Muscle Quality Research Articles

Comparisons between dual-energy X-ray absorptiometry and bioimpedance devices for appendicular lean mass and muscle quality in Hispanic adults.

The purpose of this study was to compare single- and multi-frequency bioimpedance (BIA) devices against dual-energy X-ray absorptiometry (DXA) for appendicular lean mass (ALM) and muscle quality index (MQI) metrics in Hispanic adults. One hundred thirty-one Hispanic adults (18-55 years) participated in this study. ALM was measured with single-frequency bioimpedance analysis (SFBIA), multi-frequency bioimpedance analysis (MFBIA) and DXA. ALMTOTAL (left arm + right arm + left leg + right leg) and ALMARMS (left arm + right arm) were computed for all three devices. Handgrip strength (HGS) was measured using a dynamometer. The average HGS was used for all MQI models (highest left hand + highest right hand)/2. MQIARMS was defined as the ratio between HGS and ALMARMS. MQITOTAL was established as the ratio between HGS and ALMTOTAL. SFBIA and MFBIA had strong correlations with DXA for all ALM and MQI metrics (Lin's concordance correlation coefficient values ranged from 0·86 (MQIMFBIA-ARMS) to 0·97 (Arms LMSFBIA); all P < 0·001). Equivalence testing varied between methods (e.g. SFBIA v. DXA) when examining the different metrics (i.e. ALMTOTAL, ALMARMS, MQITOTAL and MQIARMS). MQIARMS was the only metric that did not differ from the line of identity and had no proportional bias when comparing all the devices against each other. The current study findings demonstrate good overall agreement between SFBIA, MFBIA and DXA for ALMTOTAL and ALMARMS in a Hispanic population. However, SFBIA and MFBIA have better agreement with DXA when used to compute MQIARMS than MQITOTAL.

Microbiota differences of giant river prawn (Macrobrachium rosenbergii) cultured in a recirculating aquaculture system (RAS) – A prototype vertical farming and traditional pond cultured system and their impact on autolysis rate and textural characteristics

Microbial profiles, autolysis rates, and textural characteristics of giant river prawn (Macrobrachium rosenbergii) cultured in a vertical farming with a recirculating aquaculture system (RAS) were compared to those of prawns cultured in a traditional pond system (Pond). Bioinformatics analysis revealed significant differences in the quantity and diversity of microbial communities between RAS and Pond. Firmicutes were the dominant phylum found in both samples but at higher levels in Pond (P < 0.05). Conversely, Tenericutes, Proteobacteria, and Actinobacteria, known as healthy microbiomes, were more abundant in RAS (P < 0.05). At the genus level, Enterococcus, recognized for its potential to improve colonization resistance against pathogens in the gut, was detected at higher levels in RAS (P < 0.005). This variation in microbiota might affect the difference in autolysis rates and textural properties between these two samples. RAS had a lower autolysis rate at all temperatures (4, 15, 25, and 35 °C) (P ˂ 0.05), consistent with the lower TCA-soluble peptide (157.61 μmol tyrosine equivalent/g sample). The differences in textural characteristics of these two prawns were observed. RAS had more water holding capacity (WHC) (80.07%) but lower drip loss (15.75%) and cooking loss (28.36%) than Pond (73.77, 17.84, and 31.20%, respectively) (P ˂ 0.05). From TPA results, RAS showed higher chewiness and gumminess than Pond, indicating a firmer texture, which is a desirable characteristic, particularly in fresh prawn. Overall, the findings indicated an improvement in microbial profiles, which further translated into economic benefits in terms of yield production and muscle quality, particularly texture, of prawn cultured in a recirculating aquaculture system as an alternative approach.

Automated CT Analysis of Body Composition as a Frailty Biomarker in Abdominal Surgery

Prior studies demonstrated consistent associations of low skeletal muscle mass assessed on surgical planning scans with postoperative morbidity and mortality. The increasing availability of imaging artificial intelligence enables development of more comprehensive imaging biomarkers to objectively phenotype frailty in surgical patients. To evaluate the associations of body composition scores derived from multiple skeletal muscle and adipose tissue measurements from automated segmentation of computed tomography (CT) with the Hospital Frailty Risk Score (HFRS) and adverse outcomes after abdominal surgery. This retrospective cohort study used CT imaging and electronic health record data from a random sample of adults who underwent abdominal surgery at 20 medical centers within Kaiser Permanente Northern California from January 1, 2010, to December 31, 2020. Data were analyzed from April 1, 2022, to December 1, 2023. Body composition derived from automated analysis of multislice abdominal CT scans. The primary outcome of the study was all-cause 30-day postdischarge readmission or postoperative mortality. The secondary outcome was 30-day postoperative morbidity among patients undergoing abdominal surgery who were sampled for reporting to the National Surgical Quality Improvement Program. The study included 48 444 adults; mean [SD] age at surgery was 61 (17) years, and 51% were female. Using principal component analysis, 3 body composition scores were derived: body size, muscle quantity and quality, and distribution of adiposity. Higher muscle quantity and quality scores were inversely correlated (r = -0.42; 95% CI, -0.43 to -0.41) with the HFRS and associated with a reduced risk of 30-day readmission or mortality (quartile 4 vs quartile 1: relative risk, 0.61; 95% CI, 0.56-0.67) and 30-day postoperative morbidity (quartile 4 vs quartile 1: relative risk, 0.59; 95% CI, 0.52-0.67), independent of sex, age, comorbidities, body mass index, procedure characteristics, and the HFRS. In contrast to the muscle score, scores for body size and greater subcutaneous and intermuscular vs visceral adiposity had inconsistent associations with postsurgical outcomes and were attenuated and only associated with 30-day postoperative morbidity after adjustment for the HFRS. In this study, higher muscle quantity and quality scores were correlated with frailty and associated with 30-day readmission and postoperative mortality and morbidity, whereas body size and adipose tissue distribution scores were not correlated with patient frailty and had inconsistent associations with surgical outcomes. The findings suggest that assessment of muscle quantity and quality on CT can provide an objective measure of patient frailty that would not otherwise be clinically apparent and that may complement existing risk stratification tools to identify patients at high risk of mortality, morbidity, and readmission.

Assessing paraspinal muscle atrophy with electrical impedance myography: Limitations and insights.

Paraspinal muscle atrophy is gaining attention in spine surgery due to its link to back pain, spinal degeneration and worse postoperative outcomes. Electrical impedance myography (EIM) is a noninvasive diagnostic tool for muscle quality assessment, primarily utilized for patients with neuromuscular diseases. However, EIM's accuracy for paraspinal muscle assessment remains understudied. In this study, we investigated the correlation between EIM readings and MRI-derived muscle parameters, as well as the influence of dermal and subcutaneous parameters on these readings. We retrospectively analyzed patients with lumbar spinal degeneration who underwent paraspinal EIM assessment between May 2023 to July 2023. Paraspinal muscle fatty infiltration (FI) and functional cross-sectional area (fCSA), as well as the subcutaneous thickness were assessed on MRI scans. Skin ultrasound imaging was assessed for dermal thickness and the echogenicities of the dermal and subcutaneous layers. All measurements were performed on the bilaterally. The correlation between EIM readings were compared with ultrasound and MRI parameters using Spearman's correlation analyses. A total of 20 patients (65.0% female) with a median age of 69.5 years (IQR, 61.3-73.8) were analyzed. The fCSA and FI did not significantly correlate with the EIM readings, regardless of frequency. All EIM readings across frequencies correlated with subcutaneous thickness, echogenicity, or dermal thickness. With the current methodology, paraspinal EIM is not a valid alternative to MRI assessment of muscle quality, as it is strongly influenced by the dermal and subcutaneous layers. Further studies are required for refining the methodology and confirming our results.

A Preliminary Study on the Effect of Replacing Part of Fishmeal by Brewer’s Yeast in Feeding Taiwan Loach

In this experiment, brewer’s yeast was used to replace part of the fish meal in the feed to formulate a high-fat and low-protein feed for Taiwan loach. The effects of brewer’s yeast on the growth performance, muscle quality, hepatopancreas and pancreas carnitine content, intestinal flora, immunity, and antioxidant ability of Taiwan loach were preliminarily investigated. In experiment 1, 600 Taiwan loaches were randomly divided into 4 groups, and 1% (group A), 4% (group B), 8% (group C), and 12% (group D) of brewer’s yeast was substituted for an equal amount of fishmeal in the basal diets. The loaches in each group were fed for 60 d. In experiment 2, 60 Taiwan loaches were selected and randomly divided into a control group (Group E) and a test group (Group F). The loaches were fed the basal diet and the high-fat and low-protein diet supplemented with 8% fishmeal, replaced by brewer’s yeast. The experiment lasted for 60 days, and the growth performance, hepatopancreas carnitine content, muscle quality, intestinal flora, plasma antioxidant, and immune capacity indices of loaches in each group were determined. The results were as follows: the weight gain rate and specific growth rate were significantly higher in group C than those in groups A, B, and D (P &lt; 0.05); the intestinal length ratio, muscle hardness, hepatopancreatic carnitine content, plasma superoxide dismutase activity, catalase activity, total antioxidant capacity, and lysozyme activity were significantly greater in group F than those in group E (P &lt; 0.05); the Lactobacillus and Bifidobacterium counts in Group F were considerably higher than those in Group E (P &lt; 0.05), and the Salmonella counts in Group F was significantly lower than that in Group E (P &lt; 0.05); the survival rate, weight gain rate, bait coefficient, muscle crude protein, crude fat, viscosity, elasticity, cohesion, chewability, and restorative capacity were not significantly different between Group F and Group E (P &gt; 0.05). The above results showed that adding 8% brewer’s yeast to feed Taiwan loach instead of fish meal could enhance its hepatopancreatic carnitine synthesis, optimize the intestinal flora, improve the body’s immune and antioxidant ability, and have a certain promotional effect on the intestinal development and muscle quality improvement.

Exploring the Relationship between Ultrasonographic Measures of the Quadriceps and Knee Extensor Muscle Fitness in Endurance-Trained Individuals.

B-mode ultrasonography is an accessible and cost-effective method to assess muscle size and quality through muscle thickness (MT) and echo intensity (EI), respectively. Muscle thickness and EI have demonstrated relationships with maximal strength and local muscle endurance, providing a noninvasive and efficient modality to examine muscle fitness. However, these relationships have not been quantified in the individual quadriceps muscles of habitually endurance-trained populations, which may provide information to practitioners regarding rehabilitation and performance. Twenty-three participants (males: N = 10; females: N = 13) underwent B-mode ultrasonography to assess MT, EI, and adipose tissue thickness-corrected echo intensity (cEI) in the vastus intermedius (VI), vastus lateralis (VL), and rectus femoris (RF). Muscle fitness was evaluated through maximal strength (1RM) and local muscle endurance (4 sets to failure at 50% 1RM) during dynamic knee extension. Relationships between ultrasonography outcomes and muscle fitness were examined through stepwise multiple linear regression. The results indicate that VI cEI is the strongest predictor of 1RM strength (r = -0.643), while no ultrasonography-derived measures significantly predicted local muscle endurance. The study demonstrates that ultrasonography, specifically measures of cEI in the VI, has the greatest association with maximal strength in endurance-trained individuals. These findings suggest monitoring VI muscle size and quality may benefit practitioners who aim to improve knee extension strength for performance or following injury. In addition, the findings support the use of EI examinations in trained populations.

GDF5 as a rejuvenating treatment for age-related neuromuscular failure.

Sarcopenia involves a progressive loss of skeletal muscle force, quality and mass during ageing, which results in increased inability and death; however, no cure has been established thus far. Growth differentiation factor 5 (GDF5) has been described to modulate muscle mass maintenance in various contexts. For our proof of concept, we overexpressed GDF5 by AAV vector injection in Tibialis Anterior (TA) muscle of adult aged (20 months) mice and performed molecular and functional analysis of skeletal muscle. We analysed human Vastus Lateralis muscle biopsies from adult young (21-42 years) and aged (77-80 years) donors, quantifying the molecular markers modified by GDF5 overexpression (OE) in mouse muscle. We validated the major effects of GDF5 overexpression using human immortalized myotubes and Schwann Cells (SCs). We established a pre-clinical study by treating chronically (for 4 months) aged mice using recombinant GDF5 protein (rGDF5) in systemic administration and evaluated the long-term effect of this treatment on muscle mass and function. Here, we demonstrated that GDF5 OE in the old TAs promoted an increase of 16.5% of muscle weight (P = 0.0471) associated with a higher percentage of 5000-6000 µm2 large fibres (P = 0.0211), without the induction of muscle regeneration. Muscle mass gain was associated with an amelioration of 26.8% of rate of force generation (P = 0.0330) and a better neuromuscular connectivity (P = 0.0098). Moreover, GDF5 OE preserved neuromuscular junction (NMJ) morphology (38.5% of nerve terminal area increase, P < 0.0001) and stimulated the expression of re-innervation-related genes, in particular markers of SCs (fold change 3.19 for S100b gene expression, P = 0.0101). To further characterize the molecular events induced by GDF5 OE during ageing, we performed a genome-wide transcriptomic analysis of treated muscles and showed that this factor leads to a "rejuvenating" transcriptomic signature in aged mice, as 42% of the transcripts dysregulated by ageing reverted to youthful expression levels upon GDF5 OE (P < 0.05). Towards a pre-clinical approach, we performed a long-term systemic treatment using rGDF5 and showed its effectiveness in counteracting age-related muscle wasting, improving muscle function (17,8% of absolute maximal force increase, P = 0.0079), ensuring neuromuscular connectivity and preventing NMJ degeneration (7,96% of AchR area increase, P = 0.0125). In addition, in human muscle biopsies, we found the same age-related alterations than those observed in mice and improved by GDF5 and reproduced its major effects on human cells, suggesting this treatment as efficient in humans. Overall, these data provide a foundation to examine the curative potential of GDF5 drug in clinical trials for sarcopenia and, eventually, other neuromuscular diseases.

Reduced Muscle Mass and Muscle Quality in Patients with Intermittent Claudication due to Peripheral Artery Disease

ObjectivePeripheral arterial disease (PAD) is associated with reduced muscle mass and quality, but the effects of leg ischemia caused by PAD on muscle quality remain poorly understood. The purpose of this study was to evaluate leg muscle mass and muscle quality in patients with intermittent claudication due to PAD using bioelectrical impedance analysis (BIA). MethodsOne hundred forty-one patients with intermittent claudication due to PAD who visited Tokyo Medical University Hospital from April 2019 to April 2020 were retrospectively analyzed. Leg ischemia was assessed using ankle-brachial index (ABI). The skeletal muscle mass (SMM) assessed leg muscle mass, while the phase angle (PhA) assessed leg muscle quality using BIA. ResultsA total of 282 legs in 141 patients were included in the analysis. Leg PhA and SMM showed a decreasing trend according to the severity of leg ischemia (borderline/no ischemia: 2.80 ± 0.50 kg/m2, 4.38 ± 0.94°; mild ischemia: 2.83 ± 0.49 kg/m2, 4.33 ± 1.03°; moderate/severe ischemia: 2.50 ± 0.40 kg/m2, 3.89 ± 0. 88°; p<0.001 and p=0.020, respectively). The ABI was moderately correlated with leg SMM (B=0.347, β=0.134, p<0.001) and leg PhA (B=0.577, β=0.111, p=0.013) after adjustment for all significant covariates. Leg PhA was moderately correlated with leg SMM (r = 0.318, p < 0.001). ConclusionsLeg ischemia, especially when moderate or severe, has an adverse effect on both muscle mass and quality in the lower extremities and is associated with skeletal muscle myopathy.

Age-dependent loss of Crls1 causes myopathy and skeletal muscle regeneration failure

Skeletal muscle aging results in the gradual suppression of myogenesis, leading to muscle mass loss. However, the specific role of cardiolipin in myogenesis has not been determined. This study investigated the crucial role of mitochondrial cardiolipin and cardiolipin synthase 1 (Crls1) in age-related muscle deterioration and myogenesis. Our findings demonstrated that cardiolipin and Crls1 are downregulated in aged skeletal muscle. Moreover, the knockdown of Crls1 in myoblasts reduced mitochondrial mass, activity, and OXPHOS complex IV expression and disrupted the structure of the mitochondrial cristae. AAV9-shCrls1-mediated downregulation of Crls1 impaired muscle regeneration in a mouse model of cardiotoxin (CTX)-induced muscle damage, whereas AAV9-mCrls1-mediated Crls1 overexpression improved regeneration. Overall, our results highlight that the age-dependent decrease in CRLS1 expression contributes to muscle loss by diminishing mitochondrial quality in skeletal muscle myoblasts. Hence, modulating CRLS1 expression is a promising therapeutic strategy for mitigating muscle deterioration associated with aging, suggesting potential avenues for developing interventions to improve overall muscle health and quality of life in elderly individuals.

Muscle quality assessment in COVID-19 survivors: agreement between echointensity and stiffness.

Muscle quality assessment in COVID-19 survivors: agreement between echointensity and stiffness.

Construction of a molecular regulatory network for lipids and volatile flavor in Chinese indigenous and hybrid pig pork through integrating multi-omics analysis

Chinese indigenous and newly bred black pigs are often regarded as high-end pork due to their excellent muscle quality and distinctive flavor. However, the molecular regulatory mechanisms that give rise to flavor disparities among pig breeds remain unclear. This study aims to construct a molecular network that regulates pork flavor and lipid components based on volatilomics, targeted lipidomics, and transcriptomics. The results revealed that the sensory scores and most meat quality indicators of Lvjiahei and Jinhua pork were significantly superior to Duroc × (Landrace × Yorkshire) pork. Twenty-two differential volatile organic compounds (VOCs) and 21 differential lipids were detected among three breeds using partial least squares discriminant analysis (PLS-DA) and partial least squares-regression (PLS-R) models. Based on transcriptome data from the three pig breeds, 73 overlapping differentially expressed genes (DEGs) were identified as candidate genes in the three pairwise comparisons. Meanwhile, a correlation network of genes-lipids-VOCs was constructed using the Pearson correlation coefficient (|R| > 0.6). Besides, six essential DEGs might be involved in the lipid metabolic pathway based on the results of functional enrichment analysis. Our study provides a new perspective on the genes-lipids-VOCs axis in understanding pork flavor and establishes a theoretical framework for breeding high-quality pork.

Muscle density, but not size, is independently associated with cognitive health in older adults with hip fractures.

Emerging evidence indicates a complex interplay between skeletal muscle and cognitive function. Despite the known differences between muscle quantity and quality, which can be measured via computed tomography (CT), the precise nature of their associations with cognitive performance remain underexplored. To investigate the links between muscle size and density and cognitive impairment (CI) in the older adults with hip fractures, we conducted a post hoc, cross-sectional analysis within a prospective cohort study on 679 patients with hip fractures over 65. Mini-Mental State Examination (MMSE) and routine hip CT imaging were utilized to assess cognition function and muscle characteristics in older adults with hip fractures. The CT scans provided data on cross-sectional area and attenuation for the gluteus maximus (G.MaxM) and the combined gluteus medius and minimus (G.Med/MinM). Participants were categorized into CI and non-CI groups based on education levels and MMSE scores. Multivariate logistic regressions, propensity score (PS) methods, and subgroup analysis were employed to analyze associations and validate findings. This study included 123 participants (81.6 ± 6.8years, 74% female) with CI and 556 participants (78.5 ± 7.7years, 72% female) without. Compared to the non-CI group, muscle parameters, especially density, were significantly lower in the CI group. Specifically, G.Med/Min muscle density, but not size was robustly associated with CI (odds ratio (OR) = 0.77, 95% confidence interval = 0.62-0.96, P = 0.02), independent of other medical situations. Sensitivity analysis corroborated that G.Med/Min muscle density was consistently lower in the CI group than the non-CI group, as evidenced in the PS matched (P = 0.024) and weighted cohort (P = 0.033). Enhanced muscle parameters, particularly muscle density in the G.Med/MinM muscle, correlate with a lower risk of CI. Muscle density demonstrates a stronger association with cognitive performance than muscle size, highlighting its potential as a key focus in future cognitive health research.

Using texture analysis of ultrasound images to assess the effect of cupping therapy on muscle quality of the triceps.

The objectives were to investigate whether cupping therapy improves muscle quality and the interaction between duration and negative pressure of cupping therapy affects muscle quality. A 2×2 factorial design with repeated measures was used to examine the efficacy of cupping therapy on improving muscle quality. The independent factors were cupping pressures at -225 and -300 mmHg and cupping durations at 5 and 10 min, and the dependent factor was texture of B-mode ultrasound image of the triceps. Four cupping protocols were applied to 12 participants at 4 different days. Texture analysis including contrast, correlation, energy, and homogeneity was applied to assess muscle quality from 480 ultrasound images. The two-way repeated measures ANOVA showed that there was an interaction between the pressure and duration factors on the superficial layer of the triceps in contrast (F = 5.434, P = 0.004) and correlation (F = 6.274, P = 0.029). In contrast texture, the superficial layer of the triceps showed a significant increase in three protocols: -225 mmHg for 5 min (1.0434 ± 0.130), -300 mmHg for 5 min (1.0339 ±0.1407), and -300 mmHg for 10 min (1.0563 ±0.1432) except -225 mmHg for 10 min (0.9704 ±0.0985). In correlation texture, the superficial layer of the triceps showed a significant decrease in all protocols: -225 mmHg for 5 min (0.9556 ± 0.07), -225 mmHg for 10 min (0.9831 ± 0.0708), -300 mmHg for 5 min (0.9976 ± 0.055), and -300 mmHg for 10 min (0.9406 ± 0.0809). The results indicate that the interaction between the pressure and duration factors of cupping therapy significantly increases contrast texture and significantly decreases correlation texture of the superficial layer of the triceps after cupping therapy. Cupping therapy decreases homogeneity among soft tissues of the treated muscle.

Lack of vitamin D signalling in mesenchymal progenitors causes fatty infiltration in muscle.

Recent studies have indicated the importance of muscle quality in addition to muscle quantity in sarcopenia pathophysiology. Intramuscular adipose tissue (IMAT), which originates from mesenchymal progenitors (MPs) in adult skeletal muscle, is a key factor affecting muscle quality in older adults, suggesting that controlling IMAT formation is a promising therapeutic strategy for sarcopenia. However, the molecular mechanism underlying IMAT formation in older adults has not been clarified. We recently found that the vitamin D receptor (VDR) is highly expressed in MPs in comparison to myotubes (P=0.028, N=3), indicating a potential role of vitamin D signalling in MPs. In this study, we aimed to clarify the role of vitamin D signalling in MP kinetics, with a focus on adipogenesis. MPs isolated from mouse skeletal muscles were subjected to adipogenic differentiation conditions with or without vitamin D (1α,25(OH)2D3, 100nM) for 7days, and adipogenicity was evaluated based on adipogenic marker expression. For in vivo analysis, tamoxifen-inducible MP-specific VDR-deficient (VdrMPcKO) mice were newly developed to investigate whether lack of vitamin D signalling in MPs is involved in IMAT formation. To induce muscle atrophy, VdrMPcKO male mice were subjected to tenotomy of the gastrocnemius muscle, and then muscle weight, myofibre cross-sectional area, adipogenic marker expression, and fatty infiltration into the muscle were evaluated at 3weeks after operation (N=3-4). In addition, a vitamin D-deficient diet was provided to wild-type male mice (3 and 20months of age, N=5) for 3months to investigate whether vitamin D deficiency causes IMAT formation. Vitamin D treatment nearly completely inhibited adipogenesis of MPs through Runx1-mediated transcriptional modifications of early adipogenic factors such as PPARγ (P=0.0031) and C/EBPα (P=0.0027), whereas VDR-deficient MPs derived from VdrMPcKO mice differentiated into adipocytes even in the presence of vitamin D (P=0.0044, Oil-Red O+ area). In consistency with in-vitro findings, VdrMPcKO mice and mice fed a vitamin D-deficient diet exhibited fat deposition in atrophied (P=0.0311) and aged (P=0.0216) skeletal muscle, respectively. Vitamin D signalling is important to prevent fate decision of MPs towards the adipogenic lineage. As vitamin D levels decline with age, our data indicate that decreased vitamin D levels may be one of the causes of IMAT formation in older adults, and vitamin D signalling may be a novel therapeutic target for sarcopenia.

Effect of respiratory muscle training in patients with stable chronic obstructive pulmonary disease: A systematic review and meta-analysis

ObjectivesChronic obstructive pulmonary disease (COPD) is a prevalent respiratory disorder characterized by progressive airflow limitation. This meta-analysis aims to evaluate the effectiveness of respiratory muscle training (RMT) on key pulmonary function parameters, inspiratory muscle strength and quality of life in patients with stable COPD. MethodsA comprehensive search was conducted in the databases including PubMed, Cochrane, Web of Science, Embase, and ClinicalTrials.gov, from their inception to June 12, 2023. Randomized controlled trials (RCTs) evaluating the impact of RMT on stable COPD were included for meta-analysis. ResultsIn total, 12 RCTs involving 453 participants were included in the meta-analysis. RMT demonstrated a significant increase in maximal inspiratory pressure (PImax, MD, 95% CI: 14.34, 8.17 to 20.51, P < 0.001) but not on maximal expiratory pressure (PEmax). No significant improvement was observed in 6-Min walk test (6MWT), dyspnea, forced expiratory volume in 1 s (FEV1), forced vital capacity ratio (FVC) and quality of life between RMT and control groups. However, subgroup analysis revealed a significant negative effect of RMT alone on FEV1/FVC (MD, 95% CI: 2.59, −5.11 to −0.06, P = 0.04). When RMT was combined with other interventions, improvements in FEV1/FVC and FEV1 were found, although not statistically significant. ConclusionRMT can effectively improve maximal inspiratory pressure in stable COPD patients, but the effect is slight in improving lung function, dyspnea and quality of life. It is recommended to combine with other treatment strategies to comprehensively improve the prognosis of COPD patients.

Sarcopenia prevalence between obese and morbid obese patients in an obesity center

Background/Aim: Sarcopenia and obesity are independent diseases that result in decreased muscle strength and function. Few studies have been conducted on the association of sarcopenia and obesity, especially in women. This study aims to measure the possibility of sarcopenic obesity in women with obesity. Methods: Our study was organized using a prospective cross-sectional study in Turkey. A total of 135 volunteer were included in the study. Inclusion criteria required the patients to have a BMI &gt;35 kg/m2 or BMI &gt;40 kg/m2 and no current comorbid disease. The exclusion criteria included: age (&lt;18 and &gt;70 years were excluded), history of muscle disease, malignancy, psychiatric disorders such as bipolar disease and psychosis, malnutrition, and recent corticosteroid (CS) use (within the last three months). Probable sarcopenia is determined by low skeletal muscle strength, and confirmed sarcopenia is defined if there is both low skeletal muscle mass and low skeletal muscle quality. Muscle strength was measured with isometric dynamometry using the handgrip method. A six-minute walk test (6MWT), in which we measured walking speed, was performed to determine the physical performance of the patients. We adjusted appendicular skeletal muscle (ASM) using height squared (ASM/height2) bioelectrical impedance analysis (BIA) to measure the muscle mass. Results: Patients’ mean age was 43 (11.4) (20-69) years. Of the total participants, 64.6% were in the age range of 40-59; 19.2% of patients were defined as possible sarcopenia; and 2.2% had confirmed sarcopenia. A total of 78.5% of patients did not meet any of the sarcopenia criteria. We determined that there was no difference in anthropometric measurements between sarcopenic and non-sarcopenic patients (P&gt;0.05), except for waist and hip circumferences. However, we did observe a noteworthy distinction in waist and hip circumference measurements between the two groups, with sarcopenic patients exhibiting larger circumferences (P=0.05 and P=0.032, respectively). Our study revealed a significant disparity in the results of the six-minute walk test and handgrip strength values between sarcopenic and non-sarcopenic patients (P&lt;0.001). Specifically, non-sarcopenic patients demonstrated higher values in both tests.. Conclusion: Obesity and sarcopenic obesity will continue to be a public health problem in the future among middle-aged women. It should be considered that the prevalence of decreased muscle strength was high in our study group, and physical performance decreased due to muscle strength. We concluded that as success in the six-minute walk test and handgrip values increased, the diagnosis of sarcopenia decreased, and each increase in platelet count increased the risk of sarcopenia in obese female patients.

Genetic Evidence for Distinct Biological Mechanisms That Link Adiposity to Type 2 Diabetes: Toward Precision Medicine.

We aimed to unravel the mechanisms connecting adiposity to type 2 diabetes. We employed MR-Clust to cluster independent genetic variants associated with body fat percentage (388 variants) and BMI (540 variants) based on their impact on type 2 diabetes. We identified five clusters of adiposity-increasing alleles associated with higher type 2 diabetes risk (unfavorable adiposity) and three clusters associated with lower risk (favorable adiposity). We then characterized each cluster based on various biomarkers, metabolites and Magnetic Resonance Imaging-based measures of fat distribution and muscle quality. Analyzing the metabolic signatures of these clusters revealed two primary mechanisms connecting higher adiposity to reduced type 2 diabetes risk. The first involves higher adiposity in subcutaneous tissues (abdomen and thigh), lower liver fat, improved insulin sensitivity, and decreased risk of cardiometabolic diseases and diabetes complications. The second mechanism is characterized by increased body size, enhanced muscle quality, with no impact on cardiometabolic outcomes. Furthermore, our findings unveil diverse mechanisms linking higher adiposity to higher disease risk, such as cholesterol pathways or inflammation. These results reinforce the existence of adiposity-related mechanisms that may act as protective factors against type 2 diabetes and its complications, especially when accompanied by reduced ectopic liver fat.

Improvement in Muscle Fatty Acid Bioavailability and Volatile Flavor in Tilapia by Dietary α-Linolenic Acid Nutrition Strategy.

To investigate the modification of muscle quality of farmed tilapia through dietary fatty acid strategies, two diets were formulated. Diet SO, using soybean oil as the lipid source, and diet BO, using blended soybean and linseed oils, each including 0.58% and 1.35% α-linolenic acid (ALA), respectively, were formulated to feed juvenile tilapia for 10 weeks. The muscular nutrition composition, positional distribution of fatty acid in triglycerides (TAGs) and phospholipids (PLs), volatile flavor, lipid mobilization and oxidation were then analyzed. The results showed that there was no distinct difference between the SO and BO groups in terms of the nutrition composition, including crude protein, crude lipid, TAGs, PLs, and amino acid. Although the fatty acid distribution characteristics in ATGs and PLs showed a similar trend in the two groups, a higher level of n-3 PUFA (polyunsaturated fatty acid) and n-3 LC-PUFA (long-chain polyunsaturated fatty acid) bound to the glycerol backbone of TAGs and PLs was detected in the BO group than the SO group, whereas the opposite was true for n-6 PUFA. Additionally, the muscular volatile aldehyde and alcohol levels were higher in the BO group. Moreover, the expression of enzymatic genes and protein activities related to lipid mobilization (LPL, LPCAT, DGAT) and oxidation (LOX and GPX) was higher in the BO group. The results demonstrate that high-ALA diets may improve the fatty acid bioavailability and volatile flavor of tilapia by improving the lipid mobilization and oxidation, which provides new ideas for the improvement of muscle quality in farmed fish.

Polygonatum sibiricum polysaccharide ameliorates skeletal muscle aging via mitochondria-associated membrane-mediated calcium homeostasis regulation

BackgroundSarcopenia, an age-related disease, is characterized by a gradual loss of muscle mass, strength, and function. It has been linked to abnormal organelle function in myotubes, including the mitochondria and endoplasmic reticulum (ER). Recent studies revealed that mitochondria-associated membranes (MAM), the sites connecting mitochondria and the ER, may be implicated in skeletal muscle aging. In this arena, the potential of Polygonatum sibiricum polysaccharide (PSP) emerges as a beacon of hope. PSP, with its remarkable antioxidant and anti-senescence properties, is on the cusp of a therapeutic revolution, offering a promising strategy to mitigate the impacts of sarcopenia. PurposeThe objective of this research is to explore the effects of PSP on age-related muscle dysfunction and the underlying mechanisms involved both in vivo and in vitro. MethodsIn this investigation, we used in vitro experiments using D-galactose (D-gal)-induced aging in C2C12 myotubes and in vivo experiments on aged mice. Key indices were assessed, including reactive oxygen species (ROS) levels, mitochondrial function, the expression of aging-related markers, and the key proteins of mitochondria and MAM fraction. Differentially expressed genes (DEGs) related to mitochondria and ER were identified, and bioinformatic analyses were performed to explore underlying mechanisms. Muscle mass and function were determined to evaluate the quantity and quality of skeletal muscle in vivo. ResultsPSP treatment effectively mitigated oxidative stress and mitochondrial malfunction caused by D-gal in C2C12 myotubes, preserving mitochondrial fitness and reducing MAM formation. Besides, PSP attenuated D-gal-induced increases in Ca2+ concentrations intracellularly by modulating the calcium-related proteins, which were also confirmed by gene ontology (GO) analysis of DEGs. In aged mice, PSP increased muscle mass and improved grip strength, hanging time, and other parameters while reducing ROS levels and increasing antioxidant enzyme activities in skeletal muscle tissue. ConclusionPSP offers protection against age-associated muscle impairments. The proposed mechanism suggests that modulation of calcium homeostasis via regulation of the MAM results in a favorable functional outcome during skeletal muscle aging. The results of this study highlight the prospect of PSP as a curative intervention for sarcopenia and affiliated pathological conditions, warranting further investigation.

Sarcopenia in subjects with Alzheimer’s disease: prevalence and comparison of agreement between EGWSOP1, EGWSOP2, and FNIH criteria

BackgroundSarcopenia is an age-related clinical syndrome characterized by the progressive loss of muscle mass and muscle strength. It appears to be closely linked to dementia, particularly Alzheimer’s disease (AD); however, its prevalence among AD patients remains unclear. In this study, we assessed differences in sarcopenia prevalence between non-demented individuals and AD patients. Moreover, we assessed sex-specific differences in sarcopenia prevalence and explored the diagnostic value of the Muscle Quality Index (MQI) for diagnosing sarcopenia among AD patients.MethodCross-sectional study including 145 patients with probable AD and 51 older adults with normal cognition. Sarcopenia was diagnosed according to the criteria of the European Working Group on Sarcopenia in Older People (EWGSOP1 and EWGSOP2) and of the Foundation for the National Institutes of Health (FNIH). The MQI was computed as the ratio of handgrip strength to skeletal muscle mass.ResultsNo significant difference in sarcopenia prevalence was observed between AD patients and controls. Prevalence ranged from 3.4 to 23.4% in AD patients and from 2 to 11.8% in controls, depending on diagnostic criteria. Prevalence was higher using EWGSOP1 and decreased using EWGSOP2 and FNIH. Prevalence was higher in males than in females with AD. The MQI was lower in AD patients than in controls (95%CI: − 0.23, − 0.05, p < 0.001), but displayed poor diagnostic accuracy in identifying sarcopenia cases.ConclusionsAD patients and controls show comparable sarcopenia prevalence. Sarcopenia prevalence is higher in males than females among AD patients and higher when using EWGSOP1 compared to FNIH and EWGSOP2 criteria.