Sarcopenia: Aging-Related Loss of Muscle Mass and Function

The relationship between body mass index changes and mortality in geriatric peritoneal dialysis patients: a case-control study

BACKGROUND

The prevalence of chronic kidney disease (CKD) is increasing, reflecting the rising incidence of chronic diseases. With the continuous growth of the global geriatric population, a significant portion of individuals with CKD consists of those aged over 65. Regardless of the chosen treatment method, protein-energy loss in patients undergoing renal replacement therapy (RRT) has been associated with elevated morbidity and mortality rates.

METHODS

This is a retrospective, single-center study of incident adult PD patients on peritoneal dialysis (PD) from 1998 to 2022. We aimed to compare the survival outcomes of geriatric patients on PD with changing BMI measurements.

RESULTS

In the geriatric patient group exhibiting a reduced BMI after dialysis initiation, BMI significantly and negatively influenced survival (p = 0.01). The negative effect of BMI on survival was independent of known risk factors such as diabetes mellitus, a history of cardiovascular disease, gender, residual renal function, and history of hemodialysis before peritoneal dialysis (HD before PD) (p = 0.04).

CONCLUSION

Although BMI is easy and extensively measured, it is not considered the perfect monitoring parameter for dialysis patients. However, regular follow-up of BMI, especially in geriatric cases, can be a guiding tool for estimating patients' prognoses.

Systematic Review of Sarcopenia Biomarkers in Hip Fracture Patients as a Potential Tool in Clinical Evaluation

Hip fractures are associated with high morbidity and mortality. Sarcopenia is a significant factor contributing to poor prognosis; however, the clinical diagnosis of sarcopenia remains difficult in surgical patients. This systematic review aims to identify the biomarkers of sarcopenia as diagnostic and predictive tools in patients admitted for hip fracture surgery. A systematic search was conducted in the MEDLINE, EMBASE, and Google Scholar databases according to the PRISMA guidelines. Biomarker study quality was assessed using the BIOCROSS score. A total of 7 studies met the inclusion criteria and 515 patients were included, of whom 402 (78%) were female and 113 (22%) were male. The mean age of the participants was 83.1 years (SD: 5.9). Skeletal muscle biopsies were used for biomarker assessment in 14% (1/7) of studies and venous blood samples were used in the remaining 86% (6/7). The highlighted sarcopenia biomarkers included the low expression of insulin-like growth factor (IGF-I) and tumor necrosis factor-α (TNF-α), along with high serum myostatin and low serum vitamin D levels. Overall, the BIOCROSS score was satisfactory, with all studies obtaining at least a score of 13/20. The orthopedic literature is limited; however, the highlighted biomarkers in this review could be used as adjuncts in the diagnosis of sarcopenia in surgical patients.

Bibliometric Analysis of Comprehensive Geriatric Assessment from 2004 to 2023

Background

The global aging population necessitates specialized tools for complex geriatric health issues. Comprehensive Geriatric Assessment (CGA) provides multidimensional evaluations of elderly, integrating inputs from various professionals to create individualized care plans. This study aims to visually assess the research trends and hotspots in the field of CGA, review mainstream perspectives in this field, and provide a foundation for future research and treatment.

Methods

Original and review articles related to comprehensive geriatric assessment, published from 2004 to December 2023, were extracted from the Web of Science database. Four different software tools-CiteSpace, VOSviewer, Bibliometrix R package, and the Online Analysis Platform of Bibliometrics-were utilized for this comprehensive analysis.

Results

According to our retrieval strategy, we found a total of 4,411 related literatures. There has been a substantial increase in the research on comprehensive geriatric assessment in the past 20 years. These publications have been cited 157,366 times, with a mean of 35.68 citations per publication. The largest number of publications were from the US, and Italy ranked second (14.98%). Keyword burst and concurrence showed that "randomized trial", "adjuvant chemotherapy" and "breast cancer" were the top 3 most frequently occurring keywords.

Conclusion

Our bibliometric analysis reveals significant growth in CGA research over the past two decades, with a shift from cancer-focused studies to chronic conditions like frailty and sarcopenia. These findings highlight evolving priorities in geriatric care and underscore the need for future research to integrate technological advancements, such as AI, to enhance the precision, scalability, and cost-effectiveness of CGA in diverse settings.

Association of sarcopenia, ambient air pollution and cognitive function in a community-dwelling middle-aged and elderly Korean population: a community-based cohort study

OBJECTIVES

To investigate the association of sarcopenia, exposure to medium-term to long-term ambient particulate matter 2.5 µm and 10 µm (PM2.5 and PM10) pollution and cognitive function in a community-dwelling cohort of middle-aged and older adults in South Korea.

DESIGN

A community-based prospective cohort study.

SETTING

In the Korean Genome and Epidemiology Study (KoGES).

PARTICIPANTS

The participants were drawn from the seventh follow-up visit conducted between 2015 and 2016 in the KoGES community-based Ansung cohort who had participated in an ageing substudy.

OUTCOME MEASURES

Cognitive function was evaluated by the Korean version of the Mini-Mental State Examination (K-MMSE) and decreased cognitive function was defined as a K-MMSE score of 23 or less.

RESULTS

Of the 2274 participants (mean age 70.1 years, 58.3% women and mean annual PM2.5 and PM10 levels of 30.7 and 52.2 μg/m3, respectively), 8.7% (n=197) were sarcopenic, 35.8% (n=814) were possible sarcopenic and 55.5% (n=1263) were non-sarcopenic. The predictors of sarcopenia included body mass index, cognitive function, age, marital status, hypertension and physical activity. Exposure to PM2.5 and PM10 for an average duration of 1 month to 3 years was not selected as a predictor of sarcopenia. Participants with sarcopenia were associated with lower cognitive scores (β=-1.51, p<0.0001) and decreased cognitive function compared with those without sarcopenia (OR 2.34, 95% CI 1.56 to 3.52). Exposure to medium-term and long-term PM2.5 or PM10 was not associated with sarcopenia. The effect modification of PM exposure on the association between sarcopenia and cognitive function was generally not detected.

CONCLUSIONS

In this community-based observational cohort study of KoGES participants aged 50 years and older, sarcopenia was associated with decreased cognitive function. However, medium-term to long-term exposure to PM2.5 or PM10 was not associated with sarcopenia and did not modify the relationship between sarcopenia and cognitive function.

Serial changes in patient-reported outcome measures and satisfaction rate during long-term follow-up after total knee arthroplasty: a systematic review and meta-analysis

PURPOSE

This study aimed to investigate the sequential changes in patient-reported outcome measures (PROMs) and the satisfaction rate during long-term follow-up after total knee arthroplasty (TKA).

METHODS

Studies published until December 2023 were searched in MEDLINE, EMBASE, SCOPUS and Cochrane Library. The inclusion criteria were TKA as the primary procedure, a final post-operative follow-up period of at least seven years and reporting of PROMs data. The exclusion criteria were studies not reporting serial data of the same patient cohort, studies without mid-term data, comparative studies and reviews, comments or practice guidelines. Heterogeneity was assessed with the I2 and tau2 statistics. The quality of each study was evaluated using the methodological index for non-randomized studies (MINORS) criteria. The follow-up periods were divided into short-term, mid-term and long-term. Data were synthesised by narrative reviews and random-effects meta-analysis using standardised mean difference.

RESULTS

Among the 13 studies included in the review, six were included in the meta-analysis. The overall PROMs were maintained until the mid-term (0.14; 95% CI [confidence interval], -0.05 to 0.34; I2 = 96%; tau2 = 0.10; P = 0.16), but declined in the long-term (-0.23; 95% CI -0.34 to -0.13; I2 = 88%; tau2 = 0.04; P < 0.0001). According to the subgroup analysis, pain improved from the short-term to mid-term (0.21; 95% CI 0.14 to 0.29; I2 = 0%; tau2 = 0). Subscales including function (-0.28; 95% CI -0.52 to -0.03; I2 = 94%; tau2 = 0.09) and objective measure (-0.23; 95% CI -0.31 to -0.15; I2 = 62%; tau2 = 0.01) declined from the mid-term to long-term. The patient satisfaction rate remained consistent throughout the study period.

CONCLUSIONS

The overall PROMs after TKA were maintained, with improvement observed in the pain subscale until the mid-term follow-up. However, in the long-term, overall PROMs, including function and objective measure, declined compared with those in the mid-term. Despite the decline in the physical aspects of PROMs over the long-term follow-up period, the patient satisfaction rate remained consistently high throughout the study period. Providing this information to patient pre-operatively may assist in establishing realistic expectations. Trial Registration This research was registered at PROSPERO (registration number: CRD42024578579).

Lower extremity muscle hypertrophy in response to resistance training in older adults: Systematic review, meta-analysis, and meta-regression of randomized controlled trials

OBJECTIVES

This study aimed to investigate the effects of resistance training (RT) on knee extensor muscle hypertrophy in adults 65 years and older.

METHODS

A systematic search was carried out in PubMed, Embase, and Scopus to review randomized controlled trials that assessed the effects of supervised RT on 1) muscle size, 2) fiber area, and 3) leg lean mass (LLM). Random-effects meta-analyses of standardized mean difference (SMD) and raw mean difference (RMD) for LLM were calculated. We performed a meta-regression to examine the interference of age, training volume, and duration on the results related to hypertrophy at muscle and fiber levels.

RESULTS

Thirty-two studies were included in the review, and 28 were meta-analyzed. The meta-analysis found a significant effect of RT on muscle size (SMD = 0.34; 95 % CI: 0.16-0.52; p < 0.001) and fiber area (SMD = 0.54; 95 % CI: 0.24-0.84; p < 0.001), but not on LLM (RMD = 0.22; 95 % CI: -0.22-0.66 p = 0.321). A subanalysis of studies that assessed quadriceps femoris size (excluding isolated quadriceps femoris muscles from the analysis) also revealed a significant effect of RT (95 % CI: 0.20-0.69; p < 0.001). Regression analysis indicated a significant influence of intervention duration on type II fiber area (p = 0.034), while no significant influence was detected for weekly sets or age for any outcome measure.

CONCLUSIONS

RT promotes muscle hypertrophy in older adults at both whole-muscle and fiber levels, with training duration potentially influencing the response. Measures of leg lean mass may not capture RT-induced adaptation.

Unacylated Ghrelin Protects Against Age-Related Loss of Muscle Mass and Contractile Dysfunction in Skeletal Muscle

Sarcopenia, the progressive loss of muscle mass and function, universally affects older adults and is closely associated with frailty and reduced quality of life. Despite the inevitable consequences of sarcopenia and its relevance to healthspan, no pharmacological therapies are currently available. Ghrelin is a gut-released hormone that increases appetite and body weight through acylation. Acylated ghrelin activates its receptor, growth hormone secretagogue receptor 1a (GHSR1a), in the brain by binding to it. Studies have demonstrated that acyl and unacylated ghrelin (UnAG) both have protective effects against acute pathological conditions independent of receptor activation. Here, we investigated the long-term effects of UnAG in age-associated muscle atrophy and contractile dysfunction in mice. Four-month-old and 18-month-old mice were subjected to either UnAG or control treatment for 10 months. UnAG did not affect food consumption or body weight. Gastrocnemius and quadriceps muscle weights were reduced by 20%-30% with age, which was partially protected against by UnAG. Specific force, force per cross-sectional area, measured in isolated extensor digitorum longus muscle was diminished by 30% in old mice; however, UnAG prevented the loss of specific force. UnAG also protected from decreases in mitochondrial respiration and increases in hydrogen peroxide generation of skeletal muscle of old mice. Results of bulk mRNA-seq analysis and our contractile function data show that UnAG reversed neuromuscular junction impairment that occurs with age. Collectively, our data revealed the direct role of UnAG in mitigating sarcopenia in mice, independent of food consumption or body weight, implicating UnAG treatment as a potential therapy against sarcopenia.

A framework of biomarkers for skeletal muscle aging: a consensus statement by the Aging Biomarker Consortium

The skeletal muscle is an important organ for movement and metabolism in human body, and its physiological aging underlies the occurrence of muscle atrophy and sarcopenia. China has the largest aging population in the world and is facing a grand challenge with how to prevent and treat skeletal muscle aging-related diseases. To address this difficult problem, the Aging Biomarker Consortium (ABC) of China has reached an expert consensus on biomarkers of skeletal muscle aging by synthesizing literatures and insights from scientists and clinicians. This consensus attempts to provide a comprehensive assessment of biomarkers associated with skeletal muscle aging, and proposes a systematic framework to classify them into three dimensions: functional, structural, and humoral. Within each dimension, the experts recommend clinically relevant biomarkers for skeletal muscle aging. This consensus aims to lay the foundation for future research on skeletal muscle aging, facilitating precise prediction, diagnosis, and treatment of skeletal muscle aging and sarcopenia. It is anticipated to make significant contributions to healthy aging of skeletal muscle in the elderly population in China and around the world as well.

Sarcopenia: recent advances for detection, progression, and metabolic alterations along with therapeutic targets

Sarcopenia, a disorder marked by muscle loss and dysfunction, is a global health concern, particularly in aging populations. Sarcopenia is intricately related to various health conditions, including obesity, dysphagia, and frailty, which underscores the complexity. Despite recent advances in metabolomics and other omics data for early detection and treatment, the precise characterization and diagnosis of sarcopenia remains challenging. In the present review we provide an overview of the complex metabolic mechanisms that underlie sarcopenia, with particular emphasis on protein, lipid, carbohydrate, and bone metabolism. The review highlights the importance of leucine and other amino acids in promoting muscle protein synthesis and clarifies the critical role played by amino acid metabolism in preserving muscular health. In addition, the review provides insights regarding lipid metabolism on sarcopenia, with an emphasis on the effects of inflammation and insulin resistance. The development of sarcopenia is largely influenced by insulin resistance, especially with regard to glucose metabolism. Overall, the review emphasizes the complex relationship between bone and muscle health by highlighting the interaction between sarcopenia and bone metabolism. Furthermore, the review outlines various therapeutic approaches and potential biomarkers for diagnosing sarcopenia. These include pharmacological strategies such as hormone replacement therapy and anabolic steroids as well as lifestyle modifications such as exercise, nutrition, and dietary changes.

Role of AMBRA1 in mitophagy regulation: emerging evidence in aging-related diseases

Aging is a gradual and irreversible physiological process that significantly increases the risks of developing a variety of pathologies, including neurodegenerative, cardiovascular, metabolic, musculoskeletal, and immune system diseases. Mitochondria are the energy-producing organelles, and their proper functioning is crucial for overall cellular health. Over time, mitochondrial function declines causing an increased release of harmful reactive oxygen species (ROS) and DNA, which leads to oxidative stress, inflammation and cellular damage, common features associated with various age-related pathologies. The impairment of mitophagy, the selective removal of damaged or dysfunctional mitochondria by autophagy, is relevant to the development and progression of age-related diseases. The molecular mechanisms that regulates mitophagy levels in aging remain largely uncharacterized. AMBRA1 is an intrinsically disordered scaffold protein with a unique property of regulating the activity of both proliferation and autophagy core machineries. While the role of AMBRA1 during embryonic development and neoplastic transformation has been extensively investigated, its functions in post-mitotic cells of adult tissues have been limited due to the embryonic lethality caused by AMBRA1 deficiency. Recently, a key role of AMBRA1 in selectively regulating mitophagy in post-mitotic cells has emerged. Here we summarize and discuss these results with the aim of providing a comprehensive view of the mitochondrial roles of AMBRA1, and how defective activity of AMBRA1 has been functionally linked to mitophagy alterations observed in age-related degenerative disorders, including muscular dystrophy/sarcopenia, Parkinson diseases, Alzheimer diseases and age-related macular degeneration.Abbreviations: AD: Alzheimer disease; AMD: age-related macular degeneration; AMBRA1: autophagy and beclin 1 regulator 1; APOE4: apolipoprotein E4; ATAD3A: ATPase family AAA domain containing 3A; ATG: autophagy related; BCL2: BCL2 apoptosis regulator; BH3: BCL2-homology-3; BNIP3L/NIX: BCL2 interacting protein 3 like; CDK: cyclin dependent kinase; CHUK/IKKα: component of inhibitor of nuclear factor kappa B kinase complex; CRL2: CUL2-RING ubiquitin ligase; DDB1: damage specific DNA binding protein 1; ER: endoplasmic reticulum; FOXO: forkhead box O; FUNDC1: FUN14 domain containing 1; GBA/β-glucocerebrosidase: glucosylceramidase beta; HUWE1: HECT, UBA and WWE domain containing E3 ubiquitin protein ligase 1; IDR: intrinsically disordered region; LIR: LC3-interacting region; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAVS: mitochondrial antiviral signaling protein; MCL1: MCL1 apoptosis regulator, BCL2 family member; MFN2: mitofusin 2; MTOR: mechanistic target of rapamycin kinase; MSA: multiple system atrophy; MYC: MYC proto-oncogene, bHLH transcription factor; NUMA1: nuclear mitotic apparatus protein 1; OMM; mitochondria outer membrane; PD: Parkinson disease; PHB2: prohibitin 2; PINK1: PTEN induced kinase 1; PIK3C3/VPS34: phosphatidylinositol 3-kinase catalytic subunit type 3; PTK2/FAK: protein tyrosine kinase 2; ROS: reactive oxygen species; RPE: retinal pigment epithelium; SAD: sporadic AD; SOCS3: suppressor of cytokine signaling 3; SRC, SRC proto-oncogene, non-receptor tyrosine kinase; STAT3: signal transducer and activator of transcription 3; STING1: stimulator of interferon response cGAMP interactor 1; SQSTM1/p62: sequestosome 1; TBK1: TANK binding kinase 1; TGFB/TGFβ: transforming growth factor beta; TOMM: translocase of outer mitochondrial membrane; TRAF6: TNF receptor associated factor 6; TRIM32: tripartite motif containing 32; ULK1: unc-51 like autophagy activating kinase 1.

DKK3 as a diagnostic marker and potential therapeutic target for sarcopenia in chronic obstructive pulmonary disease

Sarcopenia, characterized by the progressive loss of muscle mass and function, significantly affects patients with chronic obstructive pulmonary disease (COPD) and worsens their morbidity and mortality. The pathogenesis of muscle atrophy in patients with COPD involves complex mechanisms, including protein imbalance and mitochondrial dysfunction, which have been identified in the muscle tissues of patients with COPD. DKK3 (Dickkopf-3) is a secreted glycoprotein involved in the process of myogenesis. However, the role of DKK3 in the regulation of muscle mass is largely unknown. This study investigated the role of DKK3 in COPD-related sarcopenia. DKK3 was found to be overexpressed in cigarette smoking-induced muscle atrophy and in patients with COPD. Importantly, plasma DKK3 levels in COPD patients with sarcopenia were significantly higher than those without sarcopenia, and plasma DKK3 levels could effectively predict sarcopenia in patients with COPD based on two independent cohorts. Mechanistically, DKK3 is secreted by skeletal muscle cells that acts in autocrine and paracrine manners and interacts with the cell surface-activated receptor cytoskeleton-associated protein 4 (CKAP4) to induce mitochondrial dysfunction and myotube atrophy. The inhibition of DKK3 by genetic ablation prevented cigarette smoking-induced skeletal muscle dysfunction. These results suggest that DKK3 is a potential target for the diagnosis and treatment of sarcopenia in patients with COPD.

A review of sarcopenia pathogenesis and therapeutic approaches: resistance exercise, nutrition, and monoterpenes

PURPOSE

Sarcopenia, characterized by the age-related loss of muscle mass and function, is a multifactorial condition influenced by oxidative stress, hormonal changes, and chronic inflammation. This study investigated the effects of resistance exercise and nutritional interventions, including antioxidants, such as monoterpenes, on sarcopenia prevention and treatment.

METHODS

To identify relevant studies, a comprehensive literature search was conducted using electronic databases including PubMed and Google Scholar. Keywords such as "sarcopenia," "resistance exercise," "antioxidants," "nutrition," "muscle regeneration," and related terms were utilized to gather evidence on the prevention and management of sarcopenia.

RESULTS

This review focuses on the etiological factors of sarcopenia, particularly the decline in muscle function and acceleration of muscle protein degradation. This highlights the critical importance of the combined effects of exercise and nutrition in overcoming these challenges, with special emphasis on the potential of antioxidant intake as a promising solution for managing this condition.

CONCLUSION

An integrated approach combining periodic resistance exercise with antioxidant-rich nutritional strategies is essential for the management of sarcopenia. By promoting muscle development and inhibiting protein breakdown, this dual strategy provides an effective framework for preventing and treating sarcopenia, and improving quality of life of the aging population. Further studies are warranted to explore the clinical potential of monoterpenes in the treatment of sarcopenia.

Fibin is a crucial mitochondrial regulatory gene in skeletal muscle development

Fin bud initiation factor homolog (Fibin) is a secreted protein that is relatively conserved among species. It is closely related to fin bud development and can regulate a variety of cellular processes. In our previous high-throughput chromosome conformation capture (Hi-C) study of pig embryonic muscle development, it was found that Fibin has high expression and activity during the development of pig primary muscle fibers. Therefore, we speculated Fibin participated in myogenesis severely. Specific deletion of Fibin in mouse skeletal muscle resulted in abnormal primary muscle fiber development during the embryonic period and a substantial decrease in skeletal muscle mass in adulthood. In vitro, knocking out Fibin in C2C12 cells promoted cell proliferation; however, after myogenic induction, cells lacking Fibin had almost no ability to differentiate into myotubes. During myogenic differentiation, loss of Fibin disrupts the normal function of mitochondria and impairs oxidative phosphorylation, resulting in decrease of NADH and FADH in the electron transport chain. Transmission electron microscopy also showed that mitochondrial morphology of Fibin-deficient C2C12 was impaired. In conclusion, our research has unveiled a novel mechanism of myogenesis regulation in mitochondrial function and potential target Fibin, and improved understanding of a broad range of mitochondrial muscle diseases.

Muscle quality index comparisons between Hispanics and non-Hispanic Caucasians using dual energy X-ray absorptiometry and handgrip strength

BACKGROUND & AIMS

Muscle quality index (MQI) can be computed in various ways. Also, many studies have evaluated MQI in older adults and non-Hispanic populations. The aim of this study was to compare various muscle quality indexes between Hispanics and non-Hispanic Caucasians when stratifying grip strength and appendicular lean mass measurements.

METHODS

235 participants (aged 25.5 ± 9.5 for males and 26.4 ± 9.9 for females) completed a dual energy X-ray absorptiometry (DXA) scan to assess appendicular lean mass (ALM). Handgrip strength (HGS) was assessed using a handheld dynamometer. MQI was computed using four different models: 1). MQIRA: ALM and HGS of right arm and hand, respectively; 2). MQILA: ALM and HGS of left arm and hand, respectively; 3). MQIARMS: ALM and HGS of both arms and hands, respectively; and 4). MQITOTAL: ALM of upper and lower-limbs and HGS of left and right hand.

RESULTS

Hispanic males and females exhibited lower HGS compared to Caucasians with effect sizes ranging from trivial (d = 0.17) to moderate (d = 0.80). Females demonstrated higher MQI values compared to males for MQIARMS (d = 0.70), MQIRA (d = 0.75), and MQILA (d = 0.57). However, MQITOTAL yielded a small practical effect (d = 0.33) in favor of males (3.2 ± 0.5 kg/kg vs. 3.1 ± 0.5 kg/kg). After factoring by sex and ethnicity, Hispanic males and females, compared to non-Hispanic Caucasians males and females, showed trivial-to-small practical differences (d values ranging from 0.03 to 0.39).

CONCLUSIONS

These results demonstrate MQI models vary across sex, particularly when utilizing models that account for upper extremity strength and ALM (i.e., MQIARMS, MQIRA, and MQILA). Lastly, to establish consistency in future research, the present study recommends using MQI models that account for ALM of upper- and lower-limbs (i.e., MQITOTAL). However, research measuring muscular strength via one upper-limb (e.g., left hand) might consider measuring ALM of the corresponding arm (e.g., left arm) when computing muscle quality (e.g., MQILA).

Iron homeostasis and neurodegeneration in the ageing brain: Insight into ferroptosis pathways

Ageing is a major risk factor for various chronic diseases and offers a potential target for developing novel and broadly effective preventatives or therapeutics for age-related conditions, including those affecting the brain. Mechanisms contributing to ageing have been summarized as the hallmarks of ageing, with iron imbalance being one of the major factors. Ferroptosis, an iron-mediated lipid peroxidation-induced programmed cell death, has recently been implicated in neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD) and Huntington's disease (HD). Addressing ferroptosis offers both opportunities and challenges for treating neurodegenerative diseases, though the specific mechanisms remain unclear. This research explores the key processes behind how ferroptosis contributes to brain ageing, with a focus on the complex signaling networks that are involved. The current article aims to uncover that how ferroptosis, a specific type of cell death, may drive age-related changes in the brain. Additionally, the article also unveils its role in neurodegenerative diseases, discussing how understanding these mechanisms could open up new therapeutic avenues.

Neoadjuvant immunotherapy strategies for resectable non-small cell lung cancer (NSCLC): Current evidence among special populations and future perspectives

About one third of patients with Non-Small Cell Lung Cancer (NSCLC) presents at diagnosis with localized or locally advanced disease amenable to curative surgical resection. Surgical operability refers to stage I to IIIA and selected stage IIIB NSCLC. One of the main challenges in the management of early-stage resectable NSCLC is the optimization of available therapeutic strategies to prevent local and distant disease relapse, thus improving survival outcomes. There is evidence supporting the clinical use of both adjuvant and neoadjuvant immunotherapy-based strategies for resected/resectable, stage IB-IIIA NSCLC. Available data from randomized phase III trials have led to the incorporation of several immune checkpoint blockers (ICBs) into the international guidelines for early-stage NSCLC. Preclinical rationale of targeting specific subsets of T-cells by acting early on immune checkpoint receptors (e.g., PD-(L)1 and CTLA-4) is strong. Recent evidence is in favor of the neoadjuvant approach alone or as a part of perioperative strategy, demonstrating survival benefit. Combining neoadjuvant chemotherapy and immunotherapy before surgery results in both pathologic complete response (pCR) and major pathologic response (MPR) improvement, and survival outcomes, with no major safety issues. In this review, we summarize the rationale behind neoadjuvant/perioperative immunotherapy strategies and, due to the clinical relevance of immunotherapy in resectable NSCLC, we provide current evidence of this cutting-edge approach among special populations including older adults, women, and oncogene addicted NSCLC. To conclude, we present future perspectives in the use of immunotherapy for operable NSCLC with a special focus on novel investigational combinations underway.

Skeletal muscle as a pro- and anti-inflammatory tissue: insights from children to adults and ultrasound findings

Previously regarded as a movement and posture control agent, the skeletal muscle is now recognized as an endocrine organ that may affect systemic inflammation and metabolic health. The discovery of myokines such as IL-6, released from skeletal muscle in response to physical exercise, is now one of the most recent insights. Myokines are the mediators of the balance between the pro-inflammatory and anti-inflammatory responses. This underscores the muscle function as a determinant of good health and prevention of diseases. Advances in ultrasound technology improved evaluation of muscle thickness, composition, and determining fat distribution. Combining imaging with molecular biology, researchers discovered the complicated interplay between muscle function, cytokine production and general health effects.The production of myokines with exercise showcasing the adaptability of muscles to high-stress conditions and contributing to metabolism and inflammation regulation. These findings have significant implications in order to provide improvement in metabolic and inflammatory diseases.

The impact of weight loss on fat-free mass, muscle, bone and hematopoiesis health: Implications for emerging pharmacotherapies aiming at fat reduction and lean mass preservation

Similar to bariatric surgery, incretin receptor agonists have revolutionized the treatment of obesity, achieving up to 15-25 % weight loss in many patients, i.e., at a rate approaching that achieved with bariatric surgery. However, over 25 % of total weight lost from both surgery and pharmacotherapy typically comes from fat-free mass, including skeletal muscle mass, which is often overlooked and can impair metabolic health and increase the risk of subsequent sarcopenic obesity. Loss of muscle and bone as well as anemia can compromise physical function, metabolic rate, and overall health, especially in older adults. The myostatin-activin-follistatin-inhibin system, originally implicated in reproductive function and subsequently muscle regulation, appears to be crucial for muscle and bone maintenance during weight loss. Activins and myostatin promote muscle degradation, while follistatins inhibit their activity in states of negative energy balance, thereby preserving lean mass. Novel compounds in the pipeline, such as Bimagrumab, Trevogrumab, and Garetosmab-which inhibit activin and myostatin signaling-have demonstrated promise in preventing muscle loss while promoting fat loss. Either alone or combined with incretin receptor agonists, these medications may enhance fat loss while preserving or even increasing muscle and bone mass, offering a potential solution for improving body composition and metabolic health during significant weight loss. Since this dual therapeutic approach could help address the challenges of muscle and bone loss during weight loss, well-designed studies are needed to optimize these strategies and assess long-term benefits. For the time being, considerations like advanced age and prefrailty may affect the choice of suitable candidates in clinical practice for current and emerging anti-obesity medications due to the associated risk of sarcopenia.

Diet and exercise in frailty and sarcopenia. Molecular aspects

Function declines throughout life although phenotypical manifestations in terms of frailty or disability are only seen in the later periods of our life. The causes underlying lifelong function decline are the aging process "per se", chronic diseases, and lifestyle factors. These three etiological causes result in the deterioration of several organs and systems which act synergistically to finally produce frailty and disability. Regardless of the causes, the skeletal muscle is the main organ affected by developing sarcopenia. In the first section of the manuscript, as an introduction, we review the quantitative and qualitative age-associated skeletal muscle changes leading to frailty and sarcopenia and their impact in the quality of life and independence in the elderly. The reversibility of frailty and sarcopenia are discussed in the second and third sections of the manuscript. The most effective intervention to delay and even reverse frailty is exercise training. We review the role of different training programs (resistance exercise, cardiorespiratory exercise, multicomponent exercise, and real-life interventions) not only as a preventive but also as a therapeutical strategy to promote healthy aging. We also devote a section in the text to the sexual dimorphic effects of exercise training interventions in aging. How to optimize the skeletal muscle anabolic response to exercise training with nutrition is also discussed in our manuscript. The concept of anabolic resistance and the evidence of the role of high-quality protein, essential amino acids, creatine, vitamin D, β-hydroxy-β-methylbutyrate, and Omega-3 fatty acids, is reviewed. In the last section of the manuscript, the main genetic interventions to promote robustness in preclinical models are discussed. We aim to highlight the molecular pathways that are involved in frailty and sarcopenia. The possibility to effectively target these signaling pathways in clinical practice to delay muscle aging is also discussed.

Melatonin ameliorates age-related sarcopenia by inhibiting fibrogenic conversion of satellite cell

The fibrogenic conversion of satellite cells contributes to the atrophy and fibrosis of skeletal muscle, playing a significant role in the pathogenesis of age-related sarcopenia. Melatonin, a hormone secreted by the pineal gland, exhibits anti-aging and anti-fibrotic effects in various conditions. However, the effect of melatonin on satellite cell fate and age-related sarcopenia remains under-explored. Here, we report that melatonin treatment mitigated the loss of muscle mass and strength in aged mice, replenished the satellite cell pool and curtailed muscle fibrosis. When primary SCs were cultured in vitro and subjected to aging induction via D-galactose, they exhibited a diminished myogenic potential and a conversion from myogenic to fibrogenic lineage. Notably, melatonin treatment effectively restored the myogenic potential and inhibited this lineage conversion. Furthermore, melatonin attenuated the expression of the fibrogenic cytokine, transforming growth factor-β1, and reduced the phosphorylation of its downstream targets Smad2/3 both in vivo and in vitro. In summary, our findings show melatonin's capacity to counteract muscle decline and inhibit fibrogenic conversion in aging SCs and highlight its potential therapeutic value for age-related sarcopenia.

Climbing the longevity pyramid: overview of evidence-driven healthcare prevention strategies for human longevity

Longevity medicine is an emerging and iterative healthcare discipline focusing on early detection, preventive measures, and personalized approaches that aim to extend healthy lifespan and promote healthy aging. This comprehensive review introduces the innovative concept of the "Longevity Pyramid." This conceptual framework delineates progressive intervention levels, providing a structured approach to understanding the diverse strategies available in longevity medicine. At the base of the Longevity Pyramid lies the level of prevention, emphasizing early detection strategies and advanced diagnostics or timely identification of potential health issues. Moving upwards, the next step involves lifestyle modifications, health-promoting behaviors, and proactive measures to delay the onset of age-related conditions. The Longevity Pyramid further explores the vast range of personalized interventions, highlighting the importance of tailoring medical approaches based on genetic predispositions, lifestyle factors, and unique health profiles, thereby optimizing interventions for maximal efficacy. These interventions aim to extend lifespan and reduce the impact and severity of age-related conditions, ensuring that additional years are characterized by vitality and wellbeing. By outlining these progressive levels of intervention, this review offers valuable insights into the evolving field of longevity medicine. This structured framework guides researchers and practitioners toward a nuanced strategic approach to advancing the science and practice of healthy aging.

Exploring the association between muscle mass and thyroid function in Chinese community subjects over 45 years old with normal thyroid function: a cross-sectional analysis

Background

Currently, nothing is known about the connection between muscle mass and thyroid hormone levels in middle-aged and elderly Chinese with normal thyroid function. The purpose of this study was to determine the potential association between muscle mass and thyroid function status in middle-aged and elderly Chinese subjects with normal thyroid function.

Methods

A cohort of 1868 participants in China were included in this retrospective study; their mean age was 53.97 years, and their skeletal muscle mass index was 7.44 kg/m2. Of them, 60.97% were men. Thyroid hormone concentrations, standard biochemical indices, and the frequency of chronic illnesses were among the many factors that were evaluated. Bioelectrical impedance analysis (BIA) was used to assess the patients' body composition. The skeletal muscle index (SMI) was calculated using the following formula: SMI = ASM (kg)/height 2 (m2), where ASM stands for appendicular skeletal muscle mass. To identify the correlations between the variables, the Spearman correlation coefficient was used. Binary logistic regression analysis was conducted to investigate the potential linkages between thyroid hormone levels and diminished muscle mass.

Results

In this investigation, a significant correlation was observed between low muscle mass and FT3/FT4 (OR=0.044, 95% CI: 0.004-0.440, P=0.008), as well as FT3 (OR=0.697, 95% CI: 0.508-0.957, P=0.025). Conversely, no discernible correlation trend was detected with TSH (OR=0.972, 95% CI: 0.814-1.160, P=0.753) and FT4 (OR=1.97, 95% CI=0.983-1.224, P=0.1). Following adjustment for various confounding factors, including age, vitamin D levels, triglycerides, HDL-C, LDL-C, total protein, hypertension, diabetes, hyperuricemia, and overweight/obesity, across the entire study population, a positive correlation between SMI and FT3/FT4 was identified. Subsequent gender, age, and weight-stratified analyses revealed consistent correlation trends between SMI and FT3/FT4, with all interactions yielding P-values > 0.05.

Conclusion

Our study has revealed that among middle-aged and elderly Chinese individuals exhibiting normal thyroid function, a reduction in the free T3 to free T4 ratio is associated with a decline in muscle mass.

Health and Well-Being Coaching Adjuvant to GLP-1 Induced Weight Loss

Glucagon-like peptide agonists (GLP-1) are highly effective anti-obesity medications. However, sustained effectiveness is potentially plagued by lack of adherence to the drug and resumption of pre-weight loss behaviors. Side effects are primarily severe gastrointestinal distress but can occasionally be more serious. Health and well-being coaching (HWC) is an important obesity intervention that can be used alongside GLP-1 prescription. HWC is documented to improve medication adherence and promote healthy behavior change. A coach who understands the complexities of rapid weight loss, specifically with GLP-1, can help the patient persist with the treatment. Moreover, the coach can assist in navigating GLP-1 side effects including undesirable loss of skeletal muscle during the weight loss period. A patient-centric and collaborative relationship seem essential to the HWC process. Specific coaching techniques are suggested for working with patients losing weight. The logical, but yet to be tested, expectation is that HWC as an adjuvant intervention to GLP-1 prescription will improve medication adherence and encourage sustained weight loss and health benefits in patients with obesity.

Multi-channel EMG manifestations of upper-extremity muscle coordination imbalance among community-dwelling sarcopenic seniors

BACKGROUND

Sarcopenia is an age-related, insidious, crippling but curable degenerative disease if diagnosed and treated early. However, no accessible and accurate early screening method is available for community settings that does not require specialized personnel. One of the hallmarks of sarcopenia is the pathological changes of muscle fiber type composition and motor unit firing patterns. Surface electromyography (sEMG) may serve as an effective tool for detecting differences between healthy and sarcopenic individuals due to its superior wearability and accessibility compared to other screening methods such as medical imaging and bioimpedance measurements, making it ideal for community-based sarcopenic screening. Our study aims to explore sEMG biomarkers that can be used for screening or diagnosis of sarcopenia.

RESULTS

We collected multi-channel sEMG signals from six forearm muscles of 98 healthy and 55 sarcopenic community-dwelling older adults. Participants performed grasp tasks at 20% and 50% of maximum voluntary contraction (MVC). Hexagons created by various EMG features, normalized with respect to respective MVC, and symmetry analyses were performed to estimate multi-muscle coordination patterns. An innovative index, namely incenter-circumcenter distance of muscle coordination (ICDMC), is proposed to discriminate between the healthy and sarcopenic groups. We utilized non-parametric tests to compare the ICDMC between the two groups, considering a p-value less than 0.05 statistically significant. The results showed that at 20% MVC, ICDMCs from root mean square (RMS), mean absolute value (MAV), slope sign changes (SSC) and wavelength (WL) showed statistically significant differences. More insights of this sEMG manifestation of sarcopenia were revealed by gender- and age-stratifications analyses.

CONCLUSIONS

Our results demonstrated that there are clear sEMG manifestations of altered muscle coordination in sarcopenic patients. More consistent force generation patterns were observed in the sarcopenic group, especially at lower contraction intensities. The novel ICDMC can quantify differences between sarcopenic and healthy muscle. These results warrant further research to further develop more accessible sarcopenia screening strategies in community settings based on electrophysiological measurements such as sEMG.

Adverse childhood experiences and falls in older adults: The mediating role of depression

OBJECTIVES

To explore the relationship between adverse childhood experiences and falls in older adults, and the mediating effects of depression on such associations.

METHODS

This is a prospective study used survey data from the China Health and Retirement Longitudinal Study. Twelve expanded ACEs obtained from the 2014 Life History Survey. Depression levels were assessed using the Centre for Epidemiologic Studies Depression Scale-10. Self-reported outcomes of falling evaluated based on "Have you fallen down since the last survey?" and "How many times have you fallen down seriously enough to need medical treatment?" Logistic regression models were used to explore the relationship between ACEs with falls and recurrent falls. Poisson regression models were used to explore the relationship between ACEs and number of severe falls. Besides, mediation analysis was used to explore whether depression mediates the relationship between ACEs and falls in older adults.

RESULTS

The more adverse childhood experiences experienced, the higher the risk of fall and recurrent falls, and the more severe the falls. Additionally, depression partially mediated the relationship between adverse childhood experiences and falls. Besides, middle-aged individuals were more susceptible to the impact of adverse childhood experiences on falls than older individuals, especially males.

CONCLUSIONS

Exposure to adverse childhood experiences is associated with falls in older adults, and depression partially mediates this association. Middle-aged adults were more susceptible to the impact of adverse childhood experiences on falls. These offer important information for clinical practice and public health interventions to prevent falls and reduce fall-related injuries among older adults.

Age and sex-related differences in elastic properties of the gastrocnemius muscle-tendon unit: an observational prospective study

Introduction

Changes in the mechanical properties of the gastrocnemius muscle-tendon unit can lead to abnormal biomechanics of lower limbs, which is a risk factor for the development of many diseases. However, fewer studies have explored physiological changes in the gastrocnemius muscle-tendon unit stiffness. This study aimed to investigate the age- and sex-related differences in the gastrocnemius muscle-tendon unit stiffness.

Methods

The study included 20 older women, 20 young women, and 20 older men. Shear wave elastography (SWE) was used to measure the stiffness of the medial gastrocnemius (MG), lateral gastrocnemius (LG), and Achilles tendon (AT) in all subjects in relaxed, neutral, and standing positions.

Results

The results showed no significant differences in the MG, LG, and AT stiffness between the dominant and non-dominant sides (p > 0.05). The MG, LG, and AT stiffness changed with positions (p < 0.05). The LG stiffness in older women was lower than in older men and young women in any position (p < 0.05). The MG stiffness in older men was greater than that in older women in any position, and age-related changes were found only in the relaxed and standing positions (p < 0.05). The AT stiffness was higher in older men only in the relaxed position (p < 0.05). There was no significant difference in AT stiffness between older and younger women at any position (p > 0.05).

Discussion

These results suggest that the bilateral gastrocnemius muscle-tendon unit stiffnesses were similar regardless of sex, age, and position. The stiffness of the gastrocnemius in women decreased with age. However, the effect of aging on AT stiffness was slight. Men have greater gastrocnemius stiffness in older adults.

Identifying genetic determinants of sarcopenia-related traits: a Mendelian randomization study of druggable genes

BACKGROUND

Sarcopenia, characterized by progressive muscle mass and function loss, particularly affects the elderly, and leads to severe consequences such as falls and mortality. Despite its prevalence, targeted pharmacotherapies for sarcopenia are lacking. Utilizing large-sample genome-wide association studies (GWAS) data is crucial for cost-effective drug discovery.

METHODS

Herein, we conducted four studies to understand the putative causal effects of genetic components on muscle mass and function. Study 1 employed a two-sample Mendelian randomization (MR) on 15,944 potential druggable genes, investigating their potential causality with muscle quantity and quality in a European population (N up to 461,089). Study 2 validated MR results through sensitivity analyses and colocalization analyses. Study 3 extended validation across other European cohorts, and study 4 conducted quantitative in vivo verification.

RESULTS

MR analysis revealed significant causality between four genes (BLOC-1 related complex subunit 7, BORCS7; peptidase m20 domain containing 1, PM20D1; nuclear casein kinase and cyclin dependent kinase substrate 1, NUCKS1 and ubiquinol-cytochrome c reductase complex assembly factor 1, UQCC1) and muscle mass and function (p-values range 5.98 × 10-6 to 9.26 × 10-55). To be specific, BORCS7 and UQCC1 negatively regulated muscle quantity and quality, whereas enhancing PM20D1 and NUCKS1 expression showed promise in promoting muscle mass and function. Causal relationships remained robust across sensitivity analyses, with UQCC1 exhibiting notable colocalization effects (PP·H4 93.4 % to 95.8 %). Further validation and in vivo replication verified the potential causality between these genes and muscle mass as well as function.

CONCLUSIONS

Our druggable genome-wide MR analysis identifies BORCS7, PM20D1, NUCKS1, and UQCC1 as causally associated with muscle mass and function. These findings offer insights into the genetic basis of sarcopenia, paving the way for these genes to become promising drug targets in mitigating this debilitating condition.

Associations between meeting 24-h movement guidelines and sarcopenia risk among adults aged ≥ 55 years in five low- and middle-income countries

OBJECTIVE

To diminish the negative influence of sarcopenia on senior adults, the study aimed to investigate the association between adherence to 24-h movement behavior guidelines (physical activity, sedentary behavior, sleep duration) and the risk of sarcopenia among individuals aged ≥55 years in five low- and middle-income countries (LMICs).

METHODS

A total of 16,503 adults aged ≥55 years were included in this cross-sectional study. The study utilized data from Global Aging and Adult Health Survey (SAGE). Participants reported their information about physical activity, sedentary behavior, and sleep duration using the questionnaire. Sarcopenia was identified as low skeletal muscle mass with a diminished gait speed or weakened handgrip strength. Multiple logistic regression models were used to investigate the association between adherence to 24-h movement behavior guidelines and the risk of sarcopenia.

RESULTS

Merely 32.73 % of participants met all three 24-h movement behavior guidelines (physical activity, less sedentary behavior, sleep). Meeting all three guidelines (p < 0.01) was significantly associated with a lower risk of sarcopenia. Meeting physical activity only (p < 0.05), or meeting both physical activity and sedentary behaivor (p < 0.05), or meeting both physical activity and sleep duration (p < 0.01) guidelines were also associated with a reduced risk of sarcopenia. Moreover, adults aged 65+ years who adhered to 24-h movement behavior guidelines exhibited a significantly reduced risk of developing sarcopenia.

CONCLUSION

The findings suggest that the adherence to 24-h movement behavior guidelines for regular physical activity, limited sedentary behavior, and sufficient sleep duration was associated with a reduced risk of sarcopenia in adults aged ≥55 years in five LMICs.

Experimental models as a tool for research on sarcopenia: A narrative review

Sarcopenia is a musculoskeletal disorder related to muscle mass and function; as the worldwide population ages, its growing prevalence means a decline in quality of life and an increased burden for public health systems. As sarcopenia is a reversible condition, its early diagnosis is of utmost importance. Consensus definitions and diagnosis protocols for sarcopenia have been evolving for a long time, and the identification of molecular pathways subjacent to sarcopenia is a growing research area. The use of liquid biopsies to identify circulating molecules does not provide information about specific regulatory pathways or biomarkers in relevant tissue, and the use of skeletal muscle biopsies from older people has many limitations. Complementary tools are therefore necessary to advance the knowledge of relevant molecular aspects. The development of experimental models, such as animal, cellular, or bioengineered tissue, together with knock-in or knock-out strategies, could therefore be of great interest. This narrative review will explore experimental models of healthy muscle and aged muscle cells as a tool for research on sarcopenia. We will summarize the literature and present relevant experimental models in terms of their advantages and disadvantages. All of the presented approaches could potentially contribute to the accurate and early diagnosis, follow-up, and possible treatment of sarcopenia.

Impact of sarcopenia on the prognosis of patients with advanced non-small cell lung cancer treated with antiangiogenic therapy: A propensity score matching analysis

BACKGROUND

Limited information is available regarding the impact of sarcopenia on the prognosis of antiangiogenic therapy in individuals with advanced non-small cell lung cancer (NSCLC). This study primarily sought to examine the prognostic significance of sarcopenia in individuals with advanced NSCLC undergoing antiangiogenic therapy.

METHODS

We retrospectively enrolled all patients who met the inclusion and exclusion criteria from 2019 to 2021 at Nantong University Hospital. Patients were grouped according to the presence or absence of sarcopenia. After propensity score matching (PSM), progression-free survival (PFS), overall survival (OS), and adverse event rates were compared between the two groups. Factors associated with prognosis were screened using univariate and multivariate analyses.

RESULTS

A total of 267 patients were included, with a total of 201 matched at baseline after PSM (77 in the sarcopenia group and 124 in the non-sarcopenia group). The sarcopenia group had lower PFS (p = 0.043) and OS (p = 0.011) than the non-sarcopenia group and a higher incidence of adverse events (p = 0.044). Multivariate analysis suggested that sarcopenia is an independent prognostic risk factor for OS in advanced NSCLC patients receiving antiangiogenic therapies (p = 0.009). Results of subgroup analyses showed some differences in the impact of sarcopenia on survival prognosis in populations with different characteristics.

CONCLUSION

Patients with advanced NSCLC with comorbid sarcopenia exhibit a worse prognosis when treated with antiangiogenic therapy, and preventing and ameliorating sarcopenia may lead to better survival outcomes in patients with advanced NSCLC.

Exploring the Relationship Between Gut Microbiota and Sarcopenia Based on Gut-Muscle Axis

Sarcopenia, as a disease characterized by progressive decline of quality, strength, and function of muscles, has posed an increasingly significant threat to the health of middle-aged and elderly individuals in recent years. With the continuous deepening of studies, the concept of gut-muscle axis has attracted widespread attention worldwide, and the occurrence and development of sarcopenia are believed to be closely related to the composition and functional alterations of gut microbiota. In this review, combined with existing literatures and clinical reports, we have summarized the role and impacts of gut microbiota on the muscle, the relevance between gut microbiota and sarcopenia, potential mechanisms of gut microbiota in the modulation of sarcopenia, potential methods to alleviate sarcopenia by modulating gut microbiota, and relevant advances and perspectives, thus contributing to adding more novel knowledge to this research direction and providing certain reference for future related studies.

Mechanisms of cancer cachexia and targeted therapeutic strategies

Tumor cachexia is a multifactorial syndrome characterized by systemic dysfunction, including anorexia and severe weight loss that is resistant to standard nutritional interventions. It is estimated that approximately 20 % of cancer patients succumb to cachexia in the later stages of their disease. Thus, understanding its pathogenesis is vital for improving therapeutic outcomes. Recent research has focused on the imbalance between energy intake and expenditure in cachexia. Clinically, cachexia presents with anorexia, adipose tissue atrophy, and skeletal muscle wasting, each driven by distinct mechanisms. Anorexia arises primarily from tumor-secreted factors and cancer-induced hormonal disruptions that impair hypothalamic regulation of appetite. Adipose tissue atrophy is largely attributed to enhanced lipolysis, driven by increased activity of enzymes such as adipose triglyceride lipase and hormone-sensitive lipase, coupled with decreased lipoprotein lipase activity. The browning of white adipose tissue, facilitated by uncoupling protein 1, further accelerates fat breakdown by increasing energy expenditure. Skeletal muscle atrophy, a hallmark of cachexia, results from dysregulated protein turnover via the ubiquitin-proteasome and autophagy-lysosomal pathways, as well as mitochondrial dysfunction. Additionally, chemotherapy can exacerbate cachexia. This review examines the molecular mechanisms underlying cancer cachexia and discusses current therapeutic strategies, aiming to inform future research and improve treatment approaches.

Interrelationships of cervical spine sagittal alignment and whole spinopelvic alignment under implications of musculoskeletal health among independent elderly women in Taiwan: A cross-sectional study

INTRODUCTION

Older women are at increased risk of spinal misalignment and its associated complications. This study investigated the influence of age, grip strength, and various sagittal spinal parameters on spinal alignment. The results indicate the need for comprehensive management strategies.

METHODS

This cross-sectional study included 200 older women who underwent bone health evaluations at the orthopedic department of a hospital. The study participants underwent dual-energy X-ray absorptiometry, grip strength measurement, and full-length spine radiography. Clinical and radiographic parameters were analyzed through Pearson correlation and linear regression analyses.

RESULTS

Significant correlations were identified between grip strength and spinal parameters such as C7 slope and global tilt, indicating that muscle strength affects spinal alignment. Advanced age was associated with changes in sagittal spinal parameters, indicating that changes occur in body compensation over time. Furthermore, pelvic parameters such as pelvic tilt and sacral slope were significantly correlated with spinal curvature, indicating their critical roles in maintaining spinal stability.

CONCLUSIONS

This study revealed the critical roles of muscle strength and pelvic alignment in the management of spinal health in older women with low bone mass. Targeted interventions for increasing muscle strength, correcting posture, and achieving hormonal balance can notably improve spinal stability and reduce the risk of associated complications. Longitudinal studies should be conducted to validate and refine the intervention strategies and to extend the study findings.

Association between dietary vitamin D intake and low muscle mass in US adults: results from NHANES 2011-2018

Purpose

To investigate the association between dietary vitamin D intake and low muscle mass (LMM) in a representative adult population, accounting for total energy intake and other potential confounders.

Materials and methods

This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) involving 8,443 participants. Dietary vitamin D intake was assessed using 24-h dietary recalls, and LMM was defined based on appendicular lean mass (ALM) adjusted for body mass index (BMI). Multivariable logistic regression models were used to examine the association between quartiles of dietary vitamin D intake and the odds of LMM, adjusting for age, gender, race/ethnicity, BMI, total energy intake, and additional covariates.

Results

In Model 1, after adjusting for age, gender, race/ethnicity, BMI, and poverty-to-income ratio, participants in the highest quartile of vitamin D intake had an odds ratio (OR) of 0.54 (95% CI: 0.37-0.79) compared to the lowest quartile, with a p for trend <0.001. In Model 2, after further adjustment for total energy intake and several covariates, the association was attenuated but remained borderline significant (p for trend = 0.051). In Model 3, after adjusting for additional health-related factors, the OR for the highest quartile was 0.70 (95% CI: 0.47-1.05), with a significant p for trend of 0.029.

Conclusion

This study suggests that higher dietary vitamin D intake may be associated with a reduced risk of LMM. Further longitudinal research is needed to confirm these findings and explore potential interactions between vitamin D and other dietary factors in muscle mass preservation.

Telomere Length and Biological Aging: The Role of Strength Training in 4814 US Men and Women

Telomere length is an index of cellular aging. Healthy lifestyles are associated with reduced oxidative stress and longer telomeres, whereas unhealthy behaviors are related to shorter telomeres and greater biological aging. This investigation was designed to determine if strength training accounted for differences in telomere length in a random sample of 4814 US adults. Data from the National Health and Nutrition Examination Survey (NHANES) were employed to answer the research questions using a cross-sectional design. Time spent strength training was calculated by multiplying days of strength training per week by minutes per session. Participation in other forms of physical activity was also calculated based on reported involvement in 47 other activities. Weighted multiple regression and partial correlation were used to calculate the mean differences in telomere length across levels of strength training, adjusting for differences in potential confounders. With the demographic covariates controlled, strength training and telomere length were linearly related (F = 14.7, p = 0.0006). Likewise, after adjusting for all the covariates, the linear association remained strong and significant (F = 14.7, p = 0.0006). In this national sample, 90 min per week of strength training was associated with 3.9 years less biological aging, on average. Regular strength training was strongly related to longer telomeres and less biological aging in 4814 US adults.

Weaning Failure in Elderly Patients: A Systematic Review and Meta-Analysis

Background/Objectives: Weaning failure in elderly patients undergoing mechanical ventilation presents a complex clinical challenge due to age-related physiological changes and comorbidities. Understanding the dynamics of this phenomenon through systematic analysis can provide valuable insights for clinical management. This meta-analysis aims to investigate the factors contributing to weaning failure in elderly patients and to assess the efficacy of different strategies in mitigating this challenge. Design: The design of this study is a systematic review and meta-analysis. Methods: A systematic search of electronic databases was conducted to identify relevant studies focusing on weaning failure in elderly patients. Studies reporting outcomes related to mechanical ventilation weaning failure were included. Data extraction, quality assessment, and statistical analysis were performed following established guidelines. Results: A total of 15 studies met the inclusion criteria and were included in the meta-analysis. The average age of participants throughout the studies was 66.24 ± 10.21 years. This suggests that the study population largely consisted of older adults and displayed a moderate range of ages centered around the mean. The rate of weaning failure across these studies was slightly above 31.56%, indicating a significant occurrence of this complication in the patient cohorts. The analysis revealed age-related physiological changes, such as decreased respiratory muscle strength and increased chest wall stiffness, as significant contributors to weaning failure in elderly patients. Comorbidities, including chronic pulmonary diseases and cardiovascular conditions, further exacerbated the challenge. Various interventions, including tailored weaning protocols and respiratory therapies, showed promising results in improving weaning outcomes in this population. Conclusions: Weaning failure in elderly patients undergoing mechanical ventilation is influenced by a combination of age-related physiological changes and comorbidities. Tailored interventions addressing these factors are essential for optimizing weaning success rates in this vulnerable population. Further research is warranted to refine the strategies and enhance outcomes in elderly patients requiring mechanical ventilation.

Body Composition and Senescence: Impact of Polyphenols on Aging-Associated Events

Aging is a dynamic and progressive process characterized by the gradual accumulation of cellular damage. The continuous functional decline in the intrinsic capacity of living organisms to precisely regulate homeostasis leads to an increased susceptibility and vulnerability to diseases. Among the factors contributing to these changes, body composition-comprised of fat mass and lean mass deposits-plays a crucial role in the trajectory of a disability. Particularly, visceral and intermuscular fat deposits increase with aging and are associated with adverse health outcomes, having been linked to the pathogenesis of sarcopenia. Adipose tissue is involved in the secretion of bioactive factors that can ultimately mediate inter-organ pathology, including skeletal muscle pathology, through the induction of a pro-inflammatory profile such as a SASP, cellular senescence, and immunosenescence, among other events. Extensive research has shown that natural compounds have the ability to modulate the mechanisms associated with cellular senescence, in addition to exhibiting anti-inflammatory, antioxidant, and immunomodulatory potential, making them interesting strategies for promoting healthy aging. In this review, we will discuss how factors such as cellular senescence and the presence of a pro-inflammatory phenotype can negatively impact body composition and lead to the development of age-related diseases, as well as how the use of polyphenols can be a functional measure for restoring balance, maintaining tissue quality and composition, and promoting health.

The role of amino acids in skeletal muscle health and sarcopenia: A narrative review

The skeletal muscle is the largest organ present inside the body and is responsible for mechanical activities like maintaining posture, movement, respiratory function, and support for the health and functioning of other systems of the body. Skeletal muscle atrophy is a condition associated with a reduction in muscle size, strength, and activity, which leads to an increased dependency on movement, an increased risk of falls, and a reduced quality of life. Various conditions like osteoarthritis, osteoporosis, and fractures are directly associated with an increased muscle atrophy. Additionally, numerous risk factors, like aging, malnutrition, physical inactivity, and certain disease conditions, through distinct pathways negatively affect skeletal muscle health and lead to muscle atrophy. Among the various determinants of the overall muscle health, the rate of muscle protein synthesis and degradation is an important parameter that eventually alters the fate of overall muscle health. In conditions of excessive skeletal muscle atrophy, including sarcopenia, the rate of muscle protein degradation usually exceeds the rate of protein synthesis. The availability of amino acids in the systemic circulation is a crucial step for muscle protein synthesis. The current review aimed to consolidate the existing evidence of amino acids, highlight their mechanisms of action, and assess their roles and effectiveness in enhancing skeletal muscle health.

Effects of Yi Jin Jing on enhancing muscle strength and physical performance in older individuals: a systematic review and meta-analysis

Background

The aging population is rapidly increasing, leading to physical decline and higher risks of chronic diseases, including sarcopenia, which adversely affects muscle quality and strength. Yi Jin Jing (YJJ), a traditional Chinese exercise method, can enhance flexibility and strength, but evidence regarding its effectiveness in older adults is conflicting. This meta-analysis aims to systematically evaluate the effects of YJJ on muscle strength and physical performance in this demographic.

Methods

We searched seven electronic databases: China National Knowledge Infrastructure, Wanfang Data, Sinomed, Web of Science, PubMed, Cochrane Library, and EMBASE to identify randomized controlled trials (RCTs). Following PRISMA guidelines, we quantified the effects of YJJ on muscle strength (grip strength, isokinetic strength) and physical performance (chair sit-to-stand, squatting-to-standing, shoulder flexibility, sit-and-reach tests). Treatment effects were calculated using Hedges'g. The Cochrane tool assessed risk of bias, the PEDro scale evaluated methodological quality, and the GRADE method assessed evidence quality. Data analysis was conducted using Stata 17.0 software, utilizing standardized mean differences (SMD) and 95% confidence intervals (CIs).

Results

This meta-analysis included 10 RCTs involving 590 participants. The overall risk of bias was assessed to be low. The methodological quality of these studies was generally moderate, and the quality of the main results varied from low to moderate. The findings revealed that YJJ had considerable effects on the chair sit-to-stand test (Hedges'g = 1.06), squatting-to-standing test (Hedges'g = 1.08), and small to moderate effects on handgrip strength (Hedges'g = 0.25), 60°/s extensor peak torque (Hedges'g = 0.47), 60°/s extensor average power (Hedges'g = 0.31), 60°/s extensor total work (Hedges'g = 0.29), 60°/s flexor peak torque (Hedges'g = 0.42), 60°/s flexor average power (Hedges'g = 0.37), and 180°/s extensor peak torque (Hedges'g = 0.29), and left shoulder flexibility (Hedges'g = 0.4). However, there were no significant improvement effects in 180°/s extensor average power (Hedges'g = 0.19), 180°/s extensor total work (Hedges'g = 0.11), 180°/s flexor peak torque (Hedges'g = 0.01), 180°/s flexor average power (Hedges'g = -0.08), right shoulder flexibility (Hedges'g = 0.09), and sit-and-reach test (Hedges'g = 0.15).

Conclusion

YJJ significantly enhances specific aspects of physical performance, particularly chair sit-to-stand and squatting-to-standing tests, while showing small and moderate improvements in handgrip strength and knee muscle strength. However, it had no significant effects on other metrics, including shoulder flexibility and sit-and-reach tests.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024530487, Registration number: CRD42024530487.

The Relationship Between MOTS-c K14Q Polymorphism and Sarcopenia, Blood Lipids, and Mental Health in Older Korean Adults

Background/objectives: An East Asian-specific 1382A>C polymorphism in the mitochondrial open reading frame of the 12S rRNA type-c results in an amino acid substitution from Lys (K) to Gln (Q) at the 14th amino acid residue. This study investigated the association between m.1382A>C polymorphism and sarcopenia, blood lipids, and mental health in older Korean adults. Methods: The study included 683 community-dwelling Korean adults (345 men and 338 women) aged 65 years and older. The m.1382A>C polymorphism was genotyped with a 7500 real-time PCR system. Handgrip strength (HGS) was measured, and appendicular skeletal muscle (ASM) mass was calculated. Demographics, blood lipids, falling risk, nutritional intake, cognition function, and depression were additionally measured. Results: Men carrying the C allele had significantly higher ASM (21.6 ± 3.0 vs. 19.5 ± 2.2 kg, p = 0.018), ASM/height2 (7.76 ± 0.76 vs. 7.14 ± 0.62 kg/m2, p = 0.012), lean mass (53.3 ± 6.2 vs. 46.5 ± 4.0 kg, p < 0.001), left HGS (33.3 ± 5.0 vs. 28.9 ± 4.0 kg, p = 0.010), and right HGS (35.6 ± 5.3 vs. 30.9 ± 4.3 kg, p = 0.009) than men carrying the A allele. The genotype differences in ASM (p = 0.017), ASM/height2 (p = 0.011), lean mass (p < 0.001), left HGS (p = 0.010), and right HGS (p = 0.009) remained significant even after adjusting for all measured covariates. By contrast, no significant differences in other measured parameters were found between women carrying the A and C alleles. Conclusions: Our study findings indicate that the m.1382A>C polymorphism may be used as a genetic biomarker of age-related sarcopenia in older Korean men.

Nutrition in the prevention and treatment of skeletal muscle ageing and sarcopenia: a single nutrient, a whole food and a whole diet approach

Loss of skeletal muscle strength and mass (sarcopenia) is common in older adults and associated with an increased risk of disability, frailty and premature death. Finding cost-effective prevention and treatment strategies for sarcopenia for the growing ageing population is therefore of great public health interest. Although nutrition is considered an important factor in the aetiology of sarcopenia, its potential for sarcopenia prevention and/or treatment is still being evaluated. Nutrition research for sarcopenia utilises three main approaches to understand muscle-nutrition relationships, evaluating: single nutrients, whole foods and whole diet effects - both alone or combined with exercise. Applying these approaches, we summarise recent evidence from qualitative and quantitative syntheses of findings from observational and intervention studies of healthy older adults, and those with sarcopenia. We consider protein supplements, whole foods (fruits and vegetables) and the Mediterranean diet as exemplars. There is some evidence of beneficial effects of protein supplementation ≥ 0·8 g/kg body weight/d on muscle mass when combined with exercise training in intervention studies of healthy and sarcopenic older adults. In contrast, evidence for effects on muscle function (strength and physical performance) is inconclusive. There is reasonably consistent epidemiological evidence suggesting benefits of higher fruits and vegetables consumption for better physical performance. Similarly, higher adherence to the Mediterranean diet is associated with beneficial effects on muscle function in observational studies. However, intervention studies are lacking. This review discusses how current evidence may inform the development of preventive and intervention strategies for optimal muscle ageing and nutritional public policy aimed at combatting sarcopenia.

Exploring the impact of lighting sources on walking behavior in obstructed walkways among older adults

The pandemic has reinforced older adults' reliance on their homes and the concept of "aging in place". Changes like reduced physical strength and cognitive deficit, however, have heightened the challenge of simple tasks like obstacle crossing among older adults, let alone when older adults cannot perceive the surroundings well during the nighttime. The study is, therefore, to evaluate the impact of lighting on older adults' obstacle-crossing behavior during the nighttime. Twenty-seven older adults (81 ± 6 yrs., 171 ± 12 cm, 75 ± 20 kg, 14 females) were recruited. Participants were asked to cross over the obstacle in a dark residential environment under point or line light. We found that the line light tended to (1) induce more external rotation of the trailing hip (p = 0.037) and more internal rotation of the leading ankle (p < 0.001) at leading leg liftoff; and (2) result in a more upright and erect posture during stance phase (less hip flexion, p = 0.006) and swing phase of the trailing leg (reduced pelvic flexion, p = 0.038). Postural changes induced by line light demonstrated improved body control, highlighting the influence of spatial information (horizontal & vertical directions) on crossing behavior in dark environments. The findings can provide additional evidence for the design of light systems in both retirement communities and individual homes. This is particularly important when designing built environments for the aging population, in cases where the surroundings may pose challenges such as obstructed walking, and other complex floor conditions.

Modulation of Carnitine Palmitoyl Transferase 1b Expression and Activity in Muscle Pathophysiology in Osteoarthritis and Osteoporosis

In the pathophysiology of osteoarthritis and osteoporosis, articular cartilage and bone represent the target tissues, respectively, but muscle is also involved. Since many changes in energy metabolism occur in muscle with aging, the aim of the present work was to investigate the involvement of carnitine palmitoyl transferase 1b (Cpt1b) in the muscle pathophysiology of the two diseases. Healthy subjects (CTR, n = 5), osteoarthritic (OA, n = 10), and osteoporotic (OP, n = 10) patients were enrolled. Gene expression analysis conducted on muscle and myoblasts showed up-regulation of CPT1B in OA patients; this result was confirmed by immunohistochemical and immunofluorescence analyses and enzyme activity assay, which showed increased Cpt1b activity in OA muscle. In addition, CPT1B expression resulted down-regulated in cultured OP myoblasts. Given the potential involvement of Cpt1b in the modulation of oxidative stress, we investigated ROS levels, which were found to be lower in OA myoblasts, and gene expression of nicotinamide adenine dinucleotide phosphate hydrogen oxidase 4 (Nox4), which resulted up-regulated in OA cells. Finally, the immunofluorescence of BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (Bnip3) showed a decreased expression in OP myoblasts, with respect to CTR and OA. Contextually, through an ultrastructural analysis conducted by Transmission Electron Microscopy (TEM), the presence of aberrant mitochondria was observed in OP muscle. This study highlights the potential role of Cpt1b in the regulation of muscle homeostasis in both osteoarthritis and osteoporosis, allowing for the expansion of the current knowledge of what are the molecular biological pathways involved in the regulation of muscle physiology in both diseases.

Aging Skeletal Muscles: What Are the Mechanisms of Age-Related Loss of Strength and Muscle Mass, and Can We Impede Its Development and Progression?

As we age, we lose muscle strength and power, a condition commonly referred to as sarcopenia (ICD-10-CM code (M62.84)). The prevalence of sarcopenia is about 5-10% of the elderly population, resulting in varying degrees of disability. In this review we emphasise that sarcopenia does not occur suddenly. It is an aging-induced deterioration that occurs over time and is only recognised as a disease when it manifests clinically in the 6th-7th decade of life. Evidence from animal studies, elite athletes and longitudinal population studies all confirms that the underlying process has been ongoing for decades once sarcopenia has manifested. We present hypotheses about the mechanism(s) underlying this process and their supporting evidence. We briefly review various proposals to impede sarcopenia, including cell therapy, reducing senescent cells and their secretome, utilising targets revealed by the skeletal muscle secretome, and muscle innervation. We conclude that although there are potential candidates and ongoing preclinical and clinical trials with drug treatments, the only evidence-based intervention today for humans is exercise. We present different exercise programmes and discuss to what extent the interindividual susceptibility to developing sarcopenia is due to our genetic predisposition or lifestyle factors.

Impact of Psoas Muscle Area Index on Short- and Mid-Term Mortality in Patients Undergoing Valve Surgery for Infective Endocarditis: A Retrospective Analysis

Background: Sarcopenia, characterized by the loss of skeletal muscle mass, is an emerging comorbidity associated with poor outcomes in cardiovascular surgery. Its impact on mortality in patients undergoing valve surgery for infective endocarditis (IE) remains underexplored. This study investigates the relationship between sarcopenia, measured by the Psoas muscle area index (PMAi), and mortality in patients with IE undergoing valve surgery. Materials and Methods: We retrospectively analyzed 68 patients with IE who underwent valve surgery at a tertiary care center from 2013 to 2021. Sarcopenia was defined as being in the lowest quartile of PMAi, measured via preoperative computed tomography (CT). Baseline characteristics, survival outcomes, and factors influencing mortality were analyzed using Kaplan-Meier survival curves and Cox proportional hazards regression. The predictive value of PMAi for 1-year and 3-year mortality was assessed via receiver operating characteristic (ROC) curves. Results: Sarcopenia was strongly associated with increased mortality at both 1-year (HR: 0.378, p = 0.010) and 3-year follow-ups (HR: 0.457, p = 0.012). Female sex (OR: 275.748, p < 0.001) and older age (OR: 9.995, p = 0.003) were significant predictors of sarcopenia. Chronic kidney insufficiency (CKI) and the use of heart failure medication therapy also significantly impacted survival outcomes. Conclusions: Sarcopenia is a strong independent predictor of short- and mid-term mortality in patients undergoing valve surgery for IE. Routine radiological assessment of sarcopenia using PMAi could improve risk stratification and guide preoperative interventions. Tailored management strategies, especially in older women and patients with CKI, may enhance outcomes in this high-risk population.

Acetylcholine receptor-β inhibition by interleukin-6 in skeletal muscles contributes to modulating neuromuscular junction during aging

BACKGROUND

Aging-related strength decline contributes to physiological deterioration and is a good predictor of poor prognosis. However, the mechanisms underlying neuromuscular junction disorders affecting contraction in aging are not well described. We hypothesized that the autocrine effect of interleukin (IL)-6 secreted by skeletal muscle inhibits acetylcholine receptor (AChR) expression, potentially causing aging-related strength decline. Therefore, we investigated IL-6 and AChR β-subunit (AChR-β) expression in the muscles and sera of aging C57BL/6J mice and verified the effect of IL-6 on AChR-β expression.

METHODS

Animal experiments, in vitro studies, bioinformatics, gene manipulation, dual luciferase reporter gene assays, and chromatin immunoprecipitation experiments were used to explore the role of the transcription cofactor peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC1α) and its interacting transcription factors in the IL-6-mediated regulation of AChR-β expression.

RESULTS

IL-6 expression gradually increased during aging, inhibiting AChR-β expression, which was reversed by tocilizumab. Both tocilizumab and the PGC1α agonist reversed the inhibiting effect of IL-6 expression on AChR-β. Compared to inhibition of signal transducer and activator of transcription 3, extracellular signal-regulated kinases 1/2 (ERK1/2) inhibition suppressed the effects of IL-6 on AChR-β and PGC1α. In aging mouse muscles and myotubes, myocyte enhancer factor 2 C (MEF2C) was recruited by PGC1α, which directly binds to the AChR-β promoter to regulate its expression.

CONCLUSIONS

This study verifies AChR-β regulation by the IL-6/IL-6R-ERK1/2-PGC1α/MEF2C pathway. Hence, evaluating muscle secretion, myokines, and AChRs at an earlier stage to determine pathological progression is important. Moreover, developing intervention strategies for monitoring, maintaining, and improving muscle structure and function is necessary.

Advancements in sarcopenia diagnosis: from imaging techniques to non-radiation assessments

Sarcopenia is a prevalent condition with significant clinical implications, and it is expected to escalate globally, demanding for effective diagnostic strategies, possibly at an early stage of the disease. Imaging techniques play a pivotal role in comprehensively evaluating sarcopenia, offering insights into both muscle quantity and quality. Among all the imaging techniques currently used for the diagnosis and follow up of sarcopenia, it is possible to distinguish two classes: Rx based techniques, using ionizing radiations, and non-invasive techniques, which are based on the use of safe and low risk diagnostic procedures. Dual-energy x-ray Absorptiometry and Computed Tomography, while widely utilized, entail radiation exposure concerns. Ultrasound imaging offers portability, real-time imaging, and absence of ionizing radiation, making it a promising tool Magnetic Resonance Imaging, particularly T1-weighted and Dixon sequences, provides cross- sectional and high-resolution images and fat-water separation capabilities, facilitating precise sarcopenia quantification. Bioelectrical Impedance Analysis (BIA), a non-invasive technique, estimates body composition, including muscle mass, albeit influenced by hydration status. Standardized protocols, such as those proposed by the Sarcopenia through Ultrasound (SARCUS) Working Group, are imperative for ensuring consistency across assessments. Future research should focus on refining these techniques and harnessing the potential of radiomics and artificial intelligence to enhance diagnostic accuracy and prognostic capabilities in sarcopenia.