Nerve conduction study of the association between glycemic variability and diabetes neuropathy

Cross-Sectional Study of the Relationship Between Medial Plantar Nerve Conduction Studies and Severity of Diabetic Neuropathy

Objective

Diabetic peripheral neuropathy (DPN), a complication of diabetes, is detected only in later stages. Medial plantar nerve (MPL) can identify earlier stages of neuropathy. We evaluated the correlation of MPL sensory nerve action potentials (SNAPs) and severity of DPN measured using the Toronto Clinical Neuropathy Score (TCNS).

Methods

In this hospital-based, cross-sectional study, we recruited diabetic subjects referred for suspected DPN. Neuropathy was graded with TCNS. Sural nerve conduction studies were performed using standard techniques. MPL studies were conducted using the modified Ponsford technique. All evaluations were performed on Nihon Kohden (model MEB 9200K). Averaged MPL SNAP was correlated with TCNS using Pearson's correlation coefficient. To estimate a correlation of 0.4 with 80% power (P = 0.05), we needed 46 subjects. Linear regression was conducted to adjust for age, duration, and diabetic control. Receiver operating characteristic (ROC) curve analysis was performed to obtain the cutoff for MPL SNAP values using the Youden index.

Results

Fifty-one subjects with a mean age of 53.5 years (8.7) and mean duration of diabetes of 10.2 years (7.2) were included. MPL SNAPs were recordable in 12 patients, and the mean amplitude was 5.15 (2.9) µV. There was correlation between MPL SNAP and TCNS (r = -0.43, P = 0.02). No confounding was seen. Use of MPL SNAP resulted in diagnosis of DPN in an additional six (11.8%) patients. The ROC curve suggested that MPL SNAP cutoff of 1.05 µV had an accuracy of 67% in identifying neuropathy as defined by TCNS.

Conclusions

MPL SNAP has a moderate correlation with clinical score and identifies more diabetic neuropathy than sural nerve.

Glycemic variability leads to higher levels of auto-oxidized oxysterol species in patients with type 1 diabetes mellitus

PURPOSE

Hyperglycemia and glycemic variability (GV) are associated with oxidative stress in patients with diabetes mellitus (DM). Oxysterol species, produced by the non-enzymatic oxidation of cholesterol, are potential biomarkers of oxidative stress. This study examined the relationship between auto-oxidized oxysterols and GV in patients with type 1 DM.

METHODS

Thirty patients with type 1 DM using a continuous subcutaneous insulin infusion pump therapy and a healthy control group (n = 30) were included in this prospective study. A Continuous Glucose Monitoring System device was applied for 72 h. Blood samples were taken for oxysterols produced by non-enzymatic oxidation [7-ketocholesterol (7-KC) and cholestane-3β, 5α, 6β-triol (Chol-Triol)] levels at 72 h. Short-term glycemic variability parameters, mean amplitude of glycemic excursions (MAGE), the standard deviation of glucose measurements (Glucose-SD), and mean of daily differences (MODD) were calculated with continuous glucose monitoring data. HbA1c was used to evaluate glycemic control and HbA1c-SD (the SD of HbA1c over the past year) for long-term glycemic variability.

RESULTS

7-KC and Chol-triol levels were significantly higher in the study group than in the control group. Strong positive correlations were found between 7-KC with MAGE(24-48 h) and Glucose-SD(24-48 h). 7-KC was positively correlated with MAGE(0-72 h) and Glucose-SD(0-72 h). No significant correlation was found between HbA1c and HbA1c -SD with oxysterol levels. The regression models showed that SD(24-48 h) and MAGE(24-48 h) predicted 7-KC levels while HbA1c did not.

CONCLUSIONS

Glycemic variability leads to higher levels of auto-oxidized oxysterol species in patients with type 1 DM independent of long-term glycemic control.

Clinical and Translational Imaging and Sensing of Diabetic Microangiopathy: A Narrative Review

Microvascular changes in diabetes affect the function of several critical organs, such as the kidneys, heart, brain, eye, and skin, among others. The possibility of detecting such changes early enough in order to take appropriate actions renders the development of appropriate tools and techniques an imperative need. To this end, several sensing and imaging techniques have been developed or employed in the assessment of microangiopathy in patients with diabetes. Herein, we present such techniques; we provide insights into their principles of operation while discussing the characteristics that make them appropriate for such use. Finally, apart from already established techniques, we present novel ones with great translational potential, such as optoacoustic technologies, which are expected to enter clinical practice in the foreseeable future.

Glycemic profile variability: An independent risk factor for diabetic neuropathy in patients with type 2 diabetes

BACKGROUND

Impaired glycemic control is a potential predictor for macro- and microvascular complications of diabetes, which could be recognized by glycemic variability. The aim of this 10-year prospective cohort study presented here is to gain a better understanding of the correlation between GV and diabetic peripheral neuropathy (DPN) as one of the most common complications of T2DM.

METHODS

Since February 2010, 1152 adult patients with T2DM have been followed-up. Baseline features, anthropometric measurements, and laboratory findings were collected and documented during ten years. The association between DPN incidence and glycemic profile variability was evaluated using cox regression analysis. The coefficient of variation of glycemic indices within subjects was calculated and compared using an independent sample t-test.

RESULTS

Individuals who developed neuropathy had significantly higher mean levels of glycemic indices (HbA1c, FBS, and 2hpp), urinary albumin excretion, mean creatinine levels, and a longer duration of diabetes. A significant positive correlation between incidence of DPN and glycemic profile variability (cv-FBS10 %, cv-FBS20 %, cv-2hpp20 %, cv-HbA1c5 % and cv-HbA1c10 %) was revealed. Results also showed that higher variability of FBS was associated with the higher risk of neuropathy incidence (HR: 12.29, p-value: 0.045), which indicates that glycemic profile variability is an independent risk factor for DPN in patients with T2DM.

CONCLUSION

Variability of glycemic profiles from a visit to visit, regardless of sustained hyperglycemia, was indeed a significant risk factor for DPN in diabetic type 2 patients. CV-FBS was the most critical glycemic variability indices for DPN development.

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.

Nerve conduction velocity is independently associated with bone mineral density in type 2 diabetes mellitus

AIM

This study investigated the association between nerve conduction velocity (NCV) and bone mineral density (BMD) in patients with type 2 diabetes mellitus (T2DM).

METHODS

This study retrospectively collected medical data of T2DM patients who underwent dual-energy X-ray absorptiometry and nerve conduction study at the Shanghai Ruijin Hospital, Shanghai, China. The primary outcome was the total hip BMD T-score. The main independent variables were motor nerve conduction velocities (MCVs), sensory nerve conduction velocities (SCVs), and composite Z-scores of MCV and SCV. T2DM patients were divided into total hip BMD T-scores < -1 and total hip BMD T-scores ≥ -1 groups. The association between the primary outcome and main independent variables was evaluated by Pearson bivariate correlation and multivariate linear regression.

RESULTS

195 female and 415 male patients with T2DM were identified. In male patients with T2DM, bilateral ulnar, median, and tibial MCVs and bilateral sural SCVs were lower in the total hip BMD T-score < -1 group than T-score ≥ -1 group (P < 0.05). Bilateral ulnar, median, and tibial MCVs, and bilateral sural SCVs showed positive correlations with total hip BMD T-score in male patients with T2DM (P < 0.05). Bilateral ulnar and tibial MCVs, bilateral sural SCVs, and composite MCV SCV and MSCV Z-scores were independently and positively associated with total hip BMD T-score in male patients with T2DM, respectively (P < 0.05). NCV did not show significant correlation with the total hip BMD T-score in female patients with T2DM.

CONCLUSION

NCV showed positive association with total hip BMD in male patients with T2DM. A decline in NCV indicates an elevated risk of low BMD (osteopenia/osteoporosis) in male patients with T2DM.

Entrapment partly participates in the longitudinal progression of neuropathy with anti-MAG antibodies

Neuropathy with anti-myelin-associated glycoprotein (MAG) antibodies commonly demonstrates distal-dominant prolongation of nerve conduction. However, recent electrophysiological studies have shown that distal motor demyelination is not always a distinct feature. We aimed to elucidate whether the longitudinal progression of nerve impairment occurs in a distal-dominant manner. Seven patients with neuropathy with anti-MAG antibodies were enrolled. Sequential nerve conduction studies revealed nerve conduction reduction only at the wrist segment in the median nerve of the patients, but not in the ulnar nerve. Median nerve entrapment at the wrist may play a role in longitudinal disease progression in neuropathy with anti-MAG antibodies.

Short-term Glycemic Variability and Its Association With Macrovascular and Microvascular Complications in Patients With Diabetes

The introduction of continuous glucose monitoring inaugurated a new era in clinical practice by shifting the characterization of glycemic control from HbA1c to novel metrics. The one that gained widespread attention over the past decades was glycemic variability (GV), which typically refers to peaks and nadirs of blood glucose measured over a given time interval. GV can be dichotomized into two main categories: short-term and long-term. Short-term GV reflects within-day and between-day glycemic oscillations, and its contribution to diabetic complications remains an enigma. In this review, we summarize the available data about short-term GV and its possible association with both microvascular and macrovascular complications, evaluating different pathogenic mechanisms and demonstrating nonpharmaceutical, as well as pharmaceutical, therapeutic interventions.

A Cross-Sectional Study of Electrophysiological Changes Occurring in Type II Diabetes Mellitus

Background

Diabetes is a long-term metabolic condition that results in high blood sugar levels from either reduced insulin production or diminished tissue sensitivity to insulin. Peripheral neuropathy is the most frequent consequence of diabetes. In this research project, with the aid of neurophysiological measures, we conducted a cross-sectional study to examine the impact of glycemic management on the physiological functioning of nerves, regardless of the duration of diabetes.

Objectives

The main objective of the study was to investigate the association between the degree of glycemic control and the severity of neurological changes. The study also aimed to clarify whether glycemic management, independent of the duration of diabetes, acts as an independent risk factor for the emergence of diabetic neuropathy.

Methodology

A total of 150 type 2 diabetic patients visiting the diabetic outpatient department were included in the study. The patients were divided into two groups: group A consisted of 90 subjects with HbA1c levels <10 and group B comprised 60 subjects with HbA1c levels >10. In the neurophysiology lab, an electrodiagnostic exam was conducted on the sensory (sural nerve) and motor (tibial nerve) parameters. Data on the neurophysiological parameters of the two groups were analyzed and compared.

Results

When the neurophysiological parameters of the two groups (group A having HbA1c <10 and group B having HbA1c >10) were analyzed, it was observed that group B had lower conduction velocity (CV) and amplitude potential than group A, with a significant statistical difference (p<0.05). It was also observed that sensory parameters were more affected than motor parameters.

Conclusion

Based on our findings, glycemic control is related to the severity of neuropathic changes.

Subclinical Neuropathy in Children With Type I Diabetes Mellitus: Tertiary Care Centre Experience

Introduction: Diabetic peripheral neuropathy is a common complication of diabetes mellitus (DM) type 1. However, it can occur without evidence of symptoms or clinical signs of neuropathy labeled as subclinical neuropathy, which neurophysiological studies can best detect.

Purpose: To evaluate the prevalence of subclinical neuropathy among children with DM type 1, determine the association with blood sugar control, and evaluate the pattern of nerve involvement in neurophysiological studies.

Methods: This cross-sectional study evaluated 100 children with DM type 1, aged five to 15 years, at least one year after the diagnosis. Subclinical neuropathy was evaluated using nerve conduction study. Glycemic control was assessed using hemoglobin A1c (HbA1c).

Results: The mean age of subjects was 11.5 ± 0.25 years. The average age at the onset of the disease was 5.95 ± 0.25 years. There were 64 patients who had electrophysiological evidence of peripheral neuropathy. The most observed electrophysiological changes were distal latency abnormalities in the left and right peroneal nerves in 39 and 33 patients, respectively. Sensory nerve amplitude, peak latency, and conduction velocity were normal in all patients (100%). HbA1c level did not show a statistically significant association with the incidence of subclinical neuropathy.

Conclusion: Subclinical neuropathy was prevalent in children with DM type 1. Poor glucose control was only associated with an increased odds ratio of subclinical neuropathy.

Glycemic Variability Assessment with a 14-Day Continuous Glucose Monitoring System: When and How Long to Measure MAGE (Mean Amplitude of Glucose Excursion) for Optimal Reliability?

Mean amplitude of glucose excursion (MAGE) is considered as the "gold standard" for assessing the short-term within-day glycemic variability (GV), which is an important component of overall glycemic control. A 14-day continuous glucose monitoring system is now widely used and allows easier assessment of GV. However, it is still unknown whether MAGE, usually calculated on a 48-hour period is identical whatever the time during the 14-day lifespan of the sensor and whether a longer time period might give additional information. We evaluated in 68 patients with type 1 diabetes, MAGE during three 2-day periods (day1-day3; day6-day8; day11-day13) and during periods of 3 days and 4 days. MAGE calculated at the three 2-day periods were identical and not different from MAGE of the 3-day or 4-day periods.

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.

Glucose variability as the risk factor of preeclampsia in pregnant patients with type 1 diabetes mellitus

OBJECTIVE

To analyze glucose variability and investigate its role as a predictor for preeclampsia development in pregnant women with type 1 diabetes mellitus (T1DM) with various insulin therapy regimens.

METHODS

A total of 200 pregnant women with T1DM were included in the study. A hundred women used continuous subcutaneous insulin infusion (CSII), and the rest of the group was administered with multiple daily insulin injections (MDI). Continuous glucose monitoring (CGM), index calculation of glucose variability (MAGE, MODD, CONGA, and CV), assessment of preeclampsia frequency and severity were conducted.

RESULTS

The work results show the link between the severity rate of preeclampsia and the duration of T1DM as well as the level of HbA1c before and during pregnancy. The rate of preeclampsia in the group of women, using CSII comprises 26.8% of cases that appear less than in the group of those, administered with MDI that is 46.6% (χ² = 5.45; р < .05). A negative correlation is defined between pathological glucose variability and gestational age when preeclampsia occurs. A negative correlation was also revealed between MODD, CV, and the time for the detection of preeclampsia: r = -0.30, r = -0.24, respectively. The study illustrates the correlation obtained between preeclampsia and glucose variability and the value of MAGE, MODD, CV, and SD. Preeclampsia development is affected by the duration of hyperglycemic conditions in the third trimester of pregnancy. The data in the group of women using MDI marks the early development of preeclampsia on the 33.0 [32-34] week of pregnancy compared to the group of women practicing CSII on 35.5 [33-36] week of pregnancy (Z = 5.4; p < .001). The increase of risk of preeclampsia development is proved in pregnant patients with T1DM when the hyperglycemic condition lasts more than 25% of a 24-h period according to the rate of CGM and measurements of glucose variability MODD > 1.07 and CONGA > 3.39.

CONCLUSION

Comprehensive evaluation of the glycemic profile while using CGM revealed a correlation between pathological glucose variability and the frequency and severity of preeclampsia thus proving the benefits of CSII in pregnant patients with T1DM to perform glycemic targets and decrease glucose variability, which eventually led to the decrease of preeclampsia frequency in this group of women.

Longitudinal effects of one-leg standing time on neuropathy outcomes in association with glycemic control in non-elderly patients with type 2 diabetes

Aims/Introduction

Diabetic neuropathy leads to postural instability. This study compared longitudinal changes in neuropathy outcomes relative to long‐term glycemic control in patients aged <60 years with uncontrolled type 2 diabetes with and without a short one‐leg standing time (OLST <60 s).

Materials and Methods

In this retrospective study, 58 hospitalized patients with type 2 diabetes (glycated hemoglobin [HbA1c] >7.0%; aged 17–59 years), who underwent re‐evaluation of neuropathic sensory symptoms, ankle reflexes and nerve conduction attributes, and cardiac autonomic function (R‐R interval), >1 year after discharge were divided into OLST <60 and ≥60 s groups. Patients were followed up every 2–3 months for HbA1c levels for up to 8 years. Neuropathy outcomes relative to OLST and HbA1c levels at baseline and over follow up were compared.

Results

Additional development of sensory symptoms (one patient) and abnormal ankle reflexes (five patients) were identified during follow up, and decreased peripheral and cardiac autonomic function at both baseline and follow up, only in patients with OLST <60 s. Mean HbA1c levels were significantly higher in patients with OLST <60 s versus ≥60 s (7.8 ± 0.9% vs 7.2 ± 1.2%; P = 0.022). Better glycemic control during follow up was associated with better neuropathy outcomes only in patients with OLST ≥60 s.

Conclusion

Non‐elderly type 2 diabetes patients with OLST <60 s and decreased peripheral nerve function at baseline are at increased risk for intractable diabetic neuropathy. Better glycemic control alone might not improve neuropathy outcomes in these patients.

Association of glycemic variability and hypoglycemia with distal symmetrical polyneuropathy in adults with type 1 diabetes

Previous studies exploring the influence of glycemic variability (GV) on the pathogenesis of distal symmetrical polyneuropathy (DSPN) in type 1 diabetes (T1DM) produced conflicting results. The aim of this study was to assess the relationship between GV and DSPN in T1DM. Adults with T1DM were included in this cross-sectional study and asked to undergo 3-day CGM. GV quantified by coefficient of variation (CV) and mean amplitude of glucose excursions (MAGE) were obtained from CGM. Clinical characteristics and biochemical assessments were collected for analysis. The study comprised 152 T1DM patients (53.9% males) with mean age of 44.2 year. Higher levels of age and duration of diabetes and lower levels of total cholesterol, LDL, fasting C-peptide and postprandial C-peptide were observed in DSPN subjects. DSPN groups displayed a higher blood glucose between 00:00 and 12:59 according to the CGM profile. Higher MAGE and CV were associated with increased risk of DSPN in the fully adjusted model. Meanwhile, a significant association between measurements of hypoglycemia, especially nocturnal hypoglycemia, and DSPN was found after multiple tests. CGM parameters describing the glycemic variability and hypoglycemia were potential risk factors for DSPN in adults with T1DM.

Bilirubin is inversely related to diabetic peripheral neuropathy assessed by sural nerve conduction study

AIMS/INTRODUCTION

Diagnosis of diabetic peripheral neuropathy (DPN) depends on subjective findings, certain investigations for DPN risks have not been performed enough. Bilirubin protects against vascular complications by reducing oxidative stress in diabetes, but is not fully tested for DPN. This study aimed to evaluate sural nerve conduction impairments (SNCI) as an objective DPN marker and the contribution of bilirubin to SNCI.

MATERIALS AND METHODS

Using DPN-Check® , SNCI was defined as a decline of amplitude potential or conduction velocity below the normal limit in 150 inpatients with diabetes. The correlations between SNCI and conventional DPN diagnosis criteria, the incidence of diabetic retinopathy/nephropathy, biomarkers for atherosclerosis, cardiac function by ultrasonic cardiogram, and bilirubin were statistically tested, followed by the comparison of logistic regression models for SNCI to find confounders with bilirubin.

RESULTS

The incidence of SNCI was 72.0%. The sensitivity and specificity of SNCI for DPN prediagnosis by simplified criteria were 54.6 and 90.5%, respectively, and similarly corresponded with diabetic retinopathy and nephropathy (sensitivity 57.4 and 50.0%, respectively). SNCI significantly related to diabetes duration, declined estimated glomerular filtration rate, albuminuria and total bilirubin. SNCI incidence was attenuated in the higher bilirubin tertiles (89.8/65.3/54.8%, P < 0.001). Bilirubin was an independent inverse risk factor for SNCI, even after adjustment by known risk factors for DPN and markers for microvascular complications.

CONCLUSIONS

SNCI is a comprehensive marker for diabetic complications. We first showed the independent inverse relationship between bilirubin and SNCI through the independent pathway with other complications, provably reducing oxidative stress, as previously reported.

Association of platelet count and plateletcrit with nerve conduction function and peripheral neuropathy in patients with type 2 diabetes mellitus

AIMS/INTRODUCTION

Diabetes has been considered as a 'pro-thrombotic state' with enhanced platelet reactivity. Abnormality in platelet aggregation has been found in patients with its most common chronic complication - diabetic peripheral neuropathy (DPN). The purpose of this study was to investigate the potential association of platelet indices with nerve conduction function and the presence of DPN in Chinese patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

This study involved a total of 211 inpatients with type 2 diabetes mellitus and 55 healthy individuals for whom nerve conduction studies were carried out. DPN was diagnosed according to the American Diabetes Association recommendation. Clinical data were retrospectively collected.

RESULTS

Patients with diabetes in whom neuropathy developed had lower levels of platelet count (PLT) and plateletcrit (PCT) than healthy controls (P < 0.05). Statistically significant associations of low PLT and PCT levels with the reduction of summed amplitude/velocity Z-score, and the prolongation of F-wave minimum latency in nerve conduction studies were found. Furthermore, after multivariate adjustment, logistic regression analysis showed that low levels of PLT (odds ratio 2.268, 95% confidence interval 1.072-4.797; P < 0.05; PLT <226 vs PLT ≥226) and PCT (odds ratio 2.050, 95% confidence interval 1.001-4.201; P < 0.05; PCT <0.222 vs PCT ≥0.222) in type 2 diabetes mellitus patients were risk factors for the presence of DPN.

CONCLUSIONS

Lower PLT and PCT levels are closely associated with poorer peripheral nerve conduction functions and the presence of neuropathy in patients with type 2 diabetes mellitus, which suggests that PLT and PCT might be potential biomarkers for showing DPN.

Long-term complications of type 1 diabetes: what do we know and what do we need to understand?

Long-term complications of type 1 diabetes (T1D) include microvascular complications and macrovascular disease. Despite the important advances in the treatment of T1D of the last decades, these complications still represent the leading cause of morbidity and mortality in patients with T1D. Extensive evidence indicates that structural and functional alterations of the kidney, retina, nerves and large arteries occur already in the first years after the onset of diabetes. We performed a comprehensive review of the available evidence on screening, diagnosis, prevention and treatment of vascular complications of T1D. In particular, we focused on three major challenges related to long-term complications of T1D: 1) finding of new biomarkers and diagnostic methods able to identify early signs of complications; 2) identifying specific risk factors for the development of these complications; 3) identifying and implementing new therapeutic strategies able to prevent the development and progression of vascular complications.

Inhibitory properties of saponin from Eleocharis dulcis peel against α-glucosidase

The inhibitory properties towards α-glucosidase in vitro and elevation of postprandial glycemia in mice by the saponin constituent from Eleocharis dulcis peel were evaluated for the first time. Three saponins were isolated by silica gel and HPLC, identified as stigmasterol glucoside, campesterol glucoside and daucosterol by NMR spectroscopy. Daucosterol presented the highest content and showed the strongest α-glucosidase inhibitory activity with competitive inhibition. Static fluorescence quenching of α-glucosidase was caused by the formation of the daucosterol–α-glucosidase complex, which was mainly derived from hydrogen bonds and van der Waals forces. Daucosterol formed 7 hydrogen bonds with 4 residues of the active site and produced hydrophobic interactions with 3 residues located at the exterior part of the binding pocket. The maltose-loading test results showed that daucosterol inhibited elevation of postprandial glycemia in ddY mice. This suggests that daucosterol from Eleocharis dulcis peel can potentially be used as a food supplement for anti-hyperglycemia.

Daucosterol from Eleocharis dulcis peel exhibits potent inhibitory activity against α-glucosidase.

Diabetic neuropathy in children and youth: New and emerging risk factors

Pediatric neuropathy attributed to metabolic dysfunction is a well-known complication in children and youth with type 1 diabetes. Moreover, the rise of obesity and in particular of type 2 diabetes may cause an uptick in pediatric neuropathy incidence. However, despite the anticipated increase in neuropathy incidence, pathogenic insights and strategies to prevent or manage neuropathy in the setting of diabetes and obesity in children and youth remain unknown. Data from adult studies and available youth cohort studies are providing an initial understanding of potential diagnostic, management, and preventative measures in early life. This review discusses the current state of knowledge emanating from these efforts, with particular emphasis on the prevalence, clinical presentation, diagnostic approaches and considerations, and risk factors of neuropathy in type 1 and type 2 diabetes in children and youth. Also highlighted are current management strategies and recommendations for neuropathy in children and youth with diabetes. This knowledge, along with continued and sustained emphasis on identifying and eliminating modifiable risk factors, completing randomized controlled trials to assess effectiveness of strategies like weight loss and exercise, and enhancing awareness to support early detection and prevention, are pertinent to addressing the rising incidence of neuropathy associated with diabetes and obesity in children and youth.

Glycemic variability and cardiovascular disease in patients with type 2 diabetes

Glycated hemoglobin is currently the gold standard for assessment of long-term glycemic control and response to medical treatment in patients with diabetes. Glycated hemoglobin, however, does not address fluctuations in blood glucose. Glycemic variability (GV) refers to fluctuations in blood glucose levels. Recent clinical data indicate that GV is associated with increased risk of hypoglycemia, microvascular and macrovascular complications, and mortality in patients with diabetes, independently of glycated hemoglobin level. The use of continuous glucose monitoring devices has markedly improved the assessment of GV in clinical practice and facilitated the assessment of GV as well as hypoglycemia and hyperglycemia events in patients with diabetes. We review current concepts on the definition and assessment of GV and its association with cardiovascular complications in patients with type 2 diabetes.

Comprehensive elaboration of glycemic variability in diabetic macrovascular and microvascular complications

Diabetes mellitus is the major risk factor for the development of macrovascular and microvascular complications. It is increasingly recognized that glycemic variability (GV), referring to oscillations in blood glucose levels and representing either short-term or long-term GV, is involved in the pathogenesis of diabetic complications and has emerged as a possible independent risk factor for them. In this review, we summarize the metrics and measurement of GV in clinical practice, as well as comprehensively elaborate the role and related mechanisms of GV in diabetic macrovascular and microvascular complications, aiming to provide the mechanism-based therapeutic strategies for clinicians to manage diabetes mellitus.

CGMS and Glycemic Variability, Relevance in Clinical Research to Evaluate Interventions in T2D, a Literature Review

Glycemic variability (GV) appears today as an integral component of glucose homeostasis for the management of type 2 diabetes (T2D). This review aims at investigating the use and relevance of GV parameters in interventional and observational studies for glucose control management in T2D. It will first focus on the relationships between GV parameters measured by continuous glucose monitoring system (CGMS) and glycemic control and T2D-associated complications markers. The second part will be dedicated to the analysis of GV parameters from CGMS as outcomes in interventional studies (pharmacological, nutritional, physical activity) aimed at improving glycemic control in patients with T2D. From 243 articles first identified, 63 articles were included (27 for the first part and 38 for the second part). For both analyses, the majority of the identified studies were pharmacological. Lifestyle studies (including nutritional and physical activity-based studies, N-AP) were poorly represented. Concerning the relationships of GV parameters with those for glycemic control and T2D related-complications, the standard deviation (SD), the coefficient of variation (CV), the mean blood glucose (MBG), and the mean amplitude of the glycemic excursions (MAGEs) were the most studied, showing strong relationships, in particular with HbA1c. Regarding the use and relevance of GV as an outcome in interventional studies, in pharmacological ones, SD, MAGE, MBG, and time in range (TIR) were the GV parameters used as main criteria in most studies, showing significant improvement after intervention, in parallel or not with glycemic control parameters' (HbA1c, FBG, and PPBG) improvement. In N-AP studies, the same results were observed for SD, MAGE, and TIR. Despite the small number of N-AP studies addressing both GV and glycemic control parameters compared to pharmacological ones, N-AP studies have shown promising results on GV parameters and would require more in-depth work. Evaluating CGMS-GV parameters as outcomes in interventional studies may provide a more integrative dimension of glucose control than the standard postprandial follow-up. GV appears to be a key component of T2D dysglycemia, and some parameters such as MAGE, SD, or TIR could be used routinely in addition to classical markers of glycemic control such as HbA1c, fasting, or postprandial glycemia.

Predictors of sudomotor dysfunction in patients with type 1 diabetes without clinical evidence of peripheral neuropathy

AIM

To investigate the frequency of foot sudomotor dysfunction determined by the electrochemical skin conductance test (ESC) and its independent predictors in individuals with type 1 diabetes mellitus (T1D) and no clinical evidence of diabetic peripheral neuropathy (DPN).

METHODS

Adults with T1D for longer than 5 years and without DPN defined by the Michigan Neuropathy Screening Instrument and Neuropathy Disability Score were assessed for foot sudomotor dysfunction by ESC. Multivariate logistic regression analysis was used to examine the association between foot sudomotor dysfunction (ESC < 70 µS) and demographic, clinical, and biochemical variables.

RESULTS

A total of 61 individuals with T1D were included. Their mean age was 29.5 ± 8.6 years, and mean diabetes duration was 17.8 ± 7.9 years. Foot sudomotor dysfunction was present in 16 (26.2%) participants, despite no clinical evidence of DPN. Retinopathy, hand sudomotor dysfunction and glycated haemoglobin (HbA1c) levels were identified as independent predictors of foot sudomotor dysfunction by multivariate logistic regression analysis. Retinopathy, hand sudomotor dysfunction, and every 1% increase of HbA1c increased the odds of foot sudomotor dysfunction by 2.48, 2.82, and 1.24-fold, respectively.

CONCLUSION

Our findings indicate a high frequency of foot sudomotor dysfunction among individuals with T1D and no overt DPN. Factors associated with DPN, including retinopathy and higher HbA1c levels, independently predicted the occurrence of sudomotor dysfunction, suggesting that ESC assessment is a useful tool in the clinical setting to identify early small-fiber neuropathy.

Associations between acute glucose control and peripheral nerve structure and function in type 1 diabetes

AIM

To examine the associations between continuous overlapping net glycaemic action (CONGA), percentage time in hyperglycaemia (%HG) or normoglycaemia (%NG) and peripheral nerve structure and function in type 1 diabetes.

METHODS

Twenty-seven participants with type 1 diabetes underwent continuous glucose monitoring followed by corneal confocal microscopy and nerve excitability assessments. CONGA, %HG (> 10.0 mmol/l) and %NG (3.9-10.0 mmol/l) were correlated against corneal nerve fibre length and density in the central cornea and inferior whorl region, corneal microneuromas, and a nerve excitability score while controlling for age, sex, diabetes duration and HbA_1c .

RESULTS

An increase in CONGA [median 2.5 (2.0-3.1) mmol/l] or %HG (mean 46 ± 18%) was associated with a worse nerve excitability score (r = -0.433, P = 0.036 and r = -0.670, P = 0.0012, respectively). By contrast, greater %NG (51 ± 17%) correlated with better nerve excitability scores (r = 0.672, P = 0.0011). Logistic regression revealed that increasing %HG increased the likelihood of abnormal nerve function [odds ratio (OR) 1.11, 95% confidence interval (CI) 1.01-1.23; P = 0.037). An increase in CONGA and %HG were associated with worsening nerve conduction measures, whereas longer %NG correlated with improved nerve conduction variables. CONGA and %HG were associated with inferior whorl corneal nerve fibre length (r = 0.483, P = 0.034 and r = 0.591, P = 0.021, respectively) and number of microneuromas (r = 0.433, P = 0.047 and r = 0.516, P = 0.020, respectively).

CONCLUSIONS

Short-term measures of glucose control are associated with impaired nerve function and alterations in corneal nerve morphology.

Peripheral, synaptic and central neuronal transmission is affected in type 1 diabetes

AIMS

We hypothesized that adults with type 1 diabetes and severe polyneuropathy have alterations in neuronal transmission at different anatomical levels. The aims were to investigate upstream sensory neuronal activation in terms of peripheral, spinal, precortical, and cortical transmission.

METHODS

48 participants with type-1 diabetes and polyneuropathy, and 21 age-matched healthy participants were included. Electrophysiological median nerve recordings were used to analyze peripheral transmission at Erb's point (P9-N11); spinal evoked potentials at Cv7 (P11-N14); subcortical evoked potentials at Oz (N14-P18); early cortical evoked potentials at CP5 (N20-P22); late cortical evoked potentials at C1 (N60-P80) and estimated cortical inter-peak latencies as measures of central conduction time.

RESULTS

In comparison to healthy, the presence of diabetes prolonged peripheral transmission at P9 and N11 (+0.49 ms, p = .000; +0.47 ms, p = .04, respectively), early cortical evoked potentials at CP5: N20 (+2.41 ms, p = .003) and P22 (+5.88 ms, p = .001) and cortical potentials at C1: N60 (+39.08 ms, p = .001) and P80 (+54.55 ms, p = .000) and central conduction time. Decreased amplitudes were shown peripherally (-2.13 μV, p = .000), spinally (-0.57 μV, p = .005) and pre-cortically (-0.22 μV, p = .004). In both healthy and people with diabetes increased central conduction time were associated with decreased parasympathetic tone (ρ = -0.52, p = .027; ρ = -0.35, p = .047, respectively).

CONCLUSION

Neuronal afferent transmission and brain responses were significantly impaired in diabetes and the presence of prolonged central conduction time is indicative of severe extensive neuronal damage. Trial registry number: EUDRA CT: 2013-004375-12; clinicaltrials.gov: NCT02138045.

Glycemic variability: adverse clinical outcomes and how to improve it?

Glycemic variability (GV), defined as an integral component of glucose homoeostasis, is emerging as an important metric to consider when assessing glycemic control in clinical practice. Although it remains yet no consensus, accumulating evidence has suggested that GV, representing either short-term (with-day and between-day variability) or long-term GV, was associated with an increased risk of diabetic macrovascular and microvascular complications, hypoglycemia, mortality rates and other adverse clinical outcomes. In this review, we summarize the adverse clinical outcomes of GV and discuss the beneficial measures, including continuous glucose monitoring, drugs, dietary interventions and exercise training, to improve it, aiming at better addressing the challenging aspect of blood glucose management.

The Contemporary Prevalence of Diabetic Neuropathy in Type 1 Diabetes: Findings From the T1D Exchange

OBJECTIVE

To evaluate the contemporary prevalence of diabetic peripheral neuropathy (DPN) in participants with type 1 diabetes in the T1D Exchange Clinic Registry throughout the U.S.

RESEARCH DESIGN AND METHODS

DPN was assessed with the Michigan Neuropathy Screening Instrument Questionnaire (MNSIQ) in adults with ≥5 years of type 1 diabetes duration. A score of ≥4 defined DPN. Associations of demographic, clinical, and laboratory factors with DPN were assessed.

RESULTS

Among 5,936 T1D Exchange participants (mean ± SD age 39 ± 18 years, median type 1 diabetes duration 18 years [interquartile range 11, 31], 55% female, 88% non-Hispanic white, mean glycated hemoglobin [HbA1c] 8.1 ± 1.6% [65.3 ± 17.5 mmol/mol]), DPN prevalence was 11%. Compared with those without DPN, DPN participants were older, had higher HbA1c, had longer duration of diabetes, were more likely to be female, and were less likely to have a college education and private insurance (all P < 0.001). DPN participants also were more likely to have cardiovascular disease (CVD) (P < 0.001), worse CVD risk factors of smoking (P = 0.008), hypertriglyceridemia (P = 0.002), higher BMI (P = 0.009), retinopathy (P = 0.004), reduced estimated glomerular filtration rate (P = 0.02), and Charcot neuroarthropathy (P = 0.002). There were no differences in insulin pump or continuous glucose monitor use, although DPN participants were more likely to have had severe hypoglycemia (P = 0.04) and/or diabetic ketoacidosis (P < 0.001) in the past 3 months.

CONCLUSIONS

The prevalence of DPN in this national cohort with type 1 diabetes is lower than in prior published reports but is reflective of current clinical care practices. These data also highlight that nonglycemic risk factors, such as CVD risk factors, severe hypoglycemia, diabetic ketoacidosis, and lower socioeconomic status, may also play a role in DPN development.

Glycemic Variability and Diabetic Neuropathy in Young Adults With Type 1 Diabetes

Background: Glycemic variability (GV) may attribute to the pathogenesis of diabetic neuropathy. The aim of this cross-sectional study was to investigate the association between GV and distal symmetric polyneuropathy (DSPN) and cardiovascular autonomic neuropathy (CAN) in a Danish population of young adults with type 1 diabetes. Methods: Young adults between 18 and 24 years with type 1 diabetes were included in this cross-sectional study. CAN was assessed by cardiovascular autonomic reflex tests (CARTs) and heart rate variability (HRV). DSPN was assessed by light pressure, pain and vibration perception, electrochemical skin conductance, sural nerve conduction velocity (SNCV), and amplitude potential (SNAP). GV were obtained by continuous glucose monitoring including coefficient of variation (CV), SD, continuous overall net glycemic action (CONGA), and mean amplitude of glucose excursions (MAGE). Results: The study comprised 133 young adults (43.6% males), mean age of 22 years (SD 1.6). Unadjusted, higher CV was associated with a decreased risk of sural nerve conduction (P = 0.03), abnormal SNAP (P = 0.04) and incidents of definite CAN (P = 0.04). Likewise, higher CONGA was associated with increasing incidents of subclinical DSPN (P = 0.03), abnormal SNAP (P = 0.01), and SNCV (P = 0.02). However, both associations were not statistically significant in the fully adjusted model. Higher MAGE was associated with slightly increasing measures of HRV (P = 0.03) but only when fully adjusted. When correcting for multiple tests significance was lost. A significant association was found between HbA1c and measures of both DSPN (P < 0.02) and HRV (P < 0.03) in fully adjusted models. Conclusions: No significant associations between GV and diabetic neuropathy were found after adjusting for risk factors and multiple tests. This suggests that GV may not be a risk factor for diabetic neuropathy in young adults with type 1 diabetes. However, long-term effects of GV excursions may still play a role in the pathogenic mechanisms leading to neuropathy in later life.