Insights into Pathogenesis, Nutritional and Drug Approach in Sarcopenia: A Systematic Review

Impact of body composition parameters on radiation therapy compliance in locally advanced rectal cancer: A retrospective observational analysis

Background

The impact of body composition and sarcopenia in locally advanced rectal cancer (LARC) is still unclear, even several studies have been published on this issue. Our study aims to analyze the impact of sarcopenia on neoadjuvant chemoradiotherapy (nCRT) tolerance and survival outcomes.

Methods

This is a retrospective, monocentric study where LARC patients treated between 2010 and 2020 were enrolled. A single slice, from the pre-therapy simulation computed tomography (CT) scan, was used to perform the body composition analysis with dedicated software. The primary endpoint was the impact of body composition on radiotherapy (RT) interruption secondarily on overall survival (OS), disease-free survival (DFS), and local control (LC).

Results

The study included 628 LARC patients (40.9 % female, mean age 63.4 years): 24 % had low skeletal muscle index (SMI), 30 % had low muscle density (MD) and 17 (10.3 % of obese) were sarcopenic obese. Higher BMI (OR 2.38, 95 % CI 1.36-4.01) and lower SMI (0.73, 95 % CI 0.55-0.94) resulted as independent predictors of RT interruption. Sarcopenic obesity (HR 2.83, 95 % CI 1.24-6.45) was related to worse OS, while MD (0.96, 95 % CI 0.93-0.98), and higher SMI (0.97, 95 % CI 0.95-0.99) were related to better OS; a lower MD remained also associated even in adjusted multivariable analysis (0.96, 95 % CI0.93-0.98). Moreover, higher visceral adipose tissue (VAT) resulted associated with worse DFS (1.02, 95 % CI 1.01-1.03), while higher SMI was related to better Local Control (0.96, 95 % CI 0.93-0.99).

Conclusions

Body composition analysis, particularly of muscle and fat masses, may be a useful tool for better management of LARC patients undergoing RT. Increased collaboration between radiation oncologists and clinical nutritionists is advisable, to enable early nutritional support of LARC.

Role of lifestyle and glucagon-like peptide-1 receptor agonists for weight loss in obesity, type 2 diabetes and steatotic liver diseases

BACKGROUND

The current obesity pandemic has given rise to associated comorbidities and complications, including type 2 diabetes and metabolic dysfunction-associated steatotic liver disease (MASLD). During the last decade, certain glucagon-like peptide 1 receptor agonists (GLP-1RA), originally developed as antihyperglycemic drugs, also demonstrated efficacy for weight loss.

AIMS

To review shared pathophysiologic features of common metabolic diseases and compare therapeutic strategies to reduce body weight and related complications.

METHODS

We performed an extensive literature research to describe the effects of lifestyle modification, first-generation anti-obesity drugs, and GLP-1RA on weight loss in humans with obesity, type 2 diabetes and MASLD.

RESULTS

Until recently, treatment of obesity has been limited to lifestyle modification, which offer moderate degree and sustainability of weight loss. The few approved first-generation anti-obesity drugs are either limited to short term use or to certain forms of obesity. Some GLP-1RA significantly decrease caloric intake and body weight. Liraglutide and semaglutide have therefore been approved for treating people with obesity. They also lead to a reduction of hepatic fat content and inflammation in people with biopsy-confirmed MASLD. Possible limitations comprise adverse effects, treatment adherence and persistence.

CONCLUSION

Certain GLP-1RA are superior to lifestyle modification and first-generation anti-obesity drugs in inducing weight loss. They have therefore markedly changed the portfolio of obesity treatment with additional beneficial effects on steatotic liver disease.

The Validity of Muscle Ultrasound in the Diagnostic Workup of Sarcopenia Among Older Adults: A Scoping Review

Purpose

Muscle ultrasound has emerged as a promising method in the diagnostic work-up of sarcopenia. The objective of this scoping review was to explore the validity of muscle ultrasound against the latest sarcopenia definitions among older adults.

Methods

We adhered to the PRISMA guidelines for scoping reviews. A systematic search of databases was performed by two independent reviewers. All articles comparing the performance of ultrasound to an internationally acknowledged sarcopenia definition among older adults (≥60 years) and published between 2019/01/01 (the year updated sarcopenia definitions were introduced) and 2023/11/15 were included. Data were extracted and collated by muscle and muscle parameters.

Results

Out of 2290 articles screened, six studies comprising 24 validity tests among a total of 1619 older adults (mean age 74.1 years, 52.2% female) were included. The validity tests investigated the rectus femoris (n = 7), biceps brachii (n = 5), gastrocnemius medialis (n = 4), tibialis anterior (n = 4), soleus (n = 3), and rectus abdominis (n = 1). The parameter muscle thickness (MT) (n = 14) was most commonly measured. The latest European and Asian sarcopenia definitions (EWGSOP2, AWGS2) were applied as reference standards in four validity tests each. None of the studies used the Sarcopenia Definition and Outcome Consortium (SDOC) criteria. The highest area under the curve AUC (0.92, 95% confidence interval [CI] 0.89-0.94) was found for the muscle thickness of the rectus femoris muscle. Due to substantial heterogeneity among the studies, pooling of data using a meta-analytic approach was not feasible.

Conclusion

Limited number of studies have examined the validity of muscle ultrasound for diagnosing sarcopenia based on recent definitions among older adults. Thereby, muscle thickness of the rectus femoris showed promising results regarding validity. Further studies are needed to investigate the validity of key muscles and to validate muscle ultrasound among older hospitalized patients.

Association between non-alcoholic fatty liver disease and risk of sarcopenia: a systematic review and meta-analysis

OBJECTIVES

To determine the association of non-alcoholic fatty liver disease (NAFLD) with the incidence of sarcopenia.

DESIGN

Systematic review and meta-analysis of observational clinical studies.

SETTING AND PARTICIPANTS

Adults with NAFLD.

METHODS

Databases such as PubMed, Embase, Cochrane and Web of Science were searched for eligible studies published from the inception of each database up to 4 April 2023. All cross-sectional studies on the association between NAFLD and sarcopenia were included in this study. The quality of the included studies and risk of bias was assessed using the Agency for Healthcare Research and Quality checklist. STATA V.15.1 software was used for statistical analysis.

RESULTS

Of the 1524 retrieved articles, 24 were included in this review, involving 88 609 participants. Our findings showed that the prevalence of sarcopenia was higher in the NAFLD group than in the control group (pooled OR 1.74, 95% CI 1.39 to 2.17). In a subgroup analysis by region, patients with NAFLD showed an increased risk of sarcopenia (pooled OR 1.97, 95% CI 1.54 to 2.51) in the Asian group, whereas patients with NAFLD had no statistically significant association with the risk of sarcopenia in the American and European groups, with a pooled OR of 1.31 (95% CI 0.71 to 2.40) for the American group and a pooled OR of 0.99 (95% CI 0.21 to 4.69) for the European group. Similar results were observed in the sensitivity analysis, and no evidence of publication bias was observed.

CONCLUSIONS AND IMPLICATIONS

The current study indicated a significant positive correlation between NAFLD and sarcopenia, which may be affected by regional factors. This study provides the correlation basis for the relationship between NAFLD and sarcopenia and helps to find the quality strategy of sarcopenia targeting NAFLD.

Definition, diagnosis, and treatment of respiratory sarcopenia

PURPOSE OF REVIEW

Skeletal muscle weakness and wasting also occurs in the respiratory muscles, called respiratory sarcopenia. Respiratory sarcopenia may lead to worse clinical indicators and outcomes. We present a novel definition and diagnostic criteria for respiratory sarcopenia, summarize recent reports on the association between respiratory sarcopenia, physical and nutritional status, and clinical outcomes, and provide suggestions for the prevention and treatment of respiratory sarcopenia.

RECENT FINDINGS

Recently, a novel definition and diagnostic criteria for respiratory sarcopenia have been prepared. Respiratory sarcopenia is defined as a condition in which there is both low respiratory muscle strength and low respiratory muscle mass. Respiratory muscle strength, respiratory muscle mass, and appendicular skeletal muscle mass are used to diagnose respiratory sarcopenia. Currently, it is challenging to definitively diagnose respiratory sarcopenia due to the difficulty in accurately determining low respiratory muscle mass. Decreased respiratory muscle strength and respiratory muscle mass are associated with lower physical and nutritional status and poorer clinical outcomes. Exercise interventions, especially respiratory muscle training, nutritional interventions, and their combinations may effectively treat respiratory sarcopenia. Preventive interventions for respiratory sarcopenia are unclear.

SUMMARY

The novel definition and diagnostic criteria will contribute to promoting the assessment and intervention of respiratory sarcopenia.

Restoration of epigenetic impairment in the skeletal muscle and chronic inflammation resolution as a therapeutic approach in sarcopenia

Sarcopenia is an age-associated loss of skeletal muscle mass, strength, and function, accompanied by severe adverse health outcomes, such as falls and fractures, functional decline, high health costs, and mortality. Hence, its prevention and treatment have become increasingly urgent. However, despite the wide prevalence and extensive research on sarcopenia, no FDA-approved disease-modifying drugs exist. This is probably due to a poor understanding of the mechanisms underlying its pathophysiology. Recent evidence demonstrate that sarcopenia development is characterized by two key elements: (i) epigenetic dysregulation of multiple molecular pathways associated with sarcopenia pathogenesis, such as protein remodeling, insulin resistance, mitochondria impairments, and (ii) the creation of a systemic, chronic, low-grade inflammation (SCLGI). In this review, we focus on the epigenetic regulators that have been implicated in skeletal muscle deterioration, their individual roles, and possible crosstalk. We also discuss epidrugs, which are the pharmaceuticals with the potential to restore the epigenetic mechanisms deregulated in sarcopenia. In addition, we discuss the mechanisms underlying failed SCLGI resolution in sarcopenia and the potential application of pro-resolving molecules, comprising specialized pro-resolving mediators (SPMs) and their stable mimetics and receptor agonists. These compounds, as well as epidrugs, reveal beneficial effects in preclinical studies related to sarcopenia. Based on these encouraging observations, we propose the combination of epidrugs with SCLI-resolving agents as a new therapeutic approach for sarcopenia that can effectively attenuate of its manifestations.

Highlighting the effect of reduced training volume on maintaining hormonal adaptations obtained from periodized resistance training in sarcopenic older women

BACKGROUND

This study investigated the impact of the High Intensity Interval Resistance Training (HIIRT) protocol on hormonal changes in older women.

RESEARCH DESIGN AND METHODS

Forty sarcopenic women were divided into an experimental group (EX = 30) and a control group (C = 10). The EX-group was further divided into Maintenance Training 1 (MT1 = 10), Maintenance Training 2 (MT2 = 10), and Detraining (DT = 10). The participants underwent 8 weeks of resistance training, consisting of hypertrophy and strength cycles. Following this, the EX-group had a 4-week period with no exercise or a reduced training volume. Measurements were taken at three time points.

RESULTS

After 8 weeks, the EX-group showed significant improvements in Insulin Like Growth Factor-1 (IGF-1), Myostatin (MSTN), Follistatin (Fstn), Growth Hormone (GH) and Cortisol (Cort) compared to the control group. During the volume reduction period, there were no significant differences between MT1 and MT2 groups, but both groups saw increases in IGF-1, Fstn, GH, and decreases in MSTN and Cort compared to the DT group.

CONCLUSIONS

These findings suggest that performing at least one training session per week with the HIIRT protocol is crucial for maintaining hormonal adaptations in sarcopenic older women.

Obstacles to the Early Diagnosis and Management of Sarcopenia: Current Perspectives

Research in sarcopenia has grown exponentially over the last 15 years in geriatrics and gerontology, as well as other specialties, including oncology and hepatology. There is now strong evidence for the role of resistance exercise to prevent declines in muscle strength and function, especially when combined with nutritional optimization with protein supplementation. However, there remains a disparity between research evidence and clinical practice. There are multiple factors for this, which relate to the current diagnostic criteria for sarcopenia, practical and logistical aspects of diagnosis of sarcopenia, clinician knowledge of both diagnosis and management, and the availability of pathways for interventions. Sarcopenia is currently defined based on the identification of muscle strength, in combination with muscle size or quality, below cut-off thresholds at a single timepoint. This defines sarcopenia as a binary process of either present or not present, thus early diagnosis can be challenging. In this article, we summarize current obstacles to early diagnosis and management of sarcopenia in clinical practice, and make recommendations to how these might be overcome. This includes our recommendation of incorporation of handgrip strength measurement into standard care, to enable dynamic assessment and identification of early declines in handgrip strength, so that interventions can be implemented to prevent disability.

Sarcopenia and Neuroendocrine Neoplasms

PURPOSE OF THE REVIEW

To summarise the current literature regarding the presence of sarcopenia in patients with neuroendocrine neoplasms (NENs). These are uncommon cancers separated into well-differentiated neuroendocrine tumours (NETs) and poorly differentiated neuroendocrine carcinoma (NECs). For the diagnosis of sarcopenia, there needs to be low muscle strength and low muscle quantity/quality.

RECENT FINDINGS

Five studies exist describing either low muscle strength or low muscle quantity in patients with NETs. The studies used different techniques to analyse muscle strength and muscle quantity, included heterogeneous populations, and performed the analysis at different time points following the diagnosis of the NET. Only 2 studies regarding patients with NECs could be found, both included mainly patients with a mixed adenoneuroendocrine carcinoma (MiNEN) and are, therefore, difficult to interpret for patients with a NEC. The main findings of this review are to describe the presence of sarcopenia in patients with NENs. However, results should be interpreted with caution, and future research should focus on the correct technique, homogenous population and same time point.

Association between serum estradiol level and appendicular lean mass index in middle-aged postmenopausal women

BACKGROUND

Previous studies investigating the association between loss of estrogen at menopause and skeletal muscle mass came to contradictory conclusions.

AIM

To evaluate the association between serum estradiol level and appendicular lean mass index in middle-aged postmenopausal women using population-based data.

METHODS

This study included 673 postmenopausal women, aged 40-59 years, from the National Health and Nutrition Examination Survey between 2013 and 2016. Weighted multivariable linear regression models were used to evaluate the association between serum E2 Level and appendicular lean mass index (ALMI). When non-linear associations were found by using weighted generalized additive model and smooth curve fitting, two-piecewise linear regression models were further applied to examine the threshold effects.

RESULTS

There was a positive association between serum E2 level and ALMI. Compared to individuals in quartile 1 group, those in other quartiles had higher ALMI levels. An inverted U-shaped curve relationship between serum E2 Level and ALMI was found on performing weighted generalized additive model and smooth curve fitting, and the inflection point was identified as a serum E2 level of 85 pg/mL.

CONCLUSION

Our results demonstrated an inverted U-shaped curve relationship between serum E2 levels and ALMI in middle-aged postmenopausal women, suggesting that low serum E2 levels play an important in the loss of muscle mass in middle-aged postmenopausal women.

Facilitators and barriers to the implementation of dietary nutrition interventions for community-dwelling older adults with physical frailty and sarcopenia: A qualitative meta-synthesis

Objectives

With the acceleration of an aging society, the prevalence of age-related chronic diseases such as physical frailty and sarcopenia is gradually increasing with numerous adverse effects. Dietary nutrition is an important modifiable risk factor for the management of physical frailty and sarcopenia, but there are many complex influences on its implementation in community settings. This study aimed to summarize the facilitators and barriers to the implementation of dietary nutrition interventions for community-dwelling older adults with physical frailty and sarcopenia, and to provide a reference for the formulation of relevant health management programs.

Methods

Searches were conducted in databases including PubMed, Web of Science, Medline (Ovid), Embase (Ovid), and Cochrane Library from inception to January 2023. Searches were completed for a combination of MeSH terms and free terms. The Critical Appraisal Skills Program (CASP) instrument was used to appraise quality. Coding and analysis of the extracted information were performed using the socio-ecological modeling framework. The study protocol for this review was registered on the PROSPERO ( CRD42022381339).

Results

A total of 10 studies were included. Of these, four were nutrition-only focused interventions, and six were dietary nutrition and exercise interventions. The facilitators and barriers were summarized based on the socio-ecological model that emerged at three levels: individual trait level, external environment level, and intervention-related level, containing ten subthemes.

Conclusion

Individual internal motivation and external support should be integrated with the implementation of diet- and nutrition-related interventions in community-living aged people with physical frailty and sarcopenia. Develop "tailored" interventions for participants and maximize available human and physical resources.

Musculoskeletal Diseases: From Molecular Basis to Therapy

Musculoskeletal diseases (MSDs) comprise a plethora of different disorders (more than 150 conditions) affecting the locomotor system [...].

Associations of medicine use and ejection fraction with the coexistence of frailty and sarcopenia in a sample of heart failure outpatients: a cross-sectional study

BACKGROUND

Frailty and sarcopenia have been extensively studied in heart failure (HF) patients, but their coexistence is unknown. The aim of this work is to describe the coexistence of these conditions in a sample of HF outpatients and its association with the use of medication and left-ventricular ejection fraction.

METHODS

Participants in this cross-sectional study were recruited from a HF outpatients' clinic in northern Portugal. Frailty phenotype was assessed according to Fried et al. Sarcopenia was evaluated according to the revised consensus of the European Working Group on Sarcopenia in Older People.

RESULTS

A total of 136 HF outpatients (33.8% women, median age 59 years) integrated this study. Frailty and sarcopenia accounted for 15.4% and 18.4% of the sample, respectively. Coexistence of frailty and sarcopenia was found in 8.1% of the participants, while 17.6% had only one of the conditions. In multivariable analysis (n = 132), increasing age (OR = 1.13;95%CI = 1.06,1.20), being a woman (OR = 65.65;95%CI = 13.50, 319.15), having heart failure with preserved ejection fraction (HFpEF) (OR = 5.61; 95%CI = 1.22, 25.76), and using antidepressants (OR = 11.05; 95%CI = 2.50, 48.82), anticoagulants (OR = 6.11; 95%CI = 1.69, 22.07), furosemide (OR = 3.95; 95%CI = 1.07, 14.55), and acetylsalicylic acid (OR = 5.01; 95%CI = 1.10, 22.90) were associated with increased likelihood of having coexistence of frailty and sarcopenia, while using statins showed the inverse effect (OR = 0.06; 95%CI = 0.01, 0.30).

CONCLUSIONS

The relatively low frequency of coexistence of frailty and sarcopenia signifies that each of these two conditions still deserve individual attention from health professionals in their clinical practice and should be screened separately. Being a woman, older age, having HFpEF, using anticoagulants, antidepressants, loop diuretics and acetylsalicylic acid, and not using statins, were associated with having concomitant frailty and sarcopenia. These patients can potentially benefit from interventions that impact their quality of life such as nutritional and mental health interventions and exercise training.

Bibliometric Analysis of Geriatric Sarcopenia Therapies: Highlighting Publication Trends and Leading-Edge Research Directions

The bibliometric analysis assesses the productivity of scholarship in a given field and provides information on the frontiers of relevant developments. However, no bibliometric analysis study has quantitatively analyzed publications in geriatric sarcopenia therapies. This study investigates the scholarly productivity and frontiers of publications in geriatric sarcopenia therapies. The bibliometric data came from English-language Web of Science Core Collection articles published between 1995 and October 19, 2022. Three software programs, R version 3.5.6, VOSviewer, and CiteSpace, were applied for this bibliometric analysis. In twenty-eight years, the annual publications in geriatric sarcopenia therapies have increased yearly, with an annual growth rate of 21.23 %. A total of 1379 publications have been published. The United States was the country with the highest number of publication signatures (n=1,537) (including joint publication releases), followed by Japan (n=1099). Journal of Cachexia, Sarcopenia, and Muscle contributed the best journal publications (n=80). The newest hot subjects in the study about geriatric sarcopenia therapy include malnutrition, obesity, insulin resistance, and cancer. This bibliometric study presents a comprehensive overview of the current and future research directions in geriatric sarcopenia therapies over the past 28 years. Overall, this study has complemented the gaps in bibliometric analysis in geriatric sarcopenia therapies. This paper will provide a valuable reference for future research in geriatric sarcopenia therapies.

Sarcopenia, osteoporosis and frailty

Muscles and bones are intricately connected tissues displaying marked co-variation during development, growth, aging, and in many diseases. While the diagnosis and treatment of osteoporosis are well established in clinical practice, sarcopenia has only been classified internationally as a disease in 2016. Both conditions are associated with an increased risk of adverse health outcomes such as fractures, dysmobility and mortality. Rather than focusing on one dimension of bone or muscle mass or weakness, the concept of musculoskeletal frailty captures the overall loss of physiological reserves in the locomotor system with age. The term osteosarcopenia in particular refers to the double jeopardy of osteoporosis and sarcopenia. Muscle-bone interactions at the biomechanical, cellular, paracrine, endocrine, neuronal or nutritional level may contribute to the pathophysiology of osteosarcopenia. The paradigm wherein muscle force controls bone strength is increasingly facing competition from a model centering on the exchange of myokines, osteokines and adipokines. The most promising results have been obtained in preclinical models where common drug targets have been identified to treat these conditions simultaneously. In this narrative review, we critically summarize the current understanding of the definitions, epidemiology, pathophysiology, and treatment of osteosarcopenia as part of an integrative approach to musculoskeletal frailty.

Pathogenesis, Intervention, and Current Status of Drug Development for Sarcopenia: A Review

Sarcopenia refers to the loss of muscle strength and mass in older individuals and is a major determinant of fall risk and impaired ability to perform activities of daily living, often leading to disability, loss of independence, and death. Owing to its impact on morbidity, mortality, and healthcare expenditure, sarcopenia in the elderly has become a major focus of research and public policy debates worldwide. Despite its clinical importance, sarcopenia remains under-recognized and poorly managed in routine clinical practice, partly owing to the lack of available diagnostic testing and uniform diagnostic criteria. Since the World Health Organization and the United States assigned a disease code for sarcopenia in 2016, countries worldwide have assigned their own disease codes for sarcopenia. However, there are currently no approved pharmacological agents for the treatment of sarcopenia; therefore, interventions for sarcopenia primarily focus on physical therapy for muscle strengthening and gait training as well as adequate protein intake. In this review, we aimed to examine the latest information on the epidemiology, molecular mechanisms, interventions, and possible treatments with new drugs for sarcopenia.