Pathogenesis and Management of Sarcopenia

Skeletal muscle index together with body mass index is associated with secondary osteoporosis in patients with rheumatoid arthritis

OBJECTIVE

The objective of this study was to explore the associations of body mass index (BMI), fat mass index (FMI), skeletal mass index (SMI) and secondary osteoporosis (OP) in patients with rheumatoid arthritis (RA).

METHODS

The bone mineral density (BMD) at sites of the femur neck (Neck), total hip (Hip) and lumbar vertebrae 1-4 (L1-4) was measured by dual-energy X-ray absorptiometry. The skeletal muscle index, body fat percentage and mineral content were measured by biological electrical impedance for calculating BMI, FMI and SMI.

RESULTS

A total of 433 patient with RA and 158 healthy controls were enrolled. The BMDs at each site of the RA patients were lower compared with those of the healthy controls (p < 0.0001), and the prevalence of OP (36.1%, 160/443) and sarcopenia (65.2%, 288/443) in the RA patients were higher than those in the controls (12.7%, 20/158, p < 0.0001; 9.0%, 14/156, p < 0.0001). Significant differences in the BMD, FMI, SMI, mineral content, body fat percentage and skeletal muscle mass were found among the RA patients in the different BMI groups (p < 0.05). In RA patients with BMI < 18.5 kg/m2, the prevalence of OP in the RA patients with sarcopenia was similar to that in those without sarcopenia (44.4% vs. 66. 7%, χ2 = 0. 574, p = 0.449). In the RA patients with a normal BMI or who were overweight or obese, prevalence of OP in the RA patients with sarcopenia was significantly higher than that in the RA patients without sarcopenia (42.8% vs. 21.7%, χ2 = 10.951, p = 0.001; 61.1% vs. 13.0%, χ2 = 26.270, p < 0.0001). In the RA patients without sarcopenia, the prevalence of OP in the RA patients in the different BMI groups was different (p = 0.039). In the RA patients with sarcopenia, there was no significant difference in the prevalence of OP among the RA patients in the different BMI groups (p = 0. 128). The linear correlation analysis showed that the SMI in RA patients was positively correlated with the BMD of each site measured and BMI and FMI (p < 0.0001). However, there was a negative linear correlation between SMI and disease duration (p = 0.048). The logistic regression analysis found that SMI (OR = 0.569, p = 0.002, 95% CI 0.399-0.810), BMI (OR = 0.884, p = 0.01, 95% CI 0.805-0.971) and gender (1 = female, 2 = male) (OR = 0.097, p < 0.0001, 95% CI 0.040-0.236) were protective factors for OP in RA, while age (OR = 1.098, p < 0.0001, 95% CI 1.071-1.125) was the risk factor.

CONCLUSION

BMI and SMI are associated with the occurrence of OP in RA patients, and both SMI and BMI are important protective factors for OP secondary to RA.

Molecular insights into sarcopenia: ferroptosis-related genes as diagnostic and therapeutic targets

Ferroptosis, characterized by iron accumulation and lipid peroxidation, leads to cell death. Growing evidence suggests the involvement of ferroptosis in sarcopenia. However, the fundamental ferroptosis-related genes (FRGs) for sarcopenia diagnosis, prognosis, and therapy remain elusive. This study aimed to identify molecular biomarkers of ferroptosis in sarcopenia patients. Gene expression profiles were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between normal and sarcopenia samples were identified using the 'limma' package in R software. FRGs were extracted from GeneCards and FerrDB databases. Functional enrichment analysis determined the roles of DEGs using the 'clusterProfiler' package. A protein-protein network was constructed using Cytoscape software. Immune infiltration analysis and receiver operating characteristic (ROC) analysis were performed. mRNA-miRNA, mRNA-TF, and mRNA-drug interactions were predicted using ENCORI, hTFtarget, and CHIPBase databases. The network was visualized using Cytoscape. We identified 46 FRGs in sarcopenia. Functional enrichment analysis revealed their involvement in critical biological processes, including responses to steroid hormones and glucocorticoids. KEGG enrichment analysis implicated pathways such as carbon metabolism, ferroptosis, and glyoxylate in sarcopenia. Totally, 11 hub genes were identified, and ROC analysis demonstrated their potential as sensitive and specific markers for sarcopenia in both datasets. Additionally, differences in immune cell infiltration were observed between normal and sarcopenia samples. The hub genes identified in this study are closely associated with ferroptosis in sarcopenia and can effectively differentiate sarcopenia from controls. CDKN1A, CS, DLD, FOXO1, HSPB1, LDHA, MDH2, and YWHAZ show high sensitivity and specificity for sarcopenia diagnosis.Communicated by Ramaswamy H. Sarma.

Decreased Neuromuscular Function and Muscle Quality along with Increased Systemic Inflammation and Muscle Proteolysis Occurring in the Presence of Decreased Estradiol and Protein Intake in Early to Intermediate Post-Menopausal Women

Menopause causes a reduction in estradiol (E2) and may be associated with neuromuscular degeneration. Compared to pre-menopausal (PRE-M) women, this study sought to determine dietary protein intake and whether lower levels of circulating E2 in post-menopausal women (POST-M) were occurring alongside increased levels of biomarkers of axonal and neuromuscular junction degeneration (NMJ), inflammation, muscle protein degradation, and reduced indices of muscle quality and performance. Employing a cross-sectional design, PRE-M (n = 6) and POST-M (n = 6) dietary analysis data were collected and participants then donated a blood and urine sample followed by assessments for body composition, motor unit activation, and muscle performance. Independent group t-tests were performed to determine differences between groups (p ≤ 0.05). In POST-M women, E2, motor unit activity, muscle quality, and muscle performance were significantly less than those for PRE-M women; however, the levels of c-terminal fragment of agrin, tumor necrosis factor-α, and urinary titin were significantly greater (p < 0.05). POST-M women were also shown to be ingesting fewer total calories and less protein than PRE-M (p < 0.05). Reduced E2 and dietary protein intake in POST-M women occurs in conjunction with increased levels of biomarkers of NMJ degradation, inflammation, and muscle proteolysis, which may be associated with reduced motor unit activation and muscle quality.

Leveraging Biomaterial Platforms to Study Aging-Related Neural and Muscular Degeneration

Aging is a complex multifactorial process that results in tissue function impairment across the whole organism. One of the common consequences of this process is the loss of muscle mass and the associated decline in muscle function, known as sarcopenia. Aging also presents with an increased risk of developing other pathological conditions such as neurodegeneration. Muscular and neuronal degeneration cause mobility issues and cognitive impairment, hence having a major impact on the quality of life of the older population. The development of novel therapies that can ameliorate the effects of aging is currently hindered by our limited knowledge of the underlying mechanisms and the use of models that fail to recapitulate the structure and composition of the cell microenvironment. The emergence of bioengineering techniques based on the use of biomimetic materials and biofabrication methods has opened the possibility of generating 3D models of muscular and nervous tissues that better mimic the native extracellular matrix. These platforms are particularly advantageous for drug testing and mechanistic studies. In this review, we discuss the developments made in the creation of 3D models of aging-related neuronal and muscular degeneration and we provide a perspective on the future directions for the field.

The impact of Helicobacter pylori infection on low skeletal muscle mass risk in Chinese women over 40: a cross-sectional analysis

Background

Sarcopenia can lead to significant personal, social, and economic burdens. The diagnosis of sarcopenia heavily relies on the identification of Low Skeletal Muscle Mass (LSMM), which is an independent predictor of frailty, disability, and increased risk of death among seniors. Women have physiologically lower levels of skeletal muscle mass than men, and female sarcopenia appears to be more influenced by menopause. They also tend to have higher body fat levels than man, which increases the risk of sarcopenia obesity. On another front, it's also recognized that humans are largely prone to Helicobacter pylori (H. pylori) infection, with global prevalence rates often surpassing 50%. Nevertheless, the interconnection between H. pylori infection and LSMM remains relatively unexplored. Hence, our study specifically targeted women as the research population and sought to explore several risk factors for LSMM. Additionally, we delved into the potential correlation between LSMM and H. pylori infection in women, hoping to gain insights into potential preventative measures or treatment options that may enhance the quality of life for women affected by sarcopenia.

Methods

We conducted a cross-sectional study among women aged over 18 years undergoing physical examination. We performed 13C-urea breath test (UBT) for diagnosis of H. pylori infection and Bioelectrical impedance analysis (BIA) for the assessment of LSMM. Logistic regression models were used to analyze the associations of H. pylori infection with LSMM.

Results

This study enrolled 1984 Chinese women who were undergoing health check-ups. A univariate logistic regression analysis did not reveal a direct correlation between H. pylori infection and LSMM among this female population (OR=1.149, 95% CI 0.904-1.459, p=0.257). Yet, upon dividing the participants into age-based subgroups, an evident link was observed between H. pylori infection and LSMM in women aged 40 or above (OR=1.381, 95%CI 1.032-1.848, p= 0.030). After adjusting for variables including Age, BMI, TP, ALK, Cre, this relationship remained statistically relevant (OR=1.514, 95%CI 1.085-2.113, p= 0.015).

Conclusions

Women who are over 40 years old and currently infected with H. pylori have an increased risk of developing LSMM. Therefore, timely treatment for H. pylori eradication is recommended for this group of women to reduce the occurrence of LSMM.

Association between Food Consumption Patterns and Handgrip Strength among Adults Aged ≥55 Years in Indonesia: A Cross-Sectional Analysis from the IFLS-5

We aimed to examine the association of food consumption patterns, measured by dietary diversity score (DDS) or food consumption score (FCS), with handgrip strength (HGS) among adults aged ≥55 years in Indonesia. This is a cross-sectional study involving 4351 middle-aged and older adults from the Indonesian Family Life Survey Fifth Wave (IFLS-5), collected in 2014-2015. A weighted linear regression model was used to examine the association of DDS or FCS with HGS in crude and adjusted models. In the adjusted models and compared to those with low DDS or poor FCS, those with medium/high DDS and borderline/acceptable FCS were associated with a higher mean of HGS. Good food consumption patterns, as reflected by high DDS or acceptable FCS, were shown to be significantly associated with stronger HGS among adults aged 55 years or above. More targeted nutritional interventions to promote good food consumption patterns may help improve HGS among middle-aged and older adults in Indonesia.

What Does Sarcopenia Have to Do with Nonalcoholic Fatty Liver Disease?

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease. As the second stage of developing steatosis, nonalcoholic hepatitis (NASH) carries the risk of fibrosis, cirrhosis, and hepatocellular carcinoma. Sarcopenia is defined as a condition characterized by a decrease in muscle mass and functional decline. Both NAFLD and sarcopenia are global problems. The pathophysiological mechanisms that link the two entities of the disease are insulin resistance, inflammation, nutritional deficiencies, impairment of myostatin and adiponectin, or physical inactivity. Furthermore, disorders of the gut-liver axis appear to induce the process of developing NAFLD and sarcopenia. The correlations between NAFLD and sarcopenia appear to be bidirectional, so the main objective of the review was to determine the cause-and-effect relationship between the two diseases.

The mediating role of inflammaging between mitochondrial dysfunction and sarcopenia in aging: a review

Sarcopenia, characterized by the insidious reduction of skeletal muscle mass and strength, detrimentally affects the quality of life in elderly cohorts. Present therapeutic strategies are confined to physiotherapeutic interventions, signaling a critical need for elucidation of the etiological underpinnings to facilitate the development of innovative pharmacotherapies. Recent scientific inquiries have associated mitochondrial dysfunction and inflammation with the etiology of sarcopenia. Mitochondria are integral to numerous fundamental cellular processes within muscle tissue, including but not limited to apoptosis, autophagy, signaling via reactive oxygen species, and the maintenance of protein equilibrium. Deviations in mitochondrial dynamics, coupled with compromised oxidative capabilities, autophagic processes, and protein equilibrium, result in disturbances to muscular architecture and functionality. Mitochondrial dysfunction is particularly detrimental as it diminishes oxidative phosphorylation, escalates apoptotic activity, and hinders calcium homeostasis within muscle cells. Additionally, deleterious feedback loops of deteriorated respiration, exacerbated oxidative injury, and diminished quality control mechanisms precipitate the acceleration of muscular senescence. Notably, mitochondria exhibiting deficient energetic metabolism are pivotal in precipitating the shift from normative muscle aging to a pathogenic state. This analytical review meticulously examines the complex interplay between mitochondrial dysfunction, persistent inflammation, and the pathogenesis of sarcopenia. It underscores the imperative to alleviate inflammation and amend mitochondrial anomalies within geriatric populations as a strategy to forestall and manage sarcopenia. An initial overview provides a succinct exposition of sarcopenia and its clinical repercussions. The discourse then progresses to an examination of the direct correlation between mitochondrial dysfunction and the genesis of sarcopenia. Concomitantly, it accentuates potential synergistic effects between inflammatory responses and mitochondrial insufficiencies during the aging of skeletal muscle, thereby casting light upon emergent therapeutic objectives. In culmination, this review distills the prevailing comprehension of the mitochondrial and inflammatory pathways implicated in sarcopenia and delineates extant lacunae in knowledge to orient subsequent scientific inquiry.

Addressing the Main Barrier to Sarcopenia Identification: Utility of Practical Office-Based Bioimpedance Tools Vs. Dual Energy X-ray Absorptiometry (DXA) Body Composition for Identification of Low Muscle Mass in Older Adults

Background

Sarcopenia is associated with increased morbidity and mortality. Clinically, sarcopenia can be overlooked, especially in obesity. Sarcopenia diagnostic criteria include muscle mass (MM) and function assessments. Muscle function can be readily assessed in a clinic setting (grip strength, chair stand test). However, MM requires dual-energy X-ray absorptiometry (DXA) Body Composition (BC) or other costly tools, not readily available.

Methods

Observational cohort pilot study of independently mobile, community dwelling older adults, comparing MM using two office-based, direct-to-consumer bioimpedance (BIA) scales (Ozeri® [manufactured in China] and OMRON® [OMRON HBF-510® Full Body Sensor, Shiokoji Horikawa, Kyoto, Japan] to DXA. The OMRON differs from the Ozeri scale because the OMRON also includes hand sensors. The European Working Group on Sarcopenia in Older People (EWGSOP) DXA or BIA low MM diagnostic cut-offs were used to classify participants as having low or normal MM.

Results

Fifty participants: 11 men, 39 women. Forty-two completed DXA. Age 75.8 yrs [67-90]. 81% obese based on body fat cut-offs. With DXA [ASM/height2], 15 had low MM. Using BIA [mmass/height2], 7 with Ozeri, and 27 with OMRON, had low MM. Positive predictive value for low MM versus DXA (as the gold standard) for Ozeri was 73.3% and OMRON was 92.8%. Good correlation between BIA scales and DXA for body fat estimates.

Conclusions

OMRON captured all low MM participants identified by DXA plus all on DXA diagnostic borderline. Prevalence of obesity was high. Clinically, sarcopenic obese is the most difficult phenotype, as obesity masks low muscle mass. Low cost, readily available, direct-to-consumer BIA BC scales, especially with hand sensors, provide immediate, reliable information on muscle and fat mass. This can prompt appropriate investigation and/or intervention for sarcopenia or sarcopenic obesity.

The potential of traditional herbal active ingredients in the treatment of sarcopenia animal models: focus on therapeutic effects and mechanisms

Sarcopenia is a major global public health problem that harms individual physical function. In 2018, the European Working Group on Sarcopenia in the Elderly 2 classified sarcopenia into primary and secondary sarcopenia. However, information on the pathogenesis and effective treatment of primary and secondary sarcopenia is limited. Traditional herbal active ingredients have biological activities that promote skeletal muscle health, showing potential preventive and therapeutic effects on sarcopenia. Therefore, this narrative review aims to provide a comprehensive overview of global traditional herbal active ingredients' beneficial therapeutic effects and molecular mechanisms on sarcopenia-related animal models. For this purpose, we conducted a literature search in three databases, PubMed, Web of Science, and Embase, consistent with the review objectives. After the screening, 12 animal studies met the review themes. The review results showed that the pathological mechanisms in sarcopenia-related animal models include imbalanced protein metabolism, oxidative stress, inflammation, apoptosis, insulin resistance, endoplasmic reticulum stress, impaired mitochondrial biogenesis, and autophagy-lysosome system aggravation. Eleven traditional herbal active ingredients exerted positive anti-sarcopenic effects by ameliorating these pathological mechanisms. This narrative review will provide meaningful insight into future studies regarding traditional herbal active ingredients for treating sarcopenia.

Time-restricted feeding combined with resistance exercise prevents obesity and improves lipid metabolism in the liver of mice fed a high-fat diet

Nonalcoholic fatty liver disease (NAFLD), a condition characterized by the accumulation of fat in the liver, is estimated to be the most common liver disease worldwide. Obesity is a major risk factor and contributor, and, accordingly, weight loss can improve NAFLD. Previous studies in preclinical models of diet-induced obesity and fatty liver disease have shown the independent benefits of resistance exercise training (RT) and time-restricted feeding (TRF) in preventing weight gain and hepatic build-up of fat. Here, we tested the combined effect of TRF and RT on obesity and NAFLD in mice fed a high-fat diet. Our results showed that both TRF-8-h food access in the active phase-and RT-consisting of three weekly sessions of ladder climbing-attenuated body weight gain, improved glycemic homeostasis, and decreased the accumulation of lipids in the liver. TRF combined with RT improved the respiratory exchange rate, energy expenditure, and mitochondrial respiration in the liver. Furthermore, gene expression analysis in the liver revealed lower mRNA expression of lipogenesis and inflammation genes along with increased mRNA of fatty acid oxidation genes in the TRF + RT group. Importantly, combined TRF + RT was shown to be more efficient in preventing obesity and metabolic disorders. In conclusion, TRF and RT exert complementary actions compared with isolated interventions, with significant effects on metabolic disorders and NAFLD in mice.NEW & NOTEWORTHY Whether time-restricted feeding (TRF) combined with resistance exercise training (RT) may be more efficient compared with these interventions alone is still unclear. We show that when combined with RT, TRF provided additional benefits, being more effective in increasing energy expenditure, preventing weight gain, and regulating glycemic homeostasis than each intervention alone. Thus, our results demonstrate that TRF and RT have complementary actions on some synergistic pathways that prevented obesity and hepatic liver accumulation.

Cullin-3 intervenes in muscle atrophy in the elderly by mediating the degradation of nAchRs ubiquitination

Sarcopenia involves in the loss of muscle mass associated with aging, which is the major cause of progressive muscle weakness and deterioration in older adults. Muscle atrophy is a direct presentation of sarcopenia, and it greatly contributes to the decline in quality of life among older adults. Neuromuscular junction (NMJ) stability is the key link to maintain muscle function. Besides, the degenerative change of NMJ promotes the process of muscle atrophy in the elderly. Based on previous transcriptome sequencing and bioinformatics analyses of aged muscle, this study used the 18-month-old aged mouse model and the 6-month-old young mouse model to deliberate the role and underlying mechanisms of Cullin-3 (Cul3) in age-related muscle atrophy. The results of reverse transcriptase polymerase chain reaction (RT-PCR) and immunoblotting analysis showed that the expression of CUL3 increased in aged muscle tissue, while the expression level of postsynaptic membrane nicotinic acetylcholine receptors (nAChRs) decreased significantly, which manfested a negative correlation. Meanwhile, immunofluorescence demonstrated that Cul3 was highly expressed in senile muscle NMJ. The results of ubiquitin indicated that the ubiquitin level of aged muscle nAChRs was evidently increased. Co-immunoprecipitation furtherly verified the correlation between Cul3 and nAChRs. Taken together, Cul3 may mediate the ubiquitination degradation of nAChRs protein at the NMJ site in aged mice, leading to NMJ degeneration and accelerated atrophy of fast-twitch muscle fibers in aged muscle. As a prominent element to maintain the stability of NMJ, Cul3 is supposed to be one of candidate intervention targets in sarcopenia.

Association Between Changes in Depressive Symptoms and Sarcopenia: Findings From a Nationwide Cohort Study

OBJECTIVES

The aim of this study was to investigate the association between changes in depressive symptoms and sarcopenia by repeated measures of depressive symptoms at a follow-up visit every 2 years.

DESIGN

Cross-sectional design and longitudinal design.

SETTING AND PARTICIPANTS

We conducted a cross-sectional and longitudinal study using data from the China Health and Retirement Longitudinal Study, which is a representative national survey. A total of 12,287 participants were included in Wave 1 (2011-2012) for the cross-sectional analysis, followed by a total of 5285 participants in Wave 2 (2013-2014) and Wave 3 (2015-2016) for the longitudinal analysis based on the cross-sectional analysis.

METHODS

Depressive symptoms were measured by the 10-item Center for the Epidemiological Studies of Depression Short Form. Sarcopenia was defined according to the Asian Sarcopenia Working Group criteria (AWGS 2019). Changes in depressive symptoms in Wave 1 and Wave 2 were used as exposure, and sarcopenia in Wave 3 was used as outcome. Cox proportional hazards regression model was used to test the relationship between changes in depressive symptoms and sarcopenia.

RESULTS

In cross-sectional analysis, depression was significantly associated with sarcopenia (odds ratio, 1.27; 95% CI, 1.10-1.48). In subsequent longitudinal analyses, a total of 174 sarcopenia events occurred, and those with increased depressive symptoms and persistent depressive symptoms were at higher risk for sarcopenia than those without depressive symptoms, with multivariable-adjusted hazard ratios of 1.65 (95% CI, 1.00-2.73) and 1.68 (95% CI, 1.06-2.68), respectively.

CONCLUSIONS AND IMPLICATIONS

People with increased depressive symptoms and persistent depressive symptoms may have a higher risk of developing sarcopenia over time. In the future, more research is needed to confirm the mechanism by which long-term changes in depression contribute to the risk of sarcopenia, and to propose preventive measures accordingly.

Interrelationship of Sarcopenia and Cardiovascular Diseases: A Review of Potential Mechanisms and Management

Sarcopenia refers to an age-related reduction of lean body mass. It showed a reciprocal relationship with cardiovascular diseases. Thus, it is imperative to explore pathophysiological mechanisms explaining the relationship between sarcopenia and cardiovascular diseases, along with the clinical assessment, and associated management. In this review, we discuss how processes such as inflammation, oxidative stress, endothelial dysfunction, neural and hormonal modifications, as well as other metabolic disturbances influence sarcopenia as well as its association with cardiovascular diseases. Moreover, this review provides an overview of both non-pharmacological and pharmacological management for patients with sarcopenia and cardiovascular diseases, with a focus on the potential role of cardiovascular drugs to mitigate sarcopenia.

Sarcopenia and myosteatosis diagnostic tool for gastrointestinal cancer: creatinine to cystatin C ratio as evaluation marker

OBJECTIVE

This study aimed to develop a simplified diagnostic tool for assessing sarcopenia and myosteatosis in gastrointestinal cancer patients, focusing on the creatinine to cystatin C ratio (CCR) as an evaluation marker.

METHODS

955 patients were split into training (n = 671) and validation (n = 284) cohorts. Using logistic regression, risk factors for sarcopenia and myosteatosis were identified. The predictive capacity of the developed model was examined. The association between CCR and muscle imaging parameters, along with its impact on clinical outcomes, was analyzed.

RESULTS

No significant differences were observed in baseline traits between cohorts. CCR emerged as a significant risk factor for both sarcopenia and myosteatosis. Nomograms for diagnosing these conditions demonstrated strong predictive ability, with AUC values indicating high accuracy (sarcopenia AUC: 0.865-0.872; myosteatosis AUC: 0.848-0.849). The clinical utility of the nomograms was confirmed through decision curve analysis. CCR showed significant association with muscle imaging parameters and was a reliable indicator for assessing the risk of sarcopenia, myosteatosis, and cachexia. Moreover, CCR was able to differentiate between patient survival and disease progression rates.

CONCLUSION

A diagnostic tool for sarcopenia and myosteatosis in gastrointestinal cancer patients was developed, with CCR being a pivotal biomarker for disease diagnosis and prognosis prediction.

Myogenesis Effects of RGX365 to Improve Skeletal Muscle Atrophy

Age-related skeletal muscle atrophy and weakness not only reduce the quality of life of those afflicted, but also worsen the prognosis of underlying diseases. We evaluated the effect of RGX365, a protopanaxatriol-type rare ginsenoside mixture, on improving skeletal muscle atrophy. We investigated the myogenic effect of RGX365 on mouse myoblast cells (C2C12) and dexamethasone (10 µM)-induced atrophy of differentiated C2C12. RGX365-treated myotube diameters and myosin heavy chain (MyHC) expression levels were analyzed using immunofluorescence. We evaluated the myogenic effects of RGX365 in aging sarcopenic mice. RGX365 increased myoblast differentiation and MyHC expression, and attenuated the muscle atrophy-inducing F-box (Atrogin-1) and muscle RING finger 1 (MuRF1) expression. Notably, one month of oral administration of RGX365 to 23-month-old sarcopenic mice improved muscle fiber size and the expression of skeletal muscle regeneration-associated molecules. In conclusion, rare ginsenosides, agonists of steroid receptors, can ameliorate skeletal muscle atrophy during long-term administration.

[Importance of outpatient medical consultation prior to going to the hospital emergency department in patients over 65 years of age: Impact on hospitalization results]

OBJECTIVE

Investigate factors associated with a previous outpatient medical consultation (POMC), to the health center or another physician, before attending a hospital emergency department (ED), in patients aged >65 and its impact on the hospitalization rate and variables related to ED stay. SITE: Fifty-two Spanish EDs.

PARTICIPANTS

Patients over 65 years consulting an ED.

MAIN MEASUREMENTS AND DESIGN

A cohort (n=24645) of patients aged >65 attended for one week in 52 ED. We recorded five sociodemographic variables, six functional, three episode-related severity and analyzed their crude and adjusted association with the existence of a POMC at ED consultation. The primary outcome variable was the need for admission and the secondary variables were complementary examinations and ED stay length. We analyzed whether the POMC influenced these outcomes.

RESULTS

28.5% of the patients had performed a POMC prior to their visit to the ED. Living in a residence, NEWS-2 score ≥5, aged ≥80, dependency functions, severe comorbidity, living alone, cognitive impairment, male gender and depression were independently associated with a POMC. Also was associated with a greater need for hospitalization and shorter length of stay in the ED. No minor consumption of diagnostic resources in patients with POMC.

CONCLUSION

Patients presenting to the ED following POMC are admitted more frequently, suggesting that they are appropriately referred and that minor emergencies are probably effectively resolved in the POMC. Their stay in the ED prior to hospitalization is shorter, so the POMC would facilitate clinical resolution in the ED.

Assessment of dynapenia and undernutrition in primary care, a systematic screening study in community medicine

Screening for sarcopenia is a growing public health issue since associated with functional alterations and an increase in morbidity and mortality.

OBJECTIVE

To analyze the prevalence of decreased muscle strength (dynapenia) in patients aged 18 to 74 in community medicine, as measured in the general practitioner's office, and to assess the prevalence of undernutrition in this population.

METHOD

Muscle strength was measured with a Hand Grip (HG) dynamometer according to European recommended thresholds and French guidelines. Malnutrition was defined according to the GLIM criteria.

RESULTS

Of 341 patients, 303 were evaluated (89%): mean age was 47.8 ± 17.4 years, including 51.2% women, 103 with an acute disease (AD) and 200 with a chronic disease (CD). 23.5% were below the 10th percentile threshold in the CD group and 19.4% in the AD group. For these patients, muscle age, evaluated on the median values for age, was higher by 39.3 ± 15.2 years for men and by 41.5 ± 13.6 years for women. Maximum HG values were significantly correlated with changes in International Physical Activity Questionnaire (IPAQ) score (F = 10.22; p = 0.0017) and weight changes (%) (F = 5.30; p = 0.0227) in women only, regardless of age, BMI, disease, professional status or type of work (manual or not); 19.1% suffered from malnutrition (10.9% Stage 1 and 8.3% Stage 2), with 20.0% in the CD group and 17.4% in the AD group.

CONCLUSION

This study highlights the feasibility of screening for sarcopenia in primary care community medicine. The prevalence of dynapenia in the studied population (nearly one in 5 patients) and the observed higher-than-expected undernutrition (17.5%) justify their screening for appropriate management care.

CLINICAL TRIAL REGISTRATION

NCT04451694; referred to as "observational research", "non-interventional", or « non-RIPH ».

Anabolic Resistance in the Pathogenesis of Sarcopenia in the Elderly: Role of Nutrition and Exercise in Young and Old People

The development of sarcopenia in the elderly is associated with many potential factors and/or processes that impair the renovation and maintenance of skeletal muscle mass and strength as ageing progresses. Among them, a defect by skeletal muscle to respond to anabolic stimuli is to be considered. Common anabolic stimuli/signals in skeletal muscle are hormones (insulin, growth hormones, IGF-1, androgens, and β-agonists such epinephrine), substrates (amino acids such as protein precursors on top, but also glucose and fat, as source of energy), metabolites (such as β-agonists and HMB), various biochemical/intracellular mediators), physical exercise, neurogenic and immune-modulating factors, etc. Each of them may exhibit a reduced effect upon skeletal muscle in ageing. In this article, we overview the role of anabolic signals on muscle metabolism, as well as currently available evidence of resistance, at the skeletal muscle level, to anabolic factors, from both in vitro and in vivo studies. Some indications on how to augment the effects of anabolic signals on skeletal muscle are provided.

Dipyridamole activates adenosine A2B receptor and AMPK/cAMP signaling and promotes myogenic differentiation of myoblastic C2C12 cells

Introduction: Sarcopenia is defined as a loss of muscle mass and strength. ATP homeostasis is crucial during myogenesis. We determined how the purinergic system modulates myogenesis using dipyridamole (blocks adenosine taken up by the cells) and tenofovir (inhibits ATP release) in a myoblast cell line. Methods: C2C12 cells were differentiated in the presence/absence of tenofovir/dipyridamole, with/without the A2B selective inhibitor PSB-603. Extra-/intracellular nucleotides were examined via HPLC. The expression of muscle differentiation proteins (Pax7, Mif5, MyoD, MyoG, and MHC), PKA/CREB, adenosine receptors (A1, A2A, A2B, and A3), ATP-channel pannexin-1 and the P2X7 receptor was analyzed via WB and RT-PCR. cAMP and AMPK activation was measured. Results: Tenofovir increased intracellular ATP and reduced extracellular adenosine, decreasing Pax7 expression and increasing MHC expression prematurely. Dipyridamole increased intracellular AMP and extracellular adenosine, counteracting the premature myogenesis promoted by tenofovir. All adenosine receptors were expressed during differentiation with dipyridamole, increasing A2B expression. Tenofovir maintained inactive AMPK and decreased cAMP levels, as well as PKAα and pCREB expression, which were recovered with dipyridamole. Discussion: Adenosine and ATP act as mediators in muscle myogenesis. The blockade of ATP release by tenofovir promotes premature myogenesis, with dipyridamole counteracting the premature differentiation promoted by tenofovir via the adenosine A2B receptor and cAMP/AMPK pathways. Therefore, dipyridamole might be of interest as a therapeutic approach in sarcopenia.

Association of Sarcopenia With Mortality in Patients With Chronic Limb-Threatening Ischemia Undergoing Endovascular Revascularization

INTRODUCTION

Chronic limb-threatening ischemia (CLTI) is the most severe form of peripheral artery disease and leads high mortality. Sarcopenia, characterized by the loss of muscle mass or poor muscle quality, is associated with adverse clinical outcomes. This study aimed to investigate the association between sarcopenia and the long-term outcomes in patients with CLTI after endovascular revascularization.

METHODS

We retrospectively reviewed the medical records of all patients with CLTI who underwent endovascular revascularization between January 2015, and December 2021. The skeletal muscle area was calculated at the third lumbar vertebra from computed tomography images using the manual trace method and normalized to patient height. Sarcopenia was defined as a third lumbar skeletal muscle index of <40.8 cm2/m2 in males and <34.9 cm2/m2 in females. The Kaplan-Meier and Cox proportional hazards regression analyses were used for survival analysis and to evaluate the association between sarcopenia and mortality.

RESULTS

A total of 137 patients (90 men; mean age 71.7 ± 9.6 y) were enrolled for the study, of whom 56 (40.8%) had sarcopenia. The 3-year overall survival rate in patients with CLTI who underwent endovascular revascularization was 71.2%. The sarcopenic group had a significantly worse 3-year overall survival rate than the nonsarcopenic group (55.3% versus 78.6%, P = 0.001). Multivariate Cox proportional hazard regression analyses revealed that sarcopenia (hazard ratio, 2.262; 95% confidence interval, 1.132-4.518; P = 0.021) and dialysis (hazard ratio, 3.021; 95% confidence interval, 1.337-6.823; P = 0.008) were independently associated with increased risk of all-cause mortality, whereas technical success had significantly opposing correlation with mortality. (hazard ratio, 0.400, 95% confidence interval, 0.194-0.826, P = 0.013).

CONCLUSIONS

Sarcopenia can be highly prevalent in patients with CLTI who undergo endovascular revascularization, and is independently associated with long-term mortality. These results may help risk stratification to assist in personalized assessment and clinical decision-making.

Observational cohort study of highly functioning community-dwelling older adults to assess their sarcopenic status, leisure physical activity, and quality of life over 12-months

Background

The prevalence of sarcopenia varies depending on the cohort evaluated, and the diagnostic criteria used. Older adults with sarcopenia report lower quality of life than their non-sarcopenic peers. Leisure physical activity is reported to have a variable effect on sarcopenic status. Most studies to date, have been done in "vulnerable" populations, with fewer done on independent community-dwelling older adults. None have been done in an Alberta, Canada population.

Objectives

To prospectively evaluate the sarcopenic status of independent community-dwelling older Albertan adults; whether this changed over 12-months; and any association with self-reported leisure activity or quality of life.

Methods

Independent community-dwelling older adults were invited to participate in a 12-month observational study. Assessments were done at baseline, 6 and 12-months for physical function (TUG, SPPB, gait speed, Tinetti, grip strength), muscle mass (DXA, arm and calf circumference), body fat (skinfold, DXA), reported daily exercise (aerobic, resistance), quality of life (EQ5D), and laboratory parameters. European Working Group on Sarcopenia in Older People (EWGSOP) definitions of sarcopenic status were used.

Results

All 50 participants (11 male), were independent of all basic activities of daily living at baseline, and most instrumental activities (some needed assistance with driving or finances). They had an average age of 75.8 (67-90) years, with average MMSE and MoCA cognitive scores of 28.1/30 (20-30) and 24.8/30 (14-30) respectively. Eight participants dropped out prior to their first DXA test. Of the remaining 42, 17 participants (5 male) fulfilled the EWGSOP revised criteria for probable, pre-sarcopenia, or sarcopenia, giving a rate of baseline total sarcopenia of 40.5% in this community-dwelling sample. The majority were pre-sarcopenic (28.6%), and sarcopenia was present only in 7.1%. The total sarcopenia group had a lower BMI (25.6 ± 5.1 versus 29 ± 5, p = 0.01), less body fat by skinfold measurement (36.4 ± 6.5 versus 39.3 ± 8.1, p = 0.01) and lower mid-calf (35.6 ± 3.2 versus 37.6 ± 3.4, p = 0.04) and mid-arm (29.1 ± 2.5 versus 31.9 ± 3.5, p = 0.02) circumferences when compared to their non-sarcopenic peers. After 12-months, 39 participants remained in the study. Of these, the sarcopenic status of 7 improved, 10 declined, with the remaining 56% not changing. There were no statistically significant differences in baseline laboratory parameters between the groups, including 25(OH)D status. But, of the status decliners, 40% had suboptimal 25(OH)D at baseline. Self-reported leisure activity (both total time and frequency) was not associated with sarcopenic status at 12-months. EuroQol -5D was not associated with sarcopenic status.

Conclusions

The rate of sarcopenia was 7.1%, but the total rate of pre, probable and sarcopenia in this highly functioning, community-dwelling older adult cohort was 40.5%. In the majority (75%), there was either no change, or an improvement, in their sarcopenic status over 12-months. There was no association identified with self-reported leisure activity or quality of life in this cohort.

A meta-analysis of the effect of probiotic administration on age-related sarcopenia

Global increase in the prevalence of age-related diseases, such as sarcopenia, highlights the need of recognizing agents that improve muscle health; however, the evidence synthesis on the impact of probiotic administration on sarcopenia is scarce. To summarize and evaluate findings regarding the effect of supplementation with probiotics on sarcopenia, this meta-analysis was conducted. Using databases, including PubMed, SCOPUS, ISI-Web of Science, and Cochrane Library, interventional studies were included if they investigate the effect of probiotic administration on at least one of the components of sarcopenia up to 6 October 2022. Risk of bias evaluation was conducted using the Cochrane quality assessment tool. The random-effects model which takes between-study variations into account was used to obtain the overall effect sizes. The STATA version 14.0 was used for statistical analyses. Overall, 17 studies were included. There was high certainty of evidence that probiotic supplementation has a beneficial effect on muscle mass (kg) (WMD: 0.55, 95% CI: 0.05, 1.05; I 2: 0.0%, p = .995), and muscle function (WMD: 0.13, 95% CI: 0.03, 0.23; I 2: 65.6%, p = .05). Moreover, administration of probiotics for more than 12 weeks significantly increased muscle strength (WMD: 1.16, 95% CI: 0.88, 1.44; I 2: 0.0%, p = .77). However, probiotic supplementation had no effect on anthropometric indices, including body mass index. Probiotic supplementation could improve muscle mass and muscle function in adults more than 55 years old. The beneficial effect of probiotics on muscle strength could appear after 12 weeks of supplementation.

Superimposed electromyostimulation of the thigh muscles during passive isokinetic cycling increases muscle strength without effort

Objectives

This study was designed to investigate the effects of a completely passive isokinetic cycle (PIC) exercise with electromyostimulation (EMS) on improving muscle strength and the changes in kinesthesia during daily activities.

Methods

Twenty-nine sedentary females were divided into three groups. The EMS anterior and whole groups performed the PIC exercise without EMS 3 times a week for 3 weeks, followed by a 1-week break, and then performed it with EMS applied to the anterior and entire thigh muscles, respectively, 3 times a week for 3 weeks. The control group did not perform any training.

Results

The PIC exercise with EMS significantly increased the 30s chair stand test scores by 12-16% and the maximum isometric knee extension and flexion torques by 38-68% in both EMS-applied groups. The participants found its exercise easy and felt more comfortable with daily physical activities. The exercise without EMS did not show similar improvements. Muscle soreness was significantly greater in the EMS anterior group than in the EMS whole group; however, it was not severe.

Conclusions

The PIC exercise with EMS resulted in significant increases in muscle strength, facilitating a perceived ease of daily physical activities, while minimizing difficulties, effort, and notable muscle soreness.

Mitigating Sarcopenia with Diet and Exercise

Sarcopenia is the loss of muscle mass and function from aging, inactivity, or disuse. It is a comorbidity to numerous conditions that exacerbates their severity and adversely impacts activities of daily living. While sarcopenia now receives more attention from the medical community, people with sarcopenia as a comorbidity nevertheless still sometimes receives less attention than other presenting diseases or conditions. Inevitable doctors' visits or hospital stays for those with sarcopenia as a comorbidity have far higher healthcare costs than those without this condition, which imposes a greater financial burden on the medical insurance and healthcare industries. This review offers information and guidance on this topic. Treatments for sarcopenia include dietary, exercise, and pharmacological interventions. Yet, the latter treatment is only recommended in extreme cases as it may evoke numerous side effects and has little support in the scientific literature. Currently, a more holistic approach, with an emphasis on lifestyle modification, to reduce the likelihood of sarcopenia is examined. The current review discusses dietary and exercise interventions to limit the occurrence and severity of sarcopenia. References cited in this review conformed to the Declaration of Helsinki requirements for the use of human research subjects. Most of this review's references (~97%) came from a PubMed search that spanned from 1997 to 2023. Search terms included "sarcopenia" OR "muscle wasting" OR "geriatrics"; OR "ageing"; and AND "diet" OR "exercise". In addition, papers relevant or supportive of the topic as well as those considered seminal were included in the review. Over 96% of the references were peer-reviewed articles.

Use of Chinese Herbal Medicine Was Related to Lower Risk of Osteoporotic Fracture in Sarcopenia Patients: Evidence from Population-Based Health Claims

Introduction

With population aging, sarcopenia and its accompanying risk of osteoporotic fracture has drawn increased attention. Nowadays, while Chinese herbal medicine (CHM) is often used as complementary therapy for many medical conditions, its effect against likelihood of osteoporotic fracture among sarcopenia subjects was not fully elucidated yet. We therefore conducted a population-level study to compare osteoporotic fracture risk for sarcopenia persons with or without CHM use.

Methods

Using the patient record from a nationwide insurance database, we recruited persons with newly diagnosed sarcopenia and simultaneously free of osteoporotic fracture between 2000 and 2010. Propensity score matching was then applied to randomly select sets of CHM users and non-CHM users. All of them were tracked until end of 2013 to measure the incidence and adjusted hazard ratios (HRs) for new new-onset fracture in multivariable Cox proportional hazards model.

Results

Compared to non-CHM users, the CHM users indeed had a lower incidence of osteoporotic fracture (121.22 vs 156.61 per 1000 person-years). Use of CHM correlated significantly with a lower fracture likelihood after adjusting for potential covariates, and those receiving CHM treatment for more than two years experienced a remarkably lower risk by 73%. Uses of several herbal formulae were correlated to reduced risk of osteoporotic fracture, such as Caulis Spatholobi, Xuduan, Duzhong, Danshen, Shu-Jing-Huo-Xue-Tang, Du-Huo-Ji-Sheng-Tang, Shao-Yao-Gan-Cao-Tang, and Shen-Tong-Zhu-Yu -Tang.

Conclusion

Our study depicted that cumulative CHM exposure was inversely associated with osteoporotic fracture risk in a duration-dependent manner, implying that CHM treatment may be embraced as routine care in preventing incident osteoporotic fracture.

Effectiveness and clinical application of multidisciplinary combined exercise and nutrition intervention for sarcopenic older adults with metabolic syndrome: study protocol for a multicentre randomised controlled trial

INTRODUCTION

Among chronic diseases affecting older adults, metabolic syndrome (MetS) is known to be closely related to sarcopenia. Insulin resistance may play a key role in the increased frequency of sarcopenia associated with metabolic disorders. To date, an exercise-nutrition combined intervention has been the treatment of choice for sarcopenia. However, trials of combined interventions for individuals with sarcopenia and MetS are still lacking. This study aims to develop and conduct a standardised intervention, named the Multidisciplinary combined Exercise and Nutrition inTervention fOR Sarcopenia (MENTORS), for sarcopenic older patients with MetS.

METHODS AND ANALYSIS

This multicentre, randomised controlled trial includes 168 community-dwelling older adults with sarcopenia and MetS. The 12-week MENTORS comprises an exercise intervention consisting of an introductory phase (3 weeks; twice-weekly visits), an expanded phase (3 weeks; twice-weekly visits) and a maintenance phase (6 weeks; once-weekly visits); and a nutrition intervention tailored to the nutritional status of individual subjects. Outcomes will be measured at 0-week, 12-week and 24-week postintervention. The data will be analysed using the intention-to-treat and per-protocol principle.

ETHICS AND DISSEMINATION

Before screening, all participants will be provided with oral and written information. Ethical approval has already been obtained from all participating hospitals. The study results will be disseminated in peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT04948736.

Sarcopenia and Tuberculosis: Is There Any Connection?

BACKGROUND

Tuberculosis (TB) infection is a life-threatening infection caused by certain bacteria belonging to the Mycobacterium tuberculosis complex. More than 10 million subjects are newly sick from this infection every year globally. At the same time, TB is quite prevalent among subjects who come from lower socioeconomic layers of general population, and marginalized sections and areas. Sarcopenia is a muscle disease that derives from adverse muscle alterations and is related to the loss of muscle strength and mass. It is a major medical issue due to its increased adverse outcomes including falls, functional decline, frailty, hospitalizations, increased mortality, and healthcare costs.

METHODS

This study examined the potential interplay between the TB infection and sarcopenia through conducting a non-systematic review of the current literature.

RESULTS

It has been recorded that the prevalence of sarcopenia among TB survivors is high, whilst the danger of TB among the elderly increases with sarcopenia and physical inactivity. Nevertheless, sufficient protein and total energy intake are associated with a low risk of sarcopenia in TB survivors.

CONCLUSIONS

Further studies are needed to validate these findings and shed more light on the upcoming different aspects of this intriguing association.

High-Fat and High-Sucrose Diet Leads to Skeletal Muscle Loss and Bladder Dysfunction in Rat

Purpose

In this study, we investigated skeletal muscle loss and bladder dysfunction caused by high-fat/high-sucrose (HFS) diet.

Methods

Twelve-week-old Sprague-Dawley (SD) female rats were fed on normal (Group N) or HFS (Group HFS) diet for 12 weeks. We conducted urodynamic investigation and pharmacologic in vitro. In addition, we measured gastrocnemius and tibialis muscle weight and protein concentration. The hypoxia-inducible factor (HIF)-1α and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the bladder were assayed.

Results

The urodynamic investigations revealed the significantly shorter intercontraction intervals and lower maximal voiding pressure in Group HFS than in Group N. Furthermore, the absolute and relative weights of the gastrocnemius muscle were found to be significantly lower in Group HFS than in Group N. The protein concentration of the gastrocnemius muscle was also significantly lower in Group HFS than in Group N. The absolute and relative weights of the bladder were also significantly lower in Group HFS than in Group N. The contractile responses of the bladder strips to electrical field stimulation and carbachol were significantly lower in Group HFS than in Group N. The HIF1α and 8OHdG in the bladder muscle were significantly higher in Group HFS than in Group N. The HFS diet reduced bladder capacity and contractility along with the loss of the gastrocnemius muscle.

Conclusion

HFS diet promotes bladder dysfunction similar to detrusor hyperreflexia with impaired contractility.

The Impact of Complex Rehabilitation Treatment on Sarcopenia-Pathology with an Endocrine Morphological Substrate and Musculoskeletal Implications

The pathogenesis of sarcopenia is multifactorial, including changes in the endocrine system. Easy-to-perform screening tests can guide the diagnosis of sarcopenia and the rehabilitation therapeutic conduct, which can act on many physiopathological links. This study was conducted over a period of 5 months, from April to August 2022, and included 84 patients hospitalized for a period of 10 days in the Balneal and Rehabilitation Sanatorium Techirghiol for complex physiotherapy, which included balneotherapy. In dynamics, both at admission and discharge, specific screening tests for sarcopenia (SARC-F questionnaire, grip strength, testing muscle strength at the level of the quadriceps, sit-to-stand tests (the time required for five consecutive rises and the number of rises performed in 30 s)) and the Visual Analogue Scale (VAS) for pain were performed. The study was conducted according to the norms of deontology and medical ethics. Results: A significant proportion of patients had a positive result in at least one of the tests for the screening of sarcopenia syndrome. The most eloquent results were obtained from the statistical analysis of the following parameters evaluated at admission: the SARC-F questionnaire and the sit-to-stand test-the number of rises in 30 s. In terms of dynamics, after performing the complex rehabilitation treatment, the patients recorded improvements in the established screening tests and improvements in pain symptoms evaluated with the help of the VAS. Conclusions: Sarcopenia, a pathology developed with aging, is frequently encountered among adults. In the future, it is important to perform screening for sarcopenia in both endocrinology and medical rehabilitation clinics. Good management of sarcopenia can influence therapeutic conduct and can prevent complications, improving the functional capacity and the quality of life of the patients.

Radiologic Features of T10 Paravertebral Muscle Sarcopenia: Prognostic Factors in COVID-19

Background

Sarcopenia, defined as a small cross-sectional area (CSA) in computed tomography (CT) measurements of skeletal muscles, serves as a disease severity marker in various clinical scenarios, including pulmonary conditions and critical illness. Another parameter of sarcopenia, the level of myosteatosis, reflected by the tissue's radiodensity, in the thoracic skeletal muscles group, has been linked to disease progression in coronavirus disease 2019 (COVID-19) patients. We hypothesize that CT-derived measurements of the skeletal muscle density (SMD) and the CSA of thoracic skeletal muscles can predict outcomes in COVID-19 pneumonia.

Methods

We retrospectively reviewed the CT scans of 84 patients with COVID-19 pneumonia admitted to two of Greece's largest academic teaching hospitals between April 2020 and February 2021. CSA and SMD at the level of the T10 vertebra were measured using computational imaging methods. The patient population was stratified according to survival status and CT severity score (CT-SS). Correlations were drawn between the radiologic features of sarcopenia, CT severity subgroups, serum inflammatory markers, and adverse events, e.g., death and intubation.

Results

Thoracic muscles' CSA measurements correlate with CT-SS and prominent inflammatory markers, such as white blood cell (WBC), C-reactive protein (CRP), fibrinogen, and D-dimers. Moreover, according to linear regression analysis, CSA seems to predict CT-SS variation significantly (β = -0.266, P = 0.018). CSA proved to differ significantly across survivors (P = 0.027) but not between CT severity categories and intubation subgroups. The AUC (area under the curve) of the receiver operating characteristic (ROC) curve for the predictive value of thoracic muscles' CSA in mortality is 0.774 (95% confidence interval (CI): 0.66 - 0.83, P < 0.000). The optimal cut-off value (Youden index = 0.57) for mortality prognosis, with a sensitivity of 66.7% and a specificity of 88.9%, is 15.55. Thoracic muscles' SMD analyses did not reveal any significant correlations.

Conclusions

Easy to obtain and accurately calculated, radiologic features can provide a reliable alternative to laboratory methods for predicting survival in COVID-19. Thoracic muscles' CSA measurement in the level of the T10 vertebra, an acclaimed prognostic imaging assessment that relates directly to CT-SS and inflammatory markers in COVID-19 pneumonia, is a fairly specific tool for survival prognosis.

A Systematic Review and Meta-Analysis of Exercise Beneficial for Locomotion in Community-Dwelling Elderly People with Sarcopenia

Sarcopenia, in addition to aging and reduced physical activity, is a progressive skeletal muscle disorder that causes the loss of muscle mass and strength. The most prominent functional change is mobility, which contributes to a decrease in the quality of life. Therefore, we aimed to perform qualitative and quantitative analyses by synthesizing randomized controlled trials (RCTs) that evaluated exercises that affected locomotion in patients with sarcopenia. The RCTs were retrieved in April 2023 from three international electronic databases (Embase, MEDLINE, and PubMed). RCTs published after 2013 were compared with a control group that did not include exercise. Qualitative and quantitative analyses were performed on the identified studies using RevMan 5.4 and risk of bias assessment provided by Cochrane. RCTs involving 594 patients with sarcopenia were included in this study. The analysis model was synthesized as a random effects model, and the standard mean difference (SMD) was used as the effect measure. Exercise interventions were found to not change muscle mass in individuals with sarcopenia (SMD = 0.04; 95% CI: -0.15 to 0.22). However, they had positive effects on lower extremity muscle strength (SMD = 0.34; 95% CI: 0.02 to 0.66) and walking speed (SMD = 0.42; 95% CI: 0.11 to 0.72). For community-dwelling elderly people with sarcopenia, exercise intervention did not lead to an increase in reduced muscle mass, but it brought positive improvements in lower extremity strength and gait speed to improve locomotion.

Mechanisms Underlying the Effects of the Green Tea Polyphenol EGCG in Sarcopenia Prevention and Management

Sarcopenia is prevalent among the older population and severely affects human health. Tea catechins may benefit for skeletal muscle performance and protect against secondary sarcopenia. However, the mechanisms underlying their antisarcopenic effect are still not fully understood. Despite initial successes in animal and early clinical trials regarding the safety and efficacy of (-)-epigallocatechin-3-gallate (EGCG), a major catechin of green tea, many challenges, problems, and unanswered questions remain. In this comprehensive review, we discuss the potential role and underlying mechanisms of EGCG in sarcopenia prevention and management. We thoroughly review the general biological activities and general effects of EGCG on skeletal muscle performance, EGCG's antisarcopenic mechanisms, and recent clinical evidence of the aforesaid effects and mechanisms. We also address safety issues and provide directions for future studies. The possible concerted actions of EGCG indicate the need for further studies on sarcopenia prevention and management in humans.

Cholic and deoxycholic acids induce mitochondrial dysfunction, impaired biogenesis and autophagic flux in skeletal muscle cells

BACKGROUND

Skeletal muscle is sensitive to bile acids (BA) because it expresses the TGR5 receptor for BA. Cholic (CA) and deoxycholic (DCA) acids induce a sarcopenia-like phenotype through TGR5-dependent mechanisms. Besides, a mouse model of cholestasis-induced sarcopenia was characterised by increased levels of serum BA and muscle weakness, alterations that are dependent on TGR5 expression. Mitochondrial alterations, such as decreased mitochondrial potential and oxygen consumption rate (OCR), increased mitochondrial reactive oxygen species (mtROS) and unbalanced biogenesis and mitophagy, have not been studied in BA-induced sarcopenia.

METHODS

We evaluated the effects of DCA and CA on mitochondrial alterations in C₂C₁₂ myotubes and a mouse model of cholestasis-induced sarcopenia. We measured mitochondrial mass by TOM20 levels and mitochondrial DNA; ultrastructural alterations by transmission electronic microscopy; mitochondrial biogenesis by PGC-1α plasmid reporter activity and protein levels by western blot analysis; mitophagy by the co-localisation of the MitoTracker and LysoTracker fluorescent probes; mitochondrial potential by detecting the TMRE probe signal; protein levels of OXPHOS complexes and LC3B by western blot analysis; OCR by Seahorse measures; and mtROS by MitoSOX probe signals.

RESULTS

DCA and CA caused a reduction in mitochondrial mass and decreased mitochondrial biogenesis. Interestingly, DCA and CA increased LC3II/LC3I ratio and decreased autophagic flux concordant with raised mitophagosome-like structures. In addition, DCA and CA decreased mitochondrial potential and reduced protein levels in OXPHOS complexes I and II. The results also demonstrated that DCA and CA decreased basal, ATP-linked, FCCP-induced maximal respiration and spare OCR. DCA and CA also reduced the number of cristae. In addition, DCA and CA increased the mtROS. In mice with cholestasis-induced sarcopenia, TOM20, OXPHOS complexes I, II and III, and OCR were diminished. Interestingly, the OCR and OXPHOS complexes were correlated with muscle strength and bile acid levels.

CONCLUSION

Our results showed that DCA and CA decreased mitochondrial mass, possibly by reducing mitochondrial biogenesis, which affects mitochondrial function, thereby altering potential OCR and mtROS generation. Some mitochondrial alterations were also observed in a mouse model of cholestasis-induced sarcopenia characterised by increased levels of BA, such as DCA and CA.

Sarcopenia with Depression Presents a More Severe Disability Than Only Sarcopenia among Japanese Older Adults in Need of Long-Term Care

Background and objectives: The combination of depression and sarcopenia, a condition prevalent worldwide, may cause dis-tinct problems that should not be underestimated. However, to the best of our knowledge, no reports have investigated the combined effects of depression and sarcopenia. In this study, we compared physical function, nutritional status, and daily functioning among older adults with only depression (OD), those with only sarcopenia (OS), and those with sarcopenia with depression (SD) to examine the effects of the combination of depression and sarcopenia. Materials and Methods: The participants were 186 communi-ty-dwelling older individuals who required support or care. The participants were classified into four groups based on the presence or absence of sarcopenia and depression: Control, OD, OS, and SD. The following parameters were evaluated in the four groups: grip strength, walking speed, skeletal muscle mass index (SMI), Mini Nutritional Assessment Short-Form (MNA-sf), and long-term care certification level. In addition, univariate and multivariate analyses of the survey results were performed to identify risk factors leading from OS to SD. Results: We found that 31.2% of older participants who needed support or nursing care had SD, which had more pronounced adverse effects on grip strength, walking speed, SMI, MNA-sf, and level of nursing care than OD or OS. Furthermore, multivariate analysis of SD vs. OS showed that decreased grip strength and worsening MNA-sf were independent risk factors. Conclusions: SD is common among older individuals living in the community. Patients with SD require support and care, and the condition has a greater impact on physical function, nutritional status, and decline in life function compared to OD and OS. Therefore, it is desirable to elucidate the process leading to SD and investigate the risk factors and prognosis. It is expected that sarcopenia with depression will be investigated worldwide in the future.

Liver transplantation in the patient with physical frailty

Frailty is a decline in functional reserve across multiple physiological systems. A key component of frailty is sarcopenia, which denotes a loss of skeletal muscle mass and impaired contractile function that ultimately result in physical frailty. Physical frailty/sarcopenia are frequent and contribute to adverse clinical outcomes before and after liver transplantation. Frailty indices, including the liver frailty index, focus on contractile dysfunction (physical frailty), while cross-sectional image analysis of muscle area is the most accepted and reproducible measure to define sarcopenia. Thus, physical frailty and sarcopenia are interrelated. The prevalence of physical frailty/sarcopenia is high in liver transplant candidates and these conditions have been shown to adversely impact clinical outcomes including mortality, hospitalisations, infections, and cost of care both before and after transplantation. Data on the prevalence of frailty/sarcopenia and their sex- and age-dependent impact on outcomes are not consistent in patients on the liver transplant waitlist. Physical frailty and sarcopenic obesity are frequent in the obese patient with cirrhosis, and adversely affect outcomes after liver transplantation. Nutritional interventions and physical activity remain the mainstay of management before and after transplantation, despite limited data from large scale trials. In addition to physical frailty, there is recognition that a global evaluation including a multidisciplinary approach to other components of frailty (e.g., cognition, emotional, psychosocial) also need to be addressed in patients on the transplant waitlist. Recent advances in our understanding of the underlying mechanisms of sarcopenia and contractile dysfunction have helped identify novel therapeutic targets.

Sarcopenia as a Risk Factor for Complications Following Pedicle Subtraction Osteotomy

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

The objective was to determine if sarcopenia is an independent risk factor for complications in adult spinal deformity (ASD) patients undergoing pedicle subtraction osteotomy (PSO) and define categories of complication risk by sarcopenia severity.

SUMMARY OF BACKGROUND DATA

Sarcopenia is linked to morbidity and mortality in several orthopedic procedures. Data concerning sarcopenia in ASD surgery is limited, particularly with respect to complex techniques performed such as PSO. With the high surgical burden of PSOs, appropriate patient selection is critical for minimizing complications.

METHODS

We identified 73 ASD patients with lumbar CT/MRI scans who underwent PSO with spinal fusion ≥5 levels at a tertiary care center from 2005 to 2014. Sarcopenia was assessed by the psoas-lumbar vertebral index (PLVI). Using stratum-specific likelihood ratio analysis, patients were separated into 3 sarcopenia groups by complication risk. The primary outcome measure was any 2-year complication. Secondary outcome measures included intraoperative blood loss and length of stay.

RESULTS

The mean PLVI was 0.84±0.28, with 47% of patients having complications. Patients with a complication had a 27% lower PLVI on average than those without complications (0.76 vs. 0.91, P=0.021). Stratum-specific likelihood ratio analysis produced 3 complication categories: 32% complication rate for PLVI ≥ 0.81; 61% for PLVI 0.60-0.80; and 69% for PLVI < 0.60. Relative to patients with PLVI ≥ 0.81, those with PLVI 0.60-0.80 and PLVI < 0.60 had 3.2× and 4.3× greater odds of developing a complication (P<0.05). For individual complications, patients with PLVI < 1.0 had a significantly higher risk of proximal junctional kyphosis (34% vs. 0%, P=0.022), while patients with PLVI < 0.8 had a significantly higher risk of wound infection (12% vs. 0%, P=0.028) and dural tear (14% vs. 0%, P=0.019). There were no significant associations between sarcopenia, intraoperative blood loss, and length of stay.

CONCLUSIONS

The increasing severity of sarcopenia is associated with a significantly and incrementally increased risk of complications following ASD surgery that require PSO.

LEVEL OF EVIDENCE

Level III.

Chinese expert consensus on prevention and intervention for elderly with sarcopenia (2023)

Sarcopenia is the age-related loss of skeletal muscle mass and muscle strength or physical function. It is most common in elderly individuals. Due to its high incidence, insidious onset, and extensive impact on the body, it has a huge impact on the family medical burden and the social public health expenditure in China. The understanding of sarcopenia in China is still lacking, and the recommendations for prevention, control, and intervention are not clear and unified. The purpose of this consensus report is to standardize the prevention, control, and intervention methods for sarcopenia in elderly patients in China; improve the efficacy of intervention; reduce complications during the intervention process; and reduce the risk of falls, fractures, disability, hospitalization, and even death in elderly individuals.

Curcumin as a Therapeutic Agent for Sarcopenia

Sarcopenia is the progressive loss of muscle mass, strength, and functions as we age. The pathogenesis of sarcopenia is underlined by oxidative stress and inflammation. As such, it is reasonable to suggest that a natural compound with both antioxidant and anti-inflammatory activities could prevent sarcopenia. Curcumin, a natural compound derived from turmeric with both properties, could benefit muscle health. This review aims to summarise the therapeutic effects of curcumin on cellular, animal, and human studies. The available evidence found in the literature showed that curcumin prevents muscle degeneration by upregulating the expression of genes related to protein synthesis and suppressing genes related to muscle degradation. It also protects muscle health by maintaining satellite cell number and function, protecting the mitochondrial function of muscle cells, and suppressing inflammation and oxidative stress. However, it is noted that most studies are preclinical. Evidence from randomised control trials in humans is lacking. In conclusion, curcumin has the potential to be utilised to manage muscle wasting and injury, pending more evidence from carefully planned human clinical trials.

Why Does Rehabilitation Not (Always) Work in Osteoarthritis? Does Rehabilitation Need Molecular Biology?

Osteoarthritis (OA) is a common disease among the human population worldwide. OA causes functional impairment, leads to disability and poses serious socioeconomic burden. The rehabilitation offers a function-oriented method to reduce the disability using diverse interventions (kinesiotherapy, physical therapy, occupational therapy, education, and pharmacotherapy). OA as a widespread disease among elderly patients is often treated by rehabilitation specialists and physiotherapists, however the results of rehabilitation are sometimes unsatisfactory. The understanding of molecular mechanisms activated by rehabilitation may enable the development of more effective rehabilitation procedures. Molecular biology methods may prove crucial in rehabilitation as the majority of rehabilitation procedures cannot be estimated in double-blinded placebo-controlled trials commonly used in pharmacotherapy. This article attempts to present and estimate the role of molecular biology in the development of modern rehabilitation. The role of clinicians in adequate molecular biology experimental design is also described.

Sex-specific alteration in human muscle transcriptome with age

Sarcopenia is a medical condition that progressively develops with age and results in reduced skeletal muscle mass, alteration in muscle composition, and decreased muscle strength. Several clinical studies suggested that sarcopenia disproportionally affects males and females with age. Despite this knowledge, the molecular mechanism governing the pathophysiology is not well understood in a sex-specific manner. In this study, we utilized human gastrocnemius muscles from males and females to identify differentially regulated genes with age. We found 269 genes with at least a twofold expression difference in the aged muscle transcriptome. Among the female muscle samples, there were 239 differentially regulated genes, and the novel protein-coding genes include KIF20A, PIMREG, MTRNR2L6, TRPV6, EFNA2, RNF24, and SFN. In aged male skeletal muscle, there were 166 differentially regulated genes, and the novel-protein coding genes are CENPK, CDKN2A, BHLHA15, and EPHA. Gene Ontology (GO) enrichment revealed glucose catabolism, NAD metabolic processes, and muscle fiber transition pathways that are involved in aged female skeletal muscle, whereas replicative senescence, cytochrome C release, and muscle composition pathways are disrupted in aged male skeletal muscle. Targeting these novels, differentially regulated genes, and signaling pathways could serve as sex-specific therapeutic targets to combat the age-related onset of sarcopenia and promote healthy aging.

Osteosarcopenia and Pain: Do We Have a Way Out?

Osteosarcopenia (OSP) is a geriatric syndrome characterized by the coexistence of osteoporosis and sarcopenia and associated with an increased risk of fragility fractures, disability, and mortality. For patients with this syndrome, musculoskeletal pain represents the most significant challenge since, in addition to limiting the individual's functionality and promoting disability, it has a huge psychological burden involving anxiety, depression, and social withdrawal. Unfortunately, the molecular mechanisms involved in the development and persistence of pain in OSP have not yet been fully elucidated, although immune cells are known to play a key role in these processes. Indeed, they release several molecules that promote persistent inflammation and nociceptive stimulation, resulting in the gating of ion channels responsible for the generation and propagation of the noxious stimulus. The adoption of countermeasures to counteract the OSP progression and reduce the algic component appears to be necessary, providing patients with a better quality of life and greater adherence to treatment. In addition, the development of multimodal therapies, based on an interdisciplinary approach, appears to be crucial, combining the use of anti-osteoporotic drugs with an educational programme, regular physical activity, and proper nutrition to eliminate risk factors. Based on this evidence, we conducted a narrative review using the PubMed and Google Scholar search engines to summarize the current knowledge on the molecular mechanisms involved in the pain development in OSP and the potential countermeasures to be taken. The lack of studies addressing this topic highlights the need to conduct new research into the resolution of an ever-expanding social problem.

Review article: Putting some muscle into sarcopenia-the pathogenesis, assessment and clinical impact of muscle loss in patients with inflammatory bowel disease

BACKGROUND

Sarcopenia, a loss of skeletal muscle mass or function, affects up to 50% of patients with inflammatory bowel disease (IBD) and is associated with poor clinical outcomes including increased hospitalizations, need for surgery and post-operative complications. Despite the high prevalence and clinical significance of sarcopenia in patients with IBD, few patients undergo routine muscle evaluation.

AIM

The goal of this study was to review the mechanisms of sarcopenia in patients with IBD and understand novel modalities to assess and treat impaired muscle mass or function.

METHODS

Pubmed and Cochrane databases were searched including articles published up to February 2023 utilizing the following keywords: "inflammatory bowel disease", "IBD", "Crohn's disease", "ulcerative colitis", "sarcopenia", "myosteatosis", "muscle health", and "frailty".

RESULTS

The pathogenesis of sarcopenia in IBD is not well defined, however, there is evidence supporting the role of malabsorption, reduced protein intake, chronic inflammation, dysbiosis, decreased physical activity, medication effects and hormone signaling from visceral adiposity. Traditional sarcopenia assessment techniques include direct measurements on cross sectional imaging. However, given the time, cost and radiation exposure associated with cross sectional imaging, new bedside tools are now available to estimate muscle mass, including assessment of grip strength, mid upper arm circumference and body composition utilizing bioelectrical impedance analysis. In addition, novel biomarkers for assessing muscle mass and techniques utilizing point of care ultrasound have been proposed to make sarcopenia evaluation more streamlined in the IBD clinic.

CONCLUSION

Sarcopenia is associated with poor clinical outcomes independent of IBD activity and therefore muscle health should be assessed in all IBD patients at routine intervals. Future studies to better our understanding of the pathophysiology as well as most effective management of sarcopenia in IBD will help guide clinical care and reduce disease related complications.

Potential of Food Protein-Derived Bioactive Peptides against Sarcopenia: A Comprehensive Review

Sarcopenia is an age-related progressive muscle disorder characterized by accelerated loss of muscle mass, strength, and function, which are important causes of physiological dysfunctions in the elderly. At present, the main alleviating method includes protein supplements to stimulate synthesis of muscle proteins. Food protein-derived peptides containing abundant branched-chain amino acids have a remarkable effect on the improvement of sarcopenia. Understanding the underlying molecular mechanism and clarifying the structure-activity relationship is essential for the mitigation of sarcopenia. This present review recaps the epidemiology, pathogenesis, diagnosis, and treatment of sarcopenia, which facilitates a comprehensive understanding of sarcopenia. Moreover, the latest research progress on food-derived antisarcopenic peptides is reviewed, including their antisarcopenic activity, molecular mechanism as well as structural characteristics. Food-derived bioactive peptides can indeed alleviate/mitigate sarcopenia. These antisarcopenic peptides play a pivotal role mainly by activating the PI3K/Akt/mTOR and MAPK pathways and inhibiting the ubiquitin-proteasome system and AMPK pathway, thus promoting the synthesis of muscle proteins and inhibiting their degradation. Antisarcopenic peptides alleviate sarcopenia via specific peptides, which may be absorbed into the circulation and exhibit their bioactivity in intact forms. The present review provides a theoretical reference for mitigation and prevention of sarcopenia by food protein-derived bioactive peptides.

Sarcopenia Predicts Inferior Progression-Free Survival in Lymphoma Patients Treated with Autologous Hematopoietic Stem Cell Transplantation

Autologous hematopoietic stem cell transplantation (ASCT) improves survival for patients with chemotherapy-sensitive lymphoma. Validated scoring systems are used in the clinical setting to predict treatment toxicity and survival; however, complications related to disease and treatment still occur, highlighting challenges in optimal patient selection and the need for novel predictors. Analysis of body composition and muscle mass can provide an objective assessment to identify vulnerable populations, as sarcopenia and frailty have been reported to predict outcomes in other tumor types. In this retrospective cohort study of patients undergoing ASCT for lymphoma, we investigated associations of sarcopenia with clinically significant outcomes, including overall survival (OS) and progression-free survival (PFS). Computed tomography (CT) images of 78 patients obtained routinely pretransplantation were used to assess skeletal muscle mass and are reported as skeletal muscle index (SMI). OS, PFS, and clinical outcomes of interest were compared between groups. Twenty-seven patients (34.6%) in the cohort met the criteria for sarcopenia. Patients with sarcopenia had a significantly shorter 3-year PFS (59% [95% confidence interval (CI), 38% to 75%] versus 84% [95% CI, 71% to 92%]; P = .02) after 3 years of follow up, whereas there was no difference in OS between patients with and those without sarcopenia (78% [95% CI, 57% to 89%] versus 88% [95% CI, 76% to 95%]; P = .25). Interestingly, no difference in survival was found with stratification based on the Karnofsky Performance Scale or Hematopoietic Cell Transplantation-Specific Comorbidity Index. There also were no significant between-group differences in length of hospital stay and the incidences of other clinical outcomes of interest, including febrile neutropenia, mucositis, total parenteral nutrition requirement, acute kidney injury, rate of readmission, or intensive care unit admission. This is the first study to our knowledge to correlate sarcopenia with disease control and PFS after ASCT in lymphoma. Possible explanations include a higher rate of chemotherapy-related toxicity, leading to disruptions of treatment as well as dysfunction of antitumor immunity secondary to impaired regulations from myokines from the loss of muscle mass or an unknown cause that is yet to be elucidated. Physical therapy programs and personalized regimens for treatment based on the analysis of body composition indices can be further studied and implemented to mitigate treatment-related toxicity and to optimize survival in patients with sarcopenia.

Causal relationship between insulin resistance and sarcopenia

Sarcopenia is a multifactorial disease characterized by reduced muscle mass and function, leading to disability, death, and other diseases. Recently, the prevalence of sarcopenia increased considerably, posing a serious threat to health worldwide. However, no clear international consensus has been reached regarding the etiology of sarcopenia. Several studies have shown that insulin resistance may be an important mechanism in the pathogenesis of induced muscle attenuation and that, conversely, sarcopenia can lead to insulin resistance. However, the causal relationship between the two is not clear. In this paper, the pathogenesis of sarcopenia is analyzed, the possible intrinsic causal relationship between sarcopenia and insulin resistance examined, and research progress expounded to provide a basis for the clinical diagnosis, treatment, and study of the mechanism of sarcopenia.

Sarcopenia-a geriatric pandemic : A narrative review

With growing life expectancy, the prevalence of frailty and sarcopenia will continuously increase during the next decades. Geographical differences have been described, and depending on the population studied, sarcopenia is evident in 10% of community-dwelling people, increasing up to 40 to 50% among those living in nursing homes. Sarcopenia is a complex age-related process of multifactorial pathogenesis, influenced by lifestyle, nutrition, biological processes during aging, and also immunological and endocrine mechanisms. For diagnostic criteria, physical parameters (muscle mass measurement) and functional aspects (muscle strength, gait speed, physical performance) are required. In routine clinical care, screening patients using the SARC‑F questionnaire is recommended by recent guidelines of the European Workgroup for Sarcopenia.

Low skeletal muscle mass is predictive of dose-limiting toxicities in head and neck cancer patients undergoing low-dose weekly cisplatin chemoradiotherapy

BACKGROUND

The dose-limiting effect of CT-assessed low skeletal muscle mass (LSMM) measured at the level of the third cervical vertebra has been found in head and neck cancer patients receiving high-dose cisplatin chemoradiotherapy. The aim of this study was to investigate the predictive factors for dose-limiting toxicities (DLTs) using low-dose weekly chemoradiotherapy.

MATERIALS AND METHODS

Head and neck cancer patients receiving definite chemoradiotherapy with weekly 40 mg/m2 body surface area (BSA) cisplatin or paclitaxel 45 mg/m2 BSA and carboplatin AUC2 were consecutively included and retrospectively analysed. Skeletal muscle mass was assessed using the muscle surface at the level of the third cervical vertebra in pretherapeutic CT scans. After stratification for LSMM DLT, acute toxicities and feeding status during the treatment were examined.

RESULTS

Dose-limiting toxicity was significantly higher in patients with LSMM receiving cisplatin weekly chemoradiotherapy. For paclitaxel/carboplatin, no significance regarding DLT and LSMM could be found. Patients with LSMM had significantly more dysphagia before treatment, although feeding tube placement before treatment was equal in patients with and without LSMM.

CONCLUSIONS

LSMM is a predictive factor for DLT in head and neck patients treated with low-dose weekly chemoradiotherapy with cisplatin. For paclitaxel/carboplatin, further research must be carried out.