Sarcopenia: A Contemporary Health Problem among Older Adult Populations

Sarcopenia is attenuated by mairin in SAMP8 mice via the inhibition of FAPs fibrosis through the AMPK-TGF-β-SMAD axis

Sarcopenia has become a prominent health problem among the elderly because of its adverse consequence, including physical disabilities and death. Fibro-adipogenic progenitors (FAPs) exhibit adipogenic and fibrogenic potencies and regulate skeletal muscle development, which plays important role in sarcopenia. Mairin, as an ingredient of Astragalus membranaceus, has the effect of anti-fibrosis. Therefore, we predicted that mairin targeted the fibrosis of FAPs and then affected sarcopenia. To verify our ideas, mairin (30 mg/kg/day or 60 mg/kg/day) was given to senescence accelerated mouse-prone 8 (SAMP8) mice by oral administration. Aging led to loss of weight, skeletal muscle mass, strength, and function, and an increase in muscle atrophy and fibrosis, while mairin administration inhibited physiological decline caused by aging. Similarly, mairin (20 μM or 40 μM) treatment enhanced FAP proliferation but blocked the differentiation into fibroblasts. Mechanically, mairin played an anti-fibrotic role via AMP-activated protein kinase-transforming growth factor beta-drosophila mothers against decapentaplegic protein (AMPK-TGF-β-SMAD) axis, as evidenced by increased phosphorylation of AMPKα and decreased TGF-β and phosphorylated-SMAD2/3. In addition, the potential target genes of mairin were explored by mRNA sequencing in our study. In conclusion, mairin may interfere with the AMPK/TGF-β/SMAD pathway to repress the fibrosis of FAPs and eventually ameliorate sarcopenia.

Sarcopenia and cognitive impairment in older adults: Long-term prognostic implications based on the National Health and Nutrition Examination Survey (2011-2014)

AIMS

The relationship between sarcopenia and cognitive impairment in older adults remains contentious. This study investigates this association and examines the long-term prognosis for individuals with both conditions.

METHODS

Utilizing data from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2014, this study focuses on the correlation between sarcopenia and cognitive impairment, as well as the extended prognosis for individuals managing these conditions.

RESULTS

The study cohort comprised 2890 participants, with 648 (22.4 %) diagnosed with sarcopenia. Multivariable logistic regression analysis identified a significant association between sarcopenia and an increased risk of cognitive impairment (adjusted odds ratio [aOR]: 1.68, 95 % confidence interval [CI]: 1.30-2.17). Over a median follow-up period of 48 months, 200 individuals (6.9 %) succumbed to cardiovascular and cerebrovascular diseases (CCVDs), including hypertension, congestive heart failure, coronary artery disease, and stroke, as well as Alzheimer's disease (AD). Participants had comorbid conditions such as CCVDs and diabetes mellitus. Kaplan-Meier survival analysis and the Cox proportional hazards model indicated that individuals with both sarcopenia and cognitive impairment had the highest mortality risk from CCVDs and AD (adjusted hazard ratio [aHR]: 2.73, 95 % CI: 1.48-5.02). Individuals with sarcopenia and comorbidities exhibited a higher mortality risk from CCVDs or AD compared to those without sarcopenia but with comorbidities (aHR: 2.71, 95 % CI: 1.37-5.37).

CONCLUSION

Sarcopenia is independently associated with cognitive impairment. Older adults with both sarcopenia and cognitive impairment or concurrent comorbidities face increased mortality risks from CCVDs or AD compared to their healthy counterparts.

CLINICAL IMPLICATION

Single-cell RNA sequencing analysis provides novel insights into the role of apoptosis-related genes in muscle aging

OBJECTIVE

This study employed a comprehensive single-cell analysis approach to explore the role of cell apoptosis-related genes in muscle aging.

METHODS

The single-cell RNA sequencing data from the GSE143704 dataset were used to identify distinct cell clusters and assess gene expression patterns related to apoptosis activation. The "limma" package was used to identify hub genes, after which we performed Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis to identify relevant pathways. Additionally, Gene Set Enrichment Analysis(GSEA) and Gene Set Variation Analysis (GSVA) were used to uncover relevant biological pathways. The Receiver Operating Characteristic Curve (ROC) was used to evaluate the diagnostic value of the hub genes. Single-sample Gene Set Enrichment Analysis (ssGSEA) was used to analyze the immune cell infiltration levels.

RESULTS

Single-cell sequencing data from muscle aging patients allowed the identification of various cell types, including epithelial cells, adipocytes, and tissue-resident macrophages. By conducting a differential expression analysis that intersected active and nonactive apoptosis, as well as comparing elderly and young samples, a total of 22 hub genes were identified (p < 0.05). The 22 hub genes have discriminative ability as potential biomarkers for diagnosing muscle aging. The enrichment analysis indicated that these genes were closely associated with diverse pathways, including "response to UV-B" and "extracellular matrix organization" (p < 0.05). Furthermore, GSEA and GSVA indicated that multiple pathways emerged-for example, the "complement and coagulation cascades", "proteasome", "insulin signaling pathway", and "MAPK signaling pathway". Additionally, the analysis of immune cell infiltration revealed positive correlations between most of the hub genes and immune cells.

CONCLUSION

Our study identified 22 apoptosis-related genes involved in muscle aging and indicated their potential diagnostic value. These findings offer a novel perspective on the pathogenesis of muscle aging and present potential targets for therapeutic interventions.

Effect of low muscle mass on total mortality related to metabolic disease in chronic kidney disease patients

Low muscle mass is a risk factor for mortality in patients with chronic kidney disease (CKD). However, it is not clear to what extent low muscle mass contributes to this risk, either independently or in combination with metabolic abnormalities and frailty. This study used data from the National Health and Nutrition Examination Survey 1999-2006 and 2011-2018. Low muscle mass was defined as Appendicular Skeletal Mass Index < 7 kg/m2 in men or < 5.5 kg/m2 in women. The follow-up duration was from the first anthropometric and clinical measurements to death or the last follow-up. This study enrolled 2072 patients with CKD. Low muscle mass was associated with a lower risk of metabolic abnormalities, but was associated with an elevated mortality risk. Conversely, central obesity was associated with a higher likelihood of metabolic abnormalities and frailty, yet showed no significant association with mortality risk. Subsequently conducted mediation analysis indicated that the effect of low muscle mass on mortality was direct, not mediated by frailty and metabolic abnormalities. In spite of the inverse relationship between low muscle mass and metabolic abnormalities, low muscle mass are directly associated with an increased risk of all-cause mortality. Low muscle mass may directly contribute to mortality in patients with CKD, independent of metabolic abnormalities and frailty in these patients.

Bidirectional transitions of sarcopenia states in older adults: The longitudinal evidence from CHARLS

BACKGROUND

Sarcopenia, the age-related loss of muscle mass and function, brings multiple adverse outcomes including disability and death. Several sarcopenia consensuses have newly introduced the premorbid concept of possible sarcopenia and recommended early lifestyle interventions. Bidirectional transitions of premorbid states have been revealed in several chronic diseases yet not clarified in sarcopenia. This study aims to investigate the underlying transition patterns of sarcopenia states.

METHODS

The study utilized three waves of data from a nationally representative survey, the China Health and Retirement Longitudinal Study (CHARLS), and included community-dwelling individuals aged 60 years and older with at least two sarcopenia states assessments based on the Asian Working Group for Sarcopenia criteria 2019 (AWGS2019) between 2011 and 2015. The estimated transition intensity and probability between non-sarcopenia, possible sarcopenia, sarcopenia, and death were investigated using multi-stage Markov (MSM) models.

RESULTS

The study comprised 4395 individuals (49.2% female, median age 67 years) with a total of 10 778 records of sarcopenia state assessment, and the mean follow-up period was 3.29 years. A total of 24.5% of individuals with a current state of possible sarcopenia returned to non-sarcopenia, 60.3% remained possible sarcopenia, 6.7% progressed to sarcopenia, and 8.5% died by the next follow-up. The transition intensity of recovery to non-sarcopenia (0.252, 95% CI 0.231-0.275) was 2.8 times greater than the deterioration to sarcopenia (0.090, 95% CI 0.080-0.100) for individuals with possible sarcopenia. For individuals with possible sarcopenia, the estimated probabilities of recovering to non-sarcopenia, progressing to sarcopenia, and transitioning to death within a 1-year observation were 0.181, 0.066, and 0.035, respectively. For individuals with sarcopenia, the estimated probabilities of recovering to non-sarcopenia, recovering to possible sarcopenia, and transitioning to death within 1-year observation were 0.016, 0.125, and 0.075, respectively. In covariables analysis, age, sex, body mass index, physical function impairment, smoking, hypertension, and diabetes are important factors influencing bidirectional transitions.

CONCLUSIONS

The findings highlight the bidirectional transitions of sarcopenia states among older adults and reveal a notable proportion of possible sarcopenia show potential for recovery in the natural course. Screening and intensifying interventions based on risk factors may facilitate a recovery transition.

The Association Between the Non-essential Metal Mixture and Handgrip Strength in Chinese Community-Dwelling Older Adults

There is limited research on the effects of non-essential metal (NEM) mixture on handgrip strength in the elderly. This study aimed to assess the associations of single NEMs and their mixture with handgrip strength in Chinese community-dwelling older adults. A total of 3807 elderly people aged 60 years or above were included in this study. Measurement of urinary aluminum (Al), arsenic (As), barium (Ba), cadmium (Cd), and gallium (Ga) concentrations was conducted by inductively coupled plasma mass spectrometry (ICP-MS). Handgrip strength was measured using a hand dynamometer. Four statistical models, including general linear regression and generalized additive models (GAMs), as well as Bayesian kernel machine regression (BKMR) and quantile-based computation regression (QGC) models, were used to assess the individual and joint effects of urine NEMs with handgrip strength, respectively. After adjusting for covariates, Ga (ß = - 0.27; 95% CI, - 0.54 ~  - 0.01) and As ( β  = - 0.34; 95% CI, - 0.61 ~  - 0.07) were negatively associated with handgrip strength. The GAMs and BKMR further suggested that the negative associations of Ga and As with handgrip strength were linear and inverted U-shaped, respectively. The BKMR and QGC models showed that the NEM mixture was negatively related to handgrip strength, with Ga and As contributing the most within the mixture. Moreover, we also observed an interaction between As and Ga on handgrip strength. Longitudinal studies are needed to verify these findings.

Sarcopenia Is Associated with Neoplasm of Bone and Articular Cartilage: Findings from Mendelian Randomized Study

Exploring the causal relationship between sarcopenia and neoplasm of bone and articular cartilage (NBAC) by bidirectional Mendelian randomization (MR). Genome-wide association study (GWAS) data on sarcopenia-associated traits including appendicular lean mass, low handgrip strength (including criteria from the European Working Group on Sarcopenia in Older People and the Foundation for the National Institutes of Health), and usual walking speeds were obtained from the UK Biobank. GWAS data for NBAC (benign and malignant) were provided by the Finnish Genetic Database. Three different methods of MR analysis, including inverse-variance weighted, Mendelian randomized Egger regression, and weighted median methods, were utilized. MR analysis showed that high appendicular lean mass was positively associated with the risk of developing benign NBAC (odds ratio and 95% confidence interval = 1.236 (1.026,1.489), p = 0.025). At the same time, there is no statistically significant association was found between traits related to sarcopenia and malignant neoplasm of bone and articular cartilage. There was also no reverse causal correlation between NBAC and traits related to sarcopenia. In European populations, better appendicular lean body mass is positively associated with the risk of benign neoplasm of bone and articular cartilage, representing the possibility that sarcopenia may be a protective factor against neoplasm of bone and articular cartilage.

Effect of Bimagrumab on body composition: a systematic review and meta-analysis

BACKGROUND

Sarcopenia, a condition marked by progressive muscle mass and function decline, presents significant challenges in aging populations and those with chronic illnesses. Current standard treatments such as dietary interventions and exercise programs are often unsustainable. There is increasing interest in pharmacological interventions like bimagrumab, a monoclonal antibody that promotes muscle hypertrophy by inhibiting muscle atrophy ligands. Bimagrumab has shown effectiveness in various conditions, including sarcopenia.

AIM

The primary objective of this meta-analysis is to evaluate the impact of bimagrumab treatment on both physical performance and body composition among patients diagnosed with sarcopenia.

MATERIALS AND METHODS

This meta-analysis follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We systematically searched PubMed, Ovid/Medline, Web of Science, and the Cochrane Library databases up to June 2024 using appropriate Medical Subject Headings (MeSH) terms and keywords related to bimagrumab and sarcopenia. Eligible studies were randomized controlled trials (RCTs) that assessed the effects of bimagrumab on physical performance (e.g., muscle strength, gait speed, six-minute walk distance) and body composition (e.g., muscle volume, fat-free body mass, fat body mass) in patients with sarcopenia. Data extraction was independently performed by two reviewers using a standardized form, with discrepancies resolved through discussion or consultation with a third reviewer.

RESULTS

From an initial search yielding 46 records, we screened titles, abstracts, and full texts to include seven RCTs in our meta-analysis. Bimagrumab treatment significantly increased thigh muscle volume (mean difference [MD] 5.29%, 95% confidence interval [CI] 4.08% to 6.50%, P < 0.001; moderate heterogeneity χ2 = 6.41, I2 = 38%, P = 0.17) and fat-free body mass (MD 1.90 kg, 95% CI 1.57 kg to 2.23 kg, P < 0.001; moderate heterogeneity χ2 = 8.60, I2 = 30%, P = 0.20), while decreasing fat body mass compared to placebo (MD - 4.55 kg, 95% CI - 5.08 kg to - 4.01 kg, P < 0.001; substantial heterogeneity χ2 = 27.44, I2 = 89%, P < 0.001). However, no significant improvement was observed in muscle strength or physical performance measures such as gait speed and six-minute walk distance with bimagrumab treatment, except among participants with slower baseline walking speeds or distances.

DISCUSSION AND CONCLUSION

This meta-analysis provides valuable insights into the effects of bimagrumab on sarcopenic patients, highlighting its significant improvements in body composition parameters but limited impact on functional outcomes. The observed heterogeneity in outcomes across studies underscores the need for cautious interpretation, considering variations in study populations, treatment durations, and outcome assessments. While bimagrumab shows promise as a safe pharmacological intervention for enhancing muscle mass and reducing fat mass in sarcopenia, its minimal effects on muscle strength and broader physical performance suggest potential limitations in translating body composition improvements into functional gains. Further research is needed to clarify its long-term efficacy, optimal dosing regimens, and potential benefits for specific subgroups of sarcopenic patients.

Multicomponent Physical Program: Effects on Physical Fitness of Older Women of Different Age Groups

Purpose: Experimental studies investigating the outcomes of physical exercise among age-stratified groups of older women are still incipient. This study aimed to investigate the effects of a ten-month multicomponent physical program on the physical fitness of older women in three age-stratified groups (60-69 years, 70-79 years, and ≥80 years). Method: Participants (n = 141) were divided into three age groups: GR1 60-69 years (n = 45; 65.2 ± 2.3 years); GR2 70-79 years (n = 67; 72.9 ± 2.9 years), GR3 ≥80 years (n = 29; 83.5 ± 4.5 years). The participants performed the multicomponent physical program and were evaluated before and after the intervention with Senior Fitness Test. Data were analyzed using generalized estimating equations, Bonferroni test (p ≤.05) and effect size (Cohen's d). Results: For the group factor, there were significant differences in lower limb strength (p = .003), upper limb strength (p < .001), upper limb flexibility (p < .001), balance/agility (p < .001), and cardiorespiratory fitness (p < .001). For the time factor, significant differences were observed in lower limb strength (GR2, p = .014, small effect size), upper limb strength (GR1, p = .003; GR2, p < .001; GR3, p = .017; small effect sizes), lower limb flexibility (GR1, p = .025, non-significant effect size), cardiorespiratory fitness (GR1, p < .001, medium effect size; GR2, p = .002; small effect size). Conclusion: Physical fitness improved with training, but effects differed between age groups. Positive effects were observed for GR1 and GR2, whereas GR3 showed maintenance of physical fitness. Aging interferes more strongly in women aged 80 years and older and it is necessary for specific training programs for this age group.                                                      .

The impact of quality of life on the survival of elderly patients with end-stage renal disease: a prospective multicenter cohort study in Korea

Background

Quality of life (QOL) is associated with mortality in dialysis patients. However, the impact of QOL index or score on elderly patients undergoing maintenance dialysis is unclear. We analyzed the relationship between QOL domains and survival in elderly end-stage renal disease (ESRD) patients on dialysis.

Methods

We included 492 incident ESRD patients aged ≥65 years from a Korean nationwide prospective cohort study who were assessed for QOL with a follow-up duration of 67.3 ± 34.6 months after dialysis initiation. Their QOL was evaluated using the Kidney Disease Quality of Life (KDQOL) instrument, and the effect of each QOL domain on mortality was analyzed. Multivariable Cox regression analysis was performed to identify independent risk factors for death after adjusting for confounding factors.

Results

Low physical component summary (PCS) and Short Form-36 score were significantly associated with low survival rate (P < .001 and P = .017, respectively), whereas the mental component summary and ESRD-targeted item scores were not correlated with survival rate. Multivariable Cox regression analysis confirmed that only a high PCS score was associated with better survival (hazard ratio 0.71; 95% confidence interval 0.52-0.97; P = .031). Linear regression analysis revealed that age, sex, modified Charlson comorbidity index, albumin and intact parathyroid hormone were associated with PCS. Among the PCS items, only the physical functioning score was significantly associated with mortality (P = .017).

Conclusion

PCS was an independent risk factor for death in elderly ESRD patients. A higher physical functioning score was associated with a better outcome, suggesting the importance of physical condition in elderly dialysis patients.

Dietary vitamin K intake in relation to skeletal muscle mass and strength among adults: a cross-sectional study based on NHANES

Background

Previous studies revealed that vitamin K might help maintain muscle homeostasis, but this association has received little attention. We aimed to explore the associations of vitamin K intake with skeletal muscle mass and strength.

Methods

We included cross-sectional data from the U.S. National Health and Nutrition Examination Survey (NHANES, 2011-2018). Vitamin K intake was assessed via 24-h recall. Covariate-adjusted multiple linear regression and restricted cubic splines were used to evaluate the associations of dietary vitamin K intake with skeletal muscle mass and strength, measured by dual-energy X-ray absorptiometry and handgrip dynamometer, respectively.

Results

Dietary vitamin K intake was positively associated with skeletal muscle mass in males (β = 0.05747, p = 0.0204) but not in females. We also revealed a positive association between dietary vitamin K intake and handgrip strength within the range of 0-59.871 μg/d (P nonlinear = 0.049). However, beyond this threshold, increasing vitamin K intake did not cause additional handgrip strength improvements.

Conclusion

We provided evidence for a positive relationship between dietary vitamin K intake and skeletal muscle mass in males. Moreover, our study revealed a nonlinear relationship between dietary vitamin K intake and handgrip strength, highlighting an optimal intake range.

The association between inflammatory cytokines and sarcopenia-related traits: a bi-directional Mendelian randomization study

BACKGROUND

Sarcopenia is among the most common musculoskeletal illnesses, yet its underlying biochemical mechanisms remain incompletely understood. Identifying the relationship of inflammatory cytokines with sarcopenia components would help understand the etiology of sarcopenia. We performed a bi-directional Mendelian randomization study to explore the causal relationship between 41 inflammatory cytokines and sarcopenia-related traits.

METHODS

The study was performed in two stages using bidirectional dual-sample Mendelian randomization. We obtained aggregated statistical data on inflammatory factors, low grip strength, and ALM from genome-wide association studies. To explore the causal association between exposure and outcomes, we primarily utilized the inverse variance weighted strategy. Furthermore, we conducted sensitivity analyses through the use of Mendelian randomization (MR) Egger, weighted median and simple mode methods. To evaluate robustness of the results and to identify and adjust for horizontal pleiotropy, we performed the MR Pleiotropy RESidual Sum and Outlier test, the MR Egger intercept test, and a leave-one-out analysis.

RESULTS

The results displayed a potential association between interleukin-10 (OR: 1.046, 95% CI: 1.002-1.093, p = 0.042) and vascular endothelial growth factor (OR: 1.024, 95% CI: 1.001-1.047, p = 0.038) and the risk of low hand-grip strength. Moreover, interferon gamma-induced protein 10 (OR: 1.010, 95% CI: 1.000-1.019, p = 0.042) and macrophage colony-stimulating factor (OR: 1.010, 95% CI: 1.003-1.017, p = 0.003) were significantly linked to a higher risk of ALM.

CONCLUSION

We identified a causal relationship between multiple inflammatory factors and sarcopenia-related traits. Our study offers valuable insights into innovative methods for the sarcopenia prevention and treatment by regulating inflammatory factors.

Sarcopenia definitions and their association with injurious falls in older Swedish women from the Sahlgrenska University Hospital Prospective Evaluation of Risk of Bone fractures (SUPERB) study

Associations between different sarcopenia definitions and the risk of injurious falls were investigated in 75-80-year-old women in the Swedish SUPERB cohort. Only sarcopenia according to the Sarcopenia Definitions and Outcomes Consortium (SDOC) definition was associated with incident injurious falls with and without fractures in older women.

PURPOSE

To investigate the association between three commonly used sarcopenia definitions and the risk of injurious falls in a population of older Swedish women.

METHODS

A total of 2,883 75-80-year-old women with complete data on relevant sarcopenia definitions from the Swedish SUPERB cohort were studied. Sarcopenia was defined based on the Sarcopenia Definitions and Outcomes Consortium (SDOC: low handgrip strength and gait speed), revised European Working Group on Sarcopenia in Older People (EWGSOP2: low appendicular lean mass index (ALMI, dual-energy X-ray absorptiometry (DXA)-derived), appendicular lean mass (kg)/height (m2), hand grip strength (kg), or low chair stand time (s)), and Asian Working Group for Sarcopenia (AWGS: low ALMI and hand grip strength (kg) or low gait speed (m/s)). Questionnaires captured the occurrence of falls in the past 12 months. Incident injurious falls were identified using national registers. Cox regression (hazard ratios (HR) and 95% confidence intervals (CI)) analyses were performed without adjustment and after adjustment for age, body mass index, previous falls, and the Charlson comorbidity index.

RESULTS

During a median (IQR) follow-up time of 7.06 (6.2-7.9) years, there were 491 injurious falls without fracture and 962 injurious falls when also including falls resulting in a fracture. Sarcopenia according to EWGSOP2 and AWGS was not associated with an increased risk of injurious falls. Individuals with sarcopenia defined by SDOC had a higher risk of injurious falls with and without fracture (HR 2.11; 95% CI, 1.63-2.73 and HR, 2.16; 95% CI, 1.55-3.02, respectively).

CONCLUSION

Sarcopenia definitions confined to muscle function and strength such as SDOC, rather than including DXA-determined ALMI (EWGSOP2 and AWGS), are associated with incident injurious falls with and without fractures in older women.

Targeting Crosstalk of Signaling Pathways among Muscles-Bone-Adipose Tissue: A Promising Therapeutic Approach for Sarcopenia

The aging process is associated with the development of a wide range of degenerative disorders in mammals. These diseases are characterized by a progressive decline in function at multiple levels, including the molecular, cellular, tissue, and organismal. Furthermore, it is responsible for various healthcare costs in developing and developed countries. Sarcopenia is the deterioration in the quality and functionality of muscles, which is extremely concerning as it manages many functions in the human body. This article reviews the molecular crosstalk involved in sarcopenia and the specific roles of many mediator molecules in establishing cross-talk between muscles, bone, and fatty tissues, eventually leading to sarcopenia. Besides, the involvement of various etiological factors, such as neurology, endocrinology, lifestyle, etc., makes it exceedingly difficult for clinicians to develop a coherent hypothesis that may lead to the well-organized management system required to battle this debilitating disease. The several hallmarks contributing to the progression of the disease is a vital question that needs to be addressed to ensure an efficient treatment for sarcopenia patients. Also, the intricate molecular mechanism involved in developing this disease requires more studies. The direct relationship of cellular senescence with aging is one of the pivotal issues contributing to disease pathophysiology. Some patented treatment strategies have been discussed, including drugs undergoing clinical trials and emerging options like miRNA and protein-enclosed extracellular vesicles. A clear understanding of the secretome, including the signaling pathways involved between muscles, bone, and fatty tissues, is extremely beneficial for developing novel therapeutics for curing sarcopenia.

Effect of Sarcopenia on Coronary Atherosclerotic Burden, Lesion Complexity, and Major Cardiovascular Events in Elderly Patients With Acute Coronary Syndrome: A 1-year Follow-up Study

Sarcopenia is accepted as an indicator of subclinical atherosclerosis. However, its effects on clinical coronary atherosclerotic burden and lesion complexity and major adverse cardiovascular events (MACE) in elderly patients with non-ST elevation myocardial infarction (NSTEMI) are unknown. Therefore, we evaluated these possible effects. Coronary artery disease (CAD) burden and complexity were assessed using the Gensini and TAXus and cardiac surgery (SYNTAX) score, respectively. MACE involving nonfatal myocardial infarction, rehospitalization, ischemic stroke, and total mortality were evaluated after 1 year of the index NSTEMI event. The study included 240 elderly patients; of these, 60 (25%) patients had sarcopenia. The SYNTAX score and Gensini score were similar in both groups (16.8 ± 8.7 vs 17.3 ± 9.2, P = .63 and 67.7 ± 43.9 vs 73.9 ± 45.5, P = .31, respectively). The total MACE rate was significantly higher in patients with sarcopenia than in those without sarcopenia (31.7 vs 14.4%, P = .003). In the multivariate model, age [odds ratio (OR) 1.112, 95% CI: 1.006-1.228, P = .04)], ejection fraction (OR: .923, 95% CI: .897-.951, P < .001), and sarcopenia (OR: 2.262, 95% CI: 1.039-4.924, P = .04) were independently associated with MACE. Sarcopenia was independently associated with MACE but not with CAD burden or complexity in elderly patients with NSTEMI.

Carbon monoxide-loaded cell therapy as an exercise mimetic for sarcopenia treatment

Sarcopenia is characterized by loss of muscle strength and muscle mass with aging. The growing number of sarcopenia patients as a result of the aging population has no viable treatment. Exercise maintains muscle strength and mass by increasing peroxisome growth factor activating receptor γ-conjugating factor-1α (PGC-1α) and Akt signaling in skeletal muscle. The present study focused on the carbon monoxide (CO), endogenous activator of PGC-1α and Akt, and investigated the therapeutic potential of CO-loaded red blood cells (CO-RBCs), which is bioinspired from in vivo CO delivery system, as an exercise mimetic for the treatment of sarcopenia. Treatment of C2C12 myoblasts with the CO-donor increased the protein levels of PGC-1α which enhanced mitochondrial biogenesis and energy production. The CO-donor treatment also activated Akt, indicating that CO promotes muscle synthesis. CO levels were significantly elevated in the skeletal muscle of normal mice after intravenous administration of CO-RBCs. Furthermore, CO-RBCs restored the mRNA expression levels of PGC-1α in the skeletal muscle of two experimental sarcopenia mouse models, denervated (Den) and hindlimb unloading (HU) models. CO-RBCs also restored muscle mass in Den mice by activating Akt signaling and suppressing the muscle atrophy factors myostatin and atrogin-1, and oxidative stress. Treadmill tests further showed that the reduced running distance in HU mice was significantly restored by CO-RBC administration. These findings suggest that CO-RBCs have potential as an exercise mimetic for sarcopenia treatment.

Traditional Chinese medicine constitution and sarcopenia: a cross-sectional study

Objective

Sarcopenia is a gradually advancing systemic disorder affecting skeletal muscles, primarily distinguished by diminished muscle mass and functional decline. As of present, a universally accepted diagnostic criterion for sarcopenia has yet to be established. From the perspective of the constitution theory in traditional Chinese medicine (TCM), the Yin-deficiency constitution is believed to have a significant correlation with the development of sarcopenia. The primary objective of this study was to examine the potential association between sarcopenia and Yin-deficiency constitution.

Methods

The present study is a cross-sectional analysis. The Asian Working Group for Sarcopenia (AWGS) recommended a diagnostic criterion for sarcopenia. A total of 141 participants over 50 years of age were diagnosed with sarcopenia. To determine the constitution of each patient, classification and determination standards were used in traditional Chinese medicine. In this study, a combination of logistic regression and propensity score matching (PSM) was employed to analyze a dataset comprising 1,372 eligible observations. The diagnostic efficacy of the test in distinguishing sarcopenia was assessed through receiver operating characteristic (ROC) curve analysis.

Results

The relationship between Yin-deficiency constitution and sarcopenia was examined using logistic regression analysis. In the crude model, the odds ratio (OR) was found to be 3.20 (95% confidence interval [CI]: 1.70-6.03). After adjusting for various confounding factors, including gender, sex, 6 m walking test/(m/s), SMI, and maximum grip strength/kg, the OR increased to 9.70 (95% CI: 3.20-69.38). The associations between seven other biased traditional Chinese medicine (TCM) constitutions and sarcopenia were not found to be statistically significant in the fully adjusted model. The propensity score matching (PSM) analysis yielded consistent results with the logistic regression analysis. Receiver operating characteristic (ROC) curve analysis showed that the AUC of the Yin-deficiency constitution combined with age and gender reached 0.707.

Conclusion

Among the nine TCM constitutions examined, the Yin-deficiency constitution demonstrates an independent association with sarcopenia. Yin-deficiency constitution may serve as a potential risk factor for the development of sarcopenia. To establish a causal relationship, further experimental investigations are warranted. The diagnostic performance of sarcopenia is effectively demonstrated by the Yin-deficiency constitution combined with age and gender.

The association between the triglyceride-glucose index and sarcopenia: data from the NHANES 2011-2018

BACKGROUND

The Triglyceride-glucose (TyG) index is a marker of insulin resistance, but its role in sarcopenia is controversial. The purpose of this study was to investigate the association of the TyG index with sarcopenia.

METHODS

4030 participants aged 20 years and above were selected from National Health and Nutrition Examination Survey for cross sectional study. Weighted logistic regression model was used to estimate the association between TyG index and sarcopenia. Threshold effect analysis and restricted cubic spline were employed to describe nonlinear link, with interaction tests and subgroup analyses performed.

RESULTS

It was found in the fully adjusted model that the TyG index was positively associated with sarcopenia (per 1-unit increase in the TyG index: OR = 1.31, 95%CI: 1.07, 1.60). This association was further highlighted in groups characterized by the absence of MetS or diabetes, as well as the absence of vigorous or moderate work activity. Furthermore, analysis of the curve fitting and threshold effects indicated a nonlinear relationship, which exhibited a turning point at 9.14.

CONCLUSION

The study results indicated that the TyG index was positively associated with sarcopenia. Enhancing the management of insulin resistance could help reduce the risk of developing sarcopenia.

Expression profiling by high-throughput sequencing reveals GADD45, SMAD7, EGR-1 and HOXA3 activation in Myostatin (MSTN) and GDF11 treated myoblasts

Growth differentiation factor 11 (GDF11) and myostatin (MSTN/GDF8) are closely related members of the transforming growth factor β (TGFβ) superfamily, sharing structural homology. Despite these structural similarities, recent research has shed light on the distinct roles these ligands play within muscle tissue. This study aims to uncover both the differences and similarities in gene expression at the transcriptome level by utilizing RNA sequencing. We conducted experiments involving five distinct groups, each with three biological replicates, using C2C12 cell cultures. The cells were subjected to high-throughput profiling to investigate disparities in gene expression patterns following preconditioning with either GDF11 or MSTN at concentrations of 1 nM and 10 nM, respectively. In addition, control groups were established. Our research revealed concentration-dependent gene expression patterns, with 38 genes showing significant differences when compared to the control groups. Notably, GADD45, SMAD7, EGR-1, and HOXA3 exhibited significant differential expression. We also conducted an over-representation analysis, highlighting the activation of MAPK and JNK signaling pathways, along with GO-terms related to genes that negatively regulate metabolic processes, biosynthesis, and protein phosphorylation. This study unveiled the activation of several genes not previously discussed in existing literature whose full biological implications are yet to be determined in future research.

Relationship of Handgrip Strength and Asymmetry with Walking Ability in Older Adults with Excess Adiposity

When low muscle mass and impaired strength and physical function coexist with excess adiposity, it is termed sarcopenic obesity (SO). Handgrip strength (HGS) is a predictor of disability and mortality. Asymmetry in HGS, particularly ≥ 10% strength differences between hands, may indicate neuromuscular dysfunction observable prior to declines in maximal strength are detectedand therefore could be incorporated to identify those at risk of physical limitations and SO. This study compares HGS values and asymmetry in older adults with excess adiposity and evaluates their relationships with physical function. Baseline data from two previous pilot weight loss studies in 85 older adults with body mass index values ≥ 30 kg m-2 are included with measures of body composition, walking speed, and chair stand ability. Sixty-three participants met the criteria for SO. HGS correlated to gait speed (r = 0.22), distance walked (r = 0.40), chair stand time for 5 repetitions (r = 0.42) and during 30 s (r = 0.31). HGS asymmetry is only correlated to gait speed (r = 0.31) and there are no differences in physical function between those with and without asymmetry. Maximal HGS tests should continue to be used to screen for functional decline and disability.

Association of phase angle with sarcopenia in patients undergoing maintenance hemodialysis: A case-control study

Background

Sarcopenia, characterized by reduced muscle strength and mass, is commonly observed in patients with kidney disease. This study aimed to investigate the factors that influence sarcopenia in patients undergoing maintenance hemodialysis (HD patients).

Materials and Methods

A case-control study was conducted from 2022 to 2023, involving a total of 137 HD patients receiving regular dialysis. Relevant data were collected, and based on diagnostic criteria, patients were classified into sarcopenia and nonsarcopenia groups. All patients received polysulfone membrane HD at a flow rate of 500 mL/min. Bioelectrical impedance analysis was used to evaluate phase angle (PhA), muscle volume, and body composition.

Results

The prevalence of sarcopenia among maintenance HD patients was found to be 40.14%. There was a higher proportion of women (76.36%) with sarcopenia compared to men (P < 0.001). Furthermore, a significant difference was observed in PhA (P < 0.006) between patients undergoing maintenance HD with and without sarcopenia. PhA was positively associated with body mass index, body cell mass, basal metabolic rate, fat-free mass, soft lean mass, and minerals, whereas age and skeletal muscle index showed an inverse significant correlation.

Conclusion

Sarcopenia, a condition associated with increased mortality risk, affects a considerable proportion of dialysis patients. It is imperative to urgently identify and develop preventive and therapeutic strategies to counteract the detrimental effects of sarcopenia on the health outcomes of kidney patients.

The effects of β-hydroxy-β-methylbutyrate or HMB-rich nutritional supplements on sarcopenia patients: a systematic review and meta-analysis

Background

Sarcopenia is a progressive, systemic skeletal muscle disorder. Resistance exercise and physical activity have been proven effective in its treatment, but consensus on pharmacological interventions has not yet been reached in clinical practice. β-Hydroxy-β-methylbutyrate (HMB) is a nutritional supplement that has demonstrated favorable effects on muscle protein turnover, potentially contributing to beneficial impacts on sarcopenia.

Aim

To assess the potential positive effects of HMB or HMB-containing supplements on individuals with sarcopenia, a systematic review and meta-analysis was conducted.

Methods

A systematic review and meta-analysis were conducted on randomized controlled trials (RCTs) examining the treatment of sarcopenia with HMB. Two assessors independently conducted screening, data extraction, and bias risk assessment. Outcome data were synthesized through a random-effects model in meta-analysis, using the mean difference (MD) as the effect measure.

Results

A meta-analysis was conducted on six studies. HMB or HMB-rich nutritional supplements showed a statistically significant difference in Hand Grip Strength (HGS) for sarcopenia patients [MD = 1.26, 95%CI (0.41, 2.21), p = 0.004], while there was no statistically significant difference in Gait Speed (GS) [MD = 0.04, 95%CI (-0.01, 0.08), p = 0.09], Fat Mass (FM) [MD = -0.18, 95%CI (-0.38, 0.01), p = 0.07], Fat-Free Mass (FFM) [MD = 0.09, 95%CI (-0.23, 0.42), p = 0.58], and Skeletal Muscle Index (SMI) [MD = 0.01, 95%CI (-0.00, 0.01), p = 0.13].

Conclusion

HMB or HMB-rich nutritional supplements are beneficial for muscle strength in sarcopenia patients. However, there is limited evidence demonstrating significant effects on both muscle strength and physical performance in sarcopenia individuals. HMB may be considered as a treatment option for sarcopenia patients.

Systematic review registration

CRD42024512119.

CT-derived body composition and differential association with age, TNM stage and systemic inflammation in patients with colon cancer

Low skeletal muscle index/density (SMI/SMD) is prevalent in cancer, adversely prognostic and associated with tumour stage and the systemic inflammatory response (SIR). Age and SMI/SMD has not been widely studied. The present study analyses the association between age and SMI/SMD after adjustment for other clinicopathological factors. Patients undergoing resectional surgery for TNM Stage I-III disease within the West of Scotland between 2011 and 2014 were identified. A single CT slice was obtained from each patients staging CT scan. SMI and SMD were stratified normal/abnormal. The SIR was stratified using Systemic Inflammatory Grade (SIG). When stratified by age (< 50/50s/60s/70s/80+), 39%/38%/48%/62%/74% and 27%/48%/64%/82%/92% of patients had a low SMI and SMD respectively (both p < 0.001). Older age (OR 1.47, p < 0.001), female sex (OR 1.32, p = 0.032), lower socioeconomic deprivation (OR 1.15, p = 0.004), higher ASA (OR 1.30, p = 0.019), emergency presentation (OR 1.82, p = 0.003), lower BMI (OR 0.67, p < 0.002) and higher SIG (OR 1.23, p < 0.001) were independently associated with low SMI. Older age (OR 2.28, p < 0.001), female sex (OR 1.38, p = 0.038), higher ASA (OR 1.92, p < 0.001), emergency presentation (OR 1.71, p = 0.023), and higher SIG (OR 1.37, p < 0.001) were independently associated with lower SMD. Tumour factors were not independently associated with either SMI/SMD. Age was a major factor associated with low SMI/SMD in patients with colon cancer. Therefore, in these patients it is likely that this represents largely constitutional body composition as opposed to being a disease mediated effect. Adjustment for age is required when considering the cancer mediated effect on SMI/SMD in patients with colon cancer.

Implant-related and medical complications in patients with sarcopenia undergoing total shoulder arthroplasty: A retrospective matched-cohort analysis

Background

In the continually aging United States population, the number of patients with sarcopenia who undergo shoulder arthroplasty may concomitantly increase. This retrospective cohort study aims to evaluate the rates of short-term implant-related and medical complications following shoulder arthroplasty in patients with and without a recent diagnosis of sarcopenia.

Methods

An exact 1:3 matched analysis of 4177 patients was performed using the PearlDiver database. Multivariable logistic regression was used to compare complications, Kaplan-Meier failure analysis was used to compare the cumulative hospital readmission rates. Two-sample T-testing was used to compare the 90-day cost of care.

Results

Sarcopenic patients were significantly more likely to experience postoperative shoulder instability (odds ratio (OR) = 2.32, 95% confidence interval (CI), 1.21-4.39) and periprosthetic infection (OR = 3.83, 95% CI, 1.74-8.67) within 1 year of their arthroplasty. Sarcopenic patients were at 25% and 41% greater risk of emergency department presentation and hospital readmission 1-year post-arthroplasty, respectively. Ninty-day total costs were greater among sarcopenics ($16 112.23 vs. 10 679.58, p < 0.001).

Conclusion

These results are important for orthopaedic surgeons counselling patients with a low muscle mass on the potential for increased complications after undergoing a total shoulder arthroplasty procedure.

Associations between DEET, Organophosphorus Insecticides, and Handgrip Strength in Diabetes: An NHANES Analysis

INTRODUCTION

Sarcopenia and diabetes mellitus (DM) have been shown to be related. It has been demonstrated that pesticides/insecticides are linked to various health issues, including DM. This study investigated the relationships between exposure to pesticides/insecticides and muscle strength among community-dwelling DM patients in a national sample of the United States (US).

METHODS

Data from the 2011-2012 and 2013-2014 U.S. National Health and Nutrition Examination Survey (NHANES) on people aged 20 years with diabetes were retrieved. A digital dynamometer was used to quantify handgrip strength, and urine pesticide concentrations were determined through laboratory testing. Regression models were used to investigate the relationship between pesticide/insecticide exposure and handgrip strength.

RESULTS

After weighting, the data from 412 NHANES participants represented 6,696,865 U.S. inhabitants. The mean age of the participants was 58.8 years. High para-nitrophenol levels (tertile 3 vs. tertile 1) were shown to be associated with lower handgrip strength in both males (aBeta = -7.25, 95% CI: -11.25, -3.25) and females (aBeta = -3.73, 95% CI: -6.89, -0.56). Further, females with elevated 2-isopropyl-4-methyl-pyrimidinol had decreased handgrip strength. Desethyl hydroxy N, N-diethyl-m-toluamide (DEET) was inversely related to handgrip strength in men aged ≥60 years. DEET acid and para-nitrophenol were inversely correlated to handgrip strength in women over 60 years.

CONCLUSIONS

This study has linked certain pesticides/insecticides to decreased muscle strength in people with diabetes. Para-nitrophenol, in particular, is negatively related to muscular strength in both males and females, and 2-isopropyl-4-methyl-pyrimidinol is inversely related to muscle strength in females.

Role of Nutrition in the Management of Patients with Chronic Musculoskeletal Pain

Chronic musculoskeletal pain (CMP), defined as persistent discomfort in musculoskeletal tissues persisting for over 3 months, afflicts an estimated 1.71 billion people globally, leading to significant functional impairments and psychological distress, thereby detrimentally affecting individuals' quality of life. The objective of this narrative review is to elucidate the complex relationship among dietary habits, sarcopenia, and gut microbiota composition, with an eye toward enhancing patient management and outcomes. Given the burgeoning interest in the influence of diet on CMP, a detailed examination of the current literature is warranted. Nutritional intake is a critical determinant of the gut microbiota profile, which, in turn, is linked to musculature integrity and performance, potentially leading to sarcopenia. The development of sarcopenia can aggravate CMP owing to diminished muscular strength and functionality. Additionally, disruptions in the gut microbiota may directly modulate nociception, intensifying CMP manifestations. Thus, nutritional optimization emerges as a viable approach to CMP management. Emphasizing a diet conducive to a healthy gut microbiome could forestall or mitigate sarcopenia, thereby attenuating CMP intensity. Nevertheless, the domain calls for further empirical exploration to unravel the nuances of these interactions and to forge efficacious dietary strategies for individuals with CMP. Beyond mere analgesia, comprehensive patient care for CMP requires acknowledgment of the complex and multifactorial nature of pain and its foundational elements. Embracing an integrative treatment model allows healthcare practitioners to promise better patient prognoses, enriched life quality, and a decrease in the sustained healthcare costs associated with CMP.

Impact of sarcopenia on outcomes following lumbar spine surgery for degenerative disease: an updated systematic review and meta-analysis

PURPOSE

This study aimed to consolidate the evidence regarding the prognostic influence of sarcopenia in degenerative lumbar spine surgeries.

METHODS

A literature search of public databases was conducted up to Nov 15, 2023 using combinations of the key words "sarcopenia" and "lumbar spine surgery". Eligible studies were those that focused on adults undergoing decompression or fusion surgery for degenerative lumbar spine diseases, and compared the outcomes between patients with and without preoperative sarcopenia. Primary outcomes were change in ODI and back and leg pain VAS pain scores. Secondary outcomes were changes in Eq. 5D, JOA, SFHS-p scores, and LOS.

RESULTS

Ultimately, nine retrospective studies with a total of 993 patients were included. Sarcopenic patients exhibited significantly worse functional improvement as assessed by ODI compared to non-sarcopenic patients (pooled standardized mean difference [pSMD] = 0.53, 95% confidence interval [CI]: 0.17-0.90). Back pain (pSMD = 0.31, 95% CI:0.15-0.47) and leg pain (pSMD = 0.21, 95% CI:0.02 - 0.39) improvement were also less in sarcopenic patients. Non-sarcopenic patients had greater improvements in Eq. 5D (pSMD = 0.25) and SFHS-p (pSMD = 0.39), and shorter LOS (pSMD = 0.62).

CONCLUSIONS

As compared to patients without sarcopenia, those with sarcopenia undergoing lumbar spine surgery for degenerative diseases have lower improvements in functional ability, quality of life, physical health, pain relief and extended hospitalization compared to those without sarcopenia.

Lower psoas mass indicates worse prognosis in percutaneous vertebroplasty-treated osteoporotic vertebral compression fracture

The correlation between lower psoas mass and the prognosis of osteoporotic vertebral compression fractures (OVCF) is still unclear. This study aims to investigate the impact of lower psoas mass on the prognosis of patients undergoing percutaneous vertebroplasty (PVP). One hundred and sixty-three elderly patients who underwent single-segment PVP from January 2018 to December 2021 were included. The psoas to L4 vertebral index (PLVI) via MRI were measured to assess psoas mass. Patients were divided into high PLVI (> 0.79) and low PLVI (≤ 0.79) groups based on the median PLVI in the cohort. The basic information (age, gender, body mass index (BMI) and bone mineral density (BMD)), surgical intervention-related elements (duration of operation, latency to ambulation, period of hospital stay, and surgical site), postoperative clinical outcomes (Visual Analog Scale (VAS) scores, Oswestry Disability Index (ODI) scores, Japanese Orthopaedic Association (JOA) scores), and incidence of secondary fractures) were compared. Patients showed no statistically significant differences in terms of age, gender, surgical sute, BMI, BMD and preoperative VAS, ODI, JOA scores (P > 0.05) between the two groups. However, there were significant differences in terms of latency to ambulation, period of hospital stay (P < 0.05). VAS, ODI, and JOA scores at 1, 6, and 12 months after surgery showed that the high PLVI group had significantly better outcomes than the low PLVI group (P < 0.05). Additionally, the low PLVI group had a significantly higher incidence of recurrent fracture (P < 0.05). Lower psoas mass can reduce the clinical effect of PVP in patients with osteoporotic vertebral compression fractures, and is a risk factor for recurrent vertebral fracture.

Relationship between serum uric acid and sarcopenia in geriatric heart failure patients with preserved ejection fraction

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) presents a serious risk to human health. The increased prevalence of sarcopenia in the HFpEF population has a negative impact on patient prognosis. Uric acid (UA) is the byproduct of purine metabolism and is harmful to the cardiovascular system. This study aims to establish the potential relationship between sarcopenia and serum UA in HFpEF patients.

METHODS

Data were obtained from 180 individuals (aged ≥60 years) with HFpEF admitted to the Geriatric Department of Jiangsu Province Hospital between January 2021 and December 2022. The UA values were grouped into 4 quartiles (Q1-Q4). Logistic generalized linear models and restricted cubic spline (RCS) regression were used to analyze the relationship between sarcopenia and UA. Subgroups based on gender were utilised for further analysis.

RESULTS

After adjusting for covariates, odds ratios (ORs) and 95 % confidence intervals (CIs) for sarcopenia prevalence in the 2nd, 3rd, and 4th quartiles were 2.56 (0.57-12.65), 4.94 (1.10-24.49), and 6.95 (1.30-44.25), respectively, unlike the 1st quartile (P for trend = 0.022). The RCS plot demonstrated a positive linear relationship between serum UA levels and sarcopenia (P for non-linearity = 0.190). A sex-based subgroup analysis revealed a statistically significant relationship between UA and sarcopenia in males (P < 0.05).

CONCLUSIONS

In summary, the prevalence of sarcopenia is positively related to serum UA levels among the elderly diagnosed with HFpEF. Due to the cross-sectional nature of the study design, additional investigations are necessary to validate our findings and identify the optimal range for UA reduction.

Bidirectional Association between Sarcopenia and Depressive Symptoms among Chinese Middle- and Older-Aged Adults: Longitudinal Observational Study

BACKGROUND

The study aimed to examine the bidirectional relationship between sarcopenia and depressive symptoms in a national, community-based cohort study, despite the unclear temporal sequence demonstrated previously.

METHODS

Data were derived from four waves (2011 baseline and 2013, 2015, and 2018 follow-ups) of the China Health and Retirement Longitudinal Study (CHARLS). A total of 17,708 participants aged 45 years or older who had baseline data on both sarcopenia status and depressive symptoms in 2011 were included in the study. For the two cohort analyses, a total of 8092 adults without depressive symptoms and 11,292 participants without sarcopenia in 2011 were included. Sarcopenia status was defined according to the Asian Working Group for Sarcopenia 2019 (AWGS 2019) criteria. Depressive symptoms were defined as a score of 20 or higher on the 10-item Center for Epidemiologic Studies Depressive Scale (CES-D-10). Cox proportional hazard regression models were conducted to examine the risk of depressive symptoms and sarcopenia risk, while cross-lagged panel models were used to examine the temporal sequence between depressive symptoms and sarcopenia over time.

RESULTS

During a total of 48,305.1 person-years follow-up, 1262 cases of incident depressive symptoms were identified. Sarcopenia exhibited a dose-response relationship with a higher risk of depressive symptoms (HR = 1.7, 95%CI: 1.2-2.3 for sarcopenia, and HR = 1.5, 95%CI: 1.2-1.8 for possible sarcopenia, p trend < 0.001). In the second cohort analysis, 240 incident sarcopenia cases were identified over 39,621.1 person-years. Depressive symptoms (HR = 1.5, 95%CI: 1.2-2.0) are significantly associated with a higher risk of developing sarcopenia after multivariable adjustment (p < 0.001, Cross-lagged panel analyses demonstrated that depressive symptoms were associated with subsequent sarcopenia (β = 0.003, p < 0.001). Simultaneously, baseline sarcopenia was also associated with subsequent depressive symptoms (β = 0.428, p < 0.001).

CONCLUSION

This study identified a bidirectional relationship between depressive symptoms and sarcopenia. It seems more probable that baseline sarcopenia is associated with subsequent depressive symptoms in a stronger pattern than the reverse pathway. The interlinkage indicated that maintaining normal muscle mass and strength may serve as a crucial intervention strategy for alleviating mood disorders.

Mild cognitive impairment predicts the onset of Sarcopenia: a longitudinal analysis from the English Longitudinal Study on Ageing

BACKGROUND

Mild cognitive impairment (MCI) and sarcopenia are two common conditions in older people. It is not widely known if MCI could predict the onset of sarcopenia. Therefore, we aimed to investigate whether MCI could predict the occurrence of sarcopenia in a population of older adults.

METHODS

In the ELSA (English Longitudinal Study on Ageing), MCI was defined as the absence of dementia, preserved functional capacity and low performance in three objective cognitive tests. Sarcopenia was diagnosed as having low handgrip strength and low skeletal muscle mass index during follow-up. The longitudinal association between MCI at the baseline and incident sarcopenia was assessed using a multivariable logistic regression model, reporting the data as adjusted odds ratios (OR) and 95% confidence intervals (95%CI).

RESULTS

3,106 participants (mean age of 63.1 years; 55.3% males) were included. People with MCI reported significantly lower mean handgrip strength values and Skeletal Mass Index (SMI), as well as a higher prevalence of obesity at baseline. At baseline, 729 people had MCI and during the ten years follow-up period, 12.1% of the initial population included had sarcopenia. On multivariate analysis, adjusted for 18 potential confounders, the presence of MCI (OR = 1.236; 95%CI: 1.090-1.596, p = 0.01) significantly predicted the onset of sarcopenia during follow-up.

CONCLUSION

The presence of MCI at baseline was associated with a higher incidence of sarcopenia at ten-years follow-up, demonstrating a likely role of MCI as a predictor of the onset of sarcopenia in older people.

Vertebral HU value and the pectoral muscle index based on chest CT can be used to opportunistically screen for osteoporosis

BACKGROUND

Existing studies have shown that computed tomography (CT) attenuation and skeletal muscle tissue are strongly associated with osteoporosis; however, few studies have examined whether vertebral HU values and the pectoral muscle index (PMI) measured at the level of the 4th thoracic vertebra (T4) are strongly associated with bone mineral density (BMD). In this study, we demonstrate that vertebral HU values and the PMI based on chest CT can be used to opportunistically screen for osteoporosis and reduce fracture risk through prompt treatment.

METHODS

We retrospectively evaluated 1000 patients who underwent chest CT and DXA scans from August 2020-2022. The T4 HU value and PMI were obtained using manual chest CT measurements. The participants were classified into normal, osteopenia, and osteoporosis groups based on the results of dual-energy X-ray (DXA) absorptiometry. We compared the clinical baseline data, T4 HU value, and PMI between the three groups of patients and analyzed the correlation between the T4 HU value, PMI, and BMD to further evaluate the diagnostic efficacy of the T4 HU value and PMI for patients with low BMD and osteoporosis.

RESULTS

The study ultimately enrolled 469 participants. The T4 HU value and PMI had a high screening capacity for both low BMD and osteoporosis. The combined diagnostic model-incorporating sex, age, BMI, T4 HU value, and PMI-demonstrated the best diagnostic efficacy, with areas under the receiver operating characteristic curve (AUC) of 0.887 and 0.892 for identifying low BMD and osteoporosis, respectively.

CONCLUSIONS

The measurement of T4 HU value and PMI on chest CT can be used as an opportunistic screening tool for osteoporosis with excellent diagnostic efficacy. This approach allows the early prevention of osteoporotic fractures via the timely screening of individuals at high risk of osteoporosis without requiring additional radiation.

Review: myogenic and muscle toxicity targets of environmental methylmercury exposure

A number of environmental toxicants are noted for their activity that leads to declined motor function. However, the role of muscle as a proximal toxicity target organ for environmental agents has received considerably less attention than the toxicity targets in the nervous system. Nonetheless, the effects of conventional neurotoxicants on processes of myogenesis and muscle maintenance are beginning to resolve a concerted role of muscle as a susceptible toxicity target. A large body of evidence from epidemiological, animal, and in vitro studies has established that methylmercury (MeHg) is a potent developmental toxicant, with the nervous system being a preferred target. Despite its well-recognized status as a neurotoxicant, there is accumulating evidence that MeHg also targets muscle and neuromuscular development as well as contributes to the etiology of motor defects with prenatal MeHg exposure. Here, we summarize evidence for targets of MeHg in the morphogenesis and maintenance of skeletal muscle that reveal effects on MeHg distribution, myogenesis, myotube formation, myotendinous junction formation, neuromuscular junction formation, and satellite cell-mediated muscle repair. We briefly recapitulate the molecular and cellular mechanisms of skeletal muscle development and highlight the pragmatic role of alternative model organisms, Drosophila and zebrafish, in delineating the molecular underpinnings of muscle development and MeHg-mediated myotoxicity. Finally, we discuss how toxicity targets in muscle development may inform the developmental origins of health and disease theory to explain the etiology of environmentally induced adult motor deficits and accelerated decline in muscle fitness with aging.

Orofacial and cervical myofunctional intervention programmes for older adults: A scoping review

INTRODUCTION

Senescent stomatognathic systems undergo anatomical changes that are not always compensated by physiology due to associated factors such as poorly fitted dentures, dental changes, and clinical conditions that trigger sarcopenia. When these conditions are not properly addressed, they can lead to nutritional deficiencies. Hence, this study aimed to map orofacial and cervical myofunctional intervention programmes for older adults, evaluate the current research in this area, and formulate suggestions for further investigation.

METHODS

Scoping review is based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews checklist. The EMBASE, LILACS, PubMed/Medline, Scopus, Web of Science, and grey literature databases were systematically searched. Studies addressing therapeutic programmes, myofunctional exercises, and their influence on the stomatognathic system of older adults were included. Studies with populations younger than 60 years, residing in long-term care facilities, homes, or hospital care, and with associated comorbidities were excluded, as well as secondary studies.

RESULTS

A total of 3098 studies were retrieved. After applying the eligibility criteria, nine studies were eligible for this review. The nine studies were published in English between 2008 and 2021 in the United States, Japan, and South Korea. The participants' mean ages ranged from 64 to 81 years, with a preponderance of females. Six of the studies divided the sample into intervention and control groups. Two studies referred to programmes to promote oral function through facial expression and tongue muscle exercises, salivary gland massage, and swallowing biomechanics. Seven studies report the positive influence of myofunctional exercises on the stomatognathic system.

CONCLUSION

The mapping concluded that therapeutic programmes, including educational actions, help prevent orofacial myofunctional disorders, and improve the functionality of the stomatognathic system.

Association between sleep traits and sarcopenia-related traits: A two-sample bidirectional Mendelian randomization study

AIM

Despite limited evidence regarding the impact of sleep quality on sarcopenia, it is widely recognized as being associated with various diseases. This study aimed to explore the causal relationship between sleep traits and sarcopenia-related traits.

METHODS

This study utilized a two-sample bidirectional Mendelian randomization analysis. Genetic genome-wide summary data of sleep quality indicators, including chronotype, morning wake-up time, sleep duration, daytime napping, insomnia and daytime dozing, were used. Data on sarcopenia-related traits, such as appendicular lean mass, grip strength of both hands, walking pace and waist circumference, were collected from a large cohort study. The primary method used was the inverse-variance weighted analysis.

RESULTS

A causal association was found between chronotype and appendicular lean mass (odds ratio [OR] 1.019, 95% confidence interval [CI] 1.016-1.211, P = 0.021). Napping during the day was connected with walking pace (OR 0.879, 95% CI 0.834-0.928, P = 2.289 × 10-6) and waist circumference (OR 1.234, 95% CI 1.081-1.408, P = 0.002). Insomnia was related to lower grip strength of the right hand (OR 0.844, 95% CI 0.747-0.954, P = 0.007), left hand (OR 0.836, 95% CI 0.742-0.943, P = 0.003), as well as walking pace (OR 0.871, 95% CI 0.798-0.951, P = 0.002). Furthermore, the reverse Mendelian randomization analysis showed associations between certain sarcopenia-related traits and poor sleep quality.

CONCLUSIONS

Some sleep traits were associated with the occurrence of sarcopenia. These findings emphasized the significance of prioritizing sleep quality as a preventive measure against sarcopenia. Geriatr Gerontol Int 2024; 24: 537-545.

Telomere Length is Associated with the Prevalence, Persistence, and Incidence of Sarcopenia

BACKGROUND

Telomere length (TL) shortening has been identified as a marker of aging and associated with adverse health outcomes, but evidence of its association with sarcopenia is inconclusive.

AIMS

Estimate the cross-sectional and prospective associations between TL and sarcopenia.

METHODS

We used data from Waves 3 and 4 (2017, 2021) of the Study on Global Aging and Adult Health in Mexico (SAGE-Mexico). The cross-sectional sample consisted of 1,738 adults aged 50 and older, and the longitudinal sample consisted of 1,437. Relative TL was determined by real-time quantitative polymerase chain reaction (qPCR) on DNA extracted from saliva samples and quantified as the telomere/single-copy gene (T/S) ratio. Sarcopenia was defined according to the European Working Group on Sarcopenia in Older People (EWGSOP2).

RESULTS

The mean salivary TL was 1.50 T/S units (95% CI: 1.49-1.52). The baseline prevalence of sarcopenia was 13.3% (95% CI: 9.8-16.8%). The incidence and persistence of sarcopenia were 6.8% (95% CI: 5.0-9.5%) and 7.0% (95% CI: 5.1-9.6%), respectively. The results showed that a one standard deviation decrease in TL was cross-sectionally associated with higher odds of sarcopenia (OR = 1.31; 95% CI: 1.03-1.67) and prospectively with a higher incidence (RRR = 1.55; 95% CI: 1.06-2.25) and persistence (RRR = 1.50; 95% CI: 1.01-2.24) of sarcopenia.

CONCLUSIONS

Older adults with shorter TL had higher rates of incident and persistent sarcopenia. Implementation of interventions to delay the decline of TL in older adults is warranted. Further translational studies are needed to elucidate the effects of exercise or diet on DNA repair in the telomeric region and their associations with sarcopenia.

Myeloma extracellular vesicle-derived RAGE increases inflammatory responses and myotube atrophy in multiple myeloma through activation of the TLR4/NF-κB p65 pathway

Sarcopenia manifests as muscle atrophy and loss that is complicated with malignancy. This study explored the mechanism of extracellular vesicles (EVs) in multiple myeloma (MM) with sarcopenia. SP2/0 conditioned medium (CM) was collected to isolate SP2/0-EVs. C2C12 cells were incubated with SP2/0 CM or SP2/0-EVs. ROS, TNF-α, IL-6, MuRF1 and MyHC levels were detected by DCF-DA fluorescent probe, ELISA, and Western blot. GW4869 was used to inhibit EV secretion in SP2/0 to confirm its effect on muscle atrophy. Serum was collected from MM patients with or without sarcopenia to detect RAGE mRNA expression. SP2/0 cells were transfected with RAGE siRNA and C2C12 cells were treated with the isolated si-RAGE-EVs or/and TLR4 agonist. SP2/0 tumor-bearing mouse model was established. Healthy mice and SP2/0-tumor bearing mice were treated with SP2/0-EVs or si-RAGE-EVs. SP2/0 CM or SP2/0-EVs stimulated ROS, inflammatory responses, and myotube atrophy in C2C12 cells. GW4869 blocked EV secretion and the effects of SP2/0 CM. RAGE mRNA expression in serum EVs was increased in MM&Sarcopenia patients and RAGE knockdown in SP2/0-EVs partially nullified SP2/0-EVs' effects. SP2/0-EVs activated the TLR4/NF-κB p65 pathway by translocating RAGE. SP2/0-EVs-derived RAGE elevated ROS production, inflammation, and myotube atrophy in C2C12 cells and caused muscle loss in SP2/0 tumor-bearing mice by activating the TLR4/NF-κB p65 pathway. SP2/0-EVs partially recapitulated muscle loss in healthy mice. SP2/0-EVs-derived RAGE increased ROS production, inflammation, and myotube atrophy in MM through TLR4/NF-κB p65 pathway activation.

Start with muscle mass or muscle strength in diagnosis and management of sarcopenia? A systematic review of guidance documents

BACKGROUND AND OBJECTIVES

Sarcopenia has garnered extensive attention in clinical practice since its high prevalence and significant impact on clinical outcomes. Multiple organizations have published guidance documents on sarcopenia, offering evidence-based recommendations for clinical practice and/or research. We aimed to appraise the methodological quality of the included documents and synthesize available recommendations for the screening, diagnosis, and intervention of sarcopenia.

METHODS AND STUDY DESIGN

We conducted a search on PubMed, Embase, Scopus, Cochrane Library, China National Knowledge Infrastructure, guideline database, and guideline organizations and professional societies websites for clinical practices, consensus statements and position papers in terms of sarcopenia, muscle atrophy or muscle loss published before April 17, 2023. The AGREE II instrument was used by three independent reviewers to assess the methodological quality of these documents.

RESULTS

Thirty-six guidance documents published between 2010 and 2023 were included. Seven documents fulfilled ≥ 50% of all the AGREE II domains. Seven underwent a Delphi process and six graded the strength of the recommendations. The process of screening (n=21), early diagnosis of sarcopenia (n=12), diagnosis of sarcopenia and severe sarcopenia (n=10), and management (n=21) were increasingly recommended. SARC-F (n=14) was the most recommended screening tool, and the assessment of muscle function was considered the first step in diagnosing sarcopenia. The management strategy for both age-related and disease-related sarcopenia mainly focused on exercise and nutrition intervention.

CONCLUSIONS

The guidance documents have provided referential recommendations that have great guiding significance. But the inconsistency in recommendations and variation in methodological rigour suggests that high-quality evidence is lacking yet.

Frontiers in sarcopenia: Advancements in diagnostics, molecular mechanisms, and therapeutic strategies

The onset of sarcopenia is intimately linked with aging, posing significant implications not only for individual patient quality of life but also for the broader societal healthcare framework. Early and accurate identification of sarcopenia and a comprehensive understanding of its mechanistic underpinnings and therapeutic targets paramount to addressing this condition effectively. This review endeavors to present a cohesive overview of recent advancements in sarcopenia research and diagnosis. We initially delve into the contemporary diagnostic criteria, specifically referencing the European Working Group on Sarcopenia in Older People (EWGSOP) 2 and Asian Working Group on Sarcopenia (AWGS) 2019 benchmarks. Additionally, we elucidate comprehensive assessment techniques for muscle strength, quantity, and physical performance, highlighting tools such as grip strength, chair stand test, dual-energy X-ray Absorptiometry (DEXA), bioelectrical impedance analysis (BIA), gait speed, and short physical performance battery (SPPB), while also discussing their inherent advantages and limitations. Such diagnostic advancements pave the way for early identification and unequivocal diagnosis of sarcopenia. Proceeding further, we provide a deep-dive into sarcopenia's pathogenesis, offering a thorough examination of associated signaling pathways like the Myostatin, AMP-activated protein kinase (AMPK), insulin/IGF-1 Signaling (IIS), and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways. Each pathway's role in sarcopenia mediation is detailed, underscoring potential therapeutic target avenues. From a mechanistic perspective, the review also underscores the pivotal role of mitochondrial dysfunction in sarcopenia, emphasizing elements such as mitochondrial oxidative overload, mitochondrial biogenesis, and mitophagy, and highlighting their therapeutic significance. At last, we capture recent strides made in sarcopenia treatment, ranging from nutritional and exercise interventions to potential pharmacological and supplementation strategies. In sum, this review meticulously synthesizes the latest scientific developments in sarcopenia, aiming to enhance diagnostic precision in clinical practice and provide comprehensive insights into refined mechanistic targets and innovative therapeutic interventions, ultimately contributing to optimized patient care and advancements in the field.

Association between the systemic immune-inflammation index and sarcopenia: a systematic review and meta-analysis

BACKGROUND

Sarcopenia is associated with increased morbidity and mortality. The systemic immune-inflammation index (SII) has been correlated to a variety of disorders. The present study conducted a systematic review and meta-analysis to investigate the relationship between SII and sarcopenia.

METHODS

A literature search was performed in Web of Science, PubMed, Embase, Cochrane Library, CINAHL, China National Knowledge Infrastructure, Chinese Biomedical Literature Database, Wanfang Database, and VIP Chinese Science and Technology Database, from inception to March 2024. Then, the literature quality was assessed. After the heterogeneity test, a random effects or fixed effects model was applied to establish the forest plot, and investigate the relationship between SII and sarcopenia. Then, the sensitivity analysis and publication bias were examined.

RESULTS

Nine articles, which included 18,634 adults, were analyzed. Sarcopenic adults had higher SII levels, when compared to non-sarcopenic adults (standardized mean difference [SMD] = 0.66, 95% confidence interval [CI] = 0.22 - 0.19, p = 0.003). The high SII level was associated to the increased risk of sarcopenia (odds ratio = 1.52, 95% CI = 1.09-2.13, p = 0.01). In addition, the subgroup analysis revealed that the SII levels were higher in the sarcopenic group, when compared to the non-sarcopenic group, in elderly adults, as well as in adults with or without gastrointestinal disorders. The analysis was robust with a low risk of publication bias.

CONCLUSIONS

SII is closely associated to sarcopenia. Sarcopenic adults had elevated SII levels. The high SII level increased the risk of sarcopenia. Large scale multi-center prospective studies are required to validate these study findings.

The Mini Nutritional Assessment combined with body fat for detecting the risk of sarcopenia and sarcopenic obesity in metabolic syndrome

Malnutrition is a key factor in metabolic syndrome (MS) and sarcopenia, assessing the nutritional status of these patients is a pressing issue. The purpose of this study was to clarify sarcopenia and sarcopenic obesity in patients with MS based on nutritional status. This was a case-control study between MS/non-MS. Body composition was measured by dual-energy X-ray absorptiometry. Muscle function was assessed by handgrip strength, five times sit-to-stand test, gait speed test and short physical performance battery (SPPB). The Mini Nutritional Assessment (MNA) was performed to assess the nutritional status in the participants in this study. Overall, a total of 56 % and 13 % of participants suffered from possible sarcopenia and sarcopenia, respectively. There was a higher rate of possible sarcopenic obesity in the MS group than in the non-MS group (48·9 % v. 24·7 %, P < 0·01), and all the sarcopenia participants in the MS group had sarcopenic obesity. MNA score was significantly associated with sarcopenia status (P < 0·01). The MNA combined with body fat score showed better acceptable discrimination for detecting sarcopenic obesity and sarcopenia in MS (AUC = 0·70, 95 % CI 0·53, 0·86). In summary, there was a higher prevalence of possible sarcopenic obesity in MS, and all the MS patients with sarcopenia had sarcopenic obesity in the present study. We suggest that the MNA should be combined with body fat percentage to assess the nutritional status of MS participants, and it also serves as a good indicator for sarcopenia and sarcopenic obesity in MS.

Associations of CBC-Derived inflammatory indicators with sarcopenia and mortality in adults: evidence from Nhanes 1999 ∼ 2006

BACKGROUND

It has been proposed that inflammation plays a role in the development of sarcopenia. This study aimed to investigate the links of complete blood cell count (CBC) parameters and CBC-derived inflammatory indicators with sarcopenia and mortality.

METHODS

Data pertaining to sarcopenia were extracted from the 1999-2006 National Health and Nutrition Examination Survey (NHANES), and mortality events were ascertained through the National Death Index up to December 31, 2019. The CBC-derived inflammatory indicators assessed in this study included the neutrophil-to-lymphocyte ratio (NLR), derived neutrophil-to-lymphocyte ratio (dNLR), monocyte-to-lymphocyte ratio (MLR), neutrophil-monocyte to lymphocyte ratio (NMLR), systemic inflammatory response index (SIRI), and systemic immune-inflammation index (SII). The prognostic significance of these CBC-derived inflammatory indicators was evaluated using the random survival forests (RSF) analysis.

RESULTS

The study encompassed a cohort of 12,689 individuals, among whom 1,725 were diagnosed with sarcopenia. Among individuals with sarcopenia, 782 experienced all-cause mortality, and 195 succumbed to cardiovascular causes. Following adjustment for confounding variables, it was observed that elevated levels of NLR, dNLR, NMLR, SIRI, and SII were associated with an increased prevalence of sarcopenia. Among participants with sarcopenia, those in the highest quartile of NLR (HR = 1.336 [1.095-1.631]), dNLR (HR = 1.274 [1.046-1.550]), MLR (HR = 1.619 [1.290-2.032]), NMLR (HR = 1.390 [1.132-1.707]), and SIRI (HR = 1.501 [1.210-1.862]) exhibited an elevated risk of all-cause mortality compared to those in the lowest quartile of these inflammation-derived indicators. These associations were similarly observed in cardiovascular mortality (HR = 1.874 [1.169-3.003] for MLR, HR = 1.838 [1.175-2.878] for SIRI). The RSF analysis indicated that MLR exhibited the highest predictive power for both all-cause and cardiovascular mortality among individuals with sarcopenia.

CONCLUSIONS

Our findings underscore the association between CBC-derived inflammatory indicators and mortality in adults with sarcopenia. Of note, MLR emerged as the most robust predictor of all-cause and cardiovascular mortality in this population.

Development and validation of a predictive model for the risk of sarcopenia in the older adults in China

BACKGROUND

Sarcopenia is a progressive age-related disease that can cause a range of adverse health outcomes in older adults, and older adults with severe sarcopenia are also at increased short-term mortality risk. The aim of this study was to construct and validate a risk prediction model for sarcopenia in Chinese older adults.

METHODS

This study used data from the 2015 China Health and Retirement Longitudinal Study (CHARLS), a high-quality micro-level data representative of households and individuals aged 45 years and older adults in China. The study analyzed 65 indicators, including sociodemographic indicators, health-related indicators, and biochemical indicators.

RESULTS

3454 older adults enrolled in the CHARLS database in 2015 were included in the final analysis. A total of 997 (28.8%) had phenotypes of sarcopenia. Multivariate logistic regression analysis showed that sex, Body Mass Index (BMI), Mean Systolic Blood Pressure (MSBP), Mean Diastolic Blood Pressure (MDBP) and pain were predictive factors for sarcopenia in older adults. These factors were used to construct a nomogram model, which showed good consistency and accuracy. The AUC value of the prediction model in the training set was 0.77 (95% CI = 0.75-0.79); the AUC value in the validation set was 0.76 (95% CI = 0.73-0.79). Hosmer-Lemeshow test values were P = 0.5041 and P = 0.2668 (both P > 0.05). Calibration curves showed significant agreement between the nomogram model and actual observations. ROC and DCA showed that the nomograms had good predictive properties.

CONCLUSIONS

The constructed sarcopenia risk prediction model, incorporating factors such as sex, BMI, MSBP, MDBP, and pain, demonstrates promising predictive capabilities. This model offers valuable insights for clinical practitioners, aiding in early screening and targeted interventions for sarcopenia in Chinese older adults.

Serum iron level is independently associated with sarcopenia: a retrospective study

Sarcopenia greatly reduces the quality of life of the elderly, and iron metabolism plays an important role in muscle loss. This study aimed to investigate the association between iron status and sarcopenia. A total of 286 adult patients hospitalized between 2019 and 2021 were included in this study, of which 117 were diagnosed with sarcopenia. Serum iron, total iron binding capacity (TIBC), transferrin, and transferrin saturation levels were compared between groups with and without sarcopenia and were included in the logistic analyses, with significant variables further included in the logistic regression model for the prediction of sarcopenia. Serum iron, TIBC, and transferrin levels decreased significantly in the sarcopenia group (p < 0.05), and were negatively associated with handgrip strength, relative skeletal muscle index, and multiple test performances (p < 0.05). Multivariate logistic analysis showed that sex, age, body mass index (BMI), and serum iron level were independent risk factors for sarcopenia. In the final logistic regression model, male sex (odds ratio [OR] 3.65, 95% confidence interval [CI] 1.67-7.98), age > 65 years (OR 5.40, 95% CI 2.25-12.95), BMI < 24 kg/m2 (OR 0.17, 95% CI 0.08-0.36), and serum iron < 10.95 μmol/L (OR 0.39, 95% CI 0.16-0.93) were included. Our study supported the impact of iron metabolism on muscle strength and performance.

Investigating the effects of synbiotic supplementation on functional movement, strength and muscle health in older Australians: a study protocol for a double-blind, randomized, placebo-controlled trial

BACKGROUND

Aging has been associated with a progressive loss of skeletal muscle quality, quantity and strength, which may result in a condition known as sarcopenia, leading to a decline in physical performance, loss of independence and reduced quality of life. While the cause of impaired physical functioning observed in elderly populations appears to be multifactorial, recent evidence suggests that age-associated alterations in gut microbiota could be a contributing factor. The primary objective will be to assess the effects of a dietary synbiotic formulation on sarcopenia-related functional outcomes such as handgrip strength, gait speed and physical performance within older individuals living independently. The secondary objective will be to examine associations between changes in gut microbiota composition, functional performance and lean muscle mass.

METHODS

Seventy-four elderly (60-85 years) participants will be randomized in a double-blind, placebo-controlled fashion to either an intervention or control group. The intervention group (n = 37) will receive oral synbiotic formulation daily for 16 weeks. The control group (n = 37) will receive placebo. Assessments of physical performance (including Short Physical Performance Battery, handgrip strength and timed up-and-go tests) and muscle ultrasonography will be performed at 4 time points (baseline and weeks 8, 16 and 20). Likewise, body composition via bioelectric impedance analysis and blood and stool samples will be collected at each time point. Dual-energy X-ray absorptiometry will be performed at baseline and week 16. The primary outcomes will be between-group changes in physical performance from baseline to 16 weeks. Secondary outcomes include changes in body composition, muscle mass and architecture, fecal microbiota composition and diversity, and fecal and plasma metabolomics.

DISCUSSION

Gut-modulating supplements appear to be effective in modifying gut microbiota composition in healthy older adults. However, it is unclear whether these changes translate into functional and/or health improvements. In the present study, we will investigate the effects of a synbiotic formulation on measures of physical performance, strength and muscle health in healthy older populations.

TRIAL REGISTRATION

This study was prospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN12622000652774) in May 2022.

Sarcopenia definitions and their association with fracture risk in older Swedish women

The purpose of this study was to investigate the prevalence of three sarcopenia definitions and their associations with fracture risk in older Swedish women when adjusted for fracture risk assessment (FRAX)-based risk factors; 2,883 women with a mean age of 77.8 years were included. Sarcopenia was defined based on the Sarcopenia Definitions and Outcomes Consortium (SDOC; low handgrip strength [kg] and gait speed (m/s)), revised European Working Group on Sarcopenia in Older People (EWGSOP2; low appendicular lean mass index, appendicular lean mass [ALM]/height; kg/m2], and hand grip strength [kg]), and Asian Working Group for Sarcopenia (AWGS; low ALM (kg), and hand grip strength [kg]) definitions. Femoral neck T-score was obtained from dual-energy X-ray absorptiometry. All fractures, confirmed by X-ray or medical record review, were subsequently categorized as major osteoporotic fractures (MOFs) and hip fractures. Deaths were verified through regional registers. The total follow-up time was 6.4 ± 1.3 (mean ± SD) yr. Cox regression (hazard ratios [HR] and 95% CIs) analyses were performed with adjustment for age, FRAX variables, and femoral neck T-score. Sarcopenia prevalence was 4.5% (n = 129) according to SDOC, 12.5% (n = 360) for EWGSOP2, and 10.3% (n = 296) defined by AWGS. Individuals with sarcopenia defined by SDOC had a higher mortality risk than individuals without sarcopenia (HR: 3.41; 95% CI: 2.51, 4.62) after adjusting for age and FRAX variables. Sarcopenia according to EWGSOP2 and AWGS was not associated with an increased fracture risk after adjusting for age and FRAX variables. Individuals with sarcopenia defined by SDOC had a higher risk for any fractures (HR: 1.48; 95% CI: 1.10, 1.99) and MOF (HR: 1.42; 95% CI: 1.03, 1.98) compared with individuals without sarcopenia after adjusting for clinical risk factors used in FRAX. In conclusion, sarcopenia defined by SDOC, incorporating muscle function/strength, was the only sarcopenia definition associated with fracture risk in older women.

Lower heart rate variability is associated with loss of muscle mass and sarcopenia in community-dwelling older Chinese adults

BACKGROUND/PURPOSE

Autonomic nervous system (ANS) disorders may occur in skeletal muscle disease, but the link between them has not been fully established. Studying the relationship between them may yield insights into the mechanisms and treatment of disease. This study aimed to explore the association between heart rate variability (HRV), sarcopenia, and subscales of sarcopenia (muscle mass, muscle strength, and physical mobility).

METHODS

2514 community-dwelling older Chinese participants were included in this study. The Asian Working Group for Sarcopenia guidelines were used to define sarcopenia. HRV was measured by 90-s electrocardiogram RR interval data. All HRV parameters were transformed using natural logarithms. Multiple regression analysis and multivariate linear regression was performed using potential correlates.

RESULTS

The overall prevalence of sarcopenia was 15.1 % (18.5 % in males and 12.6 % in females). In the logistic regression analysis model, there was a significant association between log-transformed standard deviation of RR interval (lnSDNN) (OR = 0.736, p = 0.019), log-transformed coefficient of variation of RR intervals (lnCVRR) (OR = 0.751, p = 0.020), log-transformed low-frequency power (lnLF) (OR = 0.861, p = 0.008), log-transformed high-frequency power (lnHF) (OR = 0.864, p = 0.003) and sarcopenia in the general population after adjusting for age, sex, body mass index (BMI), daily activity levels, hypertension, heart disease and cardiac drugs. In addition, in multivariate linear regression, lnSDNN (β = 0.146, p = 0.001), lnCVRR (β = 0.120, p = 0.010), lnLF (β = 0.066, p = 0.002) and lnHF (β = 0.065, p < 0.001) remained significantly positively associated with muscle mass, but there were no significant differences in grip strength and walking speed.

CONCLUSION

Sarcopenia was independently associated with lower heart rate variability in a community-dwelling elderly Chinese population. In addition, muscle mass was positively associated with heart rate variability in the elderly.

Increased serum adipokines are associated with sarcopenia in non-obese women with rheumatoid arthritis

Large cohort studies have disclosed the association between obesity and rheumatoid arthritis (RA) risk. The sarcopenia prevalence in RA patients can be up to 31%. However, there is little information linking adipokines to sarcopenia in RA, so this study aimed to investigate whether adipokines were indeed involved in secondary sarcopenia in RA with a focus on non-obese females. Sixty-four female patients and 36 controls were included in this study. The serum adipokine levels (leptin and adiponectin) were determined by ELISA kits. The impacts of adipokines on muscle atrophy and potential autophagy were examined in mouse myoblasts, C2C12, upon treatment with recombinant leptin and adiponectin agonist (AdipoRan). Interestingly, serum adiponectin was significantly increased but the ratio of leptin/adiponectin was dramatically decreased in the RA patients with sarcopenia. After normalization by body mass, serum leptin was positively associated but adiponectin was negatively associated with muscle mass respectively, even after adjustment for fat mass. Treating C2C12 cells with leptin and AdipoRan inhibited proliferation of mature myotube respectively, as did treatment with the serum from RA patients. A combination of low leptin and high AdipoRan greatly decreased myogenin, but instead increased MAFbx and MuRF-1 as well as increased Beclin 1, Atg5, and LC3β. Taken together, our study reveals that secondary sarcopenia of RA females may be an imbalance of RA-related, but not obesity-related, increase in adipokine production; additionally, the reduced leptin/adiponectin ratio could be a better indicator in monitoring sarcopenia in non-obese RA females. Moreover, adipokine imbalance may promote muscle atrophy through inducing autophagy.

Recent Update on the Prevalence of Sarcopenia in Koreans: Findings from the Korea National Health and Nutrition Examination Survey

BACKGROUND

As recognized by the World Health Organization in 2016 with its inclusion in the International Classification of Diseases, Tenth Revision as M62.84, and by South Korea in 2021 as M62.5, the diagnostic guidelines for sarcopenia vary globally. Despite its prevalence in older populations, data on sarcopenia in Koreans aged 60 and above is scarce, highlighting the need for research on its prevalence in this demographic.

METHODS

Utilizing the 2022 Korea National Health and Nutrition Examination Survey dataset, sarcopenia was assessed among 1,946 individuals aged 60 or older according to the Asian Working Group for Sarcopenia 2019 criteria, incorporating grip strength and bioelectrical impedance analysis measurements. Statistical analyses were performed to differentiate categorical and continuous variables using logistic regression and Student's t-tests, respectively.

RESULTS

The prevalence of sarcopenia was found to increase with age, with the highest prevalence observed in the oldest age group (80 years and older). The overall prevalence of sarcopenia in our study population was 6.8%. Among men, the prevalence of sarcopenia was 5.5% in the 60 or older age group, 9.6% in the 70 or older age group, and 21.5% in the 80 or older age group. Among women, the prevalence of sarcopenia was 7.9%, 10.5%, and 25.9%, respectively.

CONCLUSIONS

This study highlights the significant burden of sarcopenia in elderly Koreans, particularly among the oldest individuals. These findings call for targeted interventions to manage and prevent sarcopenia, along with further research on its risk factors, consequences, and effective mitigation strategies.

Skeletal muscle index based on CT at the 12th thoracic spine level can predict osteoporosis and fracture risk: a propensity score-matched cohort study

Background

Multiple studies have shown that skeletal muscle index (SMI) measured on abdominal computed tomography (CT) is strongly associated with bone mineral density (BMD) and fracture risk as estimated by the fracture risk assessment tool (FRAX). Although some studies have reported that SMI at the level of the 12th thoracic vertebra (T12) measured on chest CT images can be used to diagnose sarcopenia, it is regrettable that no studies have investigated the relationship between SMI at T12 level and BMD or fracture risk. Therefore, we further investigated the relationship between SMI at T12 level and FRAX-estimated BMD and fracture risk in this study.

Methods

A total of 349 subjects were included in this study. After 1∶1 propensity score matching (PSM) on height, weight, hypertension, diabetes, hyperlipidemia, hyperuricemia, body mass index (BMI), age, and gender, 162 subjects were finally included. The SMI, BMD, and FRAX score of the 162 participants were obtained. The correlation between SMI and BMD, as well as SMI and FRAX, was assessed using Spearman rank correlation. Additionally, the effectiveness of each index in predicting osteoporosis was evaluated through the receiver operating characteristic (ROC) curve analysis.

Results

The BMD of the lumbar spine (L1-4) demonstrated a strong correlation with SMI (r = 0.416, p < 0.001), while the BMD of the femoral neck (FN) also exhibited a correlation with SMI (r = 0.307, p < 0.001). SMI was significantly correlated with FRAX, both without and with BMD at the FN, for major osteoporotic fractures (r = -0.416, p < 0.001, and r = -0.431, p < 0.001, respectively) and hip fractures (r = -0.357, p < 0.001, and r = -0.311, p < 0.001, respectively). Moreover, the SMI of the non-osteoporosis group was significantly higher than that of the osteoporosis group (p < 0.001). SMI effectively predicts osteoporosis, with an area under the curve of 0.834 (95% confidence interval 0.771-0.897, p < 0.001).

Conclusion

SMI based on CT images of the 12th thoracic vertebrae can effectively diagnose osteoporosis and predict fracture risk. Therefore, SMI can make secondary use of chest CT to screen people who are prone to osteoporosis and fracture, and carry out timely medical intervention.