 2-2 genotype is associated with cardiac autonomic neuropathy in type 1 diabetes: the RETRO HDLc study

AIM

The haptoglobin (Hp) 2-2 genotype has been shown to increase the risk of coronary artery disease, kidney dysfunction and mortality from cardiovascular and renal causes in type 1 diabetes (T1D). Similar associations, however, have not been observed in those without diabetes. As cardiac autonomic neuropathy (CAN) is a cardiovascular disease risk factor, we assessed the presence of an association between the Hp 2-2 genotype and CAN.

METHODS

The study included 216 individuals with childhood-onset T1D and 200 individuals with normal glucose tolerance (NGT) of similar age and gender distribution to their counterparts with T1D. CAN was assessed using an electrocardiogram as an abnormal, age-specific, heart rate response to deep breathing. Multivariable logistic regression models were used to assess the association between the Hp 2-2 genotype and CAN.

RESULTS

Compared with NGT, participants with T1D had a similar proportion of Hp 2-2 carriers (41.5% vs. 32.0%, p = 0.05) but a greater CAN prevalence (28.2% vs. 5.0%, p < 0.0001). In multivariable logistic regression models, those carrying the Hp 2-2 genotype had significantly higher odds of CAN compared with Hp 1-1 or Hp 2-1 carriers (OR = 2.27, p = 0.01). The presence of T1D (OR = 4.20, p = 0.0003), hypertension (OR = 2.08, p = 0.03), eGFR (OR = 0.98, p = 0.01) and WBC count (OR = 1.21, p = 0.02) were also associated with CAN. There was no T1D by Hp interaction (p = 0.92), although in stratified analyses, the Hp-CAN association was significant only in T1D.

CONCLUSIONS

The Hp 2-2 genotype was independently associated with greater odds of CAN in T1D though no definitive conclusions could be made in NGT.

Is Neuregulin-4 a predictive marker of microvascular complications in type 2 diabetes mellitus?

BACKGROUND AND AIMS

Neuregulin-4 (Nrg-4) is a new adipokine released from brown adipose tissue. It plays pivotal role in regulating systemic energy balance, glucose and lipid metabolism and in reducing chronic inflammation. We aimed to investigate the relation between diabetic microvascular complications (DMC) and serum (Nrg-4) levels in patients with type 2 diabetes mellitus.

METHODS

Patients with type 2 diabetes mellitus were divided into DMC and diabetic patients without microvascular complications (non-DMC). Nrg-4 levels of the patients were compared.

RESULTS

Fifty and 29 patients enrolled to the DMC and non-DMC groups, respectively. Nrg-4 was 1.23 (0.02-5.1) ng/mL and 2.5 (0.21-6.01) ng/mL in DMC and in non-DMC groups, respectively (P < .001). In patients with DMC, FPG was 189.5 (89-446) mg/ dL, whereas it was 128 (95-278) mg/dL in non-DMC diabetic patients (P < .001). HbA1c was also significantly higher in the DMC group than in the non-DMC group (P < .001). Negative correlation was found between Nrg-4 and FPG (r = -0.231, P = .03), HBA1c (r = -0.312, P = .003) and microalbuminuria (r = -0.277, P = .009). Logistic regression analysis showed a 1-unit decrease in Nrg-4 to increase the presence of DMC by 1.9 times. The best cut-off value of Nrg-4 was 1.56 ng/mL with 82.1% sensitivity and 64% specificity, in predicting DMC.

CONCLUSION

In patients with diabetes, Nrg-4 levels may be a good predictor of early detection of one or more DMC, as microvascular dysfunction in an organ system is considered to be an initial onset of subclinical systemic damage.

Skin microvascular reactivity correlates to clinical microangiopathy in type 1 diabetes: A pilot study

AIM

The aim of this study was to investigate the correlation between skin microvascular reactivity and clinical microangiopathy in patients with type 1 diabetes.

METHODS

We included 61 patients with type 1 diabetes, that is, 31 patients with and 30 without clinical microangiopathy, and 31 healthy controls. A microangiopathy scoring system was introduced for comparison of data between patients with microangiopathy. Responses to iontophoresis of acetylcholine and sodium nitroprusside were assessed by laser Doppler imaging.

RESULTS

Patients with microangiopathy had reduced acetylcholine- and sodium nitroprusside-mediated flux in forearm skin microcirculation compared to healthy controls (p = 0.03 and p < 0.001, respectively, repeated measures analysis of variance), whereas no significant differences were found between patients without microangiopathy and controls. Skin reactivity was reduced in patients with microangiopathy compared to patients without microangiopathy: 1.43 ± 0.38 versus 1.59 ± 0.39 arbitrary units for acetylcholine-mediated peak flux and 1.44 ± 0.46 versus 1.74 ± 0.34 arbitrary units for sodium nitroprusside-mediated peak flux (p < 0.05 for both). A tendency of gradual decrease in acetylcholine and sodium nitroprusside responses was found in patients with increasing microangiopathy scores.

CONCLUSION

We conclude that skin microvascular reactivity is associated with clinical microangiopathy in patients with type 1 diabetes. Impaired skin microvascular function in type 1 diabetes seems to be multifactorial and involves both endothelial-dependent and endothelial-independent pathways. We introduce a novel microangiopathy score that could easily be used in a clinical setting for comparison of patients with various degrees of microangiopathy.

Correlation between kidney and peripheral nerve functions in Type 2 diabetes

BACKGROUND

Although greater impairments in nerve functions parameters are most likely to occur with a lower kidney function, there is a paucity of information on the relationship between the kidney and peripheral nerve functions parameters in Type 2 diabetes.

AIM

To address the impact of peripheral nerve functions in Type 2 diabetes patients in different stages of chronic kidney diseases (CKD).

DESIGN

This prospective study enrolled 238 patients with Type 2 diabetes at a tertiary medical center.

METHOD

We designed composite amplitude scores of nerve conductions (CAS) as a measure of severity of peripheral neuropathy (PN), and used estimated glomerular filtration rate (eGFR) and urine albumin-creatinine ratio (UACR) parameters to stage CKD in Type 2 diabetes patients. The intrapersonal mean, standard deviation and coefficient of variation of eGFR for 238 patients were obtained in the 3 years prior to the study.

RESULTS

The patients who had lower eGFR and higher UACR were older, with longer diabetes duration, a greater percentage of retinopathy and PN and higher CAS. Multiple linear regression analysis revealed that diabetes duration and eGFR were independently associated with CAS, and a cut-off value of eGFR in the presence of PN was 65.3 ml/min/1.73 m2.

CONCLUSION

We observed a close relationship between the severity of kidney and peripheral nerve function in patients with diabetes. If a patient's eGFR value is below 65.3 ml/min/1.73 m2 or the UACR value is above 98.6 mg/dl, caution is needed with the presence of PN even in diabetic patients who are asymptomatic.

The impact of demographic and clinical characteristics on diabetic painful neuropathy

INTRODUCTION

Diabetic neuropathy (DN) is one of the most devastating complications of diabetes mellitus; however, in contrast to other countries, there are no scientific studies in Portugal evaluating the impact of demographic and clinical characteristics of this pathological entity. The aim of this study was to evaluate the impact of gender, metabolic control, age of diabetic patients, as well as time of disease progression, the appearance of complaints related to neuropathic pain.

MATERIAL AND METHODS

A multicentre study with a non-probabilistic, convenience sample of 359 patients was performed employing the quantitative method, using the Statistical Package for Social Science 24 software. The p-value of p < 0.05 was defined to consider a result statistically significant. The Spearman correlation coefficient (r) was determined to determine the relationship between categorical variables.

RESULTS

There was no statistically significant difference in the prevalence of DN between genders (p = 0.633 and r = 0.025). There was a statistically significant relationship between the value of HbA1c and DN, with p = 0.010 and r = 0.136. There is a relationship between age and complaints of neuropathic pain, with p = 0.034 and r = 0.112. The variable, time of disease progression, is also correlated with the appearance of complaints of neuropathic pain with p = 0.020 and r = 0.112.

CONCLUSION

The prevalence of neuropathic pain in subjects with diabetes is not negligible and is associated with modifiable risk factors that can be identified, possibly modified and prevented. The correct approach for these patients, which involves screening and early treatment, is decisive improving functionality and quality of life.

Correlation Between Diabetic Peripheral Neuropathy and Sarcopenia in Patients with Type 2 Diabetes Mellitus and Diabetic Foot Disease: A Cross-Sectional Study

PURPOSE

The present study was designed to determine the relationships between sarcopenia and diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes mellitus (T2DM) and diabetic foot disease (DFD) respectively.

PATIENTS AND METHODS

A total of 1104 patients with T2DM and 257 patients with DFD were included in the study, which was designed as a cross-sectional study. Body composition was assessed using dual-energy X-ray-absorptiometry (DXA). The diagnosis of sarcopenia was based on the Baumgartner criteria. DPN was assessed by Neuropathy symptom score (NSS) and Neuropathy disability score (NDS), and the severity of neuropathy was divided into non-neuropathy symptom (NS), Mild NS, Moderate NS and Severe NS according to NSS. Logistic regression analyses were carried out to determine the relations of sarcopenia and DPN in patients with T2DM and NSS in patients with DFD, respectively.

RESULTS

The prevalence of DPN was 80.0% in T2DM patients with sarcopenia and 70.3% in non-sarcopenia patients (P=0.007). Logistic regression analyses showed DPN was one of the independent risk factors for sarcopenia in T2DM patients (OR 1.564 [95% CI: 1.004, 2.435], P=0.048). The prevalence of DPN had no statistical significance in DFD patients with or without sarcopenia. However, the NSS of DFD patients with sarcopenia was higher than that of non-sarcopenia patients. In the multivariate logistic regression analysis, NSS was determined to be associated with sarcopenia in DFD patients (OR 1.387[95% CI: 1.074, 1.789], P=0.012). The appendicular lean mass (ALM) of DFD patients without NS was higher than patients with mild, moderate and severe NS (20.71±2.73 vs 16.57±3.62 vs 17.99±3.54 vs 17.23±3.29 Kg, P=0.028).

CONCLUSION

DPN is an independent risk factor for sarcopenia in patients with T2DM and NSS is also independently correlated with sarcopenia in patients with DFD, with the latter being more obvious with the aggravation of neurological symptoms in DFD patients.

Variability in the clinical diagnosis of diabetic peripheral neuropathy

AIMS

The aims of this study are to assess the variability in the prevalence of diabetic peripheral neuropathy (DPN), according to the diagnostic and clinical guidelines used.

METHODS

A cross-sectional observational study was conducted of 111 patients with diabetes mellitus. The presence/absence of DPN was determined according to 12 different criteria stipulated in various clinical guidelines (ADA 2018, IWGDF 2016, IDF 2012 and CONUEI 2018). The Cohen's kappa coefficient (κ) was performed to determine the degree of agreement for DPN diagnosis among the different criteria.

RESULTS

The recorded prevalence of DPN ranged from 13.1% (criterion ADA 2018) to 68.5% (criterion IDF 2012). The sensory parameter that was most commonly affected was the non-perception of vibration (68.5%) and the absence of Achilles reflexes (59.4%). IWGDF, based on the use of a monofilament, cotton wisp and tuning fork, was the test with more agreements, presenting good agreement with 2 criteria from ADA 2018 (k=0.845), 1b2 (k=0.817), 2 criteria from IWGDF 2016 (k=0.933), (k=0.817), 1 criteria from IDF 2012 (k=0.845) and 1 criteria from CONUEI 2018 (k=0.860), all p<0.001.

CONCLUSION

The IWGDF criterion based on the use of a monofilament, cotton wisp and tuning fork for the diagnosis presented the highest level of concordance with the other criteria (>0.8).

Traditional Chinese medicine foot bath combined with acupoint massage for the treatment of diabetic peripheral neuropathy: A systematic review and meta-analysis of 31 RCTs

In this study, we aim to evaluate the efficiency and safety of traditional Chinese medicine foot bath combined with acupoint massage for the treatment of diabetic peripheral neuropathy. A total of eight online databases were searched to collect studies published up to February 2019. Study quality of each included article was evaluated by the Cochrane Collaboration risk of bias tool. Systematic reviews and meta-analyses were conducted based on the Cochrane systematic review method by using the RevMan 5.3 software. Traditional Chinese medicine foot bath combined with acupoint massage was the main therapy in experimental group. Interventions in control groups include western medicine, oral traditional Chinese medicine, other symptomatic treatment of western medicine, and blank control. Primary outcomes in this study include sensory nerve conduction velocity (SNCV), motor nerve conduction velocity (MNCV), total effective rate, and neuropathic syndrome score. Finally, 31 trials involving 3284 participants were included. The results of systematic reviews and meta-analyses showed that traditional Chinese medicine foot bath combined with acupoint massage was significantly better compared with the control groups in terms of the total effective rate, SNCV, MNCV, and neuropathic syndrome score. No case of adverse effect was reported. These findings show that traditional Chinese medicine foot bath combined with acupoint massage may be safer and more effective for the treatment of DPN. However, due to the low methodological quality, further research with randomized controlled trials (RCTs) of higher quality is required to prove its efficacy and better evidence for clinical treatment.

Attenuation of diabetic retinopathy and neuropathy by resveratrol: Review on its molecular mechanisms of action

Resveratrol is an important phenolic phytochemical from the therapeutic perspective. It has therapeutic impacts over wide range of diseases, especially the ones related to oxidative stress. Resveratrol, being primarily a potent anti-oxidant phytochemical, has significant impact against major diseases as inflammatory disorders, diabetes, and cancer. In the current review article, we intend to highlight the molecular aspects of the mechanism of action of resveratrol against major diabetic implications, namely, retinopathy and neuropathy. Both these diabetic implications are among the first fallouts of chronic hyperglycaemia. Resveratrol, via multiple molecular pathways, tend to attenuate and reverse these deformity and other disease-causing implications.

Diet-Induced Rodent Models of Diabetic Peripheral Neuropathy, Retinopathy and Nephropathy

Unhealthy dietary habits are major modifiable risk factors for the development of type 2 diabetes mellitus, a metabolic disease with increasing prevalence and serious consequences. Microvascular complications of diabetes, namely diabetic peripheral neuropathy (DPN), retinopathy (DR), and nephropathy (DN), are associated with high morbidity rates and a heavy social and economic burden. Currently, available therapeutic options to counter the evolution of diabetic microvascular complications are clearly insufficient, which strongly recommends further research. Animal models are essential tools to dissect the molecular mechanisms underlying disease progression, to unravel new therapeutic targets, as well as to evaluate the efficacy of new drugs and/or novel therapeutic approaches. However, choosing the best animal model is challenging due to the large number of factors that need to be considered. This is particularly relevant for models induced by dietary modifications, which vary markedly in terms of macronutrient composition. In this article, we revisit the rodent models of diet-induced DPN, DR, and DN, critically comparing the main features of these microvascular complications in humans and the criteria for their diagnosis with the parameters that have been used in preclinical research using rodent models, considering the possible need for factors which can accelerate or aggravate these conditions.

Non-invasive assessment of vibration perception and protective sensation in people with diabetes mellitus: inter- and intra-rater reliability

BACKGROUND

Testing of protective sensation and vibration perception are two of the most commonly used non-invasive methods of screening for diabetes-related peripheral neuropathy (DPN). However, there is limited research investigating the reliability of these tests in people with diabetes. The aim of this study was to determine the inter- and intra-rater reliability of methods used to test vibration perception and protective sensation in a community-based population of adults with type 2 diabetes.

METHODS

Three podiatrists with varying clinical experience tested four- and 10-site, 10 g monofilament and vibration perception threshold (VPT). In a separate cohort, the reliability of a graduated tuning fork as well as two methods of conventional tuning fork (on/off method and dampening method) was undertaken by a new graduate podiatrist and podiatrist with one-year's clinical experience. The intra- (Cohen's К) and inter-rater (Cohen's or Fleiss' К) reliability of each test was determined.

RESULTS

Fifty participants (66% male, 100% type 2, 32% with DPN) underwent monofilament and neurothesiometer testing with 44 returning for the retest. Twenty-four participants (63% male, 100% type 2, 4% with DPN) underwent tuning fork testing and returned for retest. All tests demonstrated acceptable inter-rater reliability ranging from moderate (10-site monofilament, К: 0.54, CI: 0.38-0.70, p = 0.02) to substantial (graduated tuning fork, К: 0.68, CI: 0.41-0.95, p < 0.01). The 10-site monofilament (К: 0.44-0.77) outperformed the 4-site test (К: 0.34-0.67) and the dampened tuning fork method (К: 0.41-0.49) showed lower intra-rater reliability compared to both conventional (К: 0.52-0.57) and graduated methods (К: 0.50-0.57).

CONCLUSION

We support the current recommendations of using more than one test to screen and monitor progression of DPN. Four- and 10-site 10 g monofilament testing have similarly acceptable levels of reliability and the neurothesiometer is the most reliable method of assessing vibration perception function. Use of a graduated tuning fork was slightly more reliable than other methods of tuning fork application however all had substantial reliability. Years of clinical experience only marginally affected test reliability overall and due to subjective nature of the tests we suggest that testing should be performed regularly and repetitively.

Nutritional Interventions and Considerations for the Development of Low Calorie or Sugar Free Foods

Diabetes is a globally prevalent chronic metabolic disease characterized by blood glucose levels higher than the normal levels. Sugar, a common constituent of diet, is also a major factor often responsible for elevating the glucose level in diabetic patients. However, diabetic patients are more prone to eat sweets amongst the human population. Therefore, we find a popular consumption of zero or low-calorie sweeteners, both natural and artificial. But, the uses of these sweeteners have proved to be controversial. Thus, the purpose of this review was to critically analyze and highlight the considerations needed for the development of sugar-free or low-calorie products for diabetic patients. For this purpose, various measures are taken such as avoiding sugary foods, using natural nectar, artificial sweeteners, etc. It cannot be ignored that many health hazards are associated with the overconsumption of artificial sweeteners only. These sweeteners are high-risk compounds and a properly balanced consideration needs to be given while making a diet plan for diabetic patients.

Glycaemic Control and Vascular Complications in Diabetes Mellitus Type 2

Diabetes mellitus is constantly increasing worldwide. Vascular complications are the most common in the setting of long-standing disease, claiming the greatest burden in terms of morbidity and mortality. Glucotoxicity is involved in vascular damage through different metabolic pathways, such as production of advanced glycation end-products, activation of protein kinase C, polyol pathway activation and production of reactive oxygen species. Vascular complications can be classified according to the calibre of the vessels involved as microvascular (such as diabetic retinopathy, nephropathy and neuropathy) or macrovascular (such as cerebrovascular, coronary and peripheral artery disease). Previous studies showed that the severity of vascular complications depends on duration and degree of hyperglycaemia and, as consequence, early trials were designed to prove that intensive glucose control could reduce the number of vascular events. Unfortunately, results were not as satisfactory as expected. Trials showed good results in reducing incidence of microvascular complications but coronary heart diseases, strokes and peripheral artery diseases were not affected despite optimal glycemia control. In 2008, after the demonstration that rosiglitazone increases cardiovascular risk, FDA demanded stricter rules for marketing glucose-lowering drugs, marking the beginning of cardiovascular outcome trials, whose function is to demonstrate the cardiovascular safety of anti-diabetic drugs. The introduction of new molecules led to a change in diabetes treatment, as some new glucose-lowering drugs showed not only to be safe but also to ensure cardiovascular benefit to diabetic patients. Empaglifozin, a sodium-glucose cotransporter 2 inhibitor, was the first molecule to show impressing results, followed on by glucagon-like peptide 1 receptor agonists, such as liraglutide. A combination of anti-atherogenic effects and hemodynamic improvements are likely explanations of the observed reduction in cardiovascular events and mortality. These evidences have opened a completely new era in the field of glucose-lowering drugs and of diabetes treatment in particular with respect to vascular complications.

Is it possible to substitute the monofilament test for the Ipswich Touch Test in screening for peripheral diabetic neuropathy?

BACKGROUND

This study aimed to assess the agreement and efficacy of the Ipswich Touch Test compared to the monofilament test in individuals with type 2 diabetes.

MATERIALS AND METHODS

A cross-sectional and analytical study was conducted. The inclusion criteria were patients with type II diabetes (n = 250) who did not present ulcers or amputation in either foot. The exclusion criteria were as follows: patients who presented sequelae of cerebrovascular disease or other neurological pathologies, as well as diagnoses of malignancy, alcohol abuse, liver cirrhosis, hepatitis B, AIDS, hypothyroidism, chronic kidney disease or lupus erythaematosus, as these clinical conditions could influence or bias the results (Won and Park in Endocrinol Metab 31:230-238, 2016). Sensitivity, specificity, predictive values, likelihood ratios, and Kappa index were calculated. Other factors assessed were glycated haemoglobin and body mass index.

RESULTS

Most of the participants were female (71.2%), and glycated haemoglobin (HbA1c) was greater than 7% in 54.4% of the patients. The mean age was 59.43 years, and the mean time since diagnosis was 12.38 years. The Kappa index was 0.819 (p < 0.001), and the Ipswich Touch Test had a sensitivity of 83.33%, a specificity of 97.66%, a positive predictive value of 85.71%, a negative predictive value of 97.21%, a positive likelihood ratio of 30.19%, and a negative likelihood ratio of 0.17%. The level of significance was 5% in this study.

CONCLUSION

The Ipswich Touch Test resented good agreement and efficacy compared to the gold standard-the 10 g monofilament test.

Supplementation with Korean Red Ginseng Improves Current Perception Threshold in Korean Type 2 Diabetes Patients: A Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Many Type 2 diabetes (T2DM) patients in Korea take Korean Red Ginseng (KRG) for various reasons. In this study, we investigated the effects of KRG administration on diabetic peripheral neuropathy in T2DM patients.

METHODS

This study was a randomized, double-blind, placebo-controlled trial. Participants were randomly allocated to either the placebo or KRG group and took corresponding tablets for 24 weeks. The primary outcomes were changes in current perception threshold (CPT) at week 24. Secondary outcomes were altered fasting plasma glucose, HbA1c, and various metabolic and inflammatory markers at week 24.

RESULTS

Sixty-one patients completed the study. The CPT of the lower extremities at various frequencies exhibited significant improvements at week 24 in the KRG group. Other metabolic parameters were not altered after 24 weeks in both groups. In the subgroup analysis, CPT levels were improved in those with a longer diabetes duration or who already had neuropathy at the beginning of the study, and insulin resistance was improved in patients with a shorter diabetes duration.

CONCLUSION

Twenty-four week administration of KRG in T2DM patients resulted in a significant improvement in neuropathy, especially in those with a longer diabetes duration. A further, larger population study with a longer follow-up period is warranted to verify the effects of KRG on diabetic neuropathy.

Simultaneous Pancreas Kidney Transplantation Improves Cardiovascular Autonomic Neuropathy with Improved Valsalva Ratio as the Most Precocious Test

BACKGROUND

Simultaneous pancreas-kidney (SPK) transplantation is a proven option of treatment for patients with type 1 diabetes mellitus (T1DM) and related end-stage renal disease. There is discrepancy between the results of different studies about the impact of prolonged normalization of glucose metabolism achieved by SPK on the course of diabetic complications including severe forms of diabetic neuropathy. The objective of the study was to evaluate the prevalence of cardiovascular autonomic neuropathy (CAN) in patients undergoing SPK transplantation and its evolution 10 years after transplantation.

METHODS

Prospective study of 81 patients transplanted in a single center from year 2002 to 2015. Autonomic function was assessed using cardiovascular autonomic reflex tests (CARTs). CARTs were made before SPK transplantation and during the follow-up. Evolution of tests after SPK transplantation was evaluated by contrasting hypotheses (paired tests). Multiple testing was adjusted with the Benjamini-Hochberg procedure with a false discovery rate of 10%.

RESULTS

48 males and 33 females, mean age 37.4 ± 5.7 years, mean BMI 24.0 ± 3.4 kg/m², and mean duration of diabetes 25.5 ± 6.5 years, received SPK transplantation. Ten years after SPK transplantation, 56 patients re tained the pancreatic graft (42 of them with normofunctioning pancreas and 14 with low doses of insulin therapy). These 42 patients were selected for the autonomic study. Before transplant procedure, all CART results were abnormal. After SPK transplantation, paired test analysis showed an improvement of systolic blood pressure (SBP) response to orthostasis at the 5^th year after SPK (p = 0.03), as well as improvement of the Valsalva ratio at the 3^rd (p < 0.001) and 5^th (p = 0.001) year after SPK. After correcting for the false discovery rate, all the variables of autonomic study reached significance at different time points.

CONCLUSIONS

Prevalence of CAN in patients who are candidates for SPK transplantation is high and is generally advanced. SPK transplantation improves CAN with improved Valsalva ratio as the most precocious test.

Secreted factors from cultured dental pulp stem cells promoted neurite outgrowth of dorsal root ganglion neurons and ameliorated neural functions in streptozotocin-induced diabetic mice

AIMS/INTRODUCTION

Transplantation of stem cells promotes axonal regeneration and angiogenesis in a paracrine manner. In the present study, we examined whether the secreted factors in conditioned medium of stem cells from human exfoliated deciduous teeth (SHED-CM) had beneficial effects on diabetic polyneuropathy in mice.

MATERIALS AND METHODS

Conditioned medium of stem cells from human exfoliated deciduous teeth was collected 48 h after culturing in serum-free Dulbecco's modified Eagle's medium (DMEM), and separated into four fractions according to molecular weight. Dorsal root ganglion neurons from C57BL/6J mice were cultured with SHED-CM or DMEM to evaluate the effect on neurite outgrowth. Streptozotocin-induced diabetic mice were injected with 100 μL of SHED-CM or DMEM into the unilateral hindlimb muscles twice a week over a period of 4 weeks. Peripheral nerve functions were evaluated by the plantar test, and motor and sensory nerve conduction velocities. Intraepidermal nerve fiber densities, capillary number-to-muscle fiber ratio, capillary blood flow and morphometry of sural nerves were also evaluated.

RESULTS

Conditioned medium of stem cells from human exfoliated deciduous teeth significantly promoted neurite outgrowth of dorsal root ganglion neurons compared with DMEM. Among four fractions of SHED-CM, the only fraction of <6 kDa promoted the neurite outgrowth of dorsal root ganglion neurons. In addition, SHED-CM significantly prevented decline in sensory nerve conduction velocities compared with DMEM in diabetic mice. Although SHED-CM did not improve intraepidermal nerve fiber densities or morphometry of sural nerves, SHED-CM ameliorated the capillary number-to-muscle fiber ratio and capillary blood flow.

CONCLUSIONS

These results suggested that SHED-CM might have a therapeutic effect on diabetic polyneuropathy through promoting neurite outgrowth, and the increase in capillaries might contribute to the improvement of neural function.

The Association Between Phosphorylated Neurofilament Heavy Chain (pNF-H) and Small Fiber Neuropathy (SFN) in Patients with Impaired Glucose Tolerance

INTRODUCTION

Small fiber neuropathy (SFN)-the early stage of diabetic peripheral neuropathy (DPN)-progresses gradually and is difficult to diagnose using neurophysiological tests. To facilitate the early diagnosis of SFN, biomarkers for SFN must be identified. The purpose of this study was to investigate the characteristics of SFN in prediabetic patients and the relationship between pNF-H and SFN.

METHODS

44 IGT patients (inpatients and outpatients) were selected at random. 33 healthy subjects served as controls. Data on clinical characteristics and laboratory parameters were collected. Quantitative sensory testing (QST), electromyography (EMG), and Sudoscan were performed, and pNF-H was measured by ELISA.

RESULTS

24 of the 44 patients with impaired glucose tolerance (IGT) were diagnosed with SFN according to the modified Toronto Diabetic Neuropathy Expert Group consensus criteria. The thermal sensory thresholds of the IGT-SFN group were significantly different from those of the CTRL group (p < 0.05), except for the heat pain threshold. The sensory nerve action potential (SNAP) of the sural nerve was 12.39 in the IGT-SFN group, which was significantly lower than those in the other groups. No significant difference in nerve conduction velocity (NCV) was observed among the three groups. The electrochemical skin conductance (ESC) in the IGT-SFN group was 69.78 ± 14.03uS, which was significantly lower than that in the CTRL group. The pNF-H in the IGT-SFN group was 170.6 (140.0, 223.6) pg/ml, which was significantly higher than those in the CTRL and IGT-non-SFN groups (76.55 and 64.7 pg/ml, respectively). Multivariate regression analysis demonstrated that pNF-H and 2h plasma glucose were independently correlated with SFN; the ORs (95% CI) were 1.429 (1.315, 1.924) and 2.375 (1.157, 4.837), respectively.

CONCLUSIONS

Serum pNF-H may be associated with SFN in IGT patients, and serum pNF-H could therefore serve as a sensitive biomarker for the detection of SFN.

The Role of Physical Therapists in Fighting the Type 2 Diabetes Epidemic

BACKGROUND

In 2014, the total prevalence of diabetes was estimated to be 422 million people worldwide. Due to the aging population and continued increase in obesity rates, the prevalence is expected to rise to 592 million by 2035. Diabetes can lead to several complications, including cardiovascular disease, stroke, peripheral arterial disease, nephropathy, neuropathy, retinopathy, lower extremity amputation, and musculoskeletal impairments.

CLINICAL QUESTION

Up to 80% of patients referred for outpatient physical therapy have diabetes or are at risk for diabetes, providing an opportunity for physical therapists to intervene. Therefore, we asked, "What is the role of physical therapists in fighting the diabetes epidemic?"

KEY RESULTS

Physical therapists commonly prescribe physical activity for the treatment of diabetes and other chronic diseases, such as cardiovascular disease and osteoarthritis. Physical therapists may also screen for risk factors for diabetes and diabetes-related complications and modify traditional musculoskeletal exercise prescription accordingly. Physical therapists must advocate for regular physical activity as a key component of the treatment of chronic diseases in all patient interactions.

CLINICAL APPLICATION

This commentary (1) describes the diabetes epidemic and the health impact of diabetes and diabetes-related complications, (2) highlights the physical therapist's role as front-line provider, and (3) provides recommendations for physical therapists in screening for diabetes risk factors and diabetes-related complications and considerations for patient management. We focus on type 2 diabetes. J Orthop Sports Phys Ther 2020;50(1):5-16. Epub 28 Nov 2019. doi:10.2519/jospt.2020.9154.

Function of Adenosine 2A Receptor in High-Fat Diet-Induced Peripheral Neuropathy

Peripheral diabetic neuropathy (DPN) is a complication observed in up to half of all patients with type 2 diabetes. DPN has also been shown to be associated with obesity. High-fat diet (HFD) affects glucose metabolism, and the impaired glucose tolerance can lead to type 2 diabetes. There is evidence to suggest a role of adenosine 2A receptors (A2ARs) and semaphorin 3A (Sema3a) signaling in DPN. The link between the expression of Sema3a and A2AR in DPN was hypothesized, but the underlying mechanisms remain poorly understood. In this study, we investigated the regulation of Sema3a by A2AR in the spinal cord and the functional implications thereof in DPN. We examined the expression of A2ARs and Sema3a, as well as Neuropilin 1 and Plexin A, the coreceptors of Sema3a, in the dorsal horn of the lumbar spinal cord of an animal model with HFD-induced diabetes. Our results demonstrate that HFD dysregulates the A2AR-mediated Sema3a expression, with functional implications for the type 2 diabetes-induced peripheral neuropathy. These observations could stimulate clinical studies to improve our understanding on the subject.