Decrease In Skeletal Muscle Mass Research Articles

The Impact of Diabetes Complications on the Physical Function of Maintenance Hemodialysis Patients.

This study investigated the impact of diabetes on the physical function of patients undergoing dialysis.This study included 22 patients undergoing outpatient dialysis with continued exercise therapy during dialysis at our hospital between January 2021 and August 2021. The participants were divided into two groups based on the presence or absence of diabetes, and various parameters were compared between the groups. To compare each physical function assessment and measurement of anterior thigh muscle thickness, repeated-measures analysis of variance was conducted to test for the presence of interactions and main effects. Significant differences were observed in the absence of dyslipidemia (p < 0.01), high-density lipoprotein cholesterol level (p < 0.01), and foot sole skin perfusion pressure (p < 0.02). In terms of physical function, a main effect between the groups was observed in the five-time sit-to-stand test, and anterior thigh muscle thickness showed a main effect over time. Significant differences in the anterior thigh muscle thickness were observed between three and six months after the intervention (p < 0.05). In patients undergoing dialysis with diabetes complications, a decrease in physical activity and lack of exercise can lead to a reduction in overall physical activity levels. Additionally, impairments such as peripheral neuropathy may contribute to an accelerated decrease in skeletal muscle mass.

Changes in Body Composition and Physical Performance after a Six-Week International Tour in Young Chilean Female Tennis Players.

Junior tennis players travel a lot to play tennis tournaments; this causes them to spend a lot of time away from their homes and disrupts their training, which could reduce their performance and increase the risk of injury. The purpose of this study was to analyze the changes in physical performance and body composition after a six-week international tour in young Chilean female tennis players. Thirty young female tennis players (15.4 ± 0.6) participated in this study. Body weight, skinfolds, and perimeters were measured. Body fat percentage (BFP) and skeletal muscle mass (SMM) were calculated. For physical performance, 5 m sprint, the 505 with stationary start test (505 test), the pro-agility test, countermovement jump (CMJ), and medicine ball throw (MBT) were evaluated. The results show a significant increase in BFP and decrease in SMM (p < 0.01; d = -0.18 and 0.19, respectively). In terms of physical performance, 5 m sprint, the 505 test (p < 0.01; d = -0.95 and -0.95, respectively), CMJ, MBT, and HJ significantly decreased post-tour (p < 0.05; d = 0.96, 0.89 and 0.47, respectively). We conclude that, after a six-week international tour, there were changes in body composition and a significant decrease in 5 m sprint, the 505 test, CMJ, and MBT.

Molecular and Structural Alterations of Skeletal Muscle Tissue Nuclei during Aging.

Aging is accompanied by a progressive loss of skeletal muscle mass and strength. The mechanisms underlying this phenomenon are certainly multifactorial and still remain to be fully elucidated. Changes in the cell nucleus structure and function have been considered among the possible contributing causes. This review offers an overview of the current knowledge on skeletal muscle nuclei in aging, focusing on the impairment of nuclear pathways potentially involved in age-related muscle decline. In skeletal muscle two types of cells are present: fiber cells, constituting the contractile muscle mass and containing hundreds of myonuclei, and the satellite cells, i.e., the myogenic mononuclear stem cells occurring at the periphery of the fibers and responsible for muscle growth and repair. Research conducted on different experimental models and with different methodological approaches demonstrated that both the myonuclei and satellite cell nuclei of aged skeletal muscles undergo several structural and molecular alterations, affecting chromatin organization, gene expression, and transcriptional and post-transcriptional activities. These alterations play a key role in the impairment of muscle fiber homeostasis and regeneration, thus contributing to the age-related decrease in skeletal muscle mass and function.

Dietary supplementation with inulin improves burn-induced skeletal muscle atrophy by regulating gut microbiota disorders

Inulin, as a prebiotic, could modulate the gut microbiota. Burn injury leads to gut microbiota disorders and skeletal muscle catabolism. Therefore, whether inulin can improve burn-induced muscle atrophy by regulating microbiota disorders remains unknown. This study aimed to clarify that inulin intake alleviates gut microbiota disorders and skeletal muscle atrophy in burned rats. Rats were divided into the sham group, burn group, prebiotic inulin intervention group, and pseudo-aseptic validation group. A 30% total body surface area (TBSA) third-degree burn wound on dorsal skin was evaluated in all groups except the sham group. Animals in the intervention group received 7 g/L inulin. Animals in the validation group received antibiotic cocktail and inulin treatment. In our study inulin intervention could significantly alleviate the burn-induced skeletal muscle mass decrease and skeletal myoblast cell apoptosis. Inulin intake increased the abundances of Firmicutes and Actinobacteria but decreased the abundance of Proteobacteria. The biosynthesis of amino acids was the most meaningful metabolic pathway distinguishing the inulin intervention group from the burn group, and further mechanistic studies have shown that inulin can promote the phosphorylation of the myogenesis-related proteins PI3K, AKT and P70S6K and activate PI3K/AKT signaling for protein synthesis. In conclusion, inulin alleviated burn induced muscle atrophy through PI3K/AKT signaling and regulated gut microbiota dysbiosis.

Lenvatinib Exacerbates the Decrease in Skeletal Muscle Mass in Patients with Hepatocellular Carcinoma, Whereas Atezolizumab Plus Bevacizumab Does Not.

This study aimed to evaluate chronological changes in skeletal muscle index (SMI), subcutaneous and visceral adipose tissue indices (SATI and VATI), AFP, PIVKA-II, and ALBI scores during atezolizumab plus bevacizumab (AB) or lenvatinib (LEN) treatment for hepatocellular carcinoma (HCC) and the effect of these changes on survival. A total of 94 patients with HCC (37 were on AB and 57 on LEN) were enrolled. SMI, SATI, VATI, AFP, PIVKA-II, and ALBI scores were analyzed at the time of the treatment introduction (Intro), 3 months after the introduction (3M), at drug discontinuation (End), and the last observational time (Last). The differences between chronological changes were analyzed using the Wilcoxon paired test. The independent predictors for survival and the changes in SMI during AB or LEN (c-SMI%) were analyzed using the Cox proportional hazards model treating all these factors as time-varying covariates and the analysis of covariance, respectively. SMI in the AB group was maintained over time (42.9-44.0-40.6-44.2 cm2/m2), whereas that in the LEN group significantly decreased during the Intro-3M (p < 0.05) and 3M-End (p < 0.05) period (46.5-45.1-42.8-42.1 cm2/m2). SMI (p < 0.001) was an independent predictor for survival together with AFP (p = 0.004) and ALBI score (p < 0.001). Drug choice (AB or LEN; p = 0.038) and PIVKA-II (p < 0.001) were extracted as independent predictors for c-SMI%. AB treatment was significantly superior to LEN in terms of maintaining skeletal muscle, which is an independent predictor for survival.

Gut microbiota dysbiosis and protein energy wasting in patients on hemodialysis: an observational longitudinal study.

Protein energy wasting (PEW) is common in patients on hemodialysis, and its development may involve gut microbial dysbiosis. However, the exact relationship between the composition of different flora and the development of PEW remains unclear. This is an observational longitudinal study on 115 patients undergoing hemodialysis who were followed up for 1 year. All the patients were evaluated at baseline, and different microbiota compositions were determined. After a 1 year follow-up period, the correlations between clinical parameter variations and the relative abundance of different gut flora were assessed using Spearman correlation. Moreover, the associations of the abundance of different gut microbiota with decrease in lean tissue mass and the development of PEW were analyzed using ROC curve and logistical regression analyses. We found that the relative abundances of Actinobacteria and Bifidobacteriaceae were significantly lower in patients with PEW than in those who did not develop PEW (p < 0.05). The abundance of Actinobacteria and Bifidobacteriaceae correlated positively with variations in serum albumin levels (r = 0.213, p = 0.035 and r = 0.214, p = 0.034, respectively), lean tissue mass (r = 0.296, p = 0.007 and r = 0.238, p = 0.002, respectively), and lean tissue index (r = 0.377, p < 0.001 and r = 0.419, p < 0.001, respectively). The area under the ROC curve or AUC values of Actinobacteria and Bifidobacteriaceae for the prediction of lean tissue mass decrease ranged from 0.676 to 0.708 (p < 0.05). Thus, decrease in the abundance of Actinobacteria and Bifidobacteriaceae may be associated with decrease in lean tissue mass and the occurrence of PEW. The present findings imply Actinobacteria and Bifidobacteriaceae may be potential markers for predicting skeletal muscle mass decrease and PEW development in patients on hemodialysis.

Association of Elevated Serum Branched-chain Amino Acid Levels With Longitudinal Skeletal Muscle Loss.

Branched-chain amino acids (BCAA) are substrates for protein synthesis. Although their intake may contribute to an increase in skeletal muscle mass, elevated serum BCAA levels have been reported to be associated with insulin resistance, potentially resulting in decreased skeletal muscle mass. This study aimed to explore the association between elevated serum BCAA levels and longitudinal skeletal muscle loss. A cohort analysis was conducted, in which serum amino acids were analyzed in healthy individuals who underwent a medical health checkup at Kameoka Municipal Hospital (HOZUGAWA study), Japan. Seventy-one participants (37 men and 34 women) underwent follow-up checkups after the baseline visit. The follow-up duration was 1.2 ± .4 years. The relationship between fasting baseline serum BCAA levels and lifestyle factors, body composition, blood test results, dietary history, and changes in skeletal muscle mass was evaluated. In both men and women, serum BCAA levels were positively correlated with body weight, body mass index, skeletal muscle mass index (SMI), and serum triglycerides but inversely correlated with serum high-density lipoprotein cholesterol. In men, fasting serum BCAA levels were inversely associated with the rate of change in SMI (adjusted β = -.529, P = .006), and elevated BCAA levels were independently associated with a longitudinal decrease in skeletal muscle mass (odds ratio: 1.740; 95% confidence interval: 1.023-2.960 per 50 nmol/mL serum BCAAs increase). Increased circulating BCAAs could be an indicator of skeletal muscle loss in men.

Moderate dietary restriction delays the onset of age-associated sarcopenia in Caenorhabditis elegans due to reduced myosin UNC-54 degradation

Sarcopenia, a gradual decrease in skeletal muscle mass and strength, is a major component of frailty in the elderly, with age, (lack of) exercise and diet found to be the major risk factors. The nematode Caenorhabditis elegans is an important model of sarcopenia. Although many studies describe loss of muscle function in ageing C. elegans, surprisingly few report on the loss of muscle mass. Here, in order to quantify loss of muscle mass under various dietary restriction (DR) conditions, we used an internal GFP standard to determine levels of the major body wall muscle myosin (UNC-54) in transgenic unc-54::gfp worms over their lifespan. Myosin density linearly increased during the first week of adulthood and there was no significant effect of DR. In contrast, an exponential decrease in myosin density was seen during the second week of adulthood, with reduced rates of myosin loss for mild and medium DR compared to control. UNC-54 turnover rates, previously determined using pulse-labelling methods, correspond well with the t1/2 value found here for UNC-54-GFP using fluorescence (control t1/2 = 12.0 days), independently validating our approach. These data indicate that sarcopenia is delayed in worms under mild and medium DR due to a reduced rate of myosin UNC-54 degradation, thereby maintaining protein homeostasis.

Особенности композиционного состава тела и метаболического профиля у детей с саркопеническим ожирением

Sarcopenic obesity (SO) is characterized by a decrease of lean mass and increase of adipose tissue and is associated with various metabolic disorders in adults. The influence of the body composition on the metabolic profile in obese children remains unclear as yet. The purpose of the research was to assess body composition and metabolic profile in children with sarcopenic obesity Methods used: cross-sectional, single-center study was conducted in Feb. 2020-Jul. 2022 which included 116 children (55 boys, 61 girls) with simple obesity (SDS BMI 2.5 [2.2;2.7]) aged 7 to 17 y/o (average age 14.2 [12.3;15.5] y/o) divided into two groups depending on the presence of sarcopenic obesity. The group with sarcopenic obesity ("SO+") included 56 children (19 boys, 37 girls) with simple obesity (SDS BMI 2.5 [2.2; 2.6]). The control group ("SO-") consisted of 60 children (36 boys, 24 girls) with constitutionally exogenous obesity (SDS BMI 2.5 [2.2; 2.7]) without sarcopenia. Results: children with sarcopenic obesity were characterized by an increase in adipose tissue (39.1% [36.4; 41.9] vs 30.6% [27.6; 32.4]; p&lt;0.0001), decrease in lean mass (55.6 [44.8; 63.7] vs 45.6 [39.5; 49.7] kg; p&lt;0.0001) and skeletal muscle mass decrease (25.0 [19.2; 28.2] vs 19.4 [16.3; 22.4] kg; p&lt;0.0001) - all compared to the "SO-" group. There were no statistically significant differences in the frequency of detection of impaired glucose tolerance (p=0.672), insulin resistance (p=0.871) and non-alcoholic fatty liver disease (p=0.657) in both groups. Conclusion: sarcopenic obesity in children is characterized by a reduction of lean mass and skeletal muscle mass and is not accompanied by changes in the metabolic profile. It makes difficult to stratify metabolic risks in this group of pediatric patients.

Subcutaneous Infusion of DNA-Aptamer Raised against Advanced Glycation End Products Prevents Loss of Skeletal Muscle Mass and Strength in Accelerated-Aging Mice.

We have developed DNA aptamers that can inhibit the toxic effects of advanced glycation end products (AGE-Apts). We herein evaluated the effects of AGE-Apts on muscle mass and strength in senescence-accelerated mouse prone 8 (SAMP8) mice. Eight-month-old male SAMP8 mice received subcutaneous infusion of control DNA aptamers (CTR-Apts) or AGE-Apts. Mice in an age-matched senescence-accelerated mouse resistant strain 1 (SAMR1) group were treated with CTR-Apts as controls. The soleus muscles were collected after the 8-week intervention for weight measurement and histological, RT-PCR, and immunofluorescence analyses. Grip strength was measured before and after the 8-week intervention. AGE-Apt treatment inhibited the progressive decrease in the grip strength of SAMP8 mice. SAMP8 mice had lower soleus muscle weight and fiber size than SAMR1 mice, which was partly restored by AGE-Apt treatment. Furthermore, AGE-Apt-treated SAMP8 mice had a lower interstitial fibrosis area of the soleus muscle than CTR-Apt-treated SAMP8 mice. The soleus muscle levels of AGEs, oxidative stress, receptor for AGEs, and muscle ring-finger protein-1 were increased in the CTR-Apt-treated mice, all of which, except for AGEs, were inhibited by AGE-Apt treatment. Our present findings suggest that the subcutaneous delivery of AGE-Apts may be a novel therapeutic strategy for aging-related decrease in skeletal muscle mass and strength.

Impact of changes in skeletal muscle mass and quality during the waiting time on outcomes of lung transplantation.

The association of changes in skeletal muscle mass and quality during the waiting time with outcomes of lung transplantation (LT) remains unclear. We aimed to examine the association of changes in skeletal muscle mass and quality during the waiting time, as well as preoperative skeletal muscle mass and quality, with outcomes of LT. This study included individuals who underwent LT from brain-dead donors. Skeletal muscle mass (cm2 /m2 ) and quality (mean Hounsfield units [HU]) of the erector spinae muscle at the 12th thoracic level were evaluated using computed tomography. Preoperative skeletal muscle mass and quality, and their changes during the waiting time were calculated. We evaluated the associations among mechanical ventilation (MV) duration, intensive care unit (ICU) length of stay (LOS), hospital LOS, 6-minute walk distance at discharge, and 5-year survival after LT. This study included 98 patients. The median waiting time was 594.5days (interquartile range [IQR], 355.0-913.0). The median changes in skeletal muscle mass and quality were -4.4% (IQR, -13.3-3.1) and -2.9% (IQR, -16.0-4.1), respectively. Severe low skeletal muscle mass at LT was associated with prolonged ICU LOS (B=8.46, 95% confidence interval [CI]: .51-16.42) and hospital LOS (B=36.00, 95% CI: 3.23-68.78). Pronounced decrease in skeletal muscle mass during the waiting time was associated with prolonged MV duration (B=7.85, 95% CI: .89-14.81) and ICU LOS (B=7.97, 95% CI: .83-15.10). Maintaining or increasing skeletal muscle mass during the waiting time would be beneficial to improve the short-term outcomes of LT.

Exercise mitigates Dapagliflozin-induced skeletal muscle atrophy in STZ-induced diabetic rats

BackgroundSodium-glucose cotransporter 2 inhibitors (SGLT2i) are commonly used in the management of type 2 diabetes mellitus (T2DM) and have been found to worsen the reduction of skeletal muscle mass in individuals with T2DM. This study aims to examine the potential of exercise in mitigating the skeletal muscle atrophy induced by SGLT2i treatment.MethodsA rat model of T2DM (40 male Sprague-Dawley rats; T2DM induced by a combination of high-fat diet and streptozotocin) was used to examine the effects of six-week treatment with Dapagliflozin (DAPA, SGLT2i) in combination with either aerobic exercise (AE) or resistance training (RT) on skeletal muscle. T2DM-eligible rats were randomized into the T2DM control group (CON, n = 6), DAPA treatment group (DAPA, n = 6), DAPA combined with aerobic exercise intervention group (DAPA + AE, n = 6), and DAPA combined with resistance training intervention group (DAPA + RT, n = 6). To assess the morphological changes in skeletal muscle, myosin ATPase and HE staining were performed. mRNA expression levels of Atrogin-1, MuRF1, and Myostatin were determined using quantitative PCR. Furthermore, protein expression levels of AKT, p70S6K, mTOR, FoXO1/3A, NF-κB, and MuRF1 were examined through western blotting.ResultsBoth the administration of DAPA alone and the combined exercise intervention with DAPA resulted in significant reductions in blood glucose levels and body weight in rats. However, DAPA alone administration led to a decrease in skeletal muscle mass, whereas RT significantly increased skeletal muscle mass and muscle fiber cross-sectional area. The DAPA + RT group exhibited notable increases in both total protein levels and phosphorylation levels of AKT and p70S6K in skeletal muscle. Moreover, the DAPA, DAPA + AE, and DAPA + RT groups demonstrated downregulation of protein expression (FoXO1/3A) and mRNA levels (Atrogin-1, MuRF1, and Myostatin) associated with muscle atrophy.ConclusionsOur findings provide support for the notion that dapagliflozin may induce skeletal muscle atrophy through mechanisms unrelated to protein metabolism impairment in skeletal muscle, as it does not hinder protein metabolic pathways while reduces muscle atrophy-related genes. Additionally, our observations reveal that RT proves more effective than AE in enhancing skeletal muscle mass and muscle fiber cross-sectional area in rats with T2DM by stimulating protein anabolism within the skeletal muscle.

Sarcopenia: The Prevalence and Associated Factors in Community-Dwelling Elderly

Sarcopenia is a syndrome characterized by a decrease in skeletal muscle mass and function due to aging. This study aims to assess the prevalence and associated factors of sarcopenia among the elderly in the Pekanbaru. 275 samples were selected using cluster sampling technique. The independent variables were socio-demographic characteristics, metabolic syndrome, independence level, physical activity, quality of life, depression, and nutritional status. Meanwhile, the dependent variable was sarcopenia. Data analysis was carried out through SPSS using statistical tests including descriptive statistics, chi-square, and multivariate logistic regression. The results show that 45.5% of the participants experienced sarcopenia. The mean age of participants was 63.3 years old; most were female; 90.2% were married; and 39.3% had moderate quality of life. The education level was mostly high school; 69.1% were not working; 72% did not experience metabolic syndrome; and 78.5% had normal nutritional status. Gender, education, metabolic syndrome, independence level, physical activity, quality of life, nutrition, marital, depression, and occupational status are associated with sarcopenia. The most significant variables for sarcopenia in the elderly were nutritional status (p=0.031) and physical activity (p= 0.016). Nutritional status and physical activity were predictors of sarcopenia. Posyandu, or integrated service post, for the elderly in the public health center, needs to be optimized which requires continuous collaboration among the doctors, nurses, nutritionists, social workers, physiotherapists, psychologists, families, religious institutions, and community shops. Furthermore, a treatment program needs to be developed, both in the community and in the health services area.

Postoperative relative decrease in skeletal muscle mass as a predictor of quality of life in patients with gastric cancer.

Low skeletal muscle mass reflects poor nutritional condition, which may impair the functional status and quality of life (QOL) of survivors of gastrectomy. The present cross-sectional study examined the association between a relative change in skeletal muscle mass and perceived postoperative health and QOL in patients with gastric cancer. The study comprised 74 patients (48 men and 26 women; median age, 68.5 years) who underwent surgery for stage I-III gastric cancer. Outcomes were measured using the Postgastrectomy Syndrome Assessment Scale-45, which was specifically developed to measure post-gastrectomy symptoms, living status, dissatisfaction with daily life and generic QOL. The skeletal muscle mass index (SMI) was estimated using computed tomography by tracing the area of the psoas major muscle to calculate the ΔSMI, defined as: (SMI before surgery-SMI at completion of the PGSAS-45 survey)/SMI before surgery x100. Associations between ΔSMI and health outcomes were assessed using univariate and multivariate analyses. The mean ΔSMI (SD) was 8.64% (10.6%). The effect size (Cohen's d) of ΔSMI <10% compared with ΔSMI ≥10% was 0.50 (95% CI: 0.02 to 0.97) for total symptom scores, -0.51 (-0.98 to -0.03) for general health, and -0.52 (-0.99 to -0.05) for the physical component summary (PCS). Multiple regression analysis showed that ΔSMI was significantly associated with PCS decline, and its standardized regression coefficient was -0.447 (-0.209 to -0.685). Determining ΔSMI may help clinicians to facilitate the objective evaluation of low skeletal mass, which reflects poor nutritional condition that can impair functional status and QOL of postoperative patients surviving gastrectomy.

Relationship between Testosterone levels with Hand Grip Strength, Calf Diameter, Lung Function, Body Mass Index and Blood Pressure in Elderly Men

The elderly population in Indonesia is increasing every year. Aging is associated with loss and decline in testosterone levels in elderly men. Testosterone deficiency is associated with decreased body mass, decreased bone density, decreased physical function and activity, decreased cognitive function, increased fat mass, increased depressive symptoms and increased risk of falls and fractures. Muscle mass is the largest tissue which covers 40%-50% of the body. To assess muscle strength, hand grip strength can be measured and to assess muscle mass, anthropometric measurements can be made, especially calf diameter. While for body fat can be measured body mass index. The age-related decrease in skeletal muscle mass also affects respiratory muscle function which can be seen from the decline in lung function (FEV1 and FVC). In addition, increased blood pressure is also common in elderly people. Objective: To determine the relationship between the hormone testosterone with hand grip strength, calf diameter, lung function, body mass index (BMI) and blood pressure in elderly men. Method: This study is observational analytic with a cross-sectional study design conducted in Manado on elderly men. Results: From this study, 38 samples of elderly men were obtained who had a significant positive relationship between testosterone levels and FVC values (p = 0.004). There was a significant positive relationship between testosterone levels and the strength of the right-hand grip (p = 0.245) and left-hand grip (p = 0.354), the same was true for FEV1 values (p = 0.078) and systole (p = 0.340) and diastole (p = 0.216). In this study there was a significant negative relationship between testosterone levels with the diameter of the right calf (p = 0.009) and left (p = 0.009) and the same thing also in the BMI value (p = 0.003). Conclusion: The better the testosterone level, the better the FVC value, while the lower the testosterone level, the greater the calf diameter and BMI. FEV1 values, hand grip strength and blood pressure were not significantly affected by testosterone levels.

Fatty acid amides as potential circulating biomarkers for sarcopenia.

Sarcopenia is characterized by a progressive decrease in skeletal muscle mass and function with age. Given that sarcopenia is associated with various metabolic disorders, effective metabolic biomarkers for its early detection are required. We aimed to investigate the metabolic biomarkers related to sarcopenia in elderly men and perform experimental studies using metabolomics. Plasma metabolites from 142 elderly men, comprising a sarcopenia group and an age-matched control group, were measured using global metabolome profiling. Muscle and plasma samples from an aging mouse model of sarcopenia, as well as cell media and cell lysates during myoblast differentiation, were analysed based on targeted metabolome profiling. Based on these experimental results, fatty acid amides were quantified from human plasma as well as human muscle tissues. The association of fatty acid amide levels with sarcopenia parameters was evaluated. Global metabolome profiling showed that fatty acid amide levels were significantly different in the plasma of elderly men with sarcopenia (all Ps<0.01). Consistent with these results in human plasma, targeted metabolome profiling in an aging mouse model of sarcopenia showed decreased levels of fatty acid amides in plasma but not in muscle tissue. In addition, the levels of fatty acid amides increased in cell lysates during muscle cell differentiation. Targeted metabolome profiling in men showed decreased docosahexaenoic acid ethanolamide (DHA EA) levels in the plasma (P=0.016) but not in the muscle of men with sarcopenia. DHA EA level was positively correlated with sarcopenia parameters such as skeletal muscle mass index (SMI) and handgrip strength (HGS) (P=0.001, P=0.001, respectively). The area under the receiver-operating characteristic curve (AUC) for DHA EA level≤4.60 fmol/μL for sarcopenia was 0.618 (95% confidence interval [CI]: 0.532-0.698). DHA EA level≤4.60 fmol/μL was associated with a significantly greater likelihood of sarcopenia (odds ratio [OR]: 2.11, 95% CI: 1.03-4.30), independent of HGS. The addition of DHA EA level to age and HGS significantly improved the AUC from 0.620 to 0.691 (P=0.0497). Our study demonstrated that fatty acid amides are potential circulating biomarkers in elderly men with sarcopenia. DHA EA, in particular, strongly related to muscle mass and strength, can be a key metabolite to become a reliable metabolic biomarker for sarcopenia. Further research on fatty acid amides will provide insights into the metabolomic changes relevant to sarcopenia from an aging perspective.

Not only muscle mass but also muscle quality is associated with knee extension muscle strength in patients with hip fractures

This study aimed to assess the relationship between isometric knee extension muscle strength on the operated or nonoperated sides and PhA in patients with hip fractures at approximately 6months postoperatively. This study was a cross-sectional study. Skeletal muscle index (SMI), PhA, knee extension muscle strength on the operated and nonoperated sides, and other physical function variables were assessed at approximately 6months postoperatively. To identify predictors of knee extension muscle strength on the operated and nonoperated sides, hierarchical multiple regression analysis was performed. A total of 90 patients with hip fractures were included (mean age, 80.1 ± 6.9years). SMI (0.45) and PhA on the operated side (0.27) were the significant associated factors extracted for isometric knee extension muscle strength on the operated side (standardized partial regression coefficients), independent of age, sex, and body mass index (BMI). Movement control during one-leg standing on the nonoperated side (0.26), SMI (0.32), and PhA on the nonoperated side (0.40) were the significant associated factors extracted for isometric knee extension muscle strength on the nonoperated side, independent of age, sex and BMI. Our results revealed that the decrease in isometric knee extension muscle strength on the operated and nonoperated sides in patients with hip fractures at approximately 6months postoperatively was associated with not only a decrease in skeletal muscle mass but also a decrease in muscle quality, characterized by a decreased PhA.

Nobiletin Improves D-Galactose-Induced Aging Mice Skeletal Muscle Atrophy by Regulating Protein Homeostasis.

Sarcopenia, a decrease in skeletal muscle mass and function caused by aging, impairs mobility, raises the risk of fractures, diabetes, and other illnesses, and severely affects a senior's quality of life. Nobiletin (Nob), polymethoxyl flavonoid, has various biological effects, such as anti-diabetic, anti-atherogenic, anti-inflammatory, anti-oxidative, and anti-tumor properties. In this investigation, we hypothesized that Nob potentially regulates protein homeostasis to prevent and treat sarcopenia. To investigate whether Nob could block skeletal muscle atrophy and elucidate its underlying molecular mechanism, we used the D-galactose-induced (D-gal-induced) C57BL/6J mice for 10 weeks to establish a skeletal muscle atrophy model. The findings demonstrated that Nob increased body weight, hindlimb muscle mass, lean mass and improved the function of skeletal muscle in D-gal-induced aging mice. Nob improved myofiber sizes and increased skeletal muscle main proteins composition in D-gal-induced aging mice. Notably, Nob activated mTOR/Akt signaling to increase protein synthesis and inhibited FOXO3a-MAFbx/MuRF1 pathway and inflammatory cytokines, thereby reducing protein degradation in D-gal-induced aging mice. In conclusion, Nob attenuated D-gal-induced skeletal muscle atrophy. It is a promising candidate for preventing and treating age-associated atrophy of skeletal muscles.

Influence of Lower Limb Ischemia on Skeletal Muscle Mass Depletion in Patients with Peripheral Artery Disease

The aim of the study was to determine the change in skeletal muscle mass over time by bioelectrical impedance analysis (BIA) in patients with peripheral artery disease (PAD). Patients with symptomatic PAD visiting Tokyo Medical University Hospital between January 2018 and October 2020 were retrospectively analyzed. PAD was diagnosed based on ankle brachial pressure index (ABI)<0.9 with either leg and confirmed by duplex scan and/or computed tomography angiography as needed. Patients undergoing endovascular treatment, surgery, or supervised exercise therapy were excluded before and during the study period. Skeletal muscle mass of the extremities was measured using BIA. The sum of skeletal muscle masses in the arms and legs was calculated as skeletal muscle mass index (SMI). Patients were scheduled to undergo BIA at an interval of 1year. Of 119 patients, 72 patients were included in the study. All patients were ambulatory and had symptoms of intermittent claudication (Fontaine's stage II). SMI significantly decreased from 6.98±1.30 at baseline to 6.83±1.29 at 1-year follow-up. Individual skeletal muscle mass of the ischemic leg was significantly reduced after 1year, but not in the nonischemic leg. A decrease in SMI (defined as SMI ≥0.1kg/m2 per year) was independently associated with low ABI. The optimal cut-off value of ABI for the decrease in SMI was 0.72. These results suggest that lower limb ischemia due to PAD, especially if ABI is<0.72 or less, may result in a decrease in skeletal muscle mass that affects health and physical function.

Evaluation of the relationship of the T and M stage with the erector spinae muscle area in male lung cancer patients

Objectives Sarcopenia is very common due to cachexia and presents with a decrease in skeletal muscle mass. In this study, we aimed to investigate the relationship between the T, M category and the erector spinae muscle area (ESMa). Material and methods The initial first thorax and high-resolution computed tomography (CT) of patients with lung cancer between 2015 and 2019 were retrospectively screened. After exclusion criterias remaining 226 male patients constituted the study group. ESMa was measured manually in the section taken from the T12 vertebra spinous process level as previously described in the literature and its relationship with the T and M stage were evaluated. Results The mean ages of patients were 70 ± 9.57 years. The T stage was T1 in 34 (15%) patients, T2 in 46 (20.4%), T3 in 59 (26.1%), and T4 in 87 (38.5%). Metastasis was detected in 83 (36.7%) patients. The mean ESMa of the patients was 34.15 ± 7.21 mm2 and did not differ according to the T stage (p = .39). ESMa was lower in the metastatic group (mean 30.42 ± 6.38 mm2) than the non-metastatic group (mean 36.32 ± 6.78 mm2) (p = .0001). Conclusions ESMa, one of the indicators of sarcopenia, is lower in patients with metastatic lung cancer than in nonmetastatic.