Comparison of Bipolar and Monopolar Electrode Configurations for FES on Biceps Brachii.

Function electrical stimulation (FES) is recommended as one of the effective methods for rehabilitation of motor function after stroke. There are two forms to deliver electrical stimulation to induce muscle contraction: Bipolar electrode configuration with two electrodes of the same size, and monopolar electrode configuration with a bigger electrode as an indifferent electrode and a smaller one as an active electrode. The purpose of this study is to compare the two kinds of configuration on biceps brachii in terms of induced muscle contraction force and muscle fatigue. In the experiment, electrical stimulation was applied on biceps brachii muscles of the right arm. Isometric contraction was induced by fixing the elbow joint during the stimulation. The experimental results showed that the induced contraction force was bigger using monopolar electrode configuration with the indifferent electrode on the antagonist muscle, and there was no significant difference in muscle fatigue between the configurations. Monopolar electrode configuration with the indifferent electrode on the antagonist muscle was suggested as the most effective method for FES on biceps brachii.Clinical Relevance- This study establishes an effective electrode configuration for FES on biceps brachii.

Plant-based dietary pattern and low muscle mass: a nation-wide cohort analysis of Chinese older adults.

BACKGROUND: It remains unclear whether plant-based or animal-based dietary patterns are more beneficial for older adults more in maintaining muscle mass. Using a prospective cohort with nationwide sample of China older adults in this study, we aimed to examine the relationship between adhering to plant-based diet patterns or animal-based diet patterns and muscle loss. METHODS: We included 2771 older adults (≥ 65 years) from the Chinese Longitudinal Health Longevity Survey (CLHLS) with normal muscle mass at baseline (2011 and 2014 waves), which followed up into 2018. Plant-based dietary pattern scores and preference subgroups were constructed using 16 common animal-based and plant-based food frequencies. We used the corrected appendicular skeletal muscle mass (ASM) prediction formula to assess muscle mass. We applied the Cox proportional hazard risk regression to explore associations between dietary patterns and low muscle mass (LMM). RESULTS: During a mean of 4.1 years follow-up, 234 (8.4%) participants with normal muscle mass at baseline showed LMM. The plant-based dietary pattern reduced the risk of LMM by 5% (Hazard Ratios [HR]: 0.95, 95% confidence intervals [95%CI]: 0.92-0.97). In addition, a high plant-based food company with a high animal-based food intake pattern reduced the risk of LMM by 60% (HR: 0.40, 95% CI: 0.240-0.661) and 73% (HR: 0.27, 95% CI: 0.11-0.61) in the BADL disability and IADL disability population compared with a low plant-based food and high animal-based food intake, whereas a high plant-based food and low animal-based food intake was more beneficial in reducing the risk of LMM in the normal BADL functioning (HR: 0.57, 95% CI: 0.35-0.90) and IADL functioning (HR: 0.51, 95% CI: 0.28-0.91) population. CONCLUSIONS: When it comes to maintaining muscle mass in older Chinese people with functional independence, a plant-based diet pattern is more beneficial and effective than the animal-based one. People with functional dependence may profit from a combination of plant-based and animal-based diets to minimize muscle loss.

Association between dietary inflammatory index and low muscle mass in diabetes/prediabetes patients.

BACKGROUND: Growing evidence has increasingly validated that individuals with diabetes/prediabetes have a higher prevalence of low skeletal muscle mass and function compared to healthy individuals. The anti-inflammatory diet is considered a promising and modifiable approach to optimize skeletal muscle quality. However, current evidence on the relation of dietary inflammatory potential with low muscle mass among diabetic/prediabetic patients is limited. METHODS: Dietary consumption was determined by trained staff using the 24-hour diet recall method, and the Dietary Inflammatory Index (DII) was scored based on a previously validated approach that included 26 food parameters. Dual-energy X-ray absorptiometry was used to assess the mass of skeletal muscle and low muscle mass was defined based on the sarcopenia index. Logistic regression was conducted to calculate odds ratios (ORs) and 95 % confidence intervals (CIs). Restricted cubic spline (RCS) analysis was also performed to visually represent the relationship between DII and low muscle mass. Furthermore, sensitivity and subgroup analyses were conducted. RESULTS: In this study, a total of 4269 eligible participants were registered, comprising 1975 (46.26 %) females and 2294 (53.74 %) males. The mean age was 49.98 ± 0.31 years old, and the mean DII score was 1.53 ± 0.04. Among them, 934 (21.88 %) patients were defined as having low muscle mass, while 3335 (78.12 %) were without low muscle mass. The highest tertile (T3) of DII had an 61 % increased risk of low muscle mass (OR = 1.61, 95%CI: 1.19-2.17, p for trend = 0.004) compared to the lowest tertile. The RCS curve displayed a linear dose-response relationship between DII score and low muscle mass risk in patients with diabetes/prediabetes. Subgroup and sensitivity analyses provided robustness to our results. CONCLUSIONS: Our results indicated that a higher DII score was associated with an increased risk of low muscle mass among diabetes/prediabetes patients. These findings provided a nutritional strategy for diabetes/prediabetes patients to prevent skeletal muscle mass loss.

Senescent adipocytes as potential effectors of muscle cells dysfunction: An in vitro model.

Recently, there has been a growing body of evidence showing a negative effect of the white adipose tissue (WAT) dysfunction on the skeletal muscle function and quality. However, little is known about the effects of senescent adipocytes on muscle cells. Therefore, to explore potential mechanisms involved in age-related loss of muscle mass and function, we performed an in vitro experiment using conditioned medium obtained from cultures of mature and aged 3 T3-L1 adipocytes, as well as from cultures of dysfunctional adipocytes exposed to oxidative stress or high insulin doses, to treat C2C12 myocytes. The results from morphological measures indicated a significant decrease in diameter and fusion index of myotubes after treatment with medium of aged or stressed adipocytes. Aged and stressed adipocytes presented different morphological characteristics as well as a different gene expression profile of proinflammatory cytokines and ROS production. In myocytes treated with different adipocytes' conditioned media, we demonstrated a significant reduction of gene expression of myogenic differentiation markers as well as a significant increase of genes involved in atrophy. Finally, a significant reduction in protein synthesis as well as a significant increase of myostatin was found in muscle cells treated with medium of aged or stressed adipocytes compared to controls. In conclusion, these preliminary results suggest that aged adipocytes could influence negatively trophism, function and regenerative capacity of myocytes by a paracrine network of signaling.

Residual effects of 12 weeks of power-oriented resistance training plus high-intensity interval training on muscle dysfunction, systemic oxidative damage, and antioxidant capacity after 10 months of training cessation in older people with COPD.

OBJECTIVE: This study aimed to assess the residual effects of a 12-week concurrent training program (power training + high-intensity interval training) in older adults with chronic obstructive pulmonary disease (COPD). METHODS: A total of 21 older adults with COPD [intervention (INT), n = 8; control (CON), n = 13; 76.9 ± 6.8 years] were assessed at baseline and 10 months after the completion of the intervention by the short physical performance battery (SPPB), health-related quality of life (EQ-5D-5L), vastus lateralis muscle thickness (MT), peak pulmonary oxygen uptake (peak VO2 ) and peak work rate (Wpeak ), early and late isometric rate of force development (RFD), leg and chest press maximum muscle power (LPmax and CPmax ), and systemic oxidative damage and antioxidant capacity. RESULTS: Compared to baseline, after 10 months of detraining, the INT group presented increased SPPB (∆ = 1.0 point), health-related quality of life (∆ = 0.07 points), early RFD (∆ = 834 N∙s-1 ), LPmax (∆ = 62.2 W), and CPmax (∆ = 16.0 W) (all p < 0.05). In addition, a positive effect was noted in INT compared to CON regarding MT and Wpeak (both p < 0.05). No between-group differences were reported in peak VO2 , late RFD, systemic oxidative damage, and antioxidant capacity from baseline to 10 months after the completion of the intervention (all p > 0.05). CONCLUSIONS: Twelve weeks of concurrent training were enough to ensure improved physical function, health-related quality of life, early RFD and maximum muscle power and to preserve MT and Wpeak but not peak VO2 , late RFD, systemic oxidative damage and antioxidant capacity in the subsequent 10 months of detraining in older adults with COPD.

Defining and diagnosing sarcopenia: Is the glass now half full?

Low muscle mass and function exert a substantial negative impact on quality of life, health and ultimately survival, but their definition, identification and combination to define sarcopenia have suffered from lack of universal consensus. Methodological issues have also contributed to incomplete agreement, as different approaches, techniques and potential surrogate measures inevitably lead to partly different conclusions. As a consequence: 1) awareness of sarcopenia and implementation of diagnostic procedures in clinical practice have been limited; 2) patient identification and evaluation of therapeutic strategies is largely incomplete. Significant progress has however recently occurred after major diagnostic algorithms have been developed, with common features and promising perspectives for growing consensus. At the same time, the need for further refinement of the sarcopenia concept has emerged, to address its increasingly recognized clinical heterogeneity. This includes potential differential underlying mechanisms and clinical features for age- and disease-driven sarcopenia, and the emerging challenge of sarcopenia in persons with obesity. Here, we will review existing algorithms to diagnose sarcopenia, and major open methodological issues to assess skeletal muscle mass and function under different clinical conditions, in order to highlight similarities and differences. Potential for consensus on sarcopenia diagnosis as well as emerging new challenges will be discussed.

[Muscle activation times facing to a perturbation in patients with early-stage Parkinson's disease]. / Tiempos de activación muscular frente a una desestabilización en pacientes con enfermedad de Parkinson en etapas iniciales.

OBJECTIVES: Parkinson's disease (PD) generates a high incidence of falls, however, there is little evidence of instabilities in the initial stages. This investigation sought to compare the muscle activation times in patients with initial PD against a postural disturbance vs. a control group. MATERIALS AND METHODS: The electromyographic activity (EMG) of 10 patients with PD in early stages (61.3 ±3.8 years) and a control group of 10 adults (62.2 ±3.0 year) was evaluated. The participants were subjected to a surface disturbance, which generated a stabilization response. The test was performed under 2conditions: eyes open (OA) v/s eyes closed (OC). Trunk (spinal erector) and lower extremity (soleus, tibialis anterior, femoral biceps, femoral rectus, adductor magnus, gluteus medius) muscle activation time was analyzed using surface EMG. RESULTS: The PD group showed faster response times compared to the control group in the soleus muscle in OC (P=.04). This same muscle showed differences when comparing OA vs. OC only in the PD group (P=.04), showing a shorter response time in the OC condition. When comparing the spinal erector muscle, the PD group showed slower response times in the OA (P=.02) and OC (P=.04) conditions compared to the control group. CONCLUSIONS: Muscle activation times show that people with PD respond slower in the trunk muscles, while activation times decrease at the distal level. In the early stages, the slower responses at the trunk level could explain the onset of instability postural in these patients.

Senescence atlas reveals an aged-like inflamed niche that blunts muscle regeneration.

Tissue regeneration requires coordination between resident stem cells and local niche cells1,2. Here we identify that senescent cells are integral components of the skeletal muscle regenerative niche that repress regeneration at all stages of life. The technical limitation of senescent-cell scarcity3 was overcome by combining single-cell transcriptomics and a senescent-cell enrichment sorting protocol. We identified and isolated different senescent cell types from damaged muscles of young and old mice. Deeper transcriptome, chromatin and pathway analyses revealed conservation of cell identity traits as well as two universal senescence hallmarks (inflammation and fibrosis) across cell type, regeneration time and ageing. Senescent cells create an aged-like inflamed niche that mirrors inflammation associated with ageing (inflammageing4) and arrests stem cell proliferation and regeneration. Reducing the burden of senescent cells, or reducing their inflammatory secretome through CD36 neutralization, accelerates regeneration in young and old mice. By contrast, transplantation of senescent cells delays regeneration. Our results provide a technique for isolating in vivo senescent cells, define a senescence blueprint for muscle, and uncover unproductive functional interactions between senescent cells and stem cells in regenerative niches that can be overcome. As senescent cells also accumulate in human muscles, our findings open potential paths for improving muscle repair throughout life.

Loss of 4E-BPs prevents the hindlimb immobilization-induced decrease in protein synthesis in skeletal muscle.

The present study was designed to test the hypothesis that upregulating protein synthesis attenuates the loss of muscle mass in a model of disuse atrophy. The studies compared the effect of unilateral hindlimb immobilization in wild-type (WT) mice and double-knockout (DKO) mice lacking the translational regulators 4E-BP1 and 4E-BP2. Immobilization-induced downregulation of protein synthesis occurred in both groups of mice, but protein synthesis was higher in gastrocnemius muscle from the immobilized hindlimb of fasted DKO compared with WT mice. Surprisingly, although protein synthesis was partially elevated in DKO compared with WT mice, atrophy occurred to the same extent in both groups of animals. This may be partially due to impaired leucine-induced stimulation of protein synthesis in DKO compared with WT mice due to downregulated eukaryotic initiation factor eIF4E expression in muscle of DKO compared with WT mice. Expression of the E3 ubiquitin ligases MAFbx and MuRF-1 mRNAs and total protein ubiquitylation was upregulated in the immobilized compared with the nonimmobilized hindlimb of both WT and DKO mice, with little difference in the magnitude of the upregulation between genotypes. Analysis of newly synthesized proteins revealed downregulation of several glycolytic enzymes in the gastrocnemius of DKO mice compared with WT mice, as well as in the immobilized compared with the nonimmobilized hindlimb. Overall, the results suggest that the elevated rate of protein synthesis during hindlimb immobilization in fasted DKO mice is insufficient to prevent disuse-induced muscle atrophy, probably due to induction of compensatory mechanisms including downregulation of eIF4E expression.NEW & NOTEWORTHY Basal rates of protein synthesis are elevated in skeletal muscle in the immobilized leg of mice lacking the translational repressors, 4E-BP1 and 4E-BP2 (knockout mice), compared with wild-type mice. However, disuse-induced muscle atrophy occurs to the same extent in both wild-type and knockout mice suggesting that compensatory mechanisms are induced that overcome the upregulation of muscle protein synthesis. Proteomic analysis revealed that mRNAs encoding several glycolytic enzymes are differentially translated in wild-type and knockout mice.

Analysis of the adiponectin paradox in healthy older people.

BACKGROUND: It remains unknown why adiponectin levels are associated with poor physical functioning, skeletal muscle mass and increased mortality in older populations. METHODS: In 190 healthy adults (59-86 years, BMI 17-37 kg/m2 , 56.8% female), whole body skeletal muscle mass (normalized by height, SMI, kg/m2 ), muscle and liver fat were determined by magnetic resonance imaging. Bone mineral content (BMC) and density (BMD) were assessed by dual X-ray absorptiometry (n = 135). Levels of insulin-like growth factor 1 (IGF-1), insulin, inflammation markers, leptin and fibroblast growth factor 21 were measured as potential determinants of the relationship between adiponectin and body composition. RESULTS: Higher adiponectin levels were associated with a lower SMI (r = -0.23, P < 0.01), BMC (r = -0.17, P < 0.05) and liver fat (r = -0.20, P < 0.05) in the total population and with higher muscle fat in women (r = 0.27, P < 0.01). By contrast, IGF-1 showed positive correlations with SMI (r = 0.33), BMD (r = 0.37) and BMC (r = 0.33) (all P < 0.01) and a negative correlation with muscle fat (r = -0.17, P < 0.05). IGF-1 was negatively associated with age (r = -0.21, P < 0.01) and with adiponectin (r = -0.15, P < 0.05). Stepwise regression analyses revealed that IGF-1, insulin and leptin explained 18% of the variance in SMI, and IGF-1, leptin and age explained 16% of the variance in BMC, whereas adiponectin did not contribute to these models. CONCLUSIONS: Associations between higher adiponectin levels and lower muscle or bone mass in healthy older adults may be explained by a decrease in IGF-1 with increasing adiponectin levels.

Muscle contractile exercise through a belt electrode device prevents myofiber atrophy, muscle contracture, and muscular pain in immobilized rat gastrocnemius muscle.

PURPOSE: Immobilization of skeletal muscles causes muscle atrophy, muscle contracture, and muscle pain, the mechanisms of which are related to macrophage accumulation. However, muscle contractile exercise through a belt electrode device may mitigate macrophage accumulation. We hypothesized that such exercise would be effective in preventing myofiber atrophy, muscle contracture, and muscular pain. This study tested this hypothesis in immobilized rat gastrocnemius muscle. MATERIALS AND METHODS: A total of 32 rats were divided into the following control and experimental groups: immobilization (immobilized treatment only), low-frequency (LF; immobilized treatment and muscle contractile exercise with a 2 s (do) /6 s (rest) duty cycle), and high-frequency (HF; immobilized treatment and muscle contractile exercise with a 2 s (do)/2 s (rest) duty cycle). Electrical stimulation was performed at 50 Hz and 4.7 mA, and muscle contractile exercise was applied to the lower limb muscles for 15 or 20 min/session (once daily) for 2 weeks (6 times/week). After the behavioral tests, the bilateral gastrocnemius muscles were collected for analysis. RESULTS: The number of macrophages, the Atrogin-1 and MuRF-1 mRNA expression, and the hydroxyproline content in the HF group were lower than those in the immobilization and LF groups. The cross-sectional area (CSA) of type IIb myofibers in the superficial region, the PGC-1α mRNA expression, and the range of motion of dorsiflexion in the HF group were significantly higher than those in the immobilization and LF groups. The pressure pain thresholds in the LF and HF groups were significantly higher than that in the immobilization group, and the nerve growth factor (NGF) content in the LF and HF groups was significantly lower than that in the immobilization group. CONCLUSION: Muscle contractile exercise through the belt electrode device may be effective in preventing immobilization-induced myofiber atrophy, muscle contracture, and muscular pain in the immobilized rat gastrocnemius muscle.

Prevention of muscle atrophy in ICU patients without nerve injury by neuromuscular electrical stimulation: a randomized controlled study.

BACKGROUND: Extensive muscle atrophy is a common occurrence in orthopaedics patients who are bedridden or immobilized. The incidence is higher in intensive care unit (ICU) inpatients. There is still controversy about how to use neuromuscular electrical stimulation (NMES) in ICU patients. We aim to compare the effectiveness and safety of NMES to prevent muscle atrophy in intensive care unit (ICU) patients without nerve injury. METHODS: ICU patients without central and peripheral nerve injury were randomized into experimental group I (Exp I: active and passive activity training (APAT) + NMES treatment on the gastrocnemius and tibialis anterior muscle), experimental group II (Exp II: APAT + NMES treatment on gastrocnemius alone), and control group (Ctl: APAT alone). Changes in the strength of gastrocnemius, the ankle range of motion, and the muscle cross-section area of the lower leg were evaluated before and after the intervention. Also, changes in prothrombin time, lactic acid, and C-reactive protein were monitored during the treatment. RESULTS: The gastrocnemius muscle strength, ankle joint range of motion, and cross-sectional muscle area of the lower leg in the three groups showed a downward trend, indicating that the overall trend of muscle atrophy in ICU patients was irreversible. The decrease in gastrocnemius muscle strength in Exp I and Exp II was smaller than that in the control group (P < 0.05), but there was no difference between Exp I and Exp II. The decrease in active ankle range of motion and cross-sectional area of the lower leg Exp I and Exp II was smaller than that in the control group (P < 0.05), and the decrease in Exp I was smaller than that of Exp II (all P < 0.05). The curative effect in Exp I was better than in Exp II. There were no significant differences in the dynamic changes of prothrombin time, lactic acid, and C-reactive protein during the three groups (P > 0.05). CONCLUSION: In addition to early exercise training, NMES should be applied to prevent muscle atrophy for patients without nerve injury in ICU. Also, simultaneous NMES treatment on agonist/antagonist muscle can enhance the effect of preventing muscle atrophy. TRIAL REGISTRATION: This study was prospectively registered in China Clinical Trial Registry ( www.chictr.org.cn ) on 16/05/2020 as ChiCTR2000032950.

Combined effect of lower muscle quality and quantity on incident falls and fall-related fractures in community-dwelling older adults: A 3-year follow-up study.

OBJECTIVE: Falls and fractures are serious geriatric adverse events worldwide, and skeletal muscle is considered to be a key factor in these incidents. The objective of this study was to investigate the combined effect of lower muscle quality and quantity on the incidence of falls and fall-related fractures in a 3-year follow-up period among community-dwelling older adults. METHODS: We recruited community-dwelling adults aged 65 years and older who were living independently in 2018. A total of 773 older participants were analyzed in this study. The outcomes were incident falls and fall-related fractures during the 3-year follow-up period. At baseline, we assessed muscle quality and quantity using ultrasonography, and we categorized the participants into four groups based on their combination of poor/better muscle quality and poor/better muscle quantity. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95 % confidence intervals (CIs) of the relationships among items in the four groups and the time to incident falls and fall-related fractures. RESULTS: During the 3-year follow-up period, 178 participants (23.0 %) had a fall incident and 51 participants (6.6 %) had fall-related fractures. Older adults with lower muscle quality and quantity had significantly elevated risks of incident falls according to multivariate analyses using older adults with better muscle quality and quantity as the reference (adjusted HR: 1.54 [95 % CI 1.06-2.23]). However, there were no significant differences in fall-related fractures among the four groups. CONCLUSION: We found that lower muscle quality and quantity led to higher incidents of falls; thus, identifying community-dwelling older adults with lower muscle quality and quantity is necessary to provide them fall preventive measures and maybe to reduce fall-related outcomes.

False-positive results in transcranial motor evoked potentials for outcome prognostication during surgery for supratentorial lesions.

During monitoring of motor evoked potentials (MEP) elicited by transcranial electrical stimulation (TES) for prognostication of postoperative motor deficit, significant MEP changes without postoperative deterioration of motor function represent false-positive results. We aimed to investigate this phenomenon in a large series of patients who underwent resection of supratentorial lesions. TES was applied in 264 patients during resection of motor-eloquent supratentorial lesions. MEP were recorded bilaterally from arm, leg, and/ or facial muscles. The threshold criterion was applied assessing percentage increase in threshold level, which was considered significant if being > 20% higher on affected side than on the unaffected side. Subcortical stimulation was additionally applied to estimate the distance to corticospinal tract. Motor function was evaluated at 24 h after surgery and at 3-month follow-up. Patients with false-positive results were analyzed regarding tumor location, tumor volume, and characteristics of the monitoring. MEP were recorded from 399 muscles (264 arm muscles, 75 leg muscles, and 60 facial muscles). Motor function was unchanged postoperatively in 359 muscles in 228 patients. Among these cases, the threshold level did not change significantly in 354 muscles in 224 patients, while it increased significantly in the remaining 5 muscles in 4 patients (abductor pollicis brevis in all four patients and orbicularis oris in one patient), leading to a false-positive rate of 1.1%. Tumor volume, opening the ventricle, and negative subcortical stimulation did not significantly correlate with false-positive results, while the tumor location in the parietal lobe dorsal to the postcentral gyrus correlated significantly (p = 0.012, odds ratio 11.2, 95% CI 1.8 to 69.8). False-negative results took place in 1.1% of cases in a large series of TES-MEP monitoring using the threshold criterion. Tumor location in the parietal lobe dorsal to the postcentral gyrus was the only predictor of false-positive results.

Functional characterization of GNE mutations prevalent in Asian subjects with GNE myopathy, an ultra-rare neuromuscular disorder.

UDP-GlcNAc 2-epimerase/ManNAc kinase (GNE) is a bifunctional enzyme (N-terminal epimerase and C-terminal Kinase domain) that catalyses the rate limiting step in sialic acid biosynthesis. More than 200 homozygous missense or compound heterozygous mutations in GNE have been reported worldwide to cause a rare neuromuscular disorder, GNE myopathy. It is characterized by a slowly progressive defect in proximal and distal skeletal muscles with patients becoming wheel-chair-bound. There are no current approved therapies available for GNE myopathy. ManNAc therapy is currently in advanced clinical trials and has shown signs of slowing the disease progression in a phase 2 trial. The present study aims to understand the effect of GNE mutation on its enzymatic activity and identification of potential small effector molecules. We characterized different GNE mutations (p.Asp207Val, p.Val603Leu, p.Val727Met, p.Ile618Thr and p.Arg193Cys) prevalent in Asian population that were cloned, expressed and purified from Escherichia coli as full-length recombinant proteins. Our study demonstrates that full length GNE can be expressed in E. coli in its active form and analysed for the functional activity. Each mutation showed variation in epimerase and kinase activity and responded to the small effector molecules (metformin, BGP-15 kaempferol, catechin, quercetin) in a differential manner. Our study opens an area for futuristic structural determination of full length GNE and identification of potential therapeutic molecules.

Free fatty acids are associated with muscle dysfunction in Chinese adults with type 2 diabetes.

PURPOSE: Muscle dysfunction is considered a sign of poor prognosis in patients with type 2 diabetes (T2D). Thus, early detection of muscle disorders is particularly important in the T2D population. Free fatty acids (FFAs) are clinical indicators of metabolic diseases and muscle function; hence, we aimed to investigate the association between FFAs and muscle function. METHODS: A total of 160 adult subjects with T2D were characterized and analyzed in this study. Muscle mass and function were measured by walking speed, grip strength and height-adjusted appendicular skeletal muscle mass (ASMM). Partial correlation was applied to explore the correlations between FFAs and muscle indicators. Receiver operating characteristic (ROC) curves were utilized to determine the diagnostic value of FFAs in muscle mass and function. RESULTS: The FFAs levels were negatively correlated with ASMM (r = -0.347, P = 1.0E-05), grip strength (r = -0.313, P = 7.1E-05) and walking speed (r = -0.167, P = 0.039). Notably, the relationships between FFAs levels and ASMM and walking speed remained significant even after adjusting for age, sex, body mass index (BMI), diabetes duration, and hemoglobin A1C (HbA1c). The combination of conventional indicators, including age, BMI, and HbA1c levels, provided a discrimination of low grip strength with an AUC of 0.648, and low walking speed with an AUC of 0.714. Importantly, when FFAs levels were added to the model, the value of the ROC curve was further improved, with an AUC of 0.785 for low grip strength and 0.755 for low walking speed. CONCLUSIONS: The current study demonstrated a negative correlation between FFAs and muscle indicators in adult patients with T2D after adjusting for HbA1c levels. FFAs may play an important role in the pathological processes of muscle dysfunction in adults with T2D.

Is the Outcome of Diagnostic Nerve Block Related to Spastic Muscle Echo Intensity? A Retrospective Observational Study on Patients with Spastic Equinovarus Foot.

OBJECTIVE: To investigate the relationship between spastic calf muscles echo intensity and the outcome of tibial nerve motor branches selective block in patients with spastic equinovarus foot. DESIGN: Retrospective observational study. PATIENTS: Forty-eight patients with spastic equinovarus foot. METHODS: Each patient was given selective diagnostic nerve block (lidocaine 2% perineural injection) of the tibial nerve motor branches. All patients were evaluated before and after block. Outcomes were: spastic calf muscles echo intensity measured with the Heckmatt scale; affected ankle dorsiflexion passive range of motion; calf muscles spasticity measured with the modified Ashworth scale and the Tardieu scale (grade and angle). RESULTS: Regarding the outcome of tibial nerve selective diagnostic block (difference between pre- and post-block condition), Spearman's correlation showed a significant inverse association of the spastic calf muscles echo intensity with the affected ankle dorsiflexion passive range of motion (p = 0.045; ρ = 00-0.269), modified Ashworth scale score (p = 0.014; ρ = -0.327), Tardieu grade (p = 0.008; ρ = -0.352) and Tardieu angle (p = 0.043; ρ = -0.306). CONCLUSION: These findings support the hypothesis that patients with spastic equinovarus foot with higher spastic calf muscles echo intensity have a poor response to selective nerve block of the tibial nerve motor branches.

Prognostic significance of the skeletal muscle index and systemic inflammatory index in patients with lymph node-positive breast cancer after radical mastectomy.

BACKGROUND: The role of skeletal muscle index (SMI) and systemic inflammation index (SII) for patients with lymph node-positive breast cancer remain controversial. This retrospective study aims to evaluate the individual and synergistic value of SMI and SII in outcomes prediction in this population. METHODS: Lymph node-positive breast cancer patients who received mastectomy between January 2011 and February 2013 were included in this retrospective study. We used abdominal computed tomography (CT) to measure skeletal muscle mass at the third lumbar (L3) level. The optimal cut-off values of SMI and SII were determined through maximizing the Youden index on the receiver operating characteristic (ROC) curves. Kaplan-Meier method was used to assess the correlation between SMI, SII, and overall survival (OS). The prognostic value of SMI and SII were analyzed with the multivariable Cox proportional hazards model. RESULTS: Of 97 patients included in our study (mean age: 46 [range: 27-73] years; median follow-up: 62.5 months), 71 had low SMI (sarcopenia), 59 had low SII, and 56 had low SMI + SII. Kaplan-Meier survival curves showed that both high SMI (P = 0.021, 5-year OS: 84.0% vs. 94.1%) and high SII (P = 0.043, 5-year OS: 81.0% vs. 97.3%) were associated with worse OS. Additionally, patients with either low SMI or low SII had significantly better OS (P = 0.0059, 5-year OS: 100.0% vs. 84.6%) than those with high SMI + SII. Multivariable analysis confirmed the predictive values of high SMI (P = 0.024, hazard ratio [HR]: 9.87) and high SII (P = 0.048, HR: 6.87) for poor OS. Moreover, high SMI + SII was significantly associated with poor survival (P = 0.016, HR: 16.36). CONCLUSIONS: In this retrospective analysis, both SMI and SII independently predicted the prognosis of patients with lymph node-positive breast cancer. SMI + SII might be a stronger prognostic factor than either alone based on our findings, but should be further verified in a larger study.

Relationship between infrared thermography and muscle damage markers in physically active men after plyometric exercise.

Plyometric training has been used in several sports and fitness programs to improve jumping ability and explosive strength, both in individual and team sports. Eccentric muscle actions, such as those performed during plyometric jumps, induce muscle damage and consequently a rise in skin temperature (Tsk). Thus, the purpose of this study is to assess the response of infrared thermography measurement as an indirect marker of muscle damage after a protocol of plyometric jumps in physically active subjects. Therefore, for the aim of this study ten male subjects with no previous experience in plyometric training participated in the research (age 22.5 ± 3.3 years, weight 71.7 ± 11.0 kg, height 171.1 ± 5.3 cm, and fat mass 15.5 ± 4.7%). To assess the muscle damage, countermovement jump (CMJ), creatine kinase (CK), delayed-onset muscle soreness (DOMS) and infrared thermography (IRT) were measured at 24, 48, and 72 h after plyometric exercise. The acute exercise protocol of plyometric jumps induced muscle damage, as shown by the CK and DOMS (24 and 48 h, p < 0.05) but no statistical difference was shown between the moments analyzed in Tsk (warm zone). Nevertheless, when comparing baseline to 48h, a moderate effect was found in the Tsk (warm zone) for anterior right thigh (ES = 1.1) and posterior left thigh (ES = 0.9) and large effect was found for anterior left thigh (ES = 1.4) and posterior right thigh (ES = 1.3). A moderate effect in the Tsk (warm zone) was found for posterior right and left thigh (ES = 0.9 and ES = 1.1, respectively) when comparing baseline to 72h of IRT. These results suggest that a plyometric jumping session alters CK and DOMS, as well as the thigh's skin temperature in an evident way, bringing up a possible relation with markers of muscle damage.

Effects of low-intensity training on the brain and muscle in the congenital muscular dystrophy 1D model.

INTRODUCTION: Congenital Muscular Dystrophy type 1D (MDC1D) is characterized by a hypoglycosylation of α-dystroglycan protein (α-DG), and this may be strongly implicated in increased skeletal muscle tissue degeneration and abnormal brain development, leading to cognitive impairment. However, the pathophysiology of brain involvement is still unclear. Low-intensity exercise training (LIET) is known to contribute to decreased muscle degeneration in animal models of other forms of progressive muscular dystrophies. AIM: The objective of this study was to analyze the effects of LIET on cognitive involvement and oxidative stress in brain tissue and gastrocnemius muscle. METHODS: Male homozygous (Largemyd-/-), heterozygous (Largemyd+/-), and wild-type mice were used. To complete 28 days of life, they were subjected to a low-intensity exercise training (LIET) for 8 weeks. After the last day of training, 24 h were expected when the animals were submitted to inhibitory avoidance and open-field test. The striatum, prefrontal cortex, hippocampus, cortex, and gastrocnemius were collected for evaluation of protein carbonylation, lipid peroxidation, and catalase and superoxide dismutase activity. RESULTS: LIET was observed to reverse the alteration in aversive and habituation memory. Increased protein carbonylation in the striatum, prefrontal cortex, and hippocampus and lipid peroxidation in the prefrontal cortex and hippocampus were also reversed by LIET. In the evaluation of the antioxidant activity, LIET increased catalase activity in the hippocampus and cortex. In the gastrocnemius, LIET decreased the protein carbonylation and lipid peroxidation and increased catalase and superoxide dismutase activity. CONCLUSION: In conclusion, it can be inferred that LIET for 8 weeks was able to reverse the cognitive damage and oxidative stress in brain tissue and gastrocnemius muscle in MDC1D animals.