Motor dysfunction in diabetes

Plantar pressure and shear stress during gait in people with diabetic neuropathy

Aims

Diabetic foot ulcers are a leading cause of lower extremity amputations, significantly affecting the quality of life. Excessive plantar surface pressure and shear stress are key factors in ulcer development and aggravation. This study aimed to determine the association of these forces with the progression of diabetic peripheral neuropathy to help in foot-ulcer treatment and prevention.

Methods

Participants were categorized into four groups: individuals with no diabetes (NS), people with diabetes without peripheral neuropathy or foot-ulcer history (DM), those with diabetes with peripheral neuropathy but no foot-ulcer history (DPN), and people with diabetes with active or past foot ulcers (DFU). Plantar pressure and shear stress were measured during walking.

Results

The study included 47 participants. The DFU group demonstrated significantly higher pressure peak value and plantar pressure time integral value at the fifth metatarsal head compared to the DPN and DM groups. The DPN group exhibited significantly higher shear-stress time integral and shear stress time compared to the NS group.

Conclusions

In the DPN group, an increase in shear stress was observed. In the DFU group, an increase in plantar pressure and a tendency for an increase in shear stress were noted. Further research is needed to understand how these changes trigger the onset of foot ulcers.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13340-024-00789-4.

Comprehensive review on diabetic foot ulcers and neuropathy: Treatment, prevention and management

Diabetic foot (DF) is a major public health concern. As evident from numerous previous studies, supervision of DF ulcer (DFU) is crucial, and a specific quality check-up is needed. Patients should be educated about glycaemic management, DFUs, foot lesions, proper care for injuries, diet, and surgery. Certain reasonably priced treatments, such as hyperbaric oxygen and vacuum-assisted closure therapy, are also available for DFUs, along with modern wound care products and techniques. Nonetheless, DF care (cleaning, applying antimicrobial cream when wounded, and foot reflexology), blood glucose monitoring to control diabetes, and monthly or quarterly examinations in individuals with diabetes are effective in managing DFUs. Between 50% and 80% of DF infections are preventable. Regardless of the intensity of the lesion, it needs to be treated carefully and checked daily during infection. Tissue regeneration can be aided by cleaning, dressing, and application of topical medicines. The choice of shoes is also important because it affects blood circulation and nerve impulses. In general, regular check-ups, monitoring of the patient's condition, measuring blood glucose levels, and providing frequent guidance regarding DFU care are crucial. Finally, this important clinical problem requires involvement of multiple professionals to properly manage it.

Physiological mechanisms of neuromuscular impairment in diabetes-related complications: Can physical exercise help prevent it?

Diabetes mellitus is a chronic disorder that progressively induces complications, compromising daily independence. Among these, diabetic neuropathy is particularly prevalent and contributes to substantial neuromuscular impairments in both types 1 and 2 diabetes. This condition leads to structural damage affecting both the central and peripheral nervous systems, resulting in a significant decline in sensorimotor functions. Alongside neuropathy, diabetic myopathy also contributes to muscle impairment and reduced motor performance, intensifying the neuromuscular decline. Diabetic neuropathy typically implicates neurogenic muscle atrophy, motoneuron loss and clustering of muscle fibres as a result of aberrant denervation-reinervation processes. These complications are associated with compromised neuromuscular junctions, where alterations occur in pre-synaptic vesicles, mitochondrial content and post-synaptic signalling. Neural damage is intensified by chronic hyperglycaemia and oxidative stress, exacerbating vascular dysfunction and reducing oxygen delivery. These complications imply a severe decline in neuromuscular performance, evidenced by reductions in maximal force and power output, rate of force development and muscle endurance. Furthermore, diabetes-related complications are compounded by age-related degenerative changes in long-term patients. Aerobic and resistance training offer promising approaches for managing blood glucose levels and neuromuscular function. Aerobic exercise promotes mitochondrial biogenesis and angiogenesis, supporting metabolic and cardiovascular health. Resistance training primarily enhances neural plasticity, muscle strength and hypertrophy, which are crucial factors for mitigating sarcopenia and preserving functional independence. This topical review examines current evidence on the physiological mechanisms underlying diabetic neuropathy and the potential impact of physical activity in counteracting this decline.

Investigation of the protective effects of dichloroacetic acid in a rat model of diabetic neuropathy

BACKGROUND

Diabetic neuropathy (DN) is a heterogeneous condition characterized by complex pathophysiological changes affecting both autonomic and somatic components of the nervous system. Inflammation and oxidative stress are recognized contributors to the pathogenesis of DN. This study aims to evaluate the therapeutic potential of dichloroacetic acid (DCA) in alleviating DN symptoms, focusing on its anti-inflammatory and antioxidant properties.

METHODS

Thirty-two adult male Sprague Dawley rats were divided into four groups: Control, Diabetic, and two DCA-treated groups receiving 5 mg/kg and 10 mg/kg of DCA, respectively. Diabetes was induced with streptozotocin (STZ) injections. Assessments included lipid peroxidation levels, plasma fibroblast growth factor-21 (FGF-21) and transforming growth factor-beta (TGF-β) levels, electrophysiological measurements, histological examination of the sciatic nerve, and motor function tests.

RESULTS

Treatment with DCA significantly reduced malondialdehyde (MDA) levels, indicating decreased lipid peroxidation. Plasma TGF-β levels were also lower in the DCA-treated groups, suggesting diminished inflammation. Conversely, plasma FGF-21 levels were elevated. Electrophysiological assessments revealed enhanced compound muscle action potential (CMAP) amplitudes and reduced distal latencies in DCA-treated rats, indicative of improved nerve conduction. Histopathological examinations showed reduced perineural thickness in the sciatic nerves of DCA-treated rats, pointing to decreased fibrosis. Enhanced performance in motor function tests was observed in these rats, implying improved muscle strength and motor capacity.

CONCLUSIONS

The study demonstrates that DCA therapy significantly reduces oxidative stress and inflammation in a rat model of DN, thereby ameliorating neuropathic symptoms. These results support the potential of DCA as a promising therapeutic agent for DN treatment. Further research is warranted to explore its clinical applications and to provide more detailed insights.

Diabetic Deformities of the Lesser Toes

The United States Centers for Disease Control and the National Institute of Diabetic, Digestive and Kidney Disorders now estimates that there are now over 34.2 million patients with diabetes in the United Sates, or over 10.2% of our population. Diabetic foot pathology leads to over 150,000 lower extremity amputations yearly in the United States alone. Many of these infections are initiated from externally applied shearing forces applied to deformities of the lesser toes.

Diabetic Foot and Fungal Infections: Etiology and Management from a Dermatologic Perspective

Diabetes Mellitus (DM) is a significant global concern. Many diabetic patients will experience complications due to angiopathy, neuropathy, and immune dysfunction, namely diabetic foot ulcers (DFU) and diabetic foot infections (DFI), which can result in lower limb amputation and potentially death. The prevalence of common superficial fungal infections, such as tinea pedis and onychomycosis, can directly increase a diabetic patient's risk of developing both DFU and DFI. In this review article, we discuss the etiology of diabetic foot complications as well as considerations for both screening and management. We also discuss the role of the dermatologist within a multidisciplinary care team in prescribing and managing treatments for tinea pedis and onychomycosis infections within this patient population. We believe that reducing the burden of these fungal infections in the context of the diabetic foot will help reduce DFU and DFI complications and their associated morbidity and mortality.

Early detection of altered cold perception in elderly with type 2 diabetes using a novel Quantitative Sensory Testing method

AIM

To compare the effectiveness of two methods for measuring cold detection thresholds in screening for temperature-perception deficits in elderly individuals with type 2 diabetes (T2 diabetes).

METHODS

Cold threshold measurements were performed on seven body regions of participants with diabetes without neuropathy (n = 30; mean age, 70.9 ± 6.5 years) and healthy participants (n = 73; mean age, 68 ± 5 years). Two protocols applying the Levels Method were used: the first used skin temperature as the starting point; the second used 40 °C.

RESULTS

Cold detection thresholds were significantly higher in subjects with diabetes, particularly on the foot. For CDT TSk, values were -2.22 ± 1.91 °C in non-diabetic and -3.27 ± 3.33 °C in diabetic groups (p = 0.023); for CDT 40, values were -9.82 ± 3.5 °C and -12.18 ± 4.5 °C (p = 0.003). However, after adjusting for age, the group effect on cold threshold with skin temperature as baseline disappeared. Sensory screens showed that the Area Under Curve of the method using a 40 °C baseline was 0.69 (p = 0.002).

CONCLUSION

Measuring the cold detection threshold on the foot with a 40 °C baseline is more effective than using skin temperature as a baseline for screening sensory alterations in elderly subjects with type 2 diabetes before neuropathy onset.

SIGNIFICANCE

These findings highlight the importance of selecting the appropriate cold detection threshold method for elderly individuals with type 2 diabetes. The optimal method can facilitate early identification of sensory changes, minimizing complications and improving overall well-being.

Cilostazol Ameliorates Motor Dysfunction and Schwann Cell Impairment in Streptozotocin-Induced Diabetic Rats

This study investigated the effects of cilostazol on motor dysfunction, spinal motor neuron abnormalities, and schwannopathy in rats with diabetes. Diabetes mellitus (DM) was induced in rats via femoral intravenous streptozotocin (STZ) injection (60 mg/kg). After successful DM induction, cilostazol was administered on day 15 via oral gavage (100 mg/kg/day) for 6 weeks until sacrifice. Behavioral assays, including motor function, were performed weekly. The sciatic nerve, L5 spinal cord, and spinal ventral root were collected to evaluate the expression of the glial fibrillary acidic protein (GFAP), myelin protein zero (P0), and choline acetyltransferase (ChAT) by immunofluorescence and Western blotting. DM rats displayed decreased running speeds, running distances, and toe spread but increased foot pressure. In addition, loss of non-myelinating Schwann cells and myelin sheaths was observed in the sciatic nerve and L5 spinal ventral root. Reduced numbers of motor neurons were also found in the L5 spinal ventral horn. Cilostazol administration significantly potentiated running speed and distance; increased hind paw toe spread; and decreased foot pressure. In the sciatic nerve and L5 spinal ventral root, cilostazol treatment significantly improved non-myelinated Schwann cells and increased myelin mass. ChAT expression in motor neurons in the spinal ventral horn was improved, but not significantly. Cilostazol administration may protect sensorimotor function in diabetic rats.

Examination time-distance characteristics of gait and pelvic kinematics in individuals with Diabetic polyneuropathy: a case-control study

BACKGROUND

Diabetic Peripheral Neuropathy (DPN) disrupts body and movement biomechanics, increases mechanical stress during walking, and predisposes individuals to injuries owing to the repetitive effects of these stresses.

AIMS

This study aimed to assess and compare the impact of neuropathy on gait and pelvic kinematics in individuals with DPN.

METHODS

This case-control study included two groups: 23 individuals diagnosed with DPN aged between 35-70 and 23 healthy individuals aged-35-70. The BTS-G, a wireless motion sensor, was used to assess the time-distance characteristics of walking in all participants. The system analyzed data pertaining to walking speed, cadence, percentages of stance and swing phases, durations of walking cycles, double-step lengths, pelvic tilt, obliquity, and rotation symmetries.

RESULTS

There were no statistically significant differences between the groups in cadence, left and right stance phase percentages, or left and right swing phase percentages (p > 0.05). However, significant differences were observed between the groups in terms of speed, left and right walking cycle durations, and left and right double-step lengths (p < 0.05). Additionally, no statistically significant difference was found between the groups in pelvic tilt symmetry and left and right pelvic tilt range of motion values (p > 0.05). Nevertheless, significant differences were identified between the groups in pelvic obliquity symmetry, pelvic rotation symmetry, left and right pelvic obliquity range of motion, and left and right pelvic rotation range of motion values (p < 0.05).

CONCLUSIONS

The findings of this study suggest that individuals with DPN exhibit decreased walking speed, prolonged gait cycle duration, increased double step length, and reduced pelvic obliquity and rotation range of motion.

Correlation of diabetic renal hypoperfusion with microvascular responses of the skeletal muscle: a rat model study using diffuse correlation spectroscopy

Using diffuse correlation spectroscopy, we assessed the renal blood flow and thigh muscle microvascular responses in a rat model of type 2 diabetes. The blood flow index at the renal surface decreased significantly with arterial clamping, cardiac extirpation, and the progression of diabetic endothelial dysfunction. Renal blood flow measured in diabetic and nondiabetic rats also showed a significant correlation with the reactive hyperemic response of the thigh muscle. These results suggest shared microcirculatory dysfunction in the kidney and skeletal muscle and support endothelial responses in the skeletal muscle as a potential noninvasive biomarker of renal hypoperfusion.

Surgical management of the diabetic foot: The current evidence

The prevalence of diabetes mellitus and its associated complications, particularly diabetic foot pathologies, poses significant healthcare challenges and economic burdens globally. This review synthesises current evidence on the surgical management of the diabetic foot, focusing on the interplay between neuropathy, ischemia, and infection that commonly culminates in ulcers, infections, and, in severe cases, amputations. The escalating incidence of diabetes mellitus underscores the urgency for effective management strategies, as diabetic foot complications are a leading cause of hospital admissions among diabetic patients, significantly impacting morbidity and mortality rates. This review explores the pathophysiological mechanisms underlying diabetic foot complications and further examines diabetic foot ulcers, infections, and skeletal pathologies such as Charcot arthropathy, emphasising the critical role of early diagnosis, comprehensive management strategies, and interdisciplinary care in mitigating adverse outcomes. In addressing surgical interventions, this review evaluates conservative surgeries, amputations, and reconstructive procedures, highlighting the importance of tailored approaches based on individual patient profiles and the specific characteristics of foot pathologies. The integration of advanced diagnostic tools, novel surgical techniques, and postoperative care, including offloading and infection control, are discussed in the context of optimising healing and preserving limb function.

Current advancement in the preclinical models used for the assessment of diabetic neuropathy

Diabetic neuropathy is one of the prevalent and debilitating microvascular complications of diabetes mellitus, affecting a significant portion of the global population. Relational preclinical animal models are essential to understand its pathophysiology and develop effective treatments. This abstract provides an overview of current knowledge and advancements in such models. Various animal models have been developed to mimic the multifaceted aspects of human diabetic neuropathy, including both type 1 and type 2 diabetes. These models involve rodents (rats and mice) and larger animals like rabbits and dogs. Induction of diabetic neuropathy in these models is achieved through chemical, genetic, or dietary interventions, such as diabetogenic agents, genetic modifications, or high-fat diets. Preclinical animal models have greatly contributed to studying the intricate molecular and cellular mechanisms underlying diabetic neuropathy. They have shed light on hyperglycemia-induced oxidative stress, neuroinflammation, mitochondrial dysfunction, and altered neurotrophic factor signaling. Additionally, these models have allowed for the investigation of morphological changes, functional alterations, and behavioral manifestations associated with diabetic neuropathy. These models have also been crucial for evaluating the efficacy and safety of potential therapeutic interventions. Novel pharmacological agents, gene therapies, stem cell-based approaches, exercise, dietary modifications, and neurostimulation techniques have been tested using these models. However, limitations and challenges remain, including physiological differences between humans and animals, complex neuropathy phenotypes, and the need for translational validation. In conclusion, preclinical animal models have played a vital role in advancing our understanding and management of diabetic neuropathy. They have enhanced our knowledge of disease mechanisms, facilitated the development of novel treatments, and provided a platform for translational research. Ongoing efforts to refine and validate these models are crucial for future treatment developments for this debilitating condition.

Association Between Physical Activity and Physical Function in a Marshallese Population with Type 2 Diabetes

Physical activity can delay functional decline in people with type 2 diabetes (T2D), but these associations have not been studied within a sample of Native Hawaiian or Pacific Islander adults with T2D. Using data from a randomized control trial in which 218 Marshallese adults with T2D participated in a 10-week diabetes self-management education intervention, this study tested our hypothesis that physical activity would predict physical function when controlling for time and other variables. Levels of physical activity were positively associated with levels of physical function, even after controlling for time and other covariates. These findings provide a more robust understanding of the relationship between physical activity and physical function in a sample of minority adults with T2D. Future studies should further explore levels of physical activity needed to maintain and improve physical function so that culturally appropriate physical activity interventions can be developed.

The effects of the use of customized silicone digital orthoses on pre-ulcerative lesions and plantar pressure during walking in people with diabetic neuropathy: A study protocol for a randomized controlled trial

Background

People with diabetes and diabetic peripheral neuropathy (DPN) often develop calluses due to toe misalignment and increased plantar pressure. Untreated, these issues can progress into ulcers, making early intervention crucial. This trial protocol aims to evaluate the efficacy and safety of customized silicone digital orthoses in preventing ulcers, pre-ulcerative lesions, and peak pressure during gait in people with DPN.

Methods

In this superiority randomized controlled parallel trial with single-blind assessment, 60 participants will be allocated to the control group (CG) or the intervention group (IG). The CG will receive specialized nurse-administered foot care, including callus removal, nail care guidance, and self-care education. The IG will receive the same care plus a customized silicone orthosis for toe realignment for 6 months. Assessments will occur at baseline and 3 and 6 months for the primary outcomes (pre-ulcerative lesions and ulcer incidence) and secondary outcomes (pressure distribution, foot function and health, quality of life, safety, and comfort). Two-way ANOVAs (p < .05) will assess group, time, and group by time effects following an intention-to-treat approach.

Conclusion

Although recommended for foot ulcer prevention, custom silicone orthosis adoption remains limited due to the low certainty of evidence. This trial seeks to provide more consistent evidence for the use of toe orthoses in preventing callus and ulcer formation for individuals with DPN.

Trial registry

ClinicalTrials.gov (NCT05683106) "Effects of Customized Silicone Digital Orthoses in People with Diabetic Neuropathy" (registered on December 20, 2022).

Impact of diabetic peripheral neuropathy on gait abnormalities in patients with type 2 diabetes mellitus

Background

Many patients with type 2 diabetes (T2DM) suffer from diabetic peripheral neuropathy (DPN) and impaired muscle coordination. These changes may lead to walking instability, and gait abnormalities resulting in increased fall risk and lower limb amputations. The aim of this study was to assess the impact of DPN and patient footwear on the gait in patients with diabetes, in addition to Comparing the peak plantar pressure (PPP) in patients with and without DPN and assessing its association with gait abnormalities.

Methodology

This is an observational case-control study. Forty Subjects with T2DM were divided into two age and sex-matched groups, 20 subjects each. Group A: subjects with DPN. Group B: subjects without DPN. All study participants were subjected to a thorough history taking, clinical examinations focusing on detailed foot examination, PPP assessment, and functional gait evaluation.

Results

The results obtained in this study showed a median gait assessment score of 21 (17.0-22.5) for group A and 26 (23.5-26.0) for group B which was statistically significant (p < 0.001). There was no statistically significant difference between both groups (p > 0.05) regarding the assessment of footwear appropriateness. Comparing the PPP measurement among both studied groups, the prevalence of an elevated PPP was 80% in group A compared to 65% in group B, which was statistically non-significant, p = 0.288.

Conclusions

Gait abnormalities are common among patients with T2DM even in the absence of DPN. However, the presence of DPN was the strongest independent risk factor for gait abnormalities among the studied factors.

Increased Frequency of Giant Miniature End-Plate Potentials at the Neuromuscular Junction in Diabetic Rats

There is a need for research addressing the functional characteristics of the motor end-plate in diabetes to identify mechanisms contributing to neuromuscular dysfunction. Here, we investigated the effect of diabetes on spontaneous acetylcholine release in the rat neuromuscular junction. We studied two randomized groups of male Wistar rats (n = 7 per group, 350 ± 50 g, 12-16 weeks of age): one with streptozotocin-induced experimental diabetes, and a healthy control group without diabetes. After 8 weeks of monitoring after diabetes induction, rats in both groups were anesthetized with pentobarbital. Then, the diaphragm muscle was dissected for electrophysiological recordings of miniature end-plate potentials (MEPPs) using a single electrode located at the region of the muscle end-plate. All experiments were conducted at environmental temperature (20-22 °C) in rat Ringer solution with constant bubbling carbogen (95% O2, 5% CO2). Compared to healthy controls, in the diaphragm neuromuscular end-plate derived from diabetic rats, the MEPPs were higher in amplitude and frequency, and the proportion of giant MEPPs was elevated (7.09% vs. 1.4% in controls). Our results showed that diabetes affected the acetylcholine MEPP pattern and increased the number of giant potentials compared to healthy controls.

The impact of diabetic polyneuropathy on toe grip strength in patients with type 2 diabetes mellitus: a cross-sectional study

Purpose

Type 2 diabetes mellitus (T2DM) and concomitant diabetic polyneuropathy (DPN) induce muscle weakness. Muscle weakness in the foot is associated with foot deformities and falls. However, factors affecting toe grip strength (TGS) are not well known. Therefore, the present study investigated factors related to TGS in patients with T2DM.

Methods

This was a cross-sectional study involving 100 patients with T2DM who were hospitalized for the treatment of T2DM and 50 healthy adults. The subjects were divided into three groups: a group of healthy subjects, a group of T2DM patients without DPN, and a group of T2DM patients with DPN. Hierarchical multiple regression analysis was performed with TGS and the TGS-to-weight ratio (TGS/Wt%) as dependent variables and with age, the presence of T2DM, and DPN as independent variables, and sex and BMI as confounders.

Results

There were no significant differences in age or sex among the three groups. In the final regression analysis, age and presence of T2DM and DPN were associated in both models with TGS and TGS/Wt% as dependent variables.

Conclusion

DPN, T2DM, and age were found to be related to TGS. The findings of this study could contribute to healthcare providers developing foot care and rehabilitation programs for diabetic patients.

Trial registration

This study was registered with UMIN-CTR (UMIN000034320) on 1 November 2018.

Effect of joint limitation and balance control on gait changes in diabetic peripheral neuropathy

Aims

This study analyzed the gait patterns of diabetic peripheral neuropathy (DPN) patients and changes in the center of mass sway to prevent the formation and recurrence of foot ulcers.

Methods

Forty-two subjects were divided into the diabetes mellitus (DM), DPN, and diabetic foot ulcer (DFU) groups. We measured the range of motion (ROM) of the lower limb joints in the resting position and the center of mass sway in the standing position. Joint angles, ROM during walking, and distance factors were evaluated.

Results

In the DFU group, ROM limitation during walking was detected at the knee joint, and functional and ROM limitations were found at the ankle joint. The step length ratio and step width in the DFU group were significantly lower and higher than those in the DM group, respectively. The sway distances in the DFU group were greater than those in the DM and DPN groups.

Conclusions

Functional joint limitations and gait changes due to the decreased ability to maintain the center of gravity were observed in the DFU group. As DPN progressed, the patients' gait became small, wide, and shuffled. Thus, supporting joint movement during walking may help reduce the incidence and recurrence of foot ulcers.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13340-023-00647-9.

Nonlinear relationship between dietary calcium and magnesium intake and peripheral neuropathy in the general population of the United States

Background

Calcium and magnesium are essential minerals that have significant roles in nerve function and regulation. There may be a correlation between dietary calcium and magnesium intake and peripheral neuropathy. However, this relationship remains unclear and requires further study.

Methods

Data from 7,726 participants in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2004 were analyzed in this study. The relationship between total dietary calcium and magnesium intake, as well as each quantile, and peripheral neuropathy was analyzed using a multifactor logistic regression model. To illustrate the dose-response relationship between calcium and magnesium intake and peripheral neuropathy, we utilized a restricted cubic spline (RCS) plot.

Results

Our analysis found a positive correlation between dietary intake of calcium and magnesium and peripheral neuropathy (calcium: OR 1.000, 95% CI 1.000-1.000; magnesium: OR 1.001, 95% CI 1.00-1.002). Participants in the first and third quantiles of dietary calcium intake had a significantly higher incidence of peripheral neuropathy than those in the second quantile (OR 1.333, 95% CI 1.034-1.719, OR 1.497, 95% CI 1.155-1.941). Those in the first and third quantiles of dietary magnesium intake also had a significantly higher incidence of peripheral neuropathy than those in the second quantile (OR 1.275, 95% CI 1.064-1.528, OR 1.525, 95% CI 1.231-1.890). The restricted cubic spline analysis revealed a U-shaped nonlinear relationship between dietary intake of calcium and magnesium and peripheral neuropathy.

Conclusion

The study found a U-shaped non-linear relationship between dietary calcium and magnesium intake levels and peripheral neuropathy, indicating that both excessive and insufficient intake of calcium and magnesium can increase the incidence of peripheral neuropathy.

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.

Mechanisms of diabetic foot ulceration: A review

Diabetic foot ulcers (DFUs) are associated with complex pathogenic factors and are considered a serious complication of diabetes. The potential mechanisms underlying DFUs have been increasingly investigated. Previous studies have focused on the three aspects of diabetic peripheral vascular disease, neuropathy, and wound infections. With advances in technology, researchers have been gradually conducting studies using immune cells, endothelial cells, keratinocytes, and fibroblasts, as they are involved in wound healing. It has been reported that the upregulation or downregulation of molecular signaling pathways is essential for the healing of DFUs. With a recent increase in the awareness of epigenetics, its regulatory role in wound healing has become a much sought-after trend in the treatment of DFUs. This review focuses on four aspects involved in the pathogenesis of DFUs: physiological and pathological mechanisms, cellular mechanisms, molecular signaling pathway mechanisms, and epigenetics. Given the challenge in the treatment of DFUs, we are hopeful that our review will provide new ideas for peers.

Motor skills training-induced activation of descending pathways mediating cortical command to hindlimb motoneurons in experimental diabetic rats

Diabetes disrupts the corticospinal tract (CST) system components that control hindlimb and trunk movement, resulting in weakness of the lower extremities. However, there is no information about a method to improve these disorders. This study aimed to investigate the rehabilitative effects of 2 weeks of aerobic training (AT) and complex motor skills training (ST) on motor disorders in streptozotocin-induced type 1 diabetic rats. In this study, electrophysiological mapping of the motor cortex showed that the diabetes mellitus (DM)-ST group had a larger motor cortical area compared to the DM-AT group and sedentary diabetic animals. Moreover, hand grip strength and rotarod latency increased in the DM-ST group; however, these two parameters did not change in the DM-AT group, as well as in control and sedentary diabetic rats. Furthermore, in the DM-ST group, cortical stimulation-induced and motor-evoked potentials were preserved after the interception of the CST; however, this potential disappeared after additional lesions were made on lateral funiculus, suggesting that their function extends to activating motor descending pathways other than the CST locating lateral funiculus. According to immunohistochemical analysis, the larger fibers present on the dorsal part of the lateral funiculus, which corresponds to the rubrospinal tract of the DM-ST group, expressed the phosphorylated growth-associated protein, 43 kD, which is a specific marker of axons with plastic changes. Additionally, electrical stimulation of the red nucleus revealed expansion of the hindlimb-responsible area and increased motor-evoked potentials of the hindlimb in the DM-ST group, suggesting a strengthening of synaptic connections between the red nucleus and spinal interneurons driving motoneurons. These results reveal that ST induces plastic changes in the rubrospinal tract in a diabetic model, which can compensate for diabetes by disrupting the CST system components that control the hindlimb. This finding suggests that ST can be a novel rehabilitation strategy to improve motor dysfunctions in diabetic patients.

Pathological gait in partial foot amputation versus peripheral neuropathy

Partial foot amputation (PFA) is a common surgical loss of part of either the forefoot or mid-foot. It is usually the sequel to a cascade of physiological foot dysfunction such as peripheral neuropathy (PN). The gait compensation mechanisms associated with these foot disorders aren't well understood yet.

PURPOSE

The aim of the study was to evaluate pathological gait compensation mechanisms in PFA due to PN versus PN alone through a comprehensive gait analysis.

METHODS

Plantar pressure, GRF, load distribution, footprint length and area, foot progression angle, step length, percentage of double limb support, and stance time were measured on 53 participants assigned into two well-matched groups: (A) 25 subjects with healed unilateral PFA and (B) 28 subjects with PN without ulcer. The gait analysis was conducted at a self-preferred walking speed using the FREEMED baropodometric platform and FREESTEP software.

RESULTS

The PFA group showed a significant decrease in load over the remaining toes and metatarsal heads compared to the PN group (p = .001 and p = .003, respectively). Conversely, the PFA group showed a significant increase in load over the mid-foot and peak plantar pressure during mid-stance (p = .007 and p = .016, respectively). All other measured variables showed no significant difference between the two groups (p > .05).

CONCLUSION

Individuals with PFA and PN or PN alone tend to shift their body loads posteriorly and redistribute their loads to compensate for the insufficient support from the forefoot. The PFA group was worse than the PN group. Furthermore, the PFA may not be the primary cause of the altered gait but rather the underlying systemic disease. The PFA surgery only worsens the compensatory mechanism.

Diabetic foot ulcers: Classification, risk factors and management

Diabetic foot ulceration is a devastating complication of diabetes that is associated with infection, amputation, and death, and is affecting increasing numbers of patients with diabetes mellitus. The pathogenesis of foot ulcers is complex, and different factors play major roles in different stages. The refractory nature of foot ulcer is reflected in that even after healing there is still a high recurrence rate and amputation rate, which means that management and nursing plans need to be considered carefully. The importance of establishment of measures for prevention and management of DFU has been emphasized. Therefore, a validated and appropriate DFU classification matching the progression is necessary for clinical diagnosis and management. In the first part of this review, we list several commonly used classification systems and describe their application conditions, scope, strengths, and limitations; in the second part, we briefly introduce the common risk factors for DFU, such as neuropathy, peripheral artery disease, foot deformities, diabetes complications, and obesity. Focusing on the relationship between the risk factors and DFU progression may facilitate prevention and timely management; in the last part, we emphasize the importance of preventive education, characterize several of the most frequently used management approaches, including glycemic control, exercise, offloading, and infection control, and call for taking into account and weighing the quality of life during the formulation of treatment plans. Multidisciplinary intervention and management of diabetic foot ulcers (DFUs) based on the effective and systematic combination of these three components will contribute to the prevention and treatment of DFUs, and improve their prognosis.

Do Patients With Chronic Diabetes Have Worse Motor Outcomes After Cervical ASIA C Traumatic Spinal Cord Injury?

STUDY DESIGN

This was a level IV retrospective prognostic study.

OBJECTIVE

The objective of this study was to determine if patients with chronic diabetes have worse functional outcomes and motor recovery after cervical traumatic spinal cord injury (TSCI).

SUMMARY OF BACKGROUND DATA

Diabetes mellitus has multiple deleterious neurological effects and has been shown to worsen elective cervical spine surgery outcomes. Prior literature has scarcely characterized the impact of chronic diabetes on motor and functional outcomes after TSCI.

METHODS

The National Spinal Cord Injury Statistical Center (NSCISC) database was utilized to retrospectively collect data on cervical American Spinal Injury Association (ASIA) C TSCI between 2011 and 2016. Patients were divided into diabetes and nondiabetes groups. Primary outcomes included wheelchair requirement and ambulatory status 1 year after injury. Secondary outcomes were motor score collected at the time of rehab admission, rehab discharge, and 1-year follow-up. All outcome variables were analyzed using univariate and multivariate regression to assess for differences between diabetes and nondiabetes groups and possible confounders.

RESULTS

A total of 219 patients met the inclusion criteria for the study: 193 without diabetes and 26 with diabetes (12.0%). After controlling for confounders, patients with diabetes had had significantly increased wheelchair requirement (83.3% vs. 51.8%, relative risk=1.63, 95% confidence interval: 1.20-1.83, P =0.009 multivariate) and decreased ambulatory rates (50% vs. 67.9%, relative risk=0.55, 95% confidence interval: 0.25-0.98, P =0.042 multivariate) at 1 year. They also had no difference in average total motor scores at rehab admission but significantly worse total motor scores at rehab discharge (50.6±23.3 vs. 60.3±21.4, P =0.033 univariate, P =0.002 multivariate).

CONCLUSIONS

Patients with diabetes have increased wheelchair requirement and decreased ambulatory ability at 1 year after the injury as well as diminished recovery in motor scores after motor-incomplete cervical TSCI. These patients may be targets for aggressive diabetic screening and intervention to minimize negative outcomes.

Diabetic Neuropathy in Hands: An Endemic Complication Waiting to Unfold?

In this cross-sectional study we aimed to quantify the somatosensory dysfunction in the hand in people with diabetes with distal symmetrical polyneuropathy (DSPN) in hands and explore early signs of nerve dysfunction in people with diabetes without DSPN in hands. The clinical diagnosis of DSPN was confirmed with electrodiagnosis and corneal confocal microscopy. Thermal and mechanical nerve function in the hand was assessed with quantitative sensory tests. Measurements were compared between healthy participants (n = 31), individuals with diabetes without DSPN (n = 35), individuals with DSPN in feet but not hands (DSPNFEET ONLY) (n = 31), and individuals with DSPN in hands and feet (DSPNHANDS & FEET) (n = 28) with one-way between-group ANOVA. The somatosensory profile of the hand in people with DSPNHANDS & FEET showed widespread loss of thermal and mechanical detection. This profile in hands is comparable with the profile in the feet of people with DSPN in feet. Remarkably, individuals with DSPNFEET ONLY already showed a similar profile of widespread loss of nerve function in their hands. People with diabetes without DSPN in feet already had some nerve dysfunction in their hands. These findings suggest that nerve function assessment in hands should become more routine in people with diabetes.

Masticatory dysfunction in patients with diabetic neuropathy: A cross-sectional study

Introduction

Chewing well is essential for successful diet therapy and control of blood glucose level in patients with diabetes. In addition, long-term hyperglycemia is a risk factor for microvascular complications, which are the main cause of morbidity and mortality in these patients. Hence, it is plausible that masticatory disorder may be relevant to diabetic microvascular complications which is caused by long-term hyperglycemia. The aim of this study was to investigate whether masticatory disorders are relevant to diabetic microvascular complications.

Methods

This cross-sectional study included 172 patients with type 2 diabetes who underwent educational hospitalization in the Department of Endocrinology and Diabetic Medicine, Hiroshima University Hospital, from April 2016 to March 2020. Masticatory efficiency was determined quantitatively by using the GLUCO SENSOR GS-Ⅱ. Multivariable linear regression models were constructed to examine which factors were related to masticatory efficiency. Statistical significance was defined as a two-sided p value of < 0.05.

Results

According to the bivariable analysis, masticatory efficiency was significantly correlated with duration of diabetes (p = 0. 049), number of remaining teeth (p < 0.0001), the number of moving teeth (p = 0.007) and condition of diabetic neuropathy (p < 0.0001). Moreover, the number of remaining teeth (p < 0.0001) and diabetic neuropathy (p = 0.007) remained significantly correlated with masticatory efficiency in the multivariable analysis.

Conclusions

For the first time, we demonstrated that patients with type 2 diabetes who developed diabetic neuropathy had significantly reduced masticatory efficiency. Effective mastication is an important factor in successful diet therapy for diabetes. To prevent the progression of diabetic complications, especially in patients with diabetic neuropathy, it may be necessary to combine individualized therapies from dentists and nutritionists with consideration for the level of masticatory dysfunction.

Alterations of tibialis anterior muscle activation pattern in subjects with type 2 diabetes and diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is associated with loss of motor units (MUs), which can cause changes in the activation pattern of muscle fibres. This study investigated the pattern of muscle activation using high-density surface electromyography (HD-sEMG) signals from subjects with type 2 diabetes mellitus (T2DM) and DPN. Thirty-five adults participated in the study: 12 healthy subjects (HV), 12 patients with T2DM without DPN (No-DPN) and 11 patients with T2DM with DPN (DPN). HD-sEMG signals were recorded in the tibialis anterior muscle during an isometric contraction of ankle dorsiflexion at 50% of the maximum voluntary isometric contraction (MVIC) during 30-s. The calculated HD-sEMG signals parameters were the normalised root mean square (RMS), normalised median frequency (MDF), coefficient of variation (CoV) and modified entropy (ME). The RMS increased significantly (p = 0.001) with time only for the DPN group, while the MDF decreased significantly (p < 0.01) with time for the three groups. Moreover, the ME was significantly lower (p = 0.005), and CoV was significantly higher (p = 0.003) for the DPN group than the HV group. Using HD-sEMG, we have demonstrated a reduction in the number of MU recruited by individuals with DPN. This study provides proof of concept for the clinical utility of this technique for identifying neuromuscular impairment caused by DPN.

Oxygen-Releasing Composites: A Promising Approach in the Management of Diabetic Foot Ulcers

In diabetes, lower extremity amputation (LEA) is an irreversible diabetic-related complication that easily occurs in patients with diabetic foot ulcers (DFUs). Because DFUs are a clinical outcome of different causes including peripheral hypoxia and diabetic foot infection (DFI), conventional wound dressing materials are often insufficient for supporting the normal wound healing potential in the ulcers. Advanced wound dressing development has recently focused on natural or biocompatible scaffolds or incorporating bioactive molecules. This review directs attention to the potential of oxygenation of diabetic wounds and highlights current fabrication techniques for oxygen-releasing composites and their medical applications. Based on different oxygen-releasable compounds such as liquid peroxides and solid peroxides, for example, a variety of oxygen-releasing composites have been fabricated and evaluated for medical applications. This review provides the challenges and limitations of utilizing current oxygen releasable compounds and provides perspectives on advancing oxygen releasing composites for diabetic-related wounds associated with DFUs.

Comparison of muscle strength between hemodialysis patients and non-dialysis patients with chronic kidney disease

[Purpose] Muscle weakness in patients with chronic kidney disease is associated with several disease-related factors, and this study aimed to examine whether hemodialysis is one of risk factors for muscle weakness in patients with chronic kidney disease. [Participants and Methods] We conducted a cross-sectional study with 74 non-dialysis and 84 hemodialysis patients. Muscle strength evaluations were performed by measuring isometric knee extensor muscle strength and grip strength. Each evaluation item was compared between the hemodialysis and non-dialysis groups, and multiple regression analysis was performed to determine the factors associated with muscle strength. In addition, the correlation between lower-extremity muscle strength and grip strength was examined in each group. [Results] Isometric knee extensor muscle strength was significantly lower in the hemodialysis group than in the non-dialysis group. Grip strength was also significantly lower in the hemodialysis group than in the non-dialysis group. Hemodialysis was determined to be an independent risk factor associated with lower limb muscle strength as well as grip strength. The positive correlation between isometric knee extensor muscle strength and grip strength was almost the same in the groups. [Conclusion] Hemodialysis treatment was an independent risk factor for muscle weakness. Regular monitoring of grip strength may facilitate better management with physical therapy in hemodialysis patients.

Molsidomine ameliorates diabetic peripheral neuropathy complications in Wistar rats

Diabetic neuropathy is a disorder that affects various regions of the nervous system and there is no specific treatment available for it. This study evaluated the protective effect of molsidomine in diabetic neuropathy in rats. Diabetes was induced in male Wistar rats by administrating streptozotocin (52 mg/kg ip). Diabetic rats were treated with molsidomine 5 mg/kg po and 10 mg/kg po. After 8 weeks of treatment, motor coordination, mechanical allodynia, mechanical hyperalgesia, nerve conduction velocity, and glycosylated hemoglobin were assessed. Thereafter, animals were killed and the sciatic nerve was isolated for measurement of reduced glutathione and lipid peroxidation, and histopathological analysis. Treatment with molsidomine significantly improved motor coordination, paw withdrawal threshold, mechanical threshold, and nerve conduction velocity. Furthermore, molsidomine treatment also reduced malondialdehyde levels and prevented depletion of reduced glutathione in the sciatic nerve homogenate. Histopathology revealed that molsidomine treatment maintained normal architecture of the sciatic nerve. The results of our study strengthen the alternative use of molsidomine in diabetic neuropathy.

Lower limb wounds in diabetes: the challenges of wound healing

Managing ulceration in the lower limb for a patient with diabetes can be complex and challenging, requiring a multiprofessional, patient-centred, holistic approach with early referral for specialist review as key. Any delay in referral and intervention can be catastrophic, as time is tissue. Peripheral arterial disease and neuropathy both contribute significantly to the delays in wound healing, and it is important to rapidly recognise the problems with an informed assessment and understand the possible reasons for delayed wound healing, so that management is appropriate, rapid referrals are made and patient outcomes are optimised. This article discusses some of the reasons why wound healing is complicated in those with diabetes as a comorbidity.

Niclosamide ethanolamine ameliorates diabetes-related muscle wasting by inhibiting autophagy

Background

Diabetes-related muscle wasting is one of the devastating complications of diabetes, which is associated with muscle autophagy due to insulin-mediated glucose starvation. However, treatment for diabetes-related muscle wasting is limited. Our previous study already found that niclosamide ethanolamine salt has the therapeutic effects on insulin deficiency of type 1 diabetes mice and muscle wasting induced by doxorubicin. Therefore, we aim to investigate the therapeutic effects of niclosamide ethanolamine salt on diabetes-induced muscle wasting and to explore whether the mechanism is associated with muscle autophagy.

Methods

Type 1 diabetes mice were induced by intraperitoneal injection of streptozotocin, then were fed with regular diet supplemented with 10 g/kg niclosamide ethanolamine salt. The whole experiment lasted for 8 weeks. At the end of the study, grip strength, weights of tibialis anterior, gastrocnemius, soleus, and extensor digitorum longus muscle were measured. Tibialis anterior muscles stained with PAS were used for evaluating the fiber cross sectional area. Immunofluorescence analysis of myosin heavy chain expression in extensor digitorum longus and soleus muscle was used for determining the composition of the muscle fiber type. Electronic microscopy was applied to observe the autophagy in the atrophied muscle. Serum insulin levels and fasting blood glucose were also measured. Tissues of gastrocnemius muscle were used for detecting the expression of the proteins related to autophagy.

Results

In this study, we found that niclosamide ethanolamine salt could ameliorate muscle atrophy in the type 1 diabetes mice as well, such as enhancing the declined grip strength, improving limb weight and increasing the numbers of glycolytic muscle fiber. Electron microscopy also confirmed that there did exist abundant autophagic vacuoles in the atrophied muscle of the type 1 diabetes mice. Specifically, niclosamide ethanolamine salt could reduce the over expression of autophagy-related proteins, including p-AMPK (Thr172), FoxO3a, p-ULK1 (Ser555), LC3B II, and p-p38 in gastrocnemius muscle of the type 1 diabetes mice.

Conclusion

Niclosamide ethanolamine salt could ameliorate muscle wasting. The mechanisms underlying might be associated with inhibition of muscle autophagy.

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.

Heel Rise and Non-Weight-Bearing Ankle Plantar Flexion Tasks to Assess Foot and Ankle Function in People With Diabetes Mellitus and Peripheral Neuropathy

OBJECTIVE

The objective of this study was to examine the effects of diabetes mellitus and peripheral neuropathy (DMPN), limited joint mobility, and weight-bearing on foot and ankle sagittal movements and characterize the foot and ankle position during heel rise.

METHODS

Sixty people with DMPN and 22 controls participated. Primary outcomes were foot (forefoot on hindfoot) and ankle (hindfoot on shank) plantar-flexion/dorsiflexion angle during 3 tasks: unilateral heel rise, bilateral heel rise, and non-weight-bearing ankle plantar flexion. A repeated-measures analysis of variance and Fisher exact test were used.

RESULTS

Main effects of task and group were significant, but not the interaction in both foot and ankle plantar flexion. Foot and ankle plantar flexion were less in people with DMPN compared with controls in all tasks. Both DMPN and control groups had significantly less foot and ankle plantar flexion with greater weight-bearing; however, the linear trend across tasks was similar between groups. The DMPN group had a greater percentage of individuals in foot and/or ankle dorsiflexion at peak unilateral heel rise compared with controls, but the foot and ankle position was similar at peak bilateral heel rise between DMPN and control groups.

CONCLUSION

Foot and ankle plantar flexion is less in people with DMPN. Less plantar flexion in non-weight-bearing suggests that people with DMPN have limited joint mobility. However, peak unilateral and bilateral heel rise is less than the available plantar flexion range of motion measured in non-weight-bearing, indicating that limited joint mobility does not limit heel rise performance. A higher frequency of people with DMPN are in foot and ankle dorsiflexion at peak unilateral heel rise compared with controls, but the position improved with lower weight-bearing.

IMPACT

Proper resistance should be considered with physical therapist interventions utilizing heel rise because foot and ankle plantar flexion position could be improved by reducing the amount of weight-bearing.

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.

Diabetes Mellitus-Related Dysfunction of the Motor System

Although motor deficits in humans with diabetic neuropathy have been extensively researched, its effect on the motor system is thought to be lesser than that on the sensory system. Therefore, motor deficits are considered to be only due to sensory and muscle impairment. However, recent clinical and experimental studies have revealed that the brain and spinal cord, which are involved in the motor control of voluntary movement, are also affected by diabetes. This review focuses on the most important systems for voluntary motor control, mainly the cortico-muscular pathways, such as corticospinal tract and spinal motor neuron abnormalities. Specifically, axonal damage characterized by the proximodistal phenotype occurs in the corticospinal tract and motor neurons with long axons, and the transmission of motor commands from the brain to the muscles is impaired. These findings provide a new perspective to explain motor deficits in humans with diabetes. Finally, pharmacological and non-pharmacological treatment strategies for these disorders are presented.

A study of nerve conduction velocity in diabetic patients and its relationship with tendon reflexes (T-Reflex)

Background and Objective:

Neuropathy is one of the most common complications of diabetes mellitus. Neuropathy can cause sensory deficit, neurological disorder, organ ulcers, osteomyelitis, and amputation. Therefore, neurological examinations, determining the nerve conduction velocity and performing sensory and motor tests are important for timely diagnosis and treatment. The present study aimed to investigate the nerve conduction velocity in diabetic patients and its relationship with tendon reflexes.

Materials and Methods:

The present study was observational-cross sectional research carried out on 77 diabetic patients who admitted to the EMG / NCV Department of Shariati Hospital in the academic year 1996-1997. In all patients, the medical history of the patient (age, duration of diabetes, gender and age of onset of diabetes), neurological examination, nerve conduction velocity, heat test, vibration test, tendon reflexes, D.L and Amplitude were examined and recorded. Finally, the raw data obtained was entered into the IBM SPSS Statistics software and the important relationships between these variables were analyzed. Moreover, in present study, the statistical significance level (P-value) was considered less than 0.05.

Results:

The present study was conducted on a population consisting of 48 women and 29 men with diabetes. The age range of participants was 14-70 years old with an average age of 50.506 ± 7.50. The results of present study showed that the participants with clinical neuropathy (11.2 ± 7.2) had significantly longer duration of diabetes than the normal group and those participants with sub-clinical neuropathy (P-value = 0.12). Statistical analyses indicated that increase in age, increase in the duration of diabetes and the gender of male significantly made the nerve conduction velocity abnormal. The analysis of the response to neural reflexes indicated that the ratio of neurological disorders in the five nerves of the ankle and knee was generally higher in the abnormal group (the patients with nerve conduction disorder) compared to the normal (the patients with normal nerve conduction) and in some cases, such as the ulnar motor nerve of ankle (P-value = 0.010), and the ulnar motor nerve of knee motor (P-value = 0.002) and also in the peroneal motor nerve of knee (P-value = 0.003) and the sural sensory nerve of knee (P-value = 0.003), increase in neurological disorders was significant.

Conclusion:

Increase in age, increase in the duration of diabetes and the gender of male can significantly make the nerve conduction velocity abnormal. (www.actabiomedica.it)

Loss of lower extremity muscle strength based on diabetic polyneuropathy in older patients with type 2 diabetes: Multicenter Survey of the Isometric Lower Extremity Strength in Type 2 Diabetes: Phase 2 study

Aims/Introduction

Diabetic polyneuropathy (DPN) is a factor that reduces lower extremity muscle strength (LEMS) in older type 2 diabetes patients. This relationship remains unclear in longitudinal studies. Therefore, we longitudinally investigated the apparent effects of DPN on changes in LEMS. Furthermore, we cross‐sectionally examined relationships among DPN, LEMS, mobility and health‐related quality of life.

Materials and Methods

Bodyweight‐normalized (relative) knee extension force (KEF) was examined in 51 DPN and 54 non‐DPN patients (68.9 ± 5.6 and 70.2 ± 5.9 years, respectively) at baseline and follow up at 3.6 ± 0.6 years. At follow up, mobility was measured using a 25‐question geriatric locomotive function scale. Health‐related quality of life was assessed using the five‐dimensions of EuroQol for quality‐adjusted life years calculation.

Results

Relative KEF in the DPN group was significantly lower at follow up (1.22 ± 0.47 Nm/kg) than at baseline (1.31 ± 0.47 Nm/kg; P < 0.05). DPN significantly affected changes in relative KEF. Mobility decreased by 41 and 65% in the non‐DPN and DPN groups, respectively. Quality‐adjusted life years were significantly lower in the DPN group (0.856 ± 0.131) than in the non‐DPN group (0.920 ± 0.105; P < 0.01). Relative KEF was a significant independent variable that explained quality‐adjusted life years.

Conclusions

DPN clearly reduced LEMS in older type 2 diabetes patients within 4 years. Furthermore, DPN resulted in a loss of LEMS and decrease in mobility. Therefore, DPN development should be monitored closely, with glycemic control and LEMS kept at a high level to maintain health‐related quality of life in older patients with type 2 diabetes.

Altered pain processing in patients with type 1 and 2 diabetes: systematic review and meta-analysis of pain detection thresholds and pain modulation mechanisms

The first signs of diabetic neuropathy typically result from small-diameter nerve fiber dysfunction. This review synthesized the evidence for small-diameter nerve fiber neuropathy measured via quantitative sensory testing (QST) in patients with diabetes with and without painful and non-painful neuropathies. Electronic databases were searched to identify studies in patients with diabetes with at least one QST measure reflecting small-diameter nerve fiber function (thermal or electrical pain detection threshold, contact heat-evoked potentials, temporal summation or conditioned pain modulation). Four groups were compared: patients with diabetes (1) without neuropathy, (2) with non-painful diabetic neuropathy, (3) with painful diabetic neuropathy and (4) healthy individuals. Recommended methods were used for article identification, selection, risk of bias assessment, data extraction and analysis. For the meta-analyses, data were pooled using random-effect models. Twenty-seven studies with 2422 participants met selection criteria; 18 studies were included in the meta-analysis. Patients with diabetes without symptoms of neuropathy already showed loss of nerve function for heat (standardized mean difference (SMD): 0.52, p<0.001), cold (SMD: -0.71, p=0.01) and electrical pain thresholds (SMD: 1.26, p=0.01). Patients with non-painful neuropathy had greater loss of function in heat pain threshold (SMD: 0.75, p=0.01) and electrical stimuli (SMD: 0.55, p=0.03) compared with patients with diabetes without neuropathy. Patients with painful diabetic neuropathy exhibited a greater loss of function in heat pain threshold (SMD: 0.55, p=0.005) compared with patients with non-painful diabetic neuropathy. Small-diameter nerve fiber function deteriorates progressively in patients with diabetes. Because the dysfunction is already present before symptoms occur, early detection is possible, which may assist in prevention and effective management of diabetic neuropathy.

Is the Wii balance board a valid and reliable instrument to assess postural stability in older adults with type 2 diabetes mellitus?

AIMS

Evaluate the validity and reliability of the data from the Wii balance board (WBB), against a force platform (FP) in patients with type 2 diabetes mellitus (T2DM).

METHODS

Forty-three adults with T2DM (age 62.1 ± 12.1 yrs) in the validity trial and 27 (age 63.5 ± 10.8 yrs) in the reliability study, were tested. Total COP area (mm) and range of antero-posterior (AP) and medio-lateral (ML) COP excursion were collected simultaneously on a FP and a WBB.

RESULTS

Mean CoP sway path values were similar in all conditions in the FP when compared with the WBB. Regression model shows that WBB is able to explain most of the variation in CoP sway path data of the FP (between 42 and 72%) for all testing conditions, indicating that the WBB has good concurrent validity. Test-retest reliability for WBB was excellent, except for the COP sway area in the 'eyes open' condition (ICC = 0.55). Both conditions showed modest to excellent reliability in the AP (0.73-0.90) and the ML (0.77-0.91) directions.

CONCLUSION

The WBB has been shown to be a valid and reliable method to quantify the COP displacement during different balance tests in older adults with T2DM.

Limb Salvage and Prevention of Ulcer Recurrence in a Chronic Refractory Diabetic Foot Osteomyelitis

Biomechanical changes caused by structural foot deformities predispose patients to plantar ulceration. Plantar ulcer recurrence often leads to osteomyelitis, which is more commonly observed in patients with diabetes. Once the infection of diabetic foot ulcer (DFU) spreads and is complicated by osteomyelitis, treatment becomes more complicated and difficult. Osteomyelitis treatment remains challenging because of low drug concentration within the tissue caused by poor circulation and inadequate localized nutrition. Moreover, tissues around plantar ulcers are fewer and are thin, making the formation of granulation tissues difficult due to elevated plantar pressure. Furthermore, the skin around the wound is excessively keratinized, and the epidermis is hard to regenerate. Meanwhile, skin grafting at that site is often not successful due to poor blood circulation. Therefore, it is technically challenging to manage diabetic pressure plantar ulcer with osteomyelitis and prevent its recurrence. Here, we present a case of chronic DFU complicated by osteomyelitis due to foot deformity. The ulcer was successfully healed using advanced wound repair technology comprising of surgical bone resection, vancomycin-loaded bone cement implant, negative-pressure wound therapy, and autologous platelet-rich gel. Subsequently, preventive foot care with custom-made offloading footwear was prescribed. The plantar ulcer did not recur and improvement in biomechanical parameters was observed after the intervention. This case represents an effective and comprehensive management strategy for limb salvage and prevention in patients with complicated foot conditions.

The impact of sensory and/or sensorimotor neuropathy on lower limb muscle endurance, explosive and maximal muscle strength in patients with type 2 diabetes mellitus

AIMS

The purpose of this study was to investigate the impact of diabetic neuropathy (dNP) on lower limb endurance, explosive and maximal muscle strength in patients with Type 2 Diabetes Mellitus (T2DM).

METHODS

Fifty-four participants, aged between 55 and 85, were enrolled in this observational comparative study. The patients with T2DM had an average HbA1c of 7.4% (±1.03) and diabetes duration of 13 years. Participants were classified by means of electroneuromyography as T2DM without dNP (dNP-; n = 8), T2DM with sensory dNP (dNPs; n = 13), T2DM with sensorimotor dNP (dNPsm; n = 14), and healthy controls without neuropathy (C; n = 19). Maximal muscle strength and muscle endurance of the dominant knee and ankle were measured by dynamometry, while explosive muscle strength was evaluated by mechanography.

RESULTS

Muscle endurance "total work" in knee extension and ankle plantar flexion was higher in the healthy controls compared to dNP-, dNPs and dNPsm, in knee flexion compared to dNPs and dNPsm, and in ankle dorsiflexion compared to dNPsm only (p<0.05). Furthermore, relative explosive muscle strength "total power/body weight" and relative maximal muscle strength "peak torque/lean body mass of the dominant leg" considering knee flexion, ankle plantar flexion and dorsiflexion, were higher in healthy controls compared to the dNPsm group, and for maximal muscle strength ankle dorsiflexion even between dNP- and dNPsm (p < 0.05).

CONCLUSIONS

Muscle endurance is impaired in patients with T2DM, independent of the presence of dNP. Explosive and maximal muscle strength are more likely affected by the presence and severity of dNP.

Moderate intensity exercise in hypoxia increases IGF-1 bioavailability and serum irisin in individuals with type 1 diabetes

AIM

This study aimed to determine the effect of moderate intensity continuous exercise (Ex) and hypoxia (Hyp) on serum brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1) and its binding protein-3 (IGFBP-3), irisin and cytokines levels in patients with type 1 diabetes (T1D).

METHODS

A total of 14 individuals with T1D (age: 28.7 ± 7.3 years) and 14 healthy adults (age: 27.1 ± 3.9 years) performed 40-min continuous Ex at moderate intensity (50% lactate threshold) on a cycle ergometer in normoxia (Nor) and Hyp (FiO₂ = 15.1%) Biochemical factors, glucose concentrations and physiological variables were measured at rest, immediately and up to 24 h after both Ex protocols.

RESULTS

Patients with T1D had significantly lower pre-Ex serum concentrations of BDNF (p < 0.05, p < 0.01), and total IGF-1 (p < 0.001, p < 0.05) and significantly higher irisin levels (p < 0.05, p < 0.01) in Nor and Hyp, compared with healthy subjects. Ex significantly increased in T1D group serum BDNF (in Nor only p < 0.05) and total IGF-1 levels in Nor and Hyp (p < 0.001 and p < 0.01, respectively). Immediately after Ex in Hyp, freeIGF-1 (p < 0.05) and irisin levels (p < 0.001) were significantly higher compared with the levels induced by Ex alone. Free IGF-1 and irisin serum levels remained elevated in 24 h post-Ex in Hyp. In T1D, significant blood glucose (BG) decrease was observed immediately after Ex in Hyp (p < 0.001) and in 24 h recovery (p < 0.001) compared with pre-Ex level.

CONCLUSION

The study results suggest that moderate intensity continuous Ex has beneficial effect on BDNF and IGF-1 levels. Ex in hypoxic conditions may be more effective in increasing availability of IGF-1. The alterations in the post-Ex irisin levels and IGF-1 system may be contributing to more effective glycaemia control in patients with T1D.

The Biomechanics of Diabetes Mellitus and Limb Preservation

Biomechanical changes to the lower extremity in patients with diabetes mellitus are typically greatest with peripheral neuropathy, although peripheral arterial disease also impacts limb function. Changes to anatomic structures can impact daily function. These static changes, coupled with kinetic and kinematic changes of gait, lead to increased vertical and shear ground reactive forces, resulting in ulcerations. Unsteadiness secondary to diminished postural stability and increased sway increase fall risk. These clinical challenges and exacerbation of foot position and dynamic changes associated with limb salvage procedures, amputations, and prostheses are necessary and can impact daily function, independence, quality of life, and mortality.

Effectiveness of Exercise Therapy on Gait Function in Diabetic Peripheral Neuropathy Patients: A Systematic Review of Randomized Controlled Trials

The purpose of this study was to review the current evidence on the effectiveness of exercise therapy on gait function in patients with diabetic peripheral neuropathy. A comprehensive search of literature published between October 2010 and May 2020 was conducted using the following electronic databases; PubMed, AMED, CINAHL, ScienceDirect, Cochrane Library, PEDro and Google Scholar. Randomized control trials conducted to determine the effectiveness of exercise therapy on gait function in patients with diabetic neuropathy were included in this review. Non-English language published papers were excluded. This review was done in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Data extraction and risk of bias assessment of the studies were carried out independently by two authors. The methodological quality of the studies was evaluated using the PEDro scale and GRADE approach. The overall methodological quality of studies rated from moderate to high. Meta-analysis was not carried out due to the heterogeneity of included trials. The primary outcome measures of gait functions were the six-minute walk test, 10-meter walk test and Tinetti scale. Nine randomized controlled trials with 370 participants were analyzed. Out of them, eight studies proved its effectiveness on gait function on individuals with diabetic peripheral neuropathy. The finding of this study suggested that multi-component exercise therapy consisted of strength, ROM exercise, balance, flexibility and stretching exercises, circuit exercise training, and gait training found to enhance gait function for individuals suffering with diabetic peripheral neuropathy compared to control groups.

Functional assessments of foot strength: a comparative and repeatability study

Background

Evaluating the strength of the small muscles of the foot may be useful in a variety of clinical applications but is challenging from a methodology standpoint. Previous efforts have focused primarily on the functional movement of toe flexion, but clear methodology guidelines are lacking. A novel foot doming test has also been proposed, but not fully evaluated. The purposes of the present study were to assess the repeatability and comparability of several functional foot strength assessment techniques.

Methods

Forty healthy volunteers were evaluated across two testing days, with a two-week doming motion practice period between them. Seven different measurements were taken using a custom toe flexion dynamometer (seated), custom doming dynamometer (standing), and a pressure mat (standing). Measurements from the doming dynamometer were evaluated for reliability (ICCs) and a learning effect (paired t-tests), while measurements from the toe flexion dynamometer and pressure mat were evaluated for reliability and comparability (correlations). Electromyography was also used to descriptively assess the extent of muscle isolation in all measurements.

Results

Doming showed excellent within-session reliability (ICCs > 0.944), but a clear learning effect was present, with strength (p < 0.001) and muscle activity increasing between sessions. Both intrinsic and extrinsic muscles were engaged during this test. All toe flexion tests also showed excellent reliability (ICCs > 0.945). Seated toe flexion tests using the dynamometer were moderately correlated to standing toe flexion tests on a pressure mat (r > 0.54); however, there were some differences in muscle activity. The former may better isolate the toe flexors, while the latter appeared to be more functional for many pathologies. On the pressure mat, reciprocal motion appeared to display slightly greater forces and reliability than isolated toe flexion.

Conclusions

This study further refines potential methodology for foot strength testing. These devices and protocols can be duplicated in the clinic to evaluate and monitor rehabilitation progress in clinical populations associated with foot muscle weakness.

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.

Vehicle ergonomics contributing to a diabetic foot ulcer

Background

Diabetes mellitus continues to be a rising concern in the United States. It affects an estimated 9.4% of the population and approximately 1.5 million Americans are diagnosed annually. Approximately 85% of diabetic foot ulcers are associated with diabetic peripheral neuropathy and an infected diabetic foot ulcer is often the first sign of diabetes. There are countless studies within the literature that investigate how insensate feet and the manifestation of a foot ulcer further decrease quality of life and increase risk for mortality. Literature focuses on gait and kinematics that contribute to the formation of a diabetic foot ulcer. While pressure and shear forces are etiologic factors that may lead to the formation of diabetic foot ulcers, the position of the foot while driving an automobile has been ignored as a possible risk factor.

Case presentation

The clinical case will describe the events of healing a neuropathic diabetic foot ulcer beyond the standard of care treatment plan. It is one of the first case reports to describe vehicle ergonomics as an etiologic factor contributing to a diabetic foot ulcer. Once the patient becomes aware of the unnecessary source of pressure, education and care is provided to manage this likely source of daily pressure to the neuropathic foot.

Conclusion

The article emphasizes the importance of a complete assessment, including nontraditional factors, which may lead to diabetic complications.

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.