Limb Grip Strength Research Articles

Chrebp Deletion and Mild Protein Restriction Additively Decrease Muscle and Bone Mass and Function

Background/Objectives: Carbohydrate and protein restriction are associated with sarcopenia and osteopenia, but the underlying mechanisms remain unclear. We aimed to determine whether mild protein restriction affects muscle and bone function in wild-type (WT) and homozygous carbohydrate response element binding protein (Chrebp) knockout (KO) mice. Methods: Eighteen-week-old male wild-type and homozygous carbohydrate response element binding protein (Chrebp) knockout (KO) mice were fed a control diet (20% protein) or a low-protein diet (15% protein) for 12 weeks. We estimated the muscle weight and limb grip strength as well as the bone mineral density, bone structure, and bone morphometry. Results: Chrebp deletion and a low-protein diet additively decreased body weight (WT control–KO low-protein: mean difference with 95% CI, 8.7 [6.3, 11.0], p < 0.0001) and epidydimal fat weight (1.0 [0.7, 1.2], p < 0.0001). Chrebp deletion and a low-protein diet additively decreased tibialis anterior muscle weight (0.03 [0.01, 0.05], p = 0.002) and limb grip strength (63.9 [37.4, 90.5], p < 0.0001) due to a decrease in insulin/insulin-like growth factor 1 mRNA and an increase in myostatin mRNA. In contrast, Chrebp deletion increased bone mineral density (BMD) (WT control–KO control: –6.1 [–1.0, –2.3], p = 0.0009), stiffness (–21.4 [–38.8, –4.1], p = 0.011), cancellous bone BV/TV (–6.517 [–10.99, –2.040], p = 0.003), and the number of trabeculae (–1.1 [–1.8, –0.5], p = 0.0008). However, in KO mice, protein restriction additively decreased BMD (KO control–KO low-protein: 8.1 [4.3, 11.9], p < 0.0001), bone stiffness (38.0 [21.3, 54.7], p < 0.0001), cancellous bone BV/TV (7.7 [3.3, 12.2], p = 0.006), and the number of trabeculae (1.2 [0.6, 1.9], p = 0.0004). The effects of mild protein restriction on bone formation parameters (osteoid volume (WT control–WT low-protein: –1.7 [–2.7, –0.7], p = 0.001) and the osteoid surface (–11.2 [–20.8, –1.5], p = 0.02) were observed only in wild-type (WT) mice. The levels of bone resorption markers, such as the number of osteoclasts on the surface, the number of osteoclasts, and surface erosion, did not differ between the groups. Conclusions: Both Chrebp deletion and protein restriction led to a decrease in muscle and bone function; therefore, an adequate intake of carbohydrates and proteins is important for maintaining muscle and bone mass and function. Further studies will be needed to elucidate the mechanisms by which ChREBP deletion and a low-protein diet cause osteosarcopenia.

Sleep Deprivation and Subchronic Arsenite Exposure Synergistically Induced Skeletal Muscle Aging by Disrupting Melatonin and Cortisol Secretion in Mice

In recent years, the influence of environmental factors on organismal aging has garnered increasing attention. Studies have shown that sleep deprivation and environmental pollutants could accelerate the emergence of multiple organismal aging phenotypes. In addition, studies have shown that chronic exposure to sodium arsenite (iAs) induces skeletal muscle atrophy and the inhibition of melatonin secretion in rats. This study aimed to reveal the synergistic effect of sleep deprivation and arsenite exposure on skeletal muscle aging, including reduced limb grip strength and skeletal muscle mass, along with the serum levels of melatonin (MT) and cortisol (COR) in C57BL/6J mice. The results demonstrated that while exposure to arsenite for 12 weeks or sleep deprivation (SD) for 4 weeks did not exert significant effects on limb grip strength or skeletal muscle mass, their combination exhibited a synergistic effect on skeletal muscle aging. Notably, the iAs+SD group exhibited a significant decline in limb grip strength by Week 12, accompanied by a reduced gastrocnemius muscle mass and muscle index. The pathological analysis showed muscle fiber atrophy, a shift towards slow-twitch muscle fibers (type I), and shortened telomere length. Additionally, oxidative damage was increased in the SD and iAs+SD groups, with decreased levels of SOD and GPx and elevated levels of MDA in the iAs+SD group. The serum MT level and MT/COR ratio were significantly reduced, while the serum COR level was elevated in the iAs+SD group compared to the other groups. A correlation analysis further revealed that the serum MT level and the MT/COR ratio were positively correlated with limb grip strength, muscle index, and telomere length, whereas the serum COR level exhibited negative correlations with these parameters. These findings suggest that sleep deprivation and subchronic exposure to arsenite synergistically induce skeletal muscle aging, and that the disruption of the balance between MT and COR potentially serves as a significant risk factor.

Use of an electrical stimulation-induced fatigue protocol to evaluate the myotropic effects of metabolic-active agents in db/db mice

Introduction. Type 2 diabetes mellitus (T2DM) is a chronic condition characterized by insulin resistance, impaired glucose tolerance, and hyperglycaemia. T2DM is a proven risk factor for peripheral neuropathies as well as muscle contractility and function impairments. The biguanide metformine, experimental compound maloben, and preparations of various Panax species have a considerable potential for the treatment of T2DM and its skeletal muscle complications. As a test to evaluate muscle contractility and the effectiveness of its recovery, Gregory et al. have developed a protocol of electrical stimulation-induced fatigue (ESIF) which includes measuring grip strength after fatiguing the biceps brachii muscle with high-frequency electrical stimulation using implantable electrodes.Aim. In this work, we attempted to assess the applicability of a modification of said protocol in order to evaluate the myotropic effects of metformin, maloben, and extracts from suspension cell cultures of Panax ginseng C.A. Mey. (PGE), P. vietnamensis Ha & Grushv. (PVE), and P. japonicus (T. Nees) C.A. Mey. (PJE) in the leptin-resistant db/db mice, one of the most popular modern T2DM models.Materials and methods. The experiments were carried out in 60 young adult (2 months old) male C57Bl/Ks-db+/+m (db/db) mice weighing 45–50 g, randomized into 6 groups: 1) Control (n = 10; 0.9 % saline); 2) PGE (n = 10; 50 mg/kg); 3) PVE (n = 10; 50 mg/kg); 4) PJE (n = 10; 50 mg/kg); 5) maloben (n = 10; 60 mg/kg); 6) metformin (n = 10; 300 mg/kg). All drugs were administered via oral gavage using a feeding tube once daily for 2 months. Following the treatment period, forelimb and all-four limb grip strength (g) was assessed using the Grip Strength Meter (TSE Systems, Germany). Using stimulation electroneuromyography, we measured the compound muscle action potential (CMAP) amplitudes in the gastrocnemius induced by single-stimulus sciatic nerve stimulation, and assessed the dynamics of CMAP amplitudes during the first 5 min following the ESIF protocol completion.Results and discussion. Following treatment period completion, no significant changes were observed between the groups in grip strength or gastrocnemius CMAP amplitude under single-stimulus stimulation. Controlled ESIF of the muscle caused a 18.83–35.23 % (relative to baseline) decrease in CMAP amplitudes (p < 0.01 for all groups) that was significantly smaller in the PVE, PJE, and maloben groups vs. control (p < 0.05). The post-ESIF recovery period was associated with a 10.18–14.79 % increase in CMAP amplitudes that was significant in all groups except PGE (p < 0.01 for control, PVE, and PJE; p < 0.05 for maloben and metformin). No significant differences from control were observed in any of the treatment groups regarding net recovery.Сonclusion. The proposed protocol represents a functional test suitable to assess the recovery effectiveness of electrical activity of a skeletal muscle following its controlled fatigue. Using the described protocol, we were able to detect beneficial effects of PVE, PJE, and maloben (but not PGE or metformin) on the recovery of gastrocnemius contractility following tetanization in diabetic db/db mice. The ESIF test is sensitive to the myotropic effects of metabolic agents, minimally invasive, and acceptable under chronic experiment conditions.

A077: Effect of Ischemic Preconditioning on Upper Limb After a Heavy Load Swimming Training

Purpose: Ischemic preconditioning (IPC) is a short, noninvasive and intermittent ischemic treatment of limbs before exercise. The aim of this study was to compare the effects of acute or repeated IPC on upper arm skeletal muscle strength and circumference after a heavy load swimming training. Methods: College students majoring in swimming were randomly divided into CON group, acute IPC group (the intervention lasted 7 days, AIPC) and repeated IPC group (intervention for 1 day, RIPC), and IPC intervention was performed before a high-load swimming training. The three groups were all 4×5min with CON pressure of 20mmHg and IPC pressure of 220mmHg. Upper limb tension, grip strength, upper arm circumference, and shoulder circumference were measured at baseline and 0h, 24h, and 48h after exercise. Results: 1) the IPC after exercise intervention group in upper limb tension, grip strength and upper arm circumference were significantly greater than the change range of CON. This indicates that the IPC intervention promoted the four indices after training to maintain and restore. 2) After 24h of exercise, the reduction of upper limb tension in RIPC group was significantly lower than that in AIPC group, and the reduction of upper arm circumference was significantly faster than that in AIPC group. Indicating that the recovery effect of RIPC on upper limb tension and upper arm circumference was better than that of AIPC group. 3) Concurrently, there were no significant differences in shoulder circumference between groups, and whether IPC intervention was performed did not seem to affect the recovery of shoulder circumference after training. Conclusion: IPC can effectively promote the upper arm skeletal muscle strength and circumference after heavy load swimming training. RIPC intervention to the recovery of tension and circumference of upper arm more effective than that of AIPC.

Is Mat pilates effective in lower limb strength and hand grip strength of people with Parkinson’s? A randomized clinical trial with follow-up

IntroductionParkinson's disease can contribute to the loss of muscle strength, and physical exercise such as Mat Pilates can be effective in improving this, core stability, flexibility, and muscle control. ObjectiveTo analyze the effects of a 12-week intervention with Mat Pilates in the short and long term, on lower limb and hand grip strength in people with Parkinson's. MethodsThe study included 23 people (61.7 ± 7.5 years) of both sexes, diagnosed with Parkinson's disease who were selected according to inclusion criteria and divided into intervention and control groups. ResultsThe hand grip variable showed improvement in the intervention group intragroup only in the right hand (p = 0.003) in the post-intervention period. In the lower limb strength variable, there was significance in the extension of the left leg both in the intervention intragroup (p = 0.042), and in the control group (p = 0.001) the result in the flexion of the left leg in the intervention group (p = 0.032). The follow-up data showed significance in the strength of extension of the right leg in the intervention group (p = 0.049) and in the control group (p = 0.024) and in the extension of the left leg in the intervention group (p = 0.021). ConclusionMat Pilates classes for people with Parkinson's with mild and moderate degrees proved to be effective in the short term in the hand grip strength of the right hand, and in the extension and flexion of the left legs, and positive effects in the long term in the strength of extension of the right also left legs.

Innovations in Sports: A Key to Enhancing Rehabilitation Outcomes

Introduction and purpose: Traditional rehabilitation methods often have limitations in improving motor function and cognitive abilities. This review aims to provide an updated overview of innovative methods in rehabilitation, focusing on the role of immersive and interactive technologies in enhancing rehabilitation outcomes. The literature suggests that these technologies can improve upper limb mobility, grip strength, and manual dexterity, as well as cognitive function, attention, and spatial awareness. Additionally, innovative balance and gait rehabilitation programs have been shown to improve functional mobility and reduce the risk of falls. The use of these technologies in combination with other rehabilitation modalities, such as electrostimulation and robotic assistance, may lead to even greater improvements in motor function and cognitive abilities. While more research is needed to fully understand the benefits and limitations of these innovative approaches, the existing evidence suggests that they have the potential to revolutionize rehabilitation and improve quality of life for patients. Materials and Methods: A literature review was conducted using PubMed with search phrases immersive and interactive technologies and rehabilitation. Description of the state of knowledge: Traditional rehabilitation methods often have limitations in improving motor function and cognitive abilities.Upper extremity impairment is a common and debilitating consequence of stroke. Summary: imersive and interactive technologies have the potential to improve upper limb mobility, grip strength, and manual dexterity, as well as cognitive function, attention, and spatial awareness. Innovative balance and gait rehabilitation programs have been shown to improve functional mobility and reduce the risk of falls. The use of these technologies in combination with other rehabilitation modalities may lead to even greater improvements in motor function and cognitive abilities.

Handgrip Strength and Upper Limb Anthropometric Characteristics among Latin American Female Volleyball Players.

Background: In volleyball, the upper limb dimensions and grip strength greatly influence offensive and defensive movements during a match. However, the relationship between these parameters remains underexplored in elite female volleyball players. Objective: This study aimed to contrast the upper limb anthropometric characteristics and handgrip strength (HGS) of female elite volleyball players against a control group. Methods: Selected upper limb anthropometric parameters and maximal HGS of 42 female volleyball players and 40 non-athletes were measured. Results: Players exhibited higher values in almost all variables studied than non-athletes. The differences were statistically significant (p < 0.001) except for body mass index and elbow and wrist diameters. Players showed a moderate correlation between dominant HGS and hand parameters (length r = 0.43 and breadth r = 0.63; p < 0.05). Weak correlations were identified with height, upper arm length, elbow diameter, and hand shape index (r = 0.32 to 0.38; p < 0.05). In the non-dominant hand, a moderate correlation with handbreadth (r = 0.55, p ≤ 0.01) and weak correlations with upper arm length, wrist diameter, hand length, and hand shape index (r = 0.32 to 0.35; p ≤ 0.05) was found. Conclusions: These findings underscore the importance of the upper limb anthropometric parameters as predictors of HGS and their utility in athlete selection. Future research should investigate biomechanical factors influencing HGS and injury prevention.

Melatonin Regulates Rheumatoid Synovial Fibroblasts-Related Inflammation: Implications for Pathological Skeletal Muscle Treatment.

Melatonin has been reported to regulate circadian rhythms and have anti-inflammatory characteristics in various inflammatory autoimmune diseases, but its effects in diseases-associated muscle atrophy remain controversial. This study is aimed to determine the evidence of melatonin in rheumatoid arthritis (RA)-related pathological muscle atrophy. We used initially bioinformatics results to show that melatonin regulated significantly the correlation between pro-inflammation and myogenesis in RA synovial fibroblasts (RASF) and myoblasts. The conditioned medium (CM) from melatonin-treated RASF was incubated in myoblasts with growth medium and differentiated medium to investigate the markers of pro-inflammation, atrophy, and myogenesis. We found that melatonin regulated RASF CM-induced pathological muscle pro-inflammation and atrophy in myoblasts and differentiated myocytes through NF-κB signaling pathways. We also showed for the first time that miR-30c-1-3p is negatively regulated by three inflammatory cytokines in human RASF, which is associated with murine-differentiated myocytes. Importantly, oral administration with melatonin in a collagen-induced arthritis (CIA) mouse model also significantly improved arthritic swelling, hind limb grip strength as well as pathological muscle atrophy. In conclusion, our study is the first to demonstrate not only the underlying mechanism whereby melatonin decreases pro-inflammation in RA-induced pathological muscle atrophy but also increases myogenesis in myoblasts and differentiated myocytes.

Reductions in functional muscle mass and ability to ambulate in Duchenne muscular dystrophy from ages 4 to 24 years.

Duchenne muscular dystrophy (DMD) results in a progressive loss of functional skeletal muscle mass (MM) and replacement with fibrofatty tissue. Accurate evaluation of MM in DMD patients has not previously been available. Our objective was to measure MM using the D3creatine (D3Cr) dilution method and determine its relationship with strength and functional capacity in patients with DMD over a wide range of ages. Subjects were recruited for participation in a 12month, longitudinal, observational study. Here, we report the baseline data. A 20mg dose of D3Cr dissolved in water was ingested by 92 patients with DMD (ages 4-25years) followed later with a fasting urine sample. Enrichment of D3creatinine was determined by liquid chromatography-mass spectrometry analysis. The North Star Ambulatory Assessment (NSAA) total score was determined for ambulatory participants, and the Performance of Upper Limb (PUL 2.0) total score and grip strength for all participants. We observed a significant age-associated increase in body weight along with a substantial decrease in MM/body weight (%MM). MM and %MM were associated with PUL score (r=0.517, P<0.0001 and r=0.764, P<0.0001 respectively). The age-associated decrease in MM and %MM was strongly associated with ambulatory status. We observed very little overlap in %MM between ambulant and non-ambulant subjects, suggesting a threshold of 18-22% associated with loss of ambulation. MM is substantially diminished with advancing age and is highly related to clinically meaningful functional status. The D3Cr dilution method may provide a biomarker of disease progression and therapeutic efficacy in patients with DMD or other neuromuscular disorders. KEY POINTS: The non-invasive D3creatine dilution method provides novel data on whole body functional muscle mass (MM) in a wide range of ages in patients with DMD and reveals profoundly low functional MM in older non-ambulant patients. The difference in %MM between ambulant and non-ambulant subjects suggests a threshold for loss of ambulatory ability between 18 and 22% MM. The data suggest that as functional MM declines with age, maintaining a lower body weight may help to conserve ambulatory ability.

Metabolomic analysis of dietary-restriction-induced attenuation of sarcopenia in prematurely aging DNA repair-deficient mice.

Sarcopenia is characterized by loss of skeletal muscle mass and function, and is a major risk factor for disability and independence in the elderly. Effective medication is not available. Dietary restriction (DR) has been found to attenuate aging and aging-related diseases, including sarcopenia, but the mechanism of both DR and sarcopenia are incompletely understood. In this study, mice body weight, fore and all limb grip strength, and motor learning and coordination performance were first analysed to evaluate the DR effects on muscle functioning. Liquid chromatography-mass spectrometry (LC-MS) was utilized for the metabolomics study of the DR effects on sarcopenia in progeroid DNA repair-deficient Ercc1∆/- and Xpg-/- mice, to identify potential biomarkers for attenuation of sarcopenia. Muscle mass was significantly (P<0.05) decreased (13-20%) by DR; however, the muscle quality was improved with retained fore limbs and all limbs grip strength in Ercc1∆/- and Xpg-/- mice. The LC-MS results revealed that metabolites and pathways related to oxidative-stress, that is, GSSG/GSH (P<0.01); inflammation, that is, 9-HODE, 11-HETE (P<0.05), PGE2, PGD2, and TXB2 (P<0.01); and muscle growth (PGF2α) (P<0.01) and regeneration stimulation (PGE2) (P<0.05) are significantly downregulated by DR. On the other hand, anti-inflammatory indicator and several related metabolites, that is, β-hydroxybutyrate (P<0.01), 14,15-DiHETE (P<0.0001), 8,9-EET, 12,13-DiHODE, and PGF1 (P<0.05); consumption of sources of energy (i.e., muscle and liver glycogen); and energy production pathways, that is, glycolysis (glucose, glucose-6-P, fructose-6-P) (P<0.01), tricarboxylic acid cycle (succinyl-CoA, malate) (P<0.001), and gluconeogenesis-related metabolite, alanine (P<0.01), are significantly upregulated by DR. The notably (P<0.01) down-modulated muscle growth (PGF2α) and regeneration (PGE2) stimulation metabolite and the increased consumption of glycogen in muscle and liver may be related to the significantly (P<0.01) lower body weight and muscle mass by DR. The downregulated oxidative stress, pro-inflammatory mediators, and upregulated anti-inflammatory metabolites resulted in a lower energy expenditure, which contributed to enhanced muscle quality together with upregulated energy production pathways by DR. The improved muscle quality may explain why grip strength is maintained and motor coordination and learning performance are improved by DR in Ercc1∆/- and Xpg-/- mice. This study provides fundamental supporting information on biomarkers and pathways related to the attenuation of sarcopenia, which might facilitate its diagnosis, prevention, and clinical therapy.

Effects of a ketogenic diet on motor function and motor unit number estimation in aged C57BL/6 mice

ObjectivePathological, age-related loss of muscle function, commonly referred to as sarcopenia, contributes to loss of mobility, impaired independence, as well as increased risk of adverse health events. Sarcopenia has been attributed to changes in both neural and muscular integrity during aging. Current treatment options are primarily limited to exercise and dietary protein fortification, but the therapeutic impact of these approaches are often inadequate. Prior work has suggested that a ketogenic diet (KD) might improve healthspan and lifespan in aging mice. Thus, we sought to investigate the effects of a KD on neuromuscular indices of sarcopenia in aged C57BL/6 mice. DesignA randomized, controlled pre-clinical experiment consisting of longitudinal assessments performed starting at 22-months of age (baseline) as well as 2, 6 and 10 weeks after the start of a KD vs. regular chow intervention. SettingPreclinical laboratory study. Sample sizeThirty-six 22-month-old mice were randomized into 2 dietary groups: KD [n = 22 (13 female and 9 male)], and regular chow [n = 15 (7 female and 8 male)]. MeasurementsMeasures included body mass, hindlimb and all limb grip strength, rotarod for motor performance, plantarflexion muscle contractility, motor unit number estimations (MUNE), and repetitive nerve stimulation (RNS) as an index of neuromuscular junction transmission efficacy recorded from the gastrocnemius muscle. At end point, muscle wet weight and blood samples were collected to assess blood beta-hydroxybutyrate levels. Statistical analysisPrimary analyses were two-way mixed effects ANOVA (diet and time × diet) to determine the effect of a KD on indices of motor function (grip, rotarod) and indices of motor unit (MUNE) and muscle (contractility) function. ResultsBeta-hydroxybutyrate (BHB) was significantly higher at 10 weeks in mice on a KD vs control group (0.83 ± 0.44 mmol/l versus 0.42 ± 0.21 mmol/l, η2 = 0.265, unpaired t-test, p = 0.0060). Mice on the KD intervention demonstrated significantly increased hindlimb grip strength (diet, p = 0.0001; time × diet, p = 0.0030), all limb grip strength (diet, p = 0.0005; time × diet, p = 0.0523), and rotarod latency to fall (diet, p = 0.0126; time × diet, p = 0.0021). Mice treated with the KD intervention also demonstrated increased MUNE (diet, p = 0.0465; time × diet, p = 0.0064), but no difference in muscle contractility (diet, p = 0.5248; time × diet, p = 0.5836) or RNS (diet, p = 0.3562; time × diet, p = 0.9871). ConclusionKD intervention improved neuromuscular and motor function in aged mice. This pre-clinical work suggests that further research is needed to assess the efficacy and physiological effects of a KD on indices of sarcopenia.

The therapeutic potential of Wild Bitter Melon to ameliorate muscle atrophy in a murine model.

Muscle atrophy due to immobility is a common complication of many diseases and a consequence of therapeutic processes. Immobility and inactivity have been shown to be associated with increased inflammation. The aim of this study was to investigate the therapeutic potential of Wild Bitter Melon (WBM) (Momordica charantia Linn) on muscle atrophy due to immobility in a mouse model. This study was performed in two phases of atrophy and recovery on male BALB/c mice which were divided into 3 groups: control, immobilized, and experimental. The treatment period with WBM at a dose of 400 mg/kg daily by gavage was 17 days, including 7 days of being immobilized and 10 days of recovery. At the end of each phase, half of the mice from each group were examined regarding the four limb grip strength, and then histological and biochemical analyses were done. The tissue level of malondialdehyde (MDA) oxidative stress index in the atrophy phase in the atrophy group (5.4567±0.522) nmol/g compared to the control group (3.455±0.065) nmol significantly (p 0.001) <) increased. Also, the tissue level of MDA in the WBM group (3.87±0.035) showed a significant decrease compared to the atrophy group (p<0.01). The strength percentage of four limbs in the mice of the treatment group (-23.46±2.45) was significantly higher than that of the atrophy group (-30.60±3.15) at the end of the atrophy phase. The results suggest that the use of WBM reduces the degree of inflammation, oxidative stress and muscle damage, as well as muscle atrophy, which may improve the muscle atrophy in mice.

Effects of Bafa Wubu and He-Style Tai Chi exercise training on physical fitness of overweight male university students: A randomized controlled trial.

This study aimed to compare the effects of 12-week Bafa Wubu Tai Chi (BW-TC) and traditional He-style Tai Chi (TH-TC) exercise training on physical fitness parameters in overweight university students and to compare the differences in their effects. A total of 81 overweight male university students were randomly assigned to the BW-TC group (N = 27), the TH-TC group (N = 27), and the control group (CG, N = 27). Upper limb grip strength, wall squat, sitting and reaching, 6-minute walk, single-leg stance, and Y-balance were measured at baseline and after 12 weeks of Tai Chi training. There were no significant differences in demographic characteristics and assessment parameters among the groups at baseline (p>0.05). Both BW-TC and TH-TC performed Tai Chi exercise program training lasting 12 weeks, with three sessions per week, each lasting 60 minutes intervention. The changes in mean scores for the sit-and-reach test were 3.11 cm and 4.52 cm, for the wall squat test were 27.56 s and 36.85 s, and for the 6-minute walk test were 22.93 m and 63.22 m, and Y-balance (p<0.05) significantly increased in both BW-TC and TH-TC groups, while the mean score of single-leg stance significantly decreased (p<0.05). Additionally, compared to the BW-TC group, the TH-TC group showed a significant increase in lower limb strength (13.89 s, p = 0.048) and the distance of the Y-balance test in the left posterior medial direction (4.04 cm, p = 0.031). BW-TC and TH-TC interventions effectively improved physical fitness in overweight university students. However, TH-TC showed superior results in lower limb strength improvement. Trial registration number: ChiCTR2200059427 (https://www.chictr.org.cn).

Assessment of the upper limb function, strength, and mobility in treatment-naive children with spinal muscular atrophy Types 2 and 3.

Current upper limb assessments in pediatric spinal muscular atrophy (SMA) may not adequately capture change with disease progression. Our aim was to examine the relationship between motor function, strength, and hand/finger mobility of the upper limb in treatment-naïve children with SMA Types 2 and 3 to assess new methods to supplement current outcomes. The Revised Upper Limb Module (RULM), grip and pinch strength, and hand/finger mobility data were collected from 19 children with SMA Types 2 and 3 aged 5.2-16.9 years over a year. A median loss between 0.5 and 2.5 points in the RULM was seen across all SMA subgroups with the biggest median loss recorded between 10 and 14 years of age. The grip strength loss was -0.06 kg (-4.69 to 3.49; IQR, 1.21); pinch improvement of 0.05 (-0.65 to 1.27; IQR, 0.48); hand/finger mobility test improvement of 4 points (-24 to 14; IQR, 6.75) for the whole cohort. Significant correlations were found between the RULM and grip strength (p < .001), RULM and pinch strength (p < .001), RULM and revised Brooke (p < .001), grip strength and pinch strength (p < .001). The combined use of the RULM, dynamometry, and hand mobility provide insight about correlations between function and strength in children with SMA. The RULM and grip strength assessments captured a significant decline in upper limb function, whereas the pinch and finger/hand mobility showed an improvement over the course of 1 year and these results should be considered for future studies.

Interaction of oat bran and exercise training improved exercise adaptability via alleviating oxidative stress and promoting energy homeostasis.

Skeletal muscle performance is influenced by both diet and the mode of exercise, with diet playing a crucial role in individuals' adaptation to exercise training. Our study investigated the interaction of oat bran (OB) diet and moderate intensity exercise training (MIET) on skeletal muscle function and athletic performance. Studies have reinforced the positive association of high-fat diet (HFD) with chronic systemic inflammation and corresponding peripheral skeletal muscle dysfunction during exercise training. OB could alleviate the inflammation, oxidative stress, and energy homeostasis disorder associated with HFD. We observed improvement in mice limb grip strength and endurance treadmill running distance with OB intake, accompanied by regulation of muscle function-related gene expression. OB intensified exercise training-induced carbohydrate and lipid metabolism, as indicated by changes in lactate, fumarate, malate, pyruvate, succinate, and citrate levels. Additionally, specific probiotic genera producing short-chain fatty acids (SCFAs) were promoted, while inflammation-related circulating metabolites were significantly decreased with oat bran intake. Our findings suggest interactions between OB and MIET improved HFD-induced skeletal muscle dysfunction on both the phenotype and the related mechanisms. This study is an extension of our previous study on the anti-fatigue effect of oat bran, providing a novel prospective by integrating exercise adaptation, gut microbiota, molecular metabolism and skeletal muscle in situ analysis.

An experimental study for quantitative assessment of fatty infiltration and blood flow perfusion in quadriceps muscle of rats using IDEAL-IQ and BOLD-MRI for early diagnosis of sarcopenia

BackgroundSevere sarcopenia may result in severe disability. Early diagnosis is currently the key to enhancing the treatment of sarcopenia, and there is an urgent need for a highly sensitive and dependable tool to evaluate the course of early sarcopenia in clinical practice. This study aims to investigate longitudinally the early diagnosability of magnetic resonance imaging (MRI)-based fat infiltration and blood flow perfusion technology in sarcopenia progression. Methods48 Sprague-Dawley rats were randomly assigned into six groups that were based on different periods of dexamethasone (DEX) injection (0, 2, 4, 6, 8, 10 days). Multimodal MRI was scanned to assess muscle mass. Grip strength and swimming exhaustion time of rats were measured to assess muscle strength and function. Immunofluorescence staining for CD31 was employed to assess skeletal muscle capillary formation, and western blot was used to detect vascular endothelial growth factor-A (VEGF-A) and muscle ring finger-1 (MuRF-1) protein expression. Subsequently, we analyzed the correlation between imaging and histopathologic parameters. A receiver operating characteristic (ROC) analysis was conducted to assess the effectiveness of quantitative MRI parameters for discriminating diagnosis in both pre- and post-modeling of DEX-induced sarcopenic rats. ResultsSignificant differences were found in PDFF, R2* and T2 values on day 2 of DEX-induction compared to the control group, occurring prior to the MRI-CSA values and limb grip strength on day 6 of induction and swimming exhaustion time on day 8 of induction. There is a strong correlation between MRI-CSA with HE-CSA values (r = 0.67; p < 0.001), oil red O (ORO) area with PDFF (r = 0.67; p < 0.001), microvascular density (MVD) (r = −0.79; p < 0.001) and VEGF-A (r = −0.73; p < 0.001) with R2*, MuRF-1 with MRI-CSA (r = −0.82; p < 0.001). The AUC of PDFF, R2*, and T2 values used for modeling evaluation are 0.81, 0.93, and 0.98, respectively. ConclusionImaging parameters PDFF, R2*, and T2 can be used to sensitively evaluate early pathological changes in sarcopenia. The successful construction of a sarcopenia rat model can be assessed when PDFF exceeds 1.25, R2* exceeds 53.85, and T2 exceeds 33.88.

Therapeutic Potential of Hydrogen-Rich Water on Muscle Atrophy Caused by Immobilization in a Mouse Model.

Skeletal muscle atrophy is associated with poor quality of life and disability. Thus, finding a new strategy for the prevention and treatment of skeletal muscle atrophy is very crucial. This study aimed to investigate the therapeutic potential of hydrogen-rich water (HRW) on muscle atrophy in a unilateral hind limb immobilization model. Thirty-six male Balb/C mice were divided into control (without immobilization), atrophy, and atrophy + hydrogen-rich water (HRW). Unilateral hind limb immobilization was induced using a splint for 7 days (atrophy) and removed for 10 days (recovery). At the end of each phase, gastrocnemius and soleus muscle weight, limb grip strength, skeletal muscle histopathology, muscle fiber size, cross-section area (CSA), serum troponin I and skeletal muscle IL-6, TNF-α and Malondialdehyde (MDA), and mRNA expression of NF-κB, BAX and Beclin-1 were evaluated. Muscle weight and limb grip strength in the H2-treated group were significantly improved during the atrophy phase, and this improvement continued during the recovery period. Treatment by HRW increased CSA and muscle fiber size and reduced muscle fibrosis, serum troponin I, IL-6, TNF-α and MDA which was more prominent in the atrophy phase. These data suggest that HRW could improve muscle atrophy in an immobilized condition and could be considered a new strategy during rehabilitation.

Correlation Between Functional Movement Screen Scores, Lower Limb Strength, Y-Balance Test, Grip Strength, and Vertical Jump and Incidence of Injury Due to Musculoskeletal Injury Among Abu Dhabi Police Recruits

Correlation Between Functional Movement Screen Scores, Lower Limb Strength, Y-Balance Test, Grip Strength, and Vertical Jump and Incidence of Injury Due to Musculoskeletal Injury Among Abu Dhabi Police Recruits

Polyethylene Glycol Fusion Restores Axonal Continuity and Improves Return of Function in a Rat Median Nerve Denervation Model.

Polyethylene glycol (PEG) can fuse severed closely apposed axolemmas and restore axonal continuity. The authors evaluated the effects of PEG fusion on functional recovery in a rodent forelimb model of peripheral nerve injury. The median nerves of male Lewis rats ( n = 5 per group) were transected and repaired with standard suture repair (SR), SR with PEG (PEG), or SR with PEG and 1% methylene blue (PEG+MB); a sham surgery group was also included. Proximal stimulation produced compound nerve and muscle action potentials recorded distally. The contralateral limb of each animal acted as an internal control for grip strength measurements. Compound nerve and muscle action potentials immediately returned in all PEG and PEG+MB animals, but not in SR animals. The PEG and PEG+MB groups demonstrated earlier return of function by postoperative day (POD) 7 (62.6 ± 7.3% and 50.9 ± 6.7% of contralateral limb grip strength, respectively) compared with the SR group, in which minimal return of function was not measurable until POD 21. At POD 98, the PEG group grip strength recovered to 77.2 ± 2.8% and the PEG+MB grip strength recovered to 79.9 ± 4.4%, compared with 34.9 ± 1.8% recovery in the SR group ( P < 0.05). The PEG and PEG+MB groups reached 50% of the sham group grip strength on POD 3.8 and POD 6.3, respectively, whereas the SR group did not reach 50% grip strength recovery of the sham group throughout the study period. PEG fusion plus neurorrhaphy with or without MB reestablished axonal continuity, shortened recovery time, and augmented functional recovery compared with suture neurorrhaphy alone. PEG fusion with neurorrhaphy may bypass Wallerian degeneration, leading to augmented and shortened functional recovery.

1628-P: Role of CD38 in the Regulation of Muscle Stem Cell Functions in Aged Mice

Skeletal muscle repair and regeneration is a complex process and is known to be delayed with aging, diabetes and obesity. This is in part due to infiltration of inflammatory macrophages which can delay the recovery process. Both macrophages and satellite cells require nicotinamide adenine dinucleotide (NAD+) for their biological functions. Aging-induced decline in NAD+ have been shown to worsen insulin resistance and muscle dysfunction. CD38 is an ectoenzyme that degrades NAD+ and is increased in inflammatory macrophages in aging, obesity and other insulin-resistant states. However, how inhibition of CD38 affects satellite cell functions in aged or obese mice, remains unknown. Here, we utilized aged CD38 knockout mice to assess the role of this protein and NAD+ in the recovery process in injured muscle. CD38 KO mice were found to be resistant to diet-induced obesity and had improved insulin sensitivity. Our data show that genetic deletion of CD38 in aged mice increased NAD+ levels and thus enhanced muscle stem/satellite cells differentiation and promote myogenesis. Deletion of CD38 also resulted in an enhanced number of regenerating myofibers. Furthermore, we found that deletion of CD38 significantly reduces fibrosis of muscle and also improved limb grip strength. Pharmacological inhibition of CD38 in C2C12 myoblasts and ex-vivo primary myoblasts significantly increased NAD+ levels and also enhanced the differentiation of satellite cells into myoblasts and myofibers. We, therefore, examined the rescue effects of 78c (CD38i) on human recombinant CD38 (hCD38) inhibition of muscle stem cells. Administration of hCD38 inhibited expression of MyoD and MyoG in primary myoblasts, while this effect was rescued through 78c treatment. Taken together, these data demonstrate that restoration of NAD+ levels either through genetic deletion/pharmacological inhibition of CD38 can improve muscle stem cell functions and muscle regeneration and might promote muscle regeneration in obesity, type 2 diabetes, and aging. Disclosure A.Nawaz: None. K.Yaku: None. I.Jeelani: None. K.Tobe: Other Relationship; MSD K.K., Novo Nordisk Pharma Ltd., Takeda Pharmaceutical Company Limited, Daiichi Sankyo, Mitsubishi Tanabe Pharma Corporation, Suntory Global Corporation, Ltd.,, Taiho Pharmaceutical Co. Ltd., Japan Diabetes Foundation, Japan Association for Diabetes Education and Care. T.Nakagawa: None.