Accelerated atrophy of lower leg and foot muscles--a follow-up study of long-term diabetic polyneuropathy using magnetic resonance imaging (MRI)

Imaging for inflammatory neuropathies

Inflammatory neuropathies comprise a heterogeneous group of conditions united by inflammation-mediated damage to peripheral nerves and their vasa nervorum. Although classification, diagnosis and management are largely based on clinical features, electrodiagnostic and laboratory examinations, imaging studies play an important supporting role. Ultrasound and MRI are the two modalities used for imaging peripheral nerves. The two techniques differ in the clinical context of application, the information provided and the diagnostic performance. This narrative review aims to provide guidance on when and how to use ultrasound or MRI in patients with inflammatory neuropathies, highlighting their respective strengths and pitfalls, and how to combine these imaging modalities to enhance their usefulness in the diagnostic-therapeutic management of these far from rare conditions.

Handgrip strength in patients with type 2 diabetes correlates with diabetic polyneuropathy. A single-center, retrospective observational study in Japanese patients

Nerve conduction studies (NCS) are the standard method for diagnosing diabetic polyneuropathy. Because a clear association between handgrip strength and diabetic neuropathy can serve as a screening tool, the present study evaluated the association between handgrip strength and NCS and diabetes-related complications. A total of 436 patients with type 2 diabetes (T2D) who were admitted to our hospital between April 1, 2018 and March 31, 2023, and evaluated using Baba's diabetic neuropathy classification (BDC) were included. The participants were grouped by sex using the grip strength tertile method to assess correlations with the prevalence of diabetic microvascular complications in the high-handgrip group (HG), middle-handgrip group (MG), and low-handgrip group (LG). The percentage of BDC-0 was 65% in the HG, 54% in the MG, and 36% in the LG. Furthermore, none of the participants in the HG had BDC-3/4, whereas 4% in the MG and 15% in the LG had BDC-3/4. The morbidity progression of diabetic neuropathy was seen in the order of LG, MG, and HG (p < 0.001). Patients with T2D and advanced diabetic neuropathy had decreased handgrip strength. Early evaluation of BDC and other NCS should be considered if decreased handgrip strength is evident.

Association between muscle fatigability and diabetic kidney disease complications in patients with type 2 diabetes

AIMS

Type 2 diabetes mellitus (T2DM) requires the maintenance of high physical activity levels and specific interventions tailored to the characteristics of each patient. We hypothesized that T2DM combined with diabetic kidney disease (DKD) could increase muscle fatigability, becoming a specific contributor to physical inactivity. This study aimed to determine the association between muscle fatigability and DKD complications and investigate the relationship between muscle fatigability and physical activity in patients with T2DM.

METHODS

Overall, 50 patients with T2DM aged 40-65 years and with an estimated glomerular filtration rate of 30 mL/min/1.73 m2 or higher were included. Muscle function was assessed using an isokinetic dynamometer. Muscle fatigability (maximal voluntary concentric contraction [ΔMVCC] velocity, maximal voluntary isometric contraction [ΔMVIC] torque), which indicated the decrease in angular velocity and muscle strength associated with the exercise task, was calculated. The patient characteristics, physical activity (IPAQ-SV), knee extensor strength, and skeletal muscle index were evaluated. Participants were divided into two groups (DKD and non-DKD) according to the presence of DKD, and ΔMVCC velocity and ΔMVIC torque were compared.

RESULTS

ΔMVCC velocity was significantly higher in the DKD group than in the non-DKD group (p < 0.05). Similarly, ΔMVIC torque was significantly higher in the DKD group than in the non-DKD group (p < 0.05). Subgroup analyses showed that ΔMVCC velocity was independently associated with physical activity in the DKD group (odds ratio: 0.93, 95 % confidence interval: 0.88-0.99).

CONCLUSIONS

Muscle fatigability increased with DKD in patients with T2DM and might be related to physical activity.

From Morphology to Therapeutic Strategies: Exploring New Applications of Ultrasound for Diabetic Peripheral Neuropathy Diagnosis and Management

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes that can result in severe lower limb pain and amputation. Early detection and treatment of DPN are vital, but this condition is often missed due to a lack of symptoms and the insensitivity of testing methods. This article reviews various ultrasound imaging modalities in the direct and indirect evaluation of peripheral neuropathy. Moreover, how ultrasound-related therapeutic strategies are playing a role in clinical treatment is discussed. Finally, the application of innovative methodologies in the diagnosis of DPN, including ultrasound attenuation, photoacoustic imaging, and artificial intelligence, is described.

Effectiveness of a web-based foot-ankle exercise program for treating ulcer risk factors in diabetic neuropathy in a randomized controlled trial

The need for strategies to prevent complications from diabetic neuropathy (DPN) is well recognized. However, foot-ankle exercise programs show weak to moderate evidence, and barriers to their implementation persist, including broad and facilitated access to exercise programs, which guarantee for equity. In this paper, we report for the first time the effectiveness of a web-based foot-ankle exercise program aiming to improve DPN-related outcomes, gait biomechanics and functional outcomes. Sixty-two participants with DPN were randomly allocated into the control group (CG; n = 31), which received the usual care, or the intervention group (IG; n = 31), which received the usual care plus a 12-week foot-ankle exercise program using a web-based software (the SOPeD software). The primary outcomes, DPN symptoms and severity, were assessed using the Brazilian version of the Michigan Neuropathy Screening Instrument and the Decision Support System for Classification of Diabetic Polyneuropathy, respectively. Secondary outcomes included tactile sensitivity (monofilaments) and vibration perception (tuning fork), functional outcomes, such as foot pain and function (Foot Health Status Questionnaire), foot muscle strength and plantar pressure during gait (emed plate), and foot-ankle kinematics and kinetics during gait. Outcomes were assessed at baseline, 12 and 24 weeks by an assessor blinded to group allocation. DPN symptoms and severity remained unchanged after the web-based foot-ankle program. However, IG showed improvements compared to CG, with greater functional reach at 12 weeks, better foot function, reduced foot pain and greater plantarflexion degree during push-off at 24 weeks. Regarding plantar loading during gait, the forefoot pressure reduced in the IG at 12 weeks compared to baseline, but at 24 weeks, forefoot load increased in the IG compared to CG. The 12-week web-based foot-ankle exercise program was feasible, acceptable, demonstrating safety with minimal adverse events, such as delayed onset muscle soreness and foot muscle cramping. While DPN-related outcomes were unaffected by the 12-week SOPeD program, modest improvements in foot pain and function, functional reach, and changes in plantar pressure and plantarflexion degree during gait were noted, mostly at 24 weeks.Trial registration: ClinicalTrials.gov, NCT04011267. Registered on 8 July 2019.

Sarcopenia in the foot on magnetic resonance imaging in patients with diabetes mellitus - a systematic review

INTRODUCTION

Sarcopenia is defined by low measures of muscle quantity, quality and reduced physical performance. It is associated with higher levels of frailty. Individuals with diabetes mellitus (DM) undergo sarcopenia at an accelerated rate resulting in structural changes potentially culminating in limb loss.

AIMS

To review the evidence on methods of detecting and measuring sarcopenic changes on magnetic resonance imaging (MRI) in the foot in patients with diabetes.

METHODS

A literature review was conducted in accordance with PRISMA guidelines. We searched Embase and Medline (via Ovid), CINAHL (via Ebsco Host), Web of Science and Scopus as well as the grey literature. The MeSH terms "sarcopenia" AND "diabetes mellitus" AND "magnetic resonance imaging" were employed in the primary search string.

RESULTS

874 studies were identified. 404 articles were excluded in the title and abstract screening. 33 studies were assessed for eligibility after abstract and title screening was completed by two reviewers. 7 studies evaluating sarcopenia in the foot were included in the final review.

CONCLUSION

Sarcopenic changes are evident on MRI of the foot in patients with diabetes and is profound in patients with diabetic neuropathy. The general extent and severity of sarcopenia seems to correlate with clinical scores to assess neuropathy and is implicated in the development of diabetic foot disease.

Improvement in physical function and lipid profile following low-intensity resistance training and a lower limb conditioning program in people with diabetic neuropathy

BACKGROUND

Diabetic peripheral neuropathy (DPN) impairs glucose and fat metabolism and physical functioning. This study examined the effects of low-intensity resistance exercise training (LI-RT) and a lower limb conditioning program (LLCP) on physical function and lipid profile in DPN.

METHODS

Forty-five diabetic women with mild to moderate neuropathy (55.5 ± 3.1 y) were randomly assigned to one of three groups: LI-RT (n = 15), LLCP (n = 15), and control (n = 15). The LI-RT and LLCP groups trained 3 times/week (90 min/session) for 12 weeks. The LI-RT group completed 3 sets of 10 repetitions for ten exercises at 30-repetition maximum; the LLCP group performed 12 lower extremity motions designed for peripheral neuropathy; and the control group followed their routine daily activities. Physical function was assessed using the Timed Up and Go Test (TUG), Five Times Sit-to-Stand (FTSTS) test, and 6-min walking test (6MWT). Blood lipid profile was assessed.

RESULTS

Both the LI-RT and LLCP groups significantly improved in TUG scores compared to the control group (p ≤ 0.05). No significant changes between groups were observed for the FTSTS and 6MWT. The LI-RT and LLCP groups, compared to the control group, showed a significant reduction in low-density lipoprotein (p ≤ 0.05), and triglycerides (p ≤ 0.001). High-density lipoproteins showed non-significant changes.

CONCLUSION

Low intensity training involving resistance exercises or lower limb range of motion enhance physical function and lipid profile in patients with DPN. High intensity exercise could be risky and deter adherence. Hence, these gentler exercise programs offer viable options for enhancing health and fitness in DPN patients.

Causality between sarcopenia and diabetic neuropathy

Background

Past studies have demonstrated that diabetic neuropathy is related to sarcopenia, but the further causal relation is still unclear. We sought to investigate the causal relationship by combining data from cross-sectional and Mendelian randomization (MR) studies.

Methods

The genome-wide association studies data were collected from the UK Biobank and the European Working Group on Sarcopenia to conduct a bi-directional two-sample MR study to explore the causality between diabetic neuropathy and relevant clinical traits of sarcopenia, including appendicular lean mass (ALM), walking speed and low hand grip strength. The inverse-variance weighted and various sensitivity analyses were used to obtain MR estimates. We also enrolled a total of 196 Type 2 diabetes patients from April 2021 to April 2024 and divided them into the Distal peripheral neuropathy (DPN) group (n=51) and non-DPN group (n=145) via vibration perception threshold (VPT) and neuropathy deficit score. Logistic regression and ROC curve analysis were used to investigate the relationship between DPN and relevant sarcopenia clinical features.

Results

According to a forward MR analysis, decreased walking speed (OR: 0.04, 95% confidence interval (CI): 0.01-0.16; P<0.001) and increased ALM (1.25 [1.05-1.50], P=0.012) had a causal effect on developing diabetic neuropathy. According to reverse MR results, developing diabetic neuropathy had a causal effect on decreased walking speed (0.99 [0.99-1.00], P=0.007) and low grip strength (1.05 [1.02-1.08], P<0.001). The cross-sectional study showed that 5-time stand time (P=0.002) and 6-meter walking speed (P=0.009) had an inverse association with DPN. Additionally, we discovered that ASMI (P=0.030) and 5-time stand time (P=0.013) were separate risk factors for DPN.ConclusionThe MR study suggested that diabetic neuropathy may have a causality with relevant clinical traits of sarcopenia, and our cross-sectional study further proved that sarcopenia indexes are predictors of diabetic neuropathy.

Does autoimmune diseases increase the risk of frailty? A Mendelian randomization study

Background

The causality of autoimmune diseases with frailty has not been firmly established. We conducted this Mendelian randomization (MR) study to unveil the causal associations between autoimmune diseases with frailty.

Methods

A MR analyses were performed to explore the relationships between autoimmune disease and frailty, using summary genome-wide association statistics.

Results

Through a comprehensive and meticulous screening process, we incorporated 46, 7, 12, 20, 5, and 53 single nucleotide polymorphisms (SNPs) as instrumental variables (IVs) for hypothyroidism, hyperthyroidism, rheumatoid arthritis (RA), type 1 diabetes (T1D), multiple sclerosis (MS), and overall autoimmune disease, respectively. Our analysis revealed that hypothyroidism (OR = 1.023, 95% CI: 1.008-1.038, p = 0.0015), hyperthyroidism (OR = 1.024, 95% CI: 1.004-1.045, p = 0.0163), RA (OR = 1.031, 95% CI: 1.011-1.052, p = 0.0017), T1D (OR = 1.011, 95% CI: 1.004-1.017, p = 0.0012), and overall autoimmune disease (OR = 1.044, 95% CI: 1.028-1.061, p = 5.32*10^-8) exhibited a positive causal effect on frailty. Conversely, there may be a negative causal association between MS (OR = 0.984, 95% CI: 0.977-0.992, p = 4.87*10^-5) and frailty. Cochran's Q test indicated heterogeneity among IVs derived from hypothyroidism, hyperthyroidism, T1D, and overall autoimmune diseases. The MR-Egger regression analyzes revealed an absence of horizontal pleiotropy in any of the conducted analyses.

Conclusion

This study elucidates that hypothyroidism, hyperthyroidism, RA, T1D, and overall autoimmune disease were linked to an elevated risk of frailty. Conversely, MS appears to be associated with a potential decrease in the risk of frailty.

Diabetic Sarcopenia. A proposed muscle screening protocol in people with diabetes : Expert document

OBJECTIVES

To propose the grounds for "diabetic sarcopenia" as a new comorbidity of diabetes, and to establish a muscle screening algorithm proposal to facilitate its diagnosis and staging in clinical practice.

METHOD

A qualitative expert opinion study was carried out using the nominal technique. A literature search was performed with the terms "screening" or "diagnostic criteria" and "muscle loss" or "sarcopenia" and "diabetes" that was sent to a multidisciplinary group of 7 experts who, in a face-to-face meeting, discussed various aspects of the screening algorithm.

RESULTS

The hallmark of diabetic sarcopenia (DS) is muscle mass atrophy characteristic of people with diabetes mellitus (DM) in contrast to the histological and physiological normality of muscle mass. The target population to be screened was defined as patients with DM with a SARC-F questionnaire > 4, glycosylated haemoglobin (HbA1C) ≥ 8.0%, more than 5 years since onset of DM, taking sulfonylureas, glinides and sodium/glucose cotransporter inhibitors (SGLT2), as well as presence of chronic complications of diabetes or clinical suspicion of sarcopenia. Diagnosis was based on the presence of criteria of low muscle strength (probable sarcopenia) and low muscle mass (confirmed sarcopenia) using methods available in any clinical consultation room, such as dynamometry, the chair stand test, and Body Mass Index (BMI)-adjusted calf circumference. DS was classified into 4 stages: Stage I corresponds to sarcopenic patients with no other diabetes complication, and Stage II corresponds to patients with some type of involvement. Within Stage II are three sublevels (a, b and c). Stage IIa refers to individuals with sarcopenic diabetes and some diabetes-specific impairment, IIb to sarcopenia with functional impairment, and IIc to sarcopenia with diabetes complications and changes in function measured using standard tests Conclusion: Diabetic sarcopenia has a significant impact on function and quality of life in people with type 2 diabetes mellitus (T2DM), and it is important to give it the same attention as all other traditionally described complications of T2DM. This document aims to establish the foundation for protocolising the screening and diagnosis of diabetic sarcopenia in a manner that is simple and accessible for all levels of healthcare.

A novel proprioceptive rehabilitation program: A pilot randomized controlled trail as an approach to address proprioceptive deficits in patients with diabetic polyneuropathy

BACKGROUND

Diabetic polyneuropathy (DPN) is a notable microvascular complication of DM, affecting 16%-66% globally. DPN often leads to proprioceptive deficits in the lower limbs (LL), leading to impaired functional performance. However, evidence supporting proprioceptive rehabilitation programs (PRP) for DPN remains scarce.

AIMS

This pilot study aims to evaluate the effectiveness of a novel 12-week PRP on LL static and dynamic proprioception and shed light on the potential benefits of PRP for DPN population.

METHODS

Randomized Controlled Trail was conducted among 30 DPN patients (age 53.25±7.72 years, BMI 24.01±1.41 and DM duration 9.48±6.45 years), randomly allocated to intervention (n = 15) or control (n = 15) groups. The intervention group received PRP 3 times/week for 12 weeks. The control group received no exercise. Both groups received regular diabetic care. Static and dynamic proprioception of both LL were assessed at baseline, 6 weeks and 12 weeks. Position-reposition test was used to assess ankle joint position sense by obtaining difference between target and reproduced angles. Error in detecting knee angle and speed were obtained by performing Lower Limb Matching and Sense of Movement tests respectively to assess dynamic proprioception.

RESULTS

Two-way ANOVA and paired comparisons revealed, no significant improvement in proprioceptive deficits at 6 weeks (p>0.05), but significant improvement was achieved at 12-weeks (p<0.05) in the intervention group. Mean errors in Pposition re-position(R:p<0.001, L;p<0.001) and Lower limb matching (R:p<0.001, L;p<0.001) tests reduced by 5° and 10° respectively, indicating a70% improvement in the intervention group. Error of detecting speed reduced only on right side by 0.041ms-1 accounting for a 42% improvement. No improvements were observed in the control group.

CONCLUSIONS

Novel 12-week PRP may yield a significant reduction in LL proprioceptive deficits among DPN patients. Future RCTs with larger samples should compare the effectiveness of this PRP compared with conventional rehabilitation programs.

Effects of individually optimized rocker midsoles and self-adjusting insoles on dynamic stability in persons with diabetes mellitus and neuropathy

BACKGROUND

Persons with diabetic peripheral neuropathy (DPN) may face challenges such as balance issues due to reduced somatosensory feedback and an increased risk of developing diabetic foot ulcers (DFUs) due to increased plantar pressure. Pressure reducing footwear is thought to further impair balance. We introduced 3D-printed rocker midsoles and self-adjusting insoles that are able to reduce elevated plantar pressure values and aimed to prevent balance deterioration. However, their effect on the balance during walking (dynamic stability) is not analyzed yet.

RESEARCH QUESTION

Is dynamic stability of persons with DPN impaired compared to healthy individuals and what is the effect of the 3D-printed rocker midsoles and self-adjusting insoles on the dynamic stability in this population?

METHODS

Dynamic stability, specifically the margins of stability (MOS) in the anterior-posterior (AP) and medio-lateral (ML) direction, was measured in ten healthy and nineteen persons with DPN. Independent-samples t-test was applied to analyze the difference in the MOS between groups. One-way repeated measures analyses of variance (ANOVA) was conducted to test the difference between the therapeutic footwear combinations within the DPN group.

RESULTS

There is no significant difference between the healthy and DPN group in MOS-AP. MOS-ML is significantly larger in DPN compared to the healthy participants. Using the self-adjusting insole shows a significantly lower (negative) MOS-AP compared to when using a rocker shoe within the DPN group.

SIGNIFICANCE

This study provides valuable information on whether DPN and our therapeutic footwear have a negative effect on the dynamic stability. DPN does not have a negative effect on dynamic stability in the AP direction. For the ML direction, DPN seems to cause larger MOS-ML by likely using a compensation strategy (e.g., wider steps) while our experimental footwear does not further impair the MOS-ML.

Use of computed tomography to identify muscle quality subgroups, spatial mapping, and preliminary relationships to function in those with diabetic peripheral neuropathy

BACKGROUND

Decreased muscle volume and increased muscle-associated adipose tissue (MAAT, sum of intra and inter-muscular adipose tissue) of the foot intrinsic muscle compartment are associated with deformity, decreased function, and increased risk of ulceration and amputation in those with diabetic peripheral neuropathy (DPN).

RESEARCH QUESTION

What is the muscle quality (normal, abnormal muscle, and adipose volumes) of the DPN foot intrinsic compartment, how does it change over time, and is muscle quality related to gait and foot function?

METHODS

Computed tomography was performed on the intrinsic foot muscle compartment of 45 subjects with DPN (mean age: 67.2 ± 6.4 years) at baseline and 3.6 years. Images were processed to obtain volumes of MAAT, highly abnormal, mildly abnormal, and normal muscle. For each category, annual rates of change were calculated. Paired t-tests compared baseline and follow-up. Foot function during gait was assessed using 3D motion analysis and the Foot and Ankle Ability Measure. Correlations between muscle compartment and foot function during gait were analyzed using Pearson's correlations.

RESULTS

Total muscle volume decreased, driven by a loss of normal muscle and mildly abnormal muscle (p<0.05). MAAT and the adipose-muscle ratio increased. At baseline, 51.5% of the compartment was abnormal muscle or MAAT, increasing to 55.0% at follow-up. Decreased total muscle volume correlated with greater midfoot collapse during gait (r = -0.40, p = 0.02). Greater volumes of highly abnormal muscle correlated with a lower FAAM score (r = -0.33, p = 0.03).

SIGNIFICANCE

Muscle volume loss may progress in parallel with MAAT accumulation, impacting contractile performance in individuals with DPN. Only 48.5% of the DPN intrinsic foot muscle compartment consists of normal muscle and greater abnormal muscle is associated with worse foot function. These changes identify an important target for rehabilitative intervention to slow or prevent muscle deterioration and poor foot outcomes.

Effects of individually optimized rocker midsoles and self-adjusting insoles on plantar pressure in persons with diabetes mellitus and loss of protective sensation

INTRODUCTION

Rocker shoes and insoles reduce peak pressure (PP) in persons with diabetes (DM) and loss of protective sensation (LOPS). However, they are handmade, leading to inconsistent effectiveness. If foot structure changes over time, high PP-locations also change. To address this, individualized algorithm based 3D-printed rockers and self-adjusting pressure-reducing insoles are applied.

METHODS

PP across seven foot regions was analyzed in 21 persons with DM and LOPS. Regions with PP < 200 kPa were considered not at risk (RnoR); regions with PP ≥ 200 kPa at risk (RaR). The aim was to offload RaR, while remaining PP < 200 kPa in RnoR.

RESULTS

Individualized rockers and self-adjusting insoles combined successfully reduce PP < 200 kPa (on average 24 % - 48 %) in all feet with toes, central and lateral forefoot identified as RaR. Same intervention reduces PP in 68 % of the feet with medial forefoot identified as RaR. With the heel as RaR, no intervention reduces PP successfully in all feet.

CONCLUSIONS

Individualized 3D-printed rockers combined with self-adjusting insoles reduce PP (< 200 kPa) in toes, central and lateral forefoot, but not in heels. Alternative insoles with medial arch support, heel cup and compliant midsole materials might enhance success rate across entire foot.

Usefulness and Clinical Impact of Whole-Body MRI in Detecting Autoimmune Neuromuscular Disorders

Autoimmune neuromuscular diseases are a group of heterogenous pathologies secondary to the activation of the immune system that damage the structures of the peripheric nerve, the neuromuscular junction, or the skeleton muscle. The diagnosis of autoimmune neuromuscular disorders comprises a combination of data from clinical, laboratory, electromyography, imaging exam, and biopsy. Particularly, the whole-body MRI examination in the last two decades has been of great use in the assessment of neuromuscular disorders. MRI provides information about the structures involved and the status of activity of the disease. It can also be used as a biomarker, detect the pattern of specific muscle involvement, and is a useful tool for targeting the optimal muscle site for biopsy. In this work, we summarized the most used technical protocol of whole-body MRI and the role of this imaging technique in autoimmune neuromuscular disorders.

Muscle atrophy in diabetic patients with Charcot foot: a case-control study

PURPOSE

To evaluate the distribution and severity of muscle atrophy in diabetic patients with active Charcot foot (CF) compared to diabetic patients without CF. Furthermore, to correlate the muscle atrophy with severity of CF disease.

MATERIAL/METHODS

In this retrospective study, MR images of 35 diabetic patients (21 male, median:62.1 years ± 9.9SD) with active CF were compared with an age- and gender-matched control group of diabetic patients without CF. Two readers evaluated fatty muscle infiltration (Goutallier-classification) in the mid- and hindfoot. Furthermore, muscle trophic (cross-sectional muscle area (CSA)), intramuscular edema (none/mild versus moderate/severe), and the severity of CF disease (Balgrist Score) were assessed.

RESULTS

Interreader correlation for fatty infiltration was substantial to almost perfect (kappa-values:0.73-1.0). Frequency of fatty muscle infiltration was high in both groups (CF:97.1-100%; control:77.1-91.4%), but severe infiltration was significantly more frequent in CF patients (p-values: < 0.001-0.043). Muscle edema was also frequently seen in both groups, but significantly more often in the CF group (p-values: < 0.001-0.003). CSAs of hindfoot muscles were significantly smaller in the CF group. For the flexor digitorum brevis muscle, a cutoff value of 139 mm2 (sensitivity:62.9%; specificity:82.9%) in the hindfoot was found to differentiate between CF disease and the control group. No correlation was seen between fatty muscle infiltration and the Balgrist Score.

CONCLUSION

Muscle atrophy and muscle edema are significantly more severe in diabetic patients with CF disease. Muscle atrophy does not correlate with the severity of active CF disease. A CSA < 139 mm2 of the flexor digitorum brevis muscle in the hindfoot may indicate CF disease.

Spectral parameters of gait differentiate diabetic patients from healthy individuals

BACKGROUND

Diabetes mellitus (DM) is a clinical condition that affects gait performance and control in millions of individuals worldwide. Contrary to basic spatiotemporal parameters, gait-based spectral analysis may provide useful insights into gait neuromotor control. Hence, this study was set to investigate the spectral content of gait at the preferred speed in patients with DM.

METHODS

Total 1117 individuals [658 DM and 649 healthy adults (HA)] performed a 10 m walk while wearing an inertial measurement unit over the fourth lumbar vertebra. Mann-Whitney-U test was used for between-group gait parameters comparisons.

RESULTS

DM group had a slower step time (1.2%, p < 0.05) and gait speed (2.4%, p < 0.05) than HA. Additionally, DM individuals showed reduced dominant frequency (DM:0.24 Hz vs HA:0.25 Hz on average, p < 0.05). Increased antero-posterior and vertical dominant frequency width (DM:1.73 Hz vs HA:1.76 Hz on average, p < 0.05) and medio-lateral relative power spectral density at the dominant frequency (DM:6.19% vs HA:5.96%, p < 0.05).

CONCLUSIONS

It was demonstrated for the first time that the gait spectral content, not only corroborates spatiotemporal characteristics, but also provides further insight into their neuromotor control deficits in diabetic patients. Ultimately, this type of analysis in the diabetic population can help guide the therapeutic interventions to prevent diabetic foot.

Ultra-high performance liquid chromatography coupled to tandem mass spectrometry-based metabolomics study of diabetic distal symmetric polyneuropathy

AIMS/INTRODUCTION

Distal symmetric polyneuropathy (DSPN) is a common complication of type 2 diabetes mellitus, but the underlining mechanisms have not yet been elucidated. The current study was designed to screen the feature metabolites classified as potential biomarkers, and to provide deeper insights into the underlying distinctive metabolic changes during disease progression.

MATERIALS AND METHODS

Plasma metabolite profiles were obtained by the ultra-high liquid chromatography coupled to tandem mass spectrometry method from healthy control participants, patients with type 2 diabetes mellitus and patients with DSPN. Potential biomarkers were selected through comprehensive analysis of statistically significant differences between groups.

RESULTS

Overall, 938 metabolites were identified. Among them, 12 metabolites (dimethylarginine, N6-acetyllysine, N-acetylhistidine, N,N,N-trimethyl-alanylproline betaine, cysteine, 7-methylguanine, N6-carbamoylthreonyladenosine, pseudouridine, 5-methylthioadenosine, N2,N2-dimethylguanosine, aconitate and C-glycosyl tryptophan) were identified as the specific biomarkers. The content of 12 metabolites were significantly higher in the DSPN group compared with the other two groups. Additionally, they showed good performance to discriminate the DSPN state. Correlation analyses showed that the levels of 12 metabolites might be more closely related to the glucose metabolic changes, followed by the levels of lipid metabolism.

CONCLUSIONS

The finding of the 12 signature metabolites might provide a novel perspective for the pathogenesis of DSPN. Future studies are required to test this observation further.

The influence of isometric resisted ankle strength on dynamic foot plantar pressure in diabetes and non-diabetes participants

<b>Introduction</b>: Patients with diabetes are more likely to fall due to increased plantar pressure and decreased strength in the lower extremities.<br /> <b>Objectives:</b> To determine the influence of isometric ankle strength on dynamic foot plantar pressure in diabetes and non-diabetes participants.<br /> <b>Methods: </b>Twenty diabetes patients and twenty non-diabetes participants with age 28-54 years, height 150-182 cm, weight 48-90 kg, and BMI 25-54 kg/m² participated in the study. The diabetes level was determined based on fasting plasma glucose levels. The resisted isometric muscle strength of the foot during dorsiflexion, plantar flexion, inversion, and eversion was measured using an electronic handheld dynamometer. The plantar pressure distribution during dynamic conditions was determined by using a 48.7×44.7 cm pressure platform. The outcome measures between diabetes and non-diabetes groups were statistically compared by student t-test. The correlation coefficient was determined by the Pearson correlation coefficient test. A p-value of less than 0.05 was considered significant.<br /> <b>Result: </b>The significant differences were found between diabetes and non-diabetes participants for the dorsiflexion (p=.048), plantarflexion (p=.031), inversion (p=.011), eversion (p=.024), peak pressure (p=.024), pressure per square inch (p=.012), pressure time integral (p=.014), and peak pressure gradient (p=.009). Significant relationships between resisted isometric ankle joint strength and foot plantar pressure for diabetes patients and non-diabetes participants were found.<br /> <b>Conclusion: </b>The present study’s findings reflect the higher frequency of plantar pressure distribution and higher muscle weakness in diabetes patients than in non-diabetes participants. These findings suggested that pressure data could help us to customize therapy strategies for patients with diabetes and prescribe a proper exercise intervention’s short-and long-term effects on gait biomechanics.

Impact of biomechanics on therapeutic interventions and rehabilitation for major chronic musculoskeletal conditions: A 50-year perspective

The pivotal role of biomechanics in the past 50 years in consolidating the basic knowledge that underpins prevention and rehabilitation measures has made this area a great spotlight for health practitioners. In clinical practice, biomechanics analysis of spatiotemporal, kinematic, kinetic, and electromyographic data in various chronic conditions serves to directly enhance deeper understanding of locomotion and the consequences of musculoskeletal dysfunctions in terms of motion and motor control. It also serves to propose straightforward and tailored interventions. The importance of this approach is supported by myriad biomechanical outcomes in clinical trials and by the development of new interventions clearly grounded on biomechanical principles. Over the past five decades, therapeutic interventions have been transformed from fundamentally passive in essence, such as orthoses and footwear, to emphasizing active prevention, including exercise approaches, such as bottom-up and top-down strengthening programs for runners and people with osteoarthritis. These approaches may be far more effective inreducing pain, dysfunction, and, ideally, incidence if they are based on the biomechanical status of the affected person. In this review, we demonstrate evidence of the impact of biomechanics and motion analysis as a foundation for physical therapy/rehabilitation and preventive strategies for three chronic conditions of high worldwide prevalence: diabetes and peripheral neuropathy, knee osteoarthritis, and running-related injuries. We conclude with a summary of recommendations for future studies needed to address current research gaps.

Mechanisms underlying altered neuromuscular function in people with DPN

Diabetes alters numerous physiological functions and can lead to disastrous consequences in the long term. Neuromuscular function is particularly affected and is impacted early, offering an opportunity to detect the onset of diabetes-related dysfunctions and follow the advancement of the disease. The role of physical training for counteracting the deleterious effects of diabetes is well accepted but at the same time, it appears difficult to reliably assess the effects of exercise on functional capacity in patients with diabetic peripheral neuropathy (DPN). In this paper, we will review the specific characteristics of various neuromuscular dysfunctions associated with diabetes according to the DPN presence or not, and their changes over time. We present several propositions regarding the onset of neuromuscular alterations in people with diabetes compared to people with DPN. It appears that motor unit loss and neuromuscular transmission impairment are among the main mechanisms explaining the considerable degradation of neuromuscular function in the transition from a diabetic to neuropathic state. Rate of force development and contractile properties could start to decrease with the onset of preferential type II fiber atrophy, commonly reported in people with DPN. Finally, M_max amplitude could decrease with neuromuscular fatigue only in people with DPN, reflecting the fatigue-related neuromuscular transmission impairment reported in people with DPN. In this review, we show that the different neuromuscular parameters are altered at different stages of diabetes, according to the presence of DPN or not. The precise evaluation of these parameters might participate in adapting the physical training prescription.

Association Between Physical Activity, Sedentary Behavior and Physical Fitness and Glycated Hemoglobin in Youth with Type 1 Diabetes: A Systematic Review and Meta-analysis

BACKGROUND

Scientific literature suggests poor glycemic control in youth with type 1 diabetes (T1D) and physical inactivity, sedentary behavior and low physical fitness levels, although results are not entirely consistent.

OBJECTIVE

To meta-analyze the association between glycated hemoglobin and physical activity, sedentary behavior, and physical fitness in children and adolescents with T1D.

METHODS

Our meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines (PRISMA). Three databases were searched for studies. All studies meeting the following criteria were included: (1) Population: children and adolescents with a mean age between 3 and 18 years diagnosed with T1D; (2) Exposition: physical activity and/or sedentary behavior and/or cardiorespiratory fitness and/or muscular fitness; (3) Outcome: glycated hemoglobin; (4) Study design: cross-sectional, longitudinal, and case-control studies. Pooled effects were calculated using a random effects inverse-variance model with the Hartung-Knapp-Sidik-Jonkman adjustment.

RESULTS

Thirty-seven studies were included, accounting for a total of 34,863 youths with T1D (51.9% girls). Twenty-nine studies evaluated physical activity, eight sedentary behavior, 14 cardiorespiratory fitness, and two muscular fitness. A negative association between physical activity (r = - 0.09, 95% CI - 0.14 to - 0.04; I² = 63.5%), cardiorespiratory fitness (r = - 0.31, 95% CI - 0.44 to - 0.19; I² = 57.0%) and glycated hemoglobin was found. Also, the association with sedentary behavior was positive (r = 0.20, 95% CI 0.04 to 0.35; I² = 92.6%). All the associations were independent of the glycated hemoglobin levels and diabetes duration.

CONCLUSIONS

Low levels of physical activity and cardiorespiratory fitness and extensive sedentary behavior may explain part of the variance in glycated hemoglobin and part of the risk for poor glycemic control in youth with T1D.

PROSPERO

Registration number: CRD42021254362.

Low rectus femoris mass index is closely associated with diabetic peripheral neuropathy

Aims

To assess the association of rectus femoris mass index (RFMI) with diabetic peripheral neuropathy (DPN) in individuals with type 2 diabetes mellitus (T2DM).

Methods

Totally 948 T2DM cases were enrolled. Nerve conduction parameters, quantitative sensory threshold and rectus femoris cross-sectional area (RFCSA) were obtained, and rectus femoris mass index (RFMI=RFCSA/height²) was derived. The patients were assigned to four groups based on interquartile spacing of RFMI.

Results

Motor/sensory nerve amplitude and conduction velocity (CV) were significantly lower in the low-level RFMI groups (all P<0.05). RFMI was positively associated with mean motor/sensory nerve amplitude and CV (both P<0.05). T2DM duration above 10 years and RFMI below 2.37cm²/m² had significant associations with DPN (both P<0.001). Receiver operating characteristic (ROC) curve analysis demonstrated cutoffs for T2DM duration and RFMI of 7 years and 2.2 cm²/m², respectively (AUC=0.75, 95% CI: 0.72-0.79; sensitivity, 68.4%; specificity, 66.8%).

Conclusion

DPN is significantly associated with reduced RFMI in T2DM patients. Decreased muscle mass seems to be associated with motor/sensory nerve amplitude and CV. RFMI combined with T2DM duration may represent a potent tool for predicting DPN occurrence in T2DM cases.

Clinical trial registration

http://www.chictr.org.cn, identifier ChiCTR2100049150.

Could an Internet-Based Foot-Ankle Therapeutic Exercise Program Modify Clinical Outcomes and Gait Biomechanics in People with Diabetic Neuropathy? A Clinical Proof-of-Concept Study

Previous studies have shown the efficacy of foot-ankle exercises in people with diabetic peripheral neuropathy (DPN), but the quality of evidence is still low. This proof-of-concept study pursues preliminary evidence for potential clinical and gait biomechanical benefits from an internet-based foot-ankle therapeutic exercise program for people with DPN. We randomized 30 individuals with DPN (IWGDF risk category 1 or 2) into either the control group (CG) receiving the usual care or the intervention group (IG) receiving the usual care plus an internet-based foot-ankle exercise program, fully guided by the Sistema de Orientação ao Pé Diabético (SOPeD; translation: Diabetic Foot Guidance System) three times per week for 12 weeks. We assessed face-to-face clinical and biomechanical outcomes at baseline, 12 weeks, and 24 weeks (follow up). Participants had good adherence to the proposed intervention and it led to only mild adverse events. The IG showed improvements in the ankle and first metatarsophalangeal joint motion after 12 and 24 weeks, changed forefoot load absorption during foot rollover during gait after 24 weeks, reduced foot pain after 12 weeks, and improved foot function after 24 weeks. A 12-week internet-based foot-ankle exercise program using the SOPeD software (version 1.0) has the potential to reduce foot pain, improve foot function, and modify some important foot-ankle kinematic outcomes in people with DPN.

Morphological and Mechanical Properties of Lower-Limb Muscles in Type 2 Diabetes: New Potential Imaging Indicators for Monitoring the Progress of DPN

The aim of this study was to explore changes in morphological and mechanical properties of lower-limb skeletal muscles in patients with diabetes with and without diabetic peripheral neuropathy (DPN) and seek to find a potential image indicator for monitoring the progress of DPN in patients with type 2 diabetes mellitus (T2DM). A total of 203 patients with T2DM, with and without DPN, were included in this study. Ultrasonography and ultrasound shear wave imaging (USWI) of the abductor hallux (AbH), tibialis anterior (TA), and peroneal longus (PER) muscles were performed for each subject, and the shear wave velocity (SWV) and cross-sectional area (CSA) of each AbH, TA, and PER were measured. The clinical factors influencing AbH_CSA and AbH_SWV were analyzed, and the risk factors for DPN complications were investigated. AbH_CSA and AbH_SWV in the T2DM group with DPN decreased significantly (P < 0.05), but no significant differences were found in the SWV and CSA of the TA and PER between the two groups. Toronto Clinical Scoring System (CSS) score and glycosylated hemoglobin (HbA1c) were independent predictors of AbH_CSA and AbH_SWV. As AbH_SWV and AbH_CSA decreased, Toronto CSS score and HbA1c increased and incidence of DPN increased significantly. In conclusion, the AbH muscle of T2DM patients with DPN became smaller and softer, while its morphological and mechanical properties were associated with the clinical indicators related to the progression of DPN. Thus, they could be potential imaging indicators for monitoring the progress of DPN in T2DM patients.

Sarcopenia and Chronic Complications of Type 2 Diabetes Mellitus

Sarcopenia, defined as the loss of skeletal muscle mass and strength and/or a decrease in physical performance, is classically related to aging. However, chronic disease, including type 2 diabetes mellitus (T2DM), may accelerate the development of sarcopenia. Previous studies found strong association between T2DM and sarcopenia. Insulin resistance that exists in T2DM is thought to be the key mediator for impaired physical function and mobility which may lead to sarcopenia. T2DM may cause sarcopenia through the mediation of insulin resistance, inflammation, accumulation of advanced glycation end-products, and oxidative stress that may affect muscle mass and strength, protein metabolism, and vascular and mitochondrial dysfunction. On the other hand, loss of muscle in sarcopenia may play a role in the development of T2DM through the decreased production of myokines that play a role in glucose and fat metabolism. This review highlights the findings of existing literature on the relationship between T2DM and sarcopenia which emphasize the pathophysiology, chronic vascular complications, and the course of macrovascular and microvascular complications in T2DM.

Exploratory analysis using machine learning of predictive factors for falls in type 2 diabetes

We aimed to investigate the status of falls and to identify important risk factors for falls in persons with type 2 diabetes (T2D) including the non-elderly. Participants were 316 persons with T2D who were assessed for medical history, laboratory data and physical capabilities during hospitalization and given a questionnaire on falls one year after discharge. Two different statistical models, logistic regression and random forest classifier, were used to identify the important predictors of falls. The response rate to the survey was 72%; of the 226 respondents, there were 129 males and 97 females (median age 62 years). The fall rate during the first year after discharge was 19%. Logistic regression revealed that knee extension strength, fasting C-peptide (F-CPR) level and dorsiflexion strength were independent predictors of falls. The random forest classifier placed grip strength, F-CPR, knee extension strength, dorsiflexion strength and proliferative diabetic retinopathy among the 5 most important variables for falls. Lower extremity muscle weakness, elevated F-CPR levels and reduced grip strength were shown to be important risk factors for falls in T2D. Analysis by random forest can identify new risk factors for falls in addition to logistic regression.

Midfoot and ankle movement coordination during heel rise is disrupted in people with diabetes and peripheral neuropathy

BACKGROUND

A heel rise task can be used to evaluate midfoot and ankle movement dysfunction in people with diabetes mellitus and peripheral neuropathy. Quantifying movement coordination during heel rise is important to better understand potentially detrimental movement strategies in people with foot pathologies; however, coordination and the impact of limited excursion on coordination is not well-understood in people with diabetes.

METHODS

Sixty patients with diabetes mellitus and peripheral neuropathy, and 22 older and 25 younger controls performed single-limb heel rise task. Midfoot (forefoot relative to hindfoot) sagittal and ankle (hindfoot relative to shank) sagittal and frontal kinematics were measured and normalized to time (0 to 100%). Cross-correlation coefficients were calculated across individuals in each group. A graphical illustration was used to interpret the relationship of midfoot and ankle excursion and cross-correlation coefficient during heel rise.

FINDINGS

People with diabetes mellitus and peripheral neuropathy showed significantly lower midfoot and ankle cross-correlation coefficients during heel rise compared to older controls (p = 0.003-0.007). There was no difference in the midfoot and ankle cross-correlation coefficients during heel rise for the older and younger controls (p = 0.059-0.425). The graphic data illustrated a trend of greater excursion of two joints and a higher cross-correlation coefficient. Some individuals with lower excursion showed a high cross-correlation coefficient.

INTERPRETATION

Foot pathologies, but not aging, impairs midfoot and ankle movement coordination during heel rise task. Investigating both movement coordination as well as joint excursion would better inform and characterize the dynamic movements of midfoot and ankle during heel rise task.

Diabetes mellitus is associated with declines in physical function among men with and without HIV

OBJECTIVE

To determine the longitudinal relationships between abnormal glucose metabolism and physical function in persons with HIV (PWH) and without HIV.

DESIGN

Prospective cohort study of men with or at risk for HIV in four United States cities between 2006 and 2018.

METHODS

Men with or at risk for HIV from the Multicenter AIDS Cohort Study (MACS) had semi-annual assessments of glycemic status, grip strength, and gait speed. We used linear mixed models with random intercept to assess associations between glycemic status and physical function. Glycemic status was categorized as normal, impaired fasting glucose (IFG), controlled diabetes mellitus [hemoglobin A1C (HbA1C) <7.5%], or uncontrolled diabetes mellitus (HbA1C ≥ 7.5%).

RESULTS

Of 2240 men, 52% were PWH. Diabetes mellitus was similar among PWH (7.7%) vs. persons without HIV (6.7%, P = 0.36) at baseline. PWH had slower gait speed (1.17 vs. 1.20 m/s, P < 0.01) but similar grip strength (40.1 vs. 39.8 kg, P = 0.76) compared with persons without HIV at baseline. In multivariate models, gait speed decline was greater with controlled diabetes mellitus [-0.018 m/s (-0.032 to -0.005), P = 0.01] and grip strength decline was greater with controlled [-0.560 kg (-1.096 to -0.024), P = 0.04] and uncontrolled diabetes mellitus [-0.937 kg (-1.684 to -0.190), P = 0.01), regardless of HIV serostatus compared with normoglycemic individuals.

DISCUSSION

Abnormal glucose metabolism was associated with declines in gait speed and grip strength regardless of HIV serostatus. These data suggest that improvement in glucose control should be investigated as an intervenable target to prevent progression of physical function limitations among PWH.

Diabetic Bone Disease and Diabetic Myopathy: Manifestations of the Impaired Muscle-Bone Unit in Type 1 Diabetes

Type 1 diabetes is associated with complications affecting muscle and bone, with diabetic bone disease and diabetic myopathy becoming increasingly reported in the past few decades. This review is aimed at succinctly reviewing the literature on the current knowledge regarding these increasingly identified and possibly interconnected complications on the musculoskeletal system. Furthermore, this review summarizes several nonmechanical factors that could be mediating the development and progression of premature musculoskeletal decline in this population and discusses preventative measures to reduce the burden of diabetes on the musculoskeletal system.

Neuromuscular dysfunction and exercise training in people with diabetic peripheral neuropathy: A narrative review

Diabetic peripheral neuropathy (DPN) is a common condition that is associated with neuromuscular dysfunction and peripheral sensory impairment. These deficits predispose patients to sensory and motor system limitations, foot ulcers and a high risk of falls. Exercise training has been proposed as an effective tool to alleviate neural deficits and improve whole-body function. Here we review the effects of DPN on neuromuscular function, the mechanisms underlying this impairment, and the neural and muscular adaptations to exercise training. Muscle dysfunction is an early hallmark of DPN. Deficits in muscle strength, power, mass and a greater fatigability are particularly severe in the lower extremity muscles. Non-enzymatic glycation of motor proteins, impaired excitation-contraction coupling and loss of motor units have been indicated as the main factors underlying muscular dysfunction. Among the exercise-based solutions, aerobic training improves neural structure and function and ameliorates neuropathic signs and symptoms. Resistance training induces marked improvement of muscle performance and may alleviate neuropathic pain. A combination of aerobic and resistance training (i.e., combined training) restores small sensory nerve damage, reduces symptoms, and improves muscle function. The evidence so far suggests that exercise training is highly beneficial and should be included in the standard care for DPN patients.

Midlife and late-life diabetes and sarcopenia in a general older Japanese population: The Hisayama Study

AIMS/INTRODUCTION

To investigate the association between midlife or late-life diabetes and the development of sarcopenia in an older Japanese population.

MATERIALS AND METHODS

A total of 824 Japanese residents aged 65 to 84 years without sarcopenia were followed up from 2012 to 2017. Sarcopenia was determined following the Asian Working Group for Sarcopenia definition. The time of diabetes diagnosis was classified as midlife or late-life diabetes by the age at first diagnosis of diabetes (< 65 or ≥ 65 years) based on annual health checkups data over the past 24 years. The duration of diabetes was categorized into three groups of < 10, 10-15, and > 15 years. The odds ratios of incident sarcopenia according to the diabetic status were estimated using a logistic regression analysis.

RESULTS

During follow-up, 47 subjects developed sarcopenia. The multivariable-adjusted odds ratio for incident sarcopenia was significantly greater in subjects with diabetes at baseline than in those without it (odds ratio 2.51, 95% confidence interval 1.26-5.00). Subjects with midlife diabetes had a significantly greater risk of incident sarcopenia, whereas no significant association between late-life diabetes and incident sarcopenia was observed. With a longer duration of diabetes, the risk of incident sarcopenia increased significantly (P for trend = 0.002).

CONCLUSIONS

The present study suggests that midlife diabetes and a longer duration of diabetes are significant risk factors for incident sarcopenia in the older population. Preventing diabetes in midlife may reduce the risk of the development of sarcopenia in later life.

Sensory-Motor Mechanisms Increasing Falls Risk in Diabetic Peripheral Neuropathy

Diabetic peripheral neuropathy (DPN) is associated with peripheral sensory and motor nerve damage that affects up to half of diabetes patients and is an independent risk factor for falls. Clinical implications of DPN-related falls include injury, psychological distress and physical activity curtailment. This review describes how the sensory and motor deficits associated with DPN underpin biomechanical alterations to the pattern of walking (gait), which contribute to balance impairments underpinning falls. Changes to gait with diabetes occur even before the onset of measurable DPN, but changes become much more marked with DPN. Gait impairments with diabetes and DPN include alterations to walking speed, step length, step width and joint ranges of motion. These alterations also impact the rotational forces around joints known as joint moments, which are reduced as part of a natural strategy to lower the muscular demands of gait to compensate for lower strength capacities due to diabetes and DPN. Muscle weakness and atrophy are most striking in patients with DPN, but also present in non-neuropathic diabetes patients, affecting not only distal muscles of the foot and ankle, but also proximal thigh muscles. Insensate feet with DPN cause a delayed neuromuscular response immediately following foot–ground contact during gait and this is a major factor contributing to increased falls risk. Pronounced balance impairments measured in the gait laboratory are only seen in DPN patients and not non-neuropathic diabetes patients. Self-perception of unsteadiness matches gait laboratory measures and can distinguish between patients with and without DPN. Diabetic foot ulcers and their associated risk factors including insensate feet with DPN and offloading devices further increase falls risk. Falls prevention strategies based on sensory and motor mechanisms should target those most at risk of falls with DPN, with further research needed to optimise interventions.

Differences and Similarities in Neuropathy in Type 1 and 2 Diabetes: A Systematic Review

Background: Diabetic neuropathy is defined as the dysfunction of the peripheral nervous system in diabetic patients. It is considered a microvascular complication of diabetes mellitus. Its presence is associated with increased morbidity and mortality. Although several studies have found alterations at somatic motor, sensory levels and at the level of autonomic nervous system in diabetic patients, there is not a systematic approach regarding the differences in neuropathy between the major variants of diabetes, e.g., type 1 and 2 diabetes at both neurological and molecular level. Data sources: we systematically (Medline, Scopus, and Cochrane databases) evaluated the literature related to the difference of neuropathy in type 1 and 2 diabetes, differences in molecular biomarkers. Study characteristics: seventeen articles were selected based on pre-defined eligibility criteria. Conclusions: both superficial sensitivity (primarily thermal sensitivity to cold) and deep sensitivity (such as vibratory sensitivity), have been reported mainly in type 2 diabetes. Cardiac autonomic neuropathy is one of the diabetic complications with the greatest impact at a clinical level but is nevertheless one of the most underdiagnosed. While for type 1 diabetes patients most neuropathy alterations have been reported for the Valsalva maneuver and for the lying-to-standing test, for type 2 diabetes patients, alterations have been reported for deep-breathing test and the Valsalva test. In addition, there is a greater sympathetic than parasympathetic impairment, as indicated by the screening tests for autonomic cardiac neuropathy. Regarding subclinical inflammation markers, patients with type 2 diabetes showed higher blood levels of inflammatory markers such as high-sensitivity C-reactive protein, proinflammatory cytokines IL-6, IL-18, soluble cell adhesion molecules and E-selectin and ICAM-1, than in type 1 diabetes patients. By contrast, the blood levels of adiponectin, an adipocyte-derived protein with multiple paracrine and endocrine activities (anti-inflammatory, insulin-sensitizing and proangiogenic effects) are higher in type 1 than in type 2 diabetic patients. This review provides new insights into the clinical differences in type 1 and 2 diabetes and provide future directions in this research field.

Painful and non-painful diabetic neuropathy, diagnostic challenges and implications for future management

Peripheral neuropathy is one of the most common complications of both type 1 and type 2 diabetes. Up to half of patients with diabetes develop neuropathy during the course of their disease, which is accompanied by neuropathic pain in 30-40% of cases. Peripheral nerve injury in diabetes can manifest as progressive distal symmetric polyneuropathy, autonomic neuropathy, radiculo-plexopathies, and mononeuropathies. The most common diabetic neuropathy is distal symmetric polyneuropathy, which we will refer to as DN, with its characteristic glove and stocking like presentation of distal sensory or motor function loss. DN or its painful counterpart, painful DN, are associated with increased mortality and morbidity; thus, early recognition and preventive measures are essential. Nevertheless, it is not easy to diagnose DN or painful DN, particularly in patients with early and mild neuropathy, and there is currently no single established diagnostic gold standard. The most common diagnostic approach in research is a hierarchical system, which combines symptoms, signs, and a series of confirmatory tests. The general lack of long-term prospective studies has limited the evaluation of the sensitivity and specificity of new morphometric and neurophysiological techniques. Thus, the best paradigm for screening DN and painful DN both in research and in clinical practice remains uncertain. Herein, we review the diagnostic challenges from both clinical and research perspectives and their implications for managing patients with DN. There is no established DN treatment, apart from improved glycaemic control, which is more effective in type 1 than in type 2 diabetes, and only symptomatic management is available for painful DN. Currently, less than one-third of patients with painful DN derive sufficient pain relief with existing pharmacotherapies. A more precise and distinct sensory profile from patients with DN and painful DN may help identify responsive patients to one treatment versus another. Detailed sensory profiles will lead to tailored treatment for patient subgroups with painful DN by matching to novel or established DN pathomechanisms and also for improved clinical trials stratification. Large randomized clinical trials are needed to identify the interventions, i.e. pharmacological, physical, cognitive, educational, etc., which lead to the best therapeutic outcomes.

New insights into intrinsic foot muscle morphology and composition using ultra-high-field (7-Tesla) magnetic resonance imaging

Background

The intrinsic muscles of the foot are key contributors to foot function and are important to evaluate in lower limb disorders. Magnetic resonance imaging (MRI), provides a non-invasive option to measure muscle morphology and composition, which are primary determinants of muscle function. Ultra-high-field (7-T) magnetic resonance imaging provides sufficient signal to evaluate the morphology of the intrinsic foot muscles, and, when combined with chemical-shift sequences, measures of muscle composition can be obtained. Here we aim to provide a proof-of-concept method for measuring intrinsic foot muscle morphology and composition with high-field MRI.

Methods

One healthy female (age 39 years, mass 65 kg, height 1.73 m) underwent MRI. A T1-weighted VIBE – radio-frequency spoiled 3D steady state GRE – sequence of the whole foot was acquired on a Siemens 7T MAGNETOM scanner, as well as a 3T MAGNETOM Prisma scanner for comparison. A high-resolution fat/water separation image was also acquired using a 3D 2-point DIXON sequence at 7T. Coronal plane images from 3T and 7T scanners were compared. Using 3D Slicer software, regions of interest were manually contoured for each muscle on 7T images. Muscle volumes and percentage of muscle fat infiltration were calculated (muscle fat infiltration % = Fat/(Fat + Water) x100) for each muscle.

Results

Compared to the 3T images, the 7T images provided superior resolution, particularly at the forefoot, to facilitate segmentation of individual muscles. Muscle volumes ranged from 1.5 cm³ and 19.8 cm³, and percentage muscle fat infiltration ranged from 9.2–15.0%.

Conclusions

This proof-of-concept study demonstrates a feasible method of quantifying muscle morphology and composition for individual intrinsic foot muscles using advanced high-field MRI techniques. This method can be used in future studies to better understand intrinsic foot muscle morphology and composition in healthy individuals, as well as those with lower disorders.

Application of High-Resolution Ultrasound on Diagnosing Diabetic Peripheral Neuropathy

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus (DM). The typical manifestation is a length-dependent "glove and sock" sensation. At present, diagnosis is mainly dependent on clinical manifestations. Since the pathogenesis is not clear, there are no effective treatment measures. Management consists mainly of glucose control, peripheral nerve nutrition, and other measures to delay the progress of the disease; early diagnosis is therefore crucial to improving prognosis and quality of life for patients with DPN. Due to the lack of obvious symptoms in 50% of patients and the low sensitivity of neuro-electrophysiology to small fibers, the missed diagnosis rate is high. High-resolution ultrasound (HRU), as a convenient noninvasive tool, has been proven by many studies to have excellent clinical value in diagnosing DPN. With the development of related new technology, HRU shows promise for the screening, diagnosing, and follow-up of DPN, which could serve as a biomarker and provide new diagnostic insights. In this paper, we review the ability of HRU to detect nerve cross-sectional area and blood flow, and echo and other image changes, and in showing the characteristics of peripheral nerve morphological changes in patients with DPN. We also explore the application of two other recent technological developments-shear wave elastography (SWE) and ultrasound scoring systems-in improving the diagnostic efficiency of HRU in peripheral neuropathy.

MRI of Skeletal Muscles in Participants with Type 2 Diabetes with or without Diabetic Polyneuropathy

BackgroundDiabetic polyneuropathy (DPN) is associated with loss of muscle strength. MRI including diffusion-tensor imaging (DTI) may enable detection of muscle abnormalities related to type 2 diabetes mellitus (DM2) and DPN.PurposeTo assess skeletal muscle abnormalities in participants with DM2 with or without DPN by using MRI.Materials and MethodsThis prospective cross-sectional study included participants with DM2 and DPN (DPN positive), participants with DM2 without DPN (DPN negative), and healthy control (HC) participants enrolled between August 2017 and June 2018. Muscle strength at the knee and ankle was determined with isokinetic dynamometry. MRI of the lower extremities included the Dixon sequence, multicomponent T2 mapping, and DTI calculated fat fractions (FFs), T2 relaxation of muscle (T2_water), fractional anisotropy (FA), and diffusivity (mean, axial, and radial). One-way analysis of variance and Tukey honestly significant difference were applied for comparison between groups, and multivariate regression models were used for association between MRI parameters, nerve conduction, strength, and body mass index (BMI).ResultsTwenty participants with DPN (mean age, 65 years ± 9 [standard deviation]; 70% men; mean BMI, 34 kg/m² ± 5), 20 participants without DPN (mean age, 64 years ± 9; 55% men; mean BMI, 30 kg/m² ± 6), and 20 HC participants (mean age, 61 years ± 10; 55% men; mean BMI, 27 kg/m² ± 5) were enrolled in this study. Muscle strength adjusted for age, sex, and BMI was lower in participants with DPN than in DPN-negative and HC participants in the upper and lower leg (plantar flexors [PF], 62% vs 78% vs 89%; P < .001; knee extensors [KE], 73% vs 95% vs 93%; P < .001). FF was higher in leg muscle groups of participants with DPN than in DPN-negative and HC participants (PF, 20% vs 10% vs 8%; P < .001; KE, 13% vs 8% vs 6%; P < .001). T2_water was prolonged in leg muscle groups of participants with DPN when compared with HC participants (PF, 33 msec vs 31 msec; P < .001; KE, 32 msec vs 31 msec; P = .002) and in the lower leg when compared with participants without DPN (PF, 33 msec vs 32 msec; P = .03). In multivariate regression models, strength was associated with FA (b = -0.0004), T2_water (b = -0.03 msec), and FF (b = -0.1%) at thigh level (P < .001). Furthermore, FA (b = -0.007), T2_water (b = -0.53 msec), and FF (b = -4.0%) were associated with nerve conduction at calf level (P < .001).ConclusionMRI of leg muscle groups revealed fat accumulation, differences in water composition, and structural changes in participants with type 2 diabetes mellitus and neuropathy. Abnormalities were most pronounced in the plantar flexors.© RSNA, 2020Online supplemental material is available for this article.See also the editorial by Sneag and Tan in this issue.

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.

Altered accelerator pedal control in a driving simulator in people with diabetic peripheral neuropathy

AIM

To investigate whether the sensory-motor impairment attributable to diabetic peripheral neuropathy would affect control of the accelerator pedal during a driving simulator task.

METHODS

A total of 32 active drivers, 11 with diabetic peripheral neuropathy (mean ± sd age 67±5.0 years), 10 with diabetes but no neuropathy (diabetes group; mean ± sd age 62±10 years), and 11 healthy individuals without diabetes (healthy group; mean ± sd age 60±11 years), undertook a test on a dynamometer to assess ankle plantar flexor muscle strength and ankle joint proprioception function of the right leg, in addition to a driving simulator task. The following variables were measured: maximal ankle plantar flexor muscle strength; speed of strength generation (Nm/s); and ankle joint proprioception (ankle repositioning error, degrees). In the driving simulator task, driving speed (mph), accelerator pedal signal (degrees) and the duration of specific 'loss-of-control events' (s) were measured during two drives (Drive 1, Drive 2).

RESULTS

Participants with diabetic peripheral neuropathy had a lower speed of strength generation (P<0.001), lower maximal ankle plantar flexor muscle strength (P<0.001) and impaired ankle proprioception (P=0.034) compared to healthy participants. The diabetic peripheral neuropathy group drove more slowly compared with the healthy group (Drive 1 P=0.048; Drive 2 P=0.042) and showed marked differences in the use of the accelerator pedal compared to both the diabetes group (P=0.010) and the healthy group (P=0.002). Participants with diabetic peripheral neuropathy had the longest duration of loss-of-control events, but after one drive, this was greatly reduced (P=0.023).

CONCLUSIONS

Muscle function, ankle proprioception and accelerator pedal control are all affected in people with diabetic peripheral neuropathy, adversely influencing driving performance, but potential for improvement with targeted practice remains possible.

Early-Stage Diabetic Neuropathy Reduces Foot Strength and Intrinsic but Not Extrinsic Foot Muscle Size

BACKGROUND

Tracking progression of diabetic peripheral polyneuropathy (DPN) is usually focused on sensory nerves and subjective testing methods. Recent studies have suggested that distal muscle atrophy may precede sensation loss. Methods to objectively measure distal muscle size and strength are needed to help understand how neuropathy affects muscle function.

PURPOSE

To evaluate individual intrinsic and extrinsic foot muscle sizes and functional foot strength in participants with DPN.

METHODS

Thirty individuals participated in this cross-sectional study (15 DPN and 15 matched controls). Sizes of 10 separate muscles of the lower leg and foot were measured using ultrasound imaging. Functional foot strength was also quantified using custom great toe and lateral toe flexion tests along with a doming test. Muscle size and strength metrics were compared between groups using ANOVAs and paired t-tests (α = 0.05). Correlations between strength and relevant muscle sizes were also evaluated.

RESULTS

The sizes of all four intrinsic foot muscles were smaller in individuals with DPN (p ≤ 0.03), while only one (toe extensor) of the six extrinsic muscles was smaller (p ≤ 0.03), while only one (toe extensor) of the six extrinsic muscles was smaller (p ≤ 0.03), while only one (toe extensor) of the six extrinsic muscles was smaller (p ≤ 0.03), while only one (toe extensor) of the six extrinsic muscles was smaller (r ≤ 0.80) with several corresponding intrinsic muscle sizes. The doming strength test did not show any difference between groups and was moderately correlated with one muscle size (r ≤ 0.80) with several corresponding intrinsic muscle sizes. The doming strength test did not show any difference between groups and was moderately correlated with one muscle size (.

CONCLUSION

Diabetic peripheral polyneuropathy affects intrinsic muscles before extrinsics. Ultrasound imaging of individual muscles and functional toe flexion tests can be used clinically to monitor DPN progression and foot function. Participants need to be trained in the doming test before a relationship can be established between this test and DPN foot function. Future studies should include muscle quality measurements to better understand characteristics of affected muscles.

Influence of Diabetic Distal Symmetric Polyneuropathy on the Performance of the Musculoskeletal System of Lower Leg and Foot

Introduction:

Complications on the lower extremities are a major cause of morbidity, disability, emotional and physical suffering in people with diabetes. Diabetic neuropathy (DN) is the most frequent complication of both types of diabetes. Lack of performance of the musculoskeletal system of lower leg and foot can results in high focal plantar pressures with increased ulceration risk in patients with neuropathy.

Aim:

To determine the impact of the severity of distal symmetric polyneuropathy (DSPN) on the foot and ankle muscle strength and the range of motion (ROM) at ankle joint (AJ), subtalar joint (SJ) and first metatarsophalangeal joint (I MTP).

Methods:

A cross-sectional study was conducted among 100 diabetic patients. The level of DSPN was assessed using the Neuropathy Disability Score. Function of ten foot and ankle muscles has been evaluated by manual muscle testing. Muscle strength was scored by semiquantitative grading system used in the Michigan Diabetic Neuropathy Score. ROM at the AJ, SJ and I MTP was measured with goniometer.

Results:

The average patients age was 61.91±10.74 and diabetes duration 12.25±8.60 years. DSPN was present in 45% of patients. The average strength of foot and ankle muscles expressed by muscle score was 11.56±5.08. The average ROM at AJ was 47.85°, at SJ 35.10° and at I MTP 72.70°. Correlations between the severity of the DSPN and muscle function, ROM at AJ, SJ and I MTP were statistically significant. ROM at SJ and I MTP declines significantly with progression of neuropathy but not significant at AJ.

Conclusion:

The severity of DSPN is significantly associated with foot and ankle muscle weakness and ROM at the SJ and the I MTP, but not significantly with the ROM at the AJ.

Lipotoxicity plays a key role in the development of both insulin resistance and muscle atrophy in patients with type 2 diabetes

Insulin resistance and muscle mass loss often coincide in individuals with type 2 diabetes. Most patients with type 2 diabetes are overweight, and it is well established that obesity and derangements in lipid metabolism play an important role in the development of insulin resistance in these individuals. Specifically, increased adipose tissue mass and dysfunctional adipose tissue lead to systemic lipid overflow and to low-grade inflammation via altered secretion of adipokines and cytokines. Furthermore, an increased flux of fatty acids from the adipose tissue may contribute to increased fat storage in the liver and in skeletal muscle, resulting in an altered secretion of hepatokines, mitochondrial dysfunction, and impaired insulin signalling in skeletal muscle. Recent studies suggest that obesity and lipid derangements in adipose tissue can also lead to the development of muscle atrophy, which would make insulin resistance and muscle atrophy two sides of the same coin. Unfortunately, the exact relationship between lipid accumulation, type 2 diabetes, and muscle atrophy remains largely unexplored. The aim of this review is to discuss the relationship between type 2 diabetes and muscle loss and to discuss some of the joint pathways through which lipid accumulation in organs may affect peripheral insulin sensitivity and muscle mass.

Effect of Sensory Impairment on Balance Performance and Lower Limb Muscle Strength in Older Adults With Type 2 Diabetes

Objective

To compare balance performance and lower limb muscle strength between older adults with type 2 diabetes mellitus (DM), with and without sensory impairments and non-DM groups. Influence of a number of sensory impairments, and muscle strength on balance performance were explored.

Methods

Ninety-two older adults with and without type 2 DM, were examined relative to visual function with the Snellen chart, Melbourne Edge test, and Howard-Dolman test, vestibular function with the modified Romberg test, proprioception of the big toe, and diabetic peripheral neuropathy with the Michigan Neuropathy Screening Instrument. Balance performances were evaluated with the Romberg test, Functional Reach Test (FRT), and Timed Up and Go test (TUG). Strength of knee and ankle muscles was measured.

Results

FRT of type 2 DM groups with at least two sensory impairments, was lower than the non-DM group (p<0.05). TUG of all DM groups, was worse than the non-DM group (p<0.01). Lower limb muscle strength of type 2 DM groups with two and three sensory impairments, was weaker than non-DM group (p<0.05). Regression analysis showed that type 2 DM with three sensory impairments, ankle dorsiflexors strength, and age were influential predictors of TUG.

Conclusion

There were significant differences, of muscle strength and balance performance among groups. Poorer balance and reduced lower limb strength were marked in older adults with type 2 DM, even ones without sensory impairment. Muscle weakness seemed to progress, from the distal part of lower limbs. A greater number of sensory impairments, weaker dorsiflexors, and advanced age influenced balance performance.

Comparação entre pico de torque e flexibilidade dos membros inferiores de indivíduos com e sem diabetes mellitus tipo 2

RESUMO O objetivo deste trabalho foi comparar o pico de torque e flexibilidade dos membros inferiores de indivíduos com e sem diabetes mellitus tipo 2 (DM2). O método foi o estudo com grupos expostos e não expostos ao DM2. Foram incluídos indivíduos com diagnóstico médico de DM2, encaminhados para eletroneuromiografia, e não expostos ao DM2. Foram excluídos da pesquisa indivíduos com idade superior a 70 anos ou que, por algum motivo, não conseguiram realizar um ou dois dos testes. A amostra foi não probabilística, composta por 64 indivíduos: 34 (53,1%) expostos ao DM2 e 30 não expostos; 50 (78,1%) eram do sexo feminino, a idade média era de 60,7±7,1 anos, e o membro inferior dominante era o direito em 57 (89,1%) dos indivíduos. Comparando indivíduos com e sem diagnóstico de DM2, observou-se redução do torque de flexão à esquerda, em velocidade angular de 120° (25,94±2,26 vs. 33,79±2,4nm, p=0,027, respectivamente). Relatou-se menor valor do torque de dorsiflexão à direita, em velocidade angular de 60°, dos diabéticos em relação aos não diabéticos (10,95±0,89 vs. 13,95±0,96nm, p=0,033, respectivamente). Ao comparar indivíduos com DM2, com e sem diagnóstico de neuropatia diabética periférica (NDP), notou-se maior déficit de flexão entre os indivíduos neuropatas em comparação com não neuropatas (46,57±9,47 vs. 11,63±13,85nm, p=0,049, respectivamente). Não foram encontradas diferenças estatisticamente significativas ao comparar os grupos de expostos e não expostos ao DM2 e diabéticos neuropatas e não neuropatas.

A Review of the Effect of Lower-Extremity Pathology on Automobile Driving Function

The effect of lower-extremity pathology and surgical intervention on automobile driving function has been a topic of contemporary interest in the medical literature. The objective of this review was to summarize the topic of driving function in the setting of lower-extremity impairment. Included studies involved lower-extremity immobilization devices, elective and traumatic lower-limb surgery, chronic musculoskeletal pathology, and diabetes as it relates to the foot and ankle, focusing on the effect each may have on driving function. We also discuss the basic US state regulations with respect to impaired driving and changes to automobile structure that can be made in the setting of lower-extremity pathology.

Sex-related differences in frailty factors in older persons with type 2 diabetes: a cross-sectional study

BACKGROUND

This cross-sectional study aimed to describe sex-related differences in diabetes-specific factors underlying the development of frailty in older persons with type 2 diabetes.

METHODS

Older persons aged 60-80 years were sequentially enrolled. Frailty and sarcopenia were evaluated using the validated Kihon checklist (KCL) and Asian Working Group for Sarcopenia algorithm, respectively. Physical function and characteristics were measured by trained nurses independently.

RESULTS

This study included 213 participants. The mean age, body mass index (BMI), and glycated hemoglobin (HbA1c) level were 70.4 years, 24.3 kg/m², and 7.4%, respectively. Prevalence of frailty was higher in women. Social and cognitive functions were lower in the prefrailty stage, while physical function was lower in the frailty stage, although there was no decrease in skeletal muscle mass. After adjustment for age, the KCL score was significantly associated with peripheral neuropathy, diet score, and coronary artery disease (CAD); frailty, with CAD and inoccupation; prefrailty, with diet score; and sarcopenia, with living alone in men. Meanwhile, the KCL score was significantly associated with living alone and skeletal muscle percentage; prefrailty, with peripheral neuropathy; and sarcopenia, with diabetes duration, LDL-cholesterol level, diet score, and irregular lifestyle in women.

CONCLUSIONS

Sex differences in the risk factors of frailty should be considered when selecting preventive strategies for older persons with type 2 diabetes, early in the prefrailty stage. In particular, it is important to evaluate social participation and diet therapy in men and skeletal muscle mass and psychosocial function in women.