Sarcopenia

The role of TGF-β signaling in muscle atrophy, sarcopenia and cancer cachexia

Skeletal muscle, comprising a significant proportion (40 to 50 percent) of total body weight in humans, plays a critical role in maintaining normal physiological conditions. Muscle atrophy occurs when the rate of protein degradation exceeds protein synthesis. Sarcopenia refers to age-related muscle atrophy, while cachexia represents a more complex form of muscle wasting associated with various diseases such as cancer, heart failure, and AIDS. Recent research has highlighted the involvement of signaling pathways, including IGF1-Akt-mTOR, MuRF1-MAFbx, and FOXO, in regulating the delicate balance between muscle protein synthesis and breakdown. Myostatin, a member of the TGF-β superfamily, negatively regulates muscle growth and promotes muscle atrophy by activating Smad2 and Smad3. It also interacts with other signaling pathways in cachexia and sarcopenia. Inhibition of myostatin has emerged as a promising therapeutic approach for sarcopenia and cachexia. Additionally, other TGF-β family members, such as TGF-β1, activin A, and GDF11, have been implicated in the regulation of skeletal muscle mass. Furthermore, myostatin cooperates with these family members to impair muscle differentiation and contribute to muscle loss. This review provides an overview of the significance of myostatin and other TGF-β signaling pathway members in muscular dystrophy, sarcopenia, and cachexia. It also discusses potential novel therapeutic strategies targeting myostatin and TGF-β signaling for the treatment of muscle atrophy.

Impaired skeletal muscle regeneration in diabetes: From cellular and molecular mechanisms to novel treatments

Diabetes represents a major public health concern with a considerable impact on human life and healthcare expenditures. It is now well established that diabetes is characterized by a severe skeletal muscle pathology that limits functional capacity and quality of life. Increasing evidence indicates that diabetes is also one of the most prevalent disorders characterized by impaired skeletal muscle regeneration, yet underlying mechanisms and therapeutic treatments remain poorly established. In this review, we describe the cellular and molecular alterations currently known to occur during skeletal muscle regeneration in people with diabetes and animal models of diabetes, including its associated comorbidities, e.g., obesity, hyperinsulinemia, and insulin resistance. We describe the role of myogenic and non-myogenic cell types on muscle regeneration in conditions with or without diabetes. Therapies for skeletal muscle regeneration and gaps in our knowledge are also discussed, while proposing future directions for the field.

Cardiorespiratory Performance, Physical Activity, and Depression in Thai Older Adults with Sarcopenia and No Sarcopenia: A Matched Case-Control Study

BACKGROUND

Older adults have a high risk for musculoskeletal, cardiorespiratory, and mental health problems. We compared respiratory muscle strength, cardiovascular endurance, physical activity (PA), and depression between older adults with and without sarcopenia.

METHODS

This matched case-control study included 200 Thai older adults (100 participants with and without sarcopenia). According to the Asian Working Group for Sarcopenia 2019, participants completed a handgrip dynamometer, a 6 m walk test, and bioimpedance analysis for sarcopenia screening. Individuals were required to evaluate their cardiovascular endurance and respiratory muscle strength and complete a set of questionnaires (i.e., depression and PA). Participants with and without sarcopenia were compared using a t-test, and ANOVA was used for subgroup analysis.

RESULTS

Participants with sarcopenia had significantly lower inspiratory muscle strength (p < 0.001), functional capacity (p = 0.032), PA (p < 0.001), and higher depression scores (p < 0.001) than those without sarcopenia. Respiratory muscle strength and PA were significantly reduced in those with severe sarcopenia, followed by those with sarcopenia, possible sarcopenia, and no sarcopenia. Older adults with severe sarcopenia had higher depression scores than those with sarcopenia, possible sarcopenia, or no sarcopenia.

CONCLUSIONS

Older adults with sarcopenia may exhibit lower cardiorespiratory performance, less PA, and higher depression than those without sarcopenia.

Sarcopenia as a Predictor of Feeding Tube Placement in Individuals with Oropharyngeal Cancer

Purpose

In oropharyngeal squamous cell carcinoma (OPSCC), systemic loss of skeletal muscle mass (SMM), or sarcopenia, is a strong prognostic predictor of survival outcomes. However, the relationship between sarcopenia and nutrition-related outcomes is not well understood. This investigation evaluated the prognostic significance of sarcopenia for feeding tube (FT) placement in a cohort of OPSCC patients.

Methods and Materials

A retrospective cohort study was conducted with data collected from 194 OPSCC patients treated with definitive radiation therapy (RT) or chemoradiation therapy (CRT). Sarcopenia was assessed from computed tomography imaging at the level of the third cervical (C3) and fourth thoracic (T4) vertebrae. The prognostic nature of pretreatment sarcopenia and its relationship with FT placement was explored using logistic regression.

Results

The median age of patients included was 61.0 years, and the majority were male (83%). In this patient cohort, 87.6% underwent concurrent CRT, and 30.9% received a FT over the course of treatment. Sarcopenia was identified at baseline in 72.7% of patients based on C3 SMM measurements and in 41.7% based on measures at the level of T4. Based on measures at both C3 and T4, those with sarcopenia were significantly more likely to receive a FT and had significantly worse freedom from FT placement compared with patients without sarcopenia. Sarcopenia assessed at T4 was a significant predictor of FT placement.

Conclusions

SMM measured at T4 may represent a novel and practical biomarker for sarcopenia detection that is associated with the need for FT placement. These findings suggest that the detection of baseline sarcopenia could guide decision-making related to the need for nutritional support in OPSCC patients undergoing RT/CRT.

Development of a tool for monitoring the jaw-opening pace and preliminary comparison the pace between young and old ages

OBJECTIVES

Studies have demonstrated that high-speed jaw-opening exercises are effective in improving swallowing function. However, there has been no objective tool available for monitoring jaw-opening pace. This study aimed to develop an objective tool for monitoring and validating jaw-opening pace and compare it between young and old ages from different age groups.

MATERIALS AND METHODS

A load cell plug-in jaw pad connected to an automatic recording and analysis system was used to record jaw-opening motions for offline analysis. We recruited 58 healthy volunteers from different age groups (20-39 y/o; 40-59y/o; 60-79y/o). During a 2-min recording session, each participant was instructed to fully open and close their jaw as quickly as possible while wearing a sensor. Bland-Altman plot, paired t-test and Pearson's correlation test were used to compare the number of jaw-opening motions between manual counting and automatic software analysis. The number of jaw-opening motions during the 2-min recording was compared between the three age groups.

RESULTS

Automated analysis of jaw-opening pace was efficient and equally comparable with the traditional manual counting method across the three age groups. A declining trend in jaw-opening pace among the old age group was found but with no statistically significant difference.

CONCLUSIONS

A jaw-opening motion monitoring tool with reliable automatic pace analysis software was validated in young and old ages. The jaw-opening pace demonstrated a tendency to decline with age.

CLINICAL RELEVANCE

This monitoring tool can also be used to provide visual feedback during jaw-opening motion training in pace control.

Community-based prevalence and associated factors of sarcopenia in the Vietnamese elderly

Sarcopenia, a condition characterized by muscle mass decline, is one of the leading health problems in the elderly. This study determined the rate of sarcopenia according to criteria by Asian Working Group for Sarcopenia (AWGS) and related factors in elderly people. A community-based cross-sectional study was conducted in 632 people aged 60 years or over in Ho Chi Minh City. Data were collected through a predefined questionnaire and direct measurement. Sarcopenia was identified based on the Inbody 770 machine and AWGS criteria. The prevalence of sarcopenia was 32.0%. Participants with advanced age, low education, unemployment, low level of family economics and frailty were more likely to have sarcopenia. Among these, frailty had the highest impact on sarcopenia, with significantly higher odds of having sarcopenia found in participants with pre-frailty (OR = 4.80, 95% CI 2.75-8.38, p < 0.001) and frailty (OR = 21.16, 95% CI 8.96-49.97, p < 0.001). In contrast, BMI was inversely associated with sarcopenia. Sarcopenia is prevalent in the Vietnamese elderly. Apart from social demographic characteristics including age, education, employment and family economic status, frailty appeared to be an important risk factor. Early screening, referral, and treatment of sarcopenia among the elderly having a high risk of sarcopenia are recommended.

Participation in youth sports influences sarcopenia parameters in older adults

Background

The degree of deterioration in sarcopenia parameters may be affected by a person's level of physical activity (PA) and sedentary behavior (SB). Our study focused on examining the PA and SB of active older adults including those with and without history of sports in youth.

Methods

Forty-four participants (20 men and 24 women, mean age of total sample 76.1 ± 5.2 years) were included in analysis of PA, SB habits and sarcopenia parameters, determined by skeletal muscle index, hand-grip strength, gait speed, Timed Up and Go tests (TUG). PA and SB were recorded with accelerometers. Our primary aim was to compare participants with (AH) or without a sport history in youth (NAH), in their sarcopenia parameters and PA and SB habits.

Results

When divided participants in two groups (AH and NAH) and adjusting for age, we have detected the differences for skeletal muscle index (p = 0.007) and hand-grip strength (p = 0.004) in favor of participants who were engaged in sports in youth. We did not find any differences in PA and SB habits between the AH and NAH groups. After adjusting for age, participants with a higher number of daily steps, longer moderate to vigorous physical activity (MVPA) bouts, a higher number of MVPA bouts in a day and higher overall MVPA engagement achieved better results in hand-grip strength and TUG. Participants with lower SB had better TUG and gait speed results.

Conclusions

Our findings suggest that engaging in sports activities in youth can make a difference with sarcopenia parameters. Although we found no differences in PA and SB habits between participants with AH and NAH, participants with an athlete history performed better results in sarcopenia parameters.

The relationship between sarcopenia and serum irisin and TNF-α levels in newly diagnosed cancer patients

OBJECTIVE

Sarcopenia in patients with cancer makes patients physically weak and adversely affects their compliance with treatment. In this study, we investigated the relationship between sarcopenia in patients with cancer and circulating irisin and tumor necrosis factor-alpha (TNF-α) levels.

MATERIAL AND METHOD

A total of 141 patients with different types of newly diagnosed cancer were divided into two groups, sarcopenia (n = 72) and non-sarcopenia (n = 69) groups. The body compositions of the patients were measured using bioelectrical impedance (BIA) and muscle strength using hand grip strength (HGS) tests. Serum irisin and TNF-α levels were measured using an enzyme-linked immunosorbent assay.

RESULTS

In our study, serum irisin levels were found to be significantly lower (p < 0.01) and TNF-α levels were found to be significantly higher (p = 0.014) in the sarcopenia group. Skeletal muscle index (SMI) and HGS values and serum irisin levels were positively correlated [(r: 0.451, p < 0.001), (r: 0.469, p < 0.001)], and SMI and HGS values and serum TNF-α levels were negatively correlated [(r: -0.181, p = 0.032) and (r: -0.143, p = 0.090), respectively]. In addition, multiple linear regression analysis showed that serum irisin and TNF-α levels were independent predictors of sarcopenia.

CONCLUSION

Serum irisin levels were found to be significantly lower in patients with cancer with sarcopenia, and TNF-α levels were found to be significantly higher. These two markers can be used as potential biomarkers for the diagnosis of sarcopenia in patients with cancer. The efficacy and possible mechanisms of action of irisin and TNF-α in the diagnosis of sarcopenia should be investigated with larger patient groups.

Mitigating Sarcopenia with Diet and Exercise

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

Sarcopenia parameters in active older adults - an eight-year longitudinal study

BACKGROUD

Sarcopenia is a common skeletal muscle syndrome that is common in older adults but can be mitigated by adequate and regular physical activity. The development and severity of sarcopenia is favored by several factors, the most influential of which are a sedentary lifestyle and physical inactivity. The aim of this observational longitudinal cohort study was to evaluate changes in sarcopenia parameters, based on the EWGSOP2 definition in a population of active older adults after eight years. It was hypothesized that selected active older adults would perform better on sarcopenia tests than the average population.

METHODS

The 52 active older adults (22 men and 30 women, mean age: 68.4 ± 5.6 years at the time of their first evaluation) participated in the study at two time points eight-years apart. Three sarcopenia parameters were assessed at both time points: Muscle strength (handgrip test), skeletal muscle mass index, and physical performance (gait speed), these parameters were used to diagnose sarcop0enia according to the EWGSOP2 definition. Additional motor tests were also performed at follow-up measurements to assess participants' overall fitness. Participants self-reported physical activity and sedentary behavior using General Physical Activity Questionnaire at baseline and at follow-up measurements.

RESULTS

In the first measurements we did not detect signs of sarcopenia in any individual, but after 8 years, we detected signs of sarcopenia in 7 participants. After eight years, we detected decline in ; muscle strength (-10.2%; p < .001), muscle mass index (-5.4%; p < .001), and physical performance measured with gait speed (-28.6%; p < .001). Similarly, self-reported physical activity and sedentary behavior declined, too (-25.0%; p = .030 and - 48.5%; p < .001, respectively).

CONCLUSIONS

Despite expected lower scores on tests of sarcopenia parameters due to age-related decline, participants performed better on motor tests than reported in similar studies. Nevertheless, the prevalence of sarcopenia was consistent with most of the published literature.

TRIAL REGISTRATION

The clinical trial protocol was registered on ClinicalTrials.gov, identifier: NCT04899531.

Monitoring of strength, inflammation and muscle function in allogenic stem-cell transplantation patients - a pilot study for novel biomarker and risk stratification determination

Background

Low aerobic capacity is associated with an increased mortality risk in allogenic stem-cell transplantation (alloSCT) patients, but currently used risk scores in the pre-transplantation workup are still underestimating physical activity as a prognostic factor.

Aim

To examine the physical condition, muscle function, blood inflammation and training adherence of alloSCT patients during inpatient time to identify potential biomarkers associated with development of myopathy and sarcopenia.

Methods

Patients undergoing alloSCT were examined at four time points (T0: before alloSCT; T_ha: hospital admission; T1: engraftment; T2: inpatient discharge). T0 included cardiopulmonary performance, body composition, grip and knee strength, motor skill tests (One-leg stand/Tinetti/Chair-rising), blood sampling (blood cell profiling and inflammation targets (Kynurenin/high sensitivity C-reactive Protein (hsCRP)/Tumor necrosis factor alpha (TNF-alpha)/Musclin/Galectin-3) and quality of life, state of health, fatigue, muscle weakness and physical activity by questionnaires (IPAQ/BSA/SARC-F/Fatigue). At T1 and T2, blood samples, grip strength and motor skill tests were repeated. Glucocorticoid dose and daily physical activity were documented during inpatient stay.

Results

26 of 35 included patients (4 females; age 55.58 ± 12.32 years; BMI 24.70 ± 3.27 kg/m²; VO_2peak 16.55 ± 4.06 ml/min/kg) could proceed to alloSCT. Grip strength and Tinetti decreased from T0 until T2, no difference in Chair-rising test, One-leg and Tandem stand. All patients engrafted after 24.9 days ± 3.9 days. HsCRP and Kynurenine increased from T0 to T1, decreased at T2. TNF-alpha (T0vsT2/T1vsT2) and Musclin (T0vsT1) decreased. At T2, Galectin-3 was higher compared to T0/T1. Correlation analysis of grip strength and inflammatory markers revealed a positive correlation with TNF-alpha at T2. 50% of patients documented physical activity and questionnaire and reported a 50%-reduction of daily endurance and strength training between T1 to T2.

Conclusion

Allogeneic stem-cell transplantation is associated with immune system vulnerability due to conditioning, increased inflammation and fatigue, and loss of muscle strength and function. In addition to hsCRP, Kynurenine seems to be a reliable biomarker to monitor acute and regenerative inflammation status of alloSCT patients, while Musclin and Galectin-3 may be added to physiological assessment regarding myopathy and sarcopenia. Grip strength and daily activity level should be documented by professionals to identify risk patients early and support them with optimal (exercise) therapy.

Sarcopenic Obesity: Involvement of Oxidative Stress and Beneficial Role of Antioxidant Flavonoids

Sarcopenic obesity, which refers to concurrent sarcopenia and obesity, is characterized by decreased muscle mass, strength, and performance along with abnormally excessive fat mass. Sarcopenic obesity has received considerable attention as a major health threat in older people. However, it has recently become a health problem in the general population. Sarcopenic obesity is a major risk factor for metabolic syndrome and other complications such as osteoarthritis, osteoporosis, liver disease, lung disease, renal disease, mental disease and functional disability. The pathogenesis of sarcopenic obesity is multifactorial and complicated, and it is caused by insulin resistance, inflammation, hormonal changes, decreased physical activity, poor diet and aging. Oxidative stress is a core mechanism underlying sarcopenic obesity. Some evidence indicates a protective role of antioxidant flavonoids in sarcopenic obesity, although the precise mechanisms remain unclear. This review summarizes the general characteristics and pathophysiology of sarcopenic obesity and focuses on the role of oxidative stress in sarcopenic obesity. The potential benefits of flavonoids in sarcopenic obesity have also been discussed.

Linolenic acid ameliorates sarcopenia in C. elegans by promoting mitophagy and fighting oxidative stress

Sarcopenia is a syndrome of age-related loss of muscle mass and strength that seriously affects human health, and there are currently no effective drugs to treat the disease. Linolenic acid as a common n-3 polyunsaturated fatty acid (n-3 PUFA) is known to have many beneficial functions. Some studies have found that n-3 PUFA might have the potential to improve sarcopenia. In this study, Caenorhabditis elegans (C. elegans) was used as a model animal to investigate the effects of linolenic acid on C. elegans muscles. The results showed that 50 μg mL^-1 linolenic acid significantly improved sarcopenia by repairing mitochondrial function by promoting mitophagy and fighting oxidative stress (p < 0.05). This included the increase of the expression of the mitophagy gene pink-1 and DAF-16/FOXO transcription factors, respectively, by linolenic acid. This study could provide some evidence for the application of n-3 PUFA in improving sarcopenia.

Upregulation of CCL5/RANTES Gene Expression in the Diaphragm of Mice with Cholestatic Liver Disease

Chronic liver diseases are a group of pathologies affecting the liver with high prevalence worldwide. Among them, cholestatic chronic liver diseases (CCLD) are characterized by alterations in liver function and increased plasma bile acids. Secondary to liver disease, under cholestasis, is developed sarcopenia, a skeletal muscle dysfunction with decreased muscle mass, strength, and physical function. CCL5/RANTES is a chemokine involved in the immune and inflammatory response. Indeed, CCL5 is a myokine because it is produced by skeletal muscle. Several studies show that bile acids induce CCL5/RANTES expression in liver cells. However, it is unknown if the expression of CCL5/RANTES is changed in the skeletal muscle of mice with cholestatic liver disease. We used a murine model of cholestasis-induced sarcopenia by intake of hepatotoxin 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC diet), in which we detected the mRNA levels for ccl5. We determined that mice fed the DDC diet presented high levels of serum bile acids and developed typical features of sarcopenia. Under these conditions, we detected the ccl5 gene expression in diaphragm muscle showing elevated mRNA levels compared to mice fed with a standard diet (chow diet). Our results collectively suggest an increased ccl5 gene expression in the diaphragm muscle concomitantly with elevated serum bile acids and the development of sarcopenia.

Sarcopenia, obesity, and their association with selected behavioral factors in active older adults

Introduction: The number of obese people in the world is increasing, as is the number of sarcopenic people among the older adults. Although both states are concerning, they can be positively influenced by selected behavioral factors such as adequate nutrition and physical activity. We were interested in the prevalence of sarcopenic obesity in active older people and the influence of behavioral factors on this phenomenon. Methods: The study included 38 older adults (21 women) with a mean age of 75.3 ± 5.0 years. Sarcopenic parameters were determined with different tests: Handgrip Test, Chair Stand Test, Gait Speed, Timed Up and Go Test, and Short Physical Performance Battery. Body composition was measured by dual-energy x-ray absorptiometry. Physical activity level was measured using accelerometers, and nutritional status was assessed using the Mini-Nutritional Assessment and MEDLIFE Index questionnaire. Results: Of all included active participants (the average number of steps per day was 8,916 ± 3,543), 47.4% of them were obese. Of all included women, 52.4% were obese. Sarcopenic obesity was found in three (7.9%) participants. Nutritional status correlated with strength of lower extremities and physical performance tests (gait speed, Timed Up and Go Test and Short Physical performance battery). Higher number of steps per day positively correlates with physical performance. Discussion: Interestingly, we did not find any correlation between the main obesity parameter such as percent body fat or body mass index (and thus sarcopenic obesity) and any of the selected behavioral factors (physical activity, sedentary behavior, or dietary habits). In conclusion, reaching the recommended levels of physical activity in older adults may not be sufficient to prevent the occurrence of obesity and sarcopenic obesity.

Prevalence of possible sarcopenia in community-dwelling older Chinese adults: a cross-sectional study

OBJECTIVES

To determine the prevalence of possible sarcopenia and its association with other conditions in older adults in Bengbu, China.

DESIGN, SETTING AND PARTICIPANTS

A cross-sectional study of 1082 community-dwelling Chinese people aged at least 60 years from March to June 2022.

METHODS

Handgrip strength and information regarding associated conditions were collected. Possible sarcopenia was estimated based on handgrip strength with cut-off values (<28 kg in men; <18 kg in women) recommended by the Asia Working Group for Sarcopenia in 2019. Mann-Whitney U tests, χ² tests and binary logistic regression analyses were used to explore relationships between possible sarcopenia and associated conditions.

RESULTS

Possible sarcopenia was more prevalent in men (52.79%, n=246, age 79.43±7.33 years among men with possible sarcopenia) than in women (44.48%, n=274, age 78.90±7.71 years among women with possible sarcopenia). In men, possible sarcopenia positively correlated with high age (OR 2.658, 95% CI 1.758 to 4.019), physical inactivity (OR 2.779, 95% CI 1.646 to 4.691) and diabetes (OR 4.269, 95% CI 2.397 to 7.602), and negatively with hypertension (OR 0.586, 95% CI 0.384 to 0.893). The risk of possible sarcopenia in men decreased by 12.6% for every 1 kg/m² increase of body mass index (OR 0.874, 95% CI 0.817 to 0.935). In women, possible sarcopenia positively correlated with high age (OR 3.821, 95% CI 2.677 to 5.455), physical inactivity (OR 2.185, 95% CI 1.488 to 3.210) and arthritis (OR 2.076, 95% CI 1.411 to 3.056).

CONCLUSION

Possible sarcopenia is prevalent in older adults and the factors affecting possible sarcopenia are different in men and women. Health education about these target factors can be considered as a potential measure to prevent possible sarcopenia.

Contributions of physical inactivity and sedentary behavior to metabolic and endocrine diseases

Physical inactivity is the fourth leading global cause of death and is a major contributor to metabolic and endocrine diseases. In this review we provide a current update of the past 5 years in the field as it pertains to the most prevalent and deadly chronic diseases. Despite the prevalence of physical inactivity in modern society, it remains largely overlooked relative to other comparable risk factors such as obesity, and our molecular understanding of how physical inactivity impacts metabolism is still partially unknown. Therefore, we discuss current clinical inactivity models along with their most recent findings regarding health outcomes along with any discrepancies that are present in the field. Lastly, we discuss future directions and the need for translatable animal models of physical inactivity to discover novel molecular targets for the prevention of chronic disease.

Long-term voluntary wheel running effects on markers of Long Interspersed Nuclear Element-1 in skeletal muscle, liver, and brain tissue of female rats

We sought to determine the effects of long-term voluntary wheel running on markers of Long Interspersed Nuclear Element-1 (L1) in skeletal muscle, liver, and the hippocampus of female rats. Additionally, markers of the cGAS-STING DNA sensing pathway that results in inflammation were interrogated. Female Lewis rats (n=34) were separated into one of three groups including a 6-month-old group to serve as a young comparator group (CTL, n=10), a group that had access to a running wheel for voluntary wheel running (EX, n=12), and an age-matched group that did not (SED, n=12). Both SED and EX groups were carried out from 6 months to 15 months of age. There were no significant differences in L1 mRNA expression for any of the tissues between groups. Methylation of the L1 promoter in the soleus and hippocampus was significantly higher in SED and EX compared to CTL (p<0.05). ORF1p expression was higher in older SED and EX rats compared to CTL for every tissue (p<0.05). There were no differences between groups for L1 mRNA or cGAS-STING pathway markers. Our results suggest there is an increased ORF1 protein expression across tissues with aging that is not mitigated by voluntary wheel running. Additionally, while previous data imply that L1 methylation changes may play a role in acute exercise for L1 RNA expression, this does not seem to occur during extended periods of voluntary wheel running.

Muscle Weakness and Walking Slowness for the Identification of Sarcopenia in the Older Adults from Northern Brazil: A Cross-Sectional Study

Background: This study aimed to analyze the prevalence of sarcopenia in elderly people from Northern Brazil according to muscle weakness or walking slowness. Methods: The sample consisted of 312 elderly people (72.6 ± 7.8 years). For walking slowness, a gait speed ≤ 0.8 m/s was used as a cut-off value, and for muscle weakness the following handgrip strength criteria were used for men and women, respectively: CI: <27.0/16.0 kg; CII: <35.5/20.0 kg; CIII: grip strength corrected for body mass index (BMI) < 1.05/0.79; CIV: grip strength corrected for total fat mass: <1.66/0.65; CV: grip strength corrected for body mass: <0.45/0.34. Results: Walking speed was reduced in 27.0% of women and 15.2% of men (p < 0.05). According to grip strength criteria, 28.5% of women and 30.4% of men (CI), 58.0% of women and 75.0% of men (CII), 66.0% of women and 39.3% of men (CIII), 28.8% of women and 19.6% of men (CIV), and 56.5% of women and 50.0% of men (CV) were identified as having sarcopenia. Conclusions: Walking slowness is more prevalent in women and muscle weakness is more prevalent in men in Northern Brazil. Walking slowness proved to be more concordant with muscle weakness in both sexes when the CI for handgrip strength was adopted.

Exercise mitigates the Toll of muscle atrophy: A narrative review of the effects of exercise on Toll-like receptor-4 in leukocytes and skeletal muscle

Conditions characterized by muscle wasting such as cachexia and sarcopenia are devastating at the individual level, and they place a profound burden on public health. Evidence suggests that inflammation is likely a mechanistic contributor to the pathogenesis of these conditions. One specific molecule, lipopolysaccharide, has gained attention due to its role in initiating inflammation. Toll-like receptor-4 is the primary receptor for lipopolysaccharide and has been shown to be implicit in the downstream proinflammatory response associated with lipopolysaccharide. Importantly, Toll-like receptor-4 is expressed on various cell types throughout the human body such as leukocytes and skeletal muscle fibers and may have site-specific effects that contribute to muscle wasting conditions based on the location in which activation occurs. Accordingly, reducing proinflammatory signaling at these locations may be an effective strategy at mitigating muscle wasting. Regular exercise training is believed to elicit anti-inflammatory adaptations, but the mechanisms by which this occurs are yet to be fully understood. Understanding the mechanisms by which Toll-like receptor-4 activation contributes to muscle wasting and how exercise affects this, may allow for the development of a non-pharmacological therapeutic intervention. Therefore, in this review, we summarize the current understanding of the lipopolysaccharide/Toll-like receptor-4 axis in leukocytes and skeletal muscle fibers on the pathogenesis of muscle wasting conditions and we critically examine the current evidence regarding the effects of exercise on this axis.

Klotho: An Emerging Factor With Ergogenic Potential

Sarcopenia and impaired cardiorespiratory fitness are commonly observed in older individuals and patients with chronic kidney disease (CKD). Declines in skeletal muscle function and aerobic capacity can progress into impaired physical function and inability to perform activities of daily living. Physical function is highly associated with important clinical outcomes such as hospitalization, functional independence, quality of life, and mortality. While lifestyle modifications such as exercise and dietary interventions have been shown to prevent and reverse declines in physical function, the utility of these treatment strategies is limited by poor widespread adoption and adherence due to a wide variety of both perceived and actual barriers to exercise. Therefore, identifying novel treatment targets to manage physical function decline is critically important. Klotho, a remarkable protein with powerful anti-aging properties has recently been investigated for its role in musculoskeletal health and physical function. Klotho is involved in several key processes that regulate skeletal muscle function, such as muscle regeneration, mitochondrial biogenesis, endothelial function, oxidative stress, and inflammation. This is particularly important for older adults and patients with CKD, which are known states of Klotho deficiency. Emerging data support the existence of Klotho-related benefits to exercise and for potential Klotho-based therapeutic interventions for the treatment of sarcopenia and its progression to physical disability. However, significant gaps in our understanding of Klotho must first be overcome before we can consider its potential ergogenic benefits. These advances will be critical to establish the optimal approach to future Klotho-based interventional trials and to determine if Klotho can regulate physical dysfunction.

General and Central Obesity Are Associated With Increased Severity of the VMS and Sexual Symptoms of Menopause Among Chinese Women: A Longitudinal Study

BACKGROUND

Strong evidence has linked overweight and obesity to increased risks of cardiovascular disease and all-cause mortality in Chinese populations. Menopause is considered associated with increased obesity and central body fat distribution. However, the correlation between obesity and menopausal symptoms has not been well studied.

OBJECTIVE

To examine the associations between obesity or abdominal obesity and menopausal symptoms as women progressed from premenopausal to postmenopausal status.

DESIGN

This study included 430 midlife Chinese women who had experienced natural menopause and were followed up for 10 years. Physical examinations and questionnaires should be completed annually. The questionnaires include the Menopause-Specific Quality of Life questionnaire, the Hospital Anxiety and Depression Scale, and other physical and behavioral factors.

RESULTS

Among women who were not obese (n=345) or not abdominal obese (n=372) at baseline, 5.8% and 31.7% became obese or abdominal obese at the recent follow-up visit, respectively. Women at the recent follow-up visit had an increased body mass index (BMI) by 0.14%, and the waist-to-hip ratio (WHR) increased by 5.2% compared with the data at baseline. In multivariate analysis, more frequent hot flashes, moderate/severe bothered vasomotor symptoms (VMS), mild bothered sexual functioning, and less anxiety symptoms were significantly associated with obesity. Increasing age, moderate/severe bothered VMS, and less anxiety symptoms were independently associated with abdominal obesity. Multivariable analysis also showed that less education level is independently associated with both obesity and abdominal obesity.

CONCLUSION

Our findings suggest that the proportion of obesity and abdominal obesity increased gradually during menopause. The increase of abdominal obesity is more rapidly than obesity in middle-aged women. Both obesity and abdominal obesity are related with severe or frequent VMS and anxiety symptoms in Chinese women. Although the proportion of obese women in China is lower than in western countries, the problem of abdominal obesity and related complications cannot be ignored.

The Therapeutic Intervention of Sex Steroid Hormones for Sarcopenia

Sarcopenia, characterized by the excessive loss of skeletal muscle mass, strength, and function, is associated with the overall poor muscle performance status of the elderly, and occurs more frequently in those with chronic diseases. The causes of sarcopenia are multifactorial due to the inherent relationship between muscles and molecular mechanisms, such as mitochondrial function, inflammatory pathways, and circulating hormones. Age-related changes in sex steroid hormone concentrations, including testosterone, estrogen, progesterone, and their precursors and derivatives, are an important aspect of the pathogenesis of sarcopenia. In this review, we provide an understanding of the treatment of sarcopenia through the regulation of sex steroid hormones. The potential benefits and future research emphasis of each sex steroid hormone therapeutic intervention (testosterone, SARMs, estrogen, SERMs, DHEA, and progesterone) for sarcopenia are discussed. Enhanced understanding of the role of sex steroid hormones in the treatment for sarcopenia could lead to the development of hormone therapeutic approaches in combination with specific exercise and nutrition regimens.

The Critical Role of Oxidative Stress in Sarcopenic Obesity

Sarcopenic obesity (SO) is a combination of obesity and sarcopenia that primarily develops in older people. Patients with SO have high fat mass, low muscle mass, low muscle strength, and low physical function. SO relates to metabolic syndrome and an increased risk of morbimortality. The prevalence of SO varies because of lacking consensus criteria regarding its definition and the methodological difficulty in diagnosing sarcopenia and obesity. SO includes systemic alterations such as insulin resistance, increased proinflammatory cytokines, age-associated hormonal changes, and decreased physical activity at pathophysiological levels. Interestingly, these alterations are influenced by oxidative stress, which is a critical factor in altering muscle function and the generation of metabolic dysfunctions. Thus, oxidative stress in SO alters muscle mass, the signaling pathways that control it, satellite cell functions, and mitochondrial and endoplasmic reticulum activities. Considering this background, our objectives in this review are to describe SO as a highly prevalent condition and look at the role of oxidative stress in SO pathophysiology.

Skeletal muscle atrophy: From mechanisms to treatments

Skeletal muscle is a crucial tissue for movement, gestural assistance, metabolic homeostasis, and thermogenesis. It makes up approximately 40% of the total body weight and 50% of total protein. However, several pathological abnormalities (e.g., chronic diseases, cancer, long-term infection, aging) can induce an imbalance in skeletal muscle protein synthesis and degradation, which triggers muscle wasting and even leads to atrophy. Skeletal muscle atrophy is characterized by weakening, shrinking, and decreasing muscle mass and fiber cross-sectional area at the histological level. It manifests as a reduction in force production, easy fatigue and decreased exercise capability, along with a lower quality of life. Mechanistically, there are several pathophysiological processes involved in skeletal muscle atrophy, including oxidative stress and inflammation, which then activate signal transduction, such as the ubiquitin proteasome system, autophagy lysosome system, and mTOR. Considering the great economic and social burden that muscle atrophy can inflict, effective prevention and treatment strategies are essential but still limited. Exercise is widely acknowledged as the most effective therapy for skeletal muscle atrophy; unfortunately, it is not applicable for all patients. Several active substances for skeletal muscle atrophy have been discovered and evaluated in clinical trials, however, they have not been marketed to date. Knowledge is being gained on the underlying mechanisms, highlighting more promising treatment strategies in the future. In this paper, the mechanisms and treatment strategies for skeletal muscle atrophy are briefly reviewed.

Cystathionine gamma-lyase/H2 S signaling facilitates myogenesis under aging and injury condition

Hydrogen sulfide (H₂ S) can be endogenously produced and belongs to the class of signaling molecules known as gasotransmitters. Cystathionine gamma-lyase (CSE)-derived H₂ S is implicated in the regulation of cell differentiation and the aging process, but the involvements of the CSE/H₂ S system in myogenesis upon aging and injury have not been explored. In this study, we demonstrated that CSE acts as a major H₂ S-generating enzyme in skeletal muscles and is significantly down-regulated in aged skeletal muscles in mice. CSE deficiency exacerbated the age-dependent sarcopenia and cardiotoxin-induced injury/regeneration in mouse skeletal muscle, possibly attributed to inefficient myogenesis. In contrast, supplement of NaHS (an H₂ S donor) induced the expressions of myogenic genes and promoted muscle regeneration in mice. In vitro, incubation of myoblast cells (C2C12) with H₂ S promoted myogenesis, as evidenced by the inhibition of cell cycle progression and migration, altered expressions of myogenic markers, elongation of myoblasts, and formation of multinucleated myotubes. Myogenesis was also found to upregulate CSE expression, while blockage of CSE/H₂ S signaling resulted in a suppression of myogenesis. Mechanically, H₂ S significantly induced the heterodimer formation between MEF2c and MRF4 and promoted the binding of MEF2c/MRF4 to myogenin promoter. MEF2c was S-sulfhydrated at both cysteine 361 and 420 in the C-terminal transactivation domain, and blockage of MEF2c S-sulfhydration abolished the stimulatory role of H₂ S on MEF2c/MRF4 heterodimer formation. These findings support an essential role for H₂ S in maintaining myogenesis, presenting it as a potential candidate for the prevention of age-related sarcopenia and treatment of muscle injury.

Screening for Sarcopenia (Physical Frailty) in the COVID-19 Era

Although the numbers of aged populations have risen considerably in the last few decades, the current coronavirus disease 2019 (COVID-19) has revealed an extensive vulnerability among these populations. Sarcopenia is an age-related disorder that increases hospitalization, dependencies, and mortality in older adults. It starts to develop in midlife or even earlier as a result of unbalanced diet/poor nutrition and low levels of physical activity, in addition to chronic disorders such as obesity and diabetes mellitus. Given that social isolation is adopted as the most protective measure against COVID-19, the level of physical activity and the intake of adequate diet have considerably declined, especially among older adults-denoting an increased possibility for developing sarcopenia. Research also shows a higher vulnerability of sarcopenic people to COVID-19 as well as the development of wasting disorders such as sarcopenia and cachexia in a considerable proportion of symptomatic and recovering COVID-19 patients. Muscular wasting in COVID-19 is associated with poor prognosis. Accordingly, early detection and proper management of sarcopenia and wasting conditions in older adults and COVID-19 patients may minimize morbidity and mortality during the current COVID-19 crisis. This review explored different aspects of screening for sarcopenia, stressing their relevance to the detection of altered muscular structure and performance in patients with COVID-19. Current guidelines recommend prior evaluation of muscle strength by simple measures such as grip strength to identify individuals with proven weakness who then would be screened for muscle mass loss. The latter is best measured by MRI and CT. However, due to the high cost and radiation risk entailed by these techniques, other simpler and cheaper techniques such as DXA and ultrasound are given preference. Muscle loss in COVID-19 patients was measured during the acute phase by CT scanning of the pectoralis muscle simultaneously during a routine check for lung fibrosis, which seems to be an efficient evaluation of sarcopenia among those patients with no additional cost. In recovering patients, muscle strength and physical performance have been evaluated by electromyography and traditional tests such as the six-minute walk test. Effective preventive and therapeutic interventions are necessary in order to prevent muscle loss and associated physical decline in COVID-19 patients.

Long-term silk peptide intake promotes skeletal muscle mass, reduces inflammation, and modulates gut microbiota in middle-aged female rats

Aging alters body composition to induce sarcopenia, particularly in women, but the mechanism remains unclear. We hypothesized that silk peptide(SP) intake could prevent an age-related decrease in muscle mass and strength in middle-aged female rats and explored the action mechanism. After the acute intake of SP and defatted soybean peptides, serum concentrations of amino acids were measured in ten middle-aged rats in each group. Forty 12-month-old female Sprague-Dawley rats were fed a high-fat and high-carbohydrate diet for 12 weeks including 0.5 g casein/kg body weight(BW)/day(Aged), 0.15 g SP plus 0.35 g casein/kg BW/day(Low-SP), 0.5 g SP/kg BW/day(High-SP), or 40 mg metformin plus 0.5 g casein/kg BW/day(Metformin). Ten rats aged 7-week old(Young) had the same treatment as the Aged-group. The body composition, grip strength, glucose metabolism, intestinal tissue morphology, and gut microbiota were also determined. After an acute consumption, total amino acids were more quickly absorbed and maintained at higher levels in SP than soybean peptides. Lean body mass(LBM) and grip strength were lower in the Aged-group than the Young and Low-SP groups, and the High-SP regimen increased these parameters as much as the Young-group. Serum concentrations and mRNA expression of TNF-α in the gastrocnemius and quadriceps muscles were higher in the Aged-group than the Young-group, whereas SP intake reduced their serum levels and skeletal muscles. Glucose and insulin tolerance indicated that insulin resistance was elevated in the Aged-group compared to the Young-group, while Low-SP and High-SP alleviated them as much as the Young-group. High-SP increased serum propionate and butyrate concentrations compared to the Aged-group. SP intake increased the relative abundance of Bacteroides and Prevotella and decreased Blautia and Clostridium in the feces. In conclusion, SP intake protects against a decrease in lean body mass and grip strength in middle-aged female rats. The protection was partly related to maintaining higher serum concentrations of total amino acids after SP consumption and decreasing inflammation and insulin resistance through gut microbiota modulation.

Approaches to Nutritional Screening in Patients with Coronavirus Disease 2019 (COVID-19)

Malnutrition is common among severe patients with coronavirus disease 2019 (COVID-19), mainly elderly adults and patients with comorbidities. It is also associated with atypical presentation of the disease. Despite the possible contribution of malnutrition to the acquisition and severity of COVID-19, it is not clear which nutritional screening measures may best diagnose malnutrition in these patients at early stages. This is of crucial importance given the urgency and rapid progression of the disease in vulnerable groups. Accordingly, this review examines the available literature for different nutritional screening approaches implemented among COVID-19 patients, with a special focus on elderly adults. After a literature search, we selected and scrutinized 14 studies assessing malnutrition among COVID-19 patients. The Nutrition Risk Screening 2002 (NRS-2002) has demonstrated superior sensitivity to other traditional screening measures. The controlling nutritional status (CONUT) score, which comprises serum albumin level, cholesterol level, and lymphocytes count, as well as a combined CONUT-lactate dehydrogenase-C-reactive protein score expressed a predictive capacity even superior to that of NRS-2002 (0.81% and 0.92% vs. 0.79%) in midlife and elder COVID-19 patients. Therefore, simple measures based on routinely conducted laboratory investigations such as the CONUT score may be timely, cheap, and valuable alternatives for identifying COVID-19 patients with high nutritional risk. Mini Nutritional Assessment (MNA) was the only measure used to detect residual malnutrition and high malnutrition risk in remitting patients-MNA scores correlated with hypoalbuminemia, hypercytokinemia, and weight loss. Older males with severe inflammation, gastrointestinal symptoms, and pre-existing comorbidities (diabetes, obesity, or hypertension) are more prone to malnutrition and subsequently poor COVID-19 prognosis both during the acute phase and during convalescence. Thus, they are in need of frequent nutritional monitoring and support while detecting and treating malnutrition in the general public might be necessary to increase resilience against COVID-19.

Comparison of calorie and nutrient intake among elderly with and without sarcopenia: A systematic review and meta-analysis

CONTEXT

Sarcopenia, besides having an impact on functional capacity, has been associated with increased hospitalization and mortality, and stands out as an essential cause of disability among older people.

OBJECTIVE

We conducted a systematic review and meta-analysis of published studies comparing the calories and nutrients ingested by elderly people with and without sarcopenia.

DATA SOURCES

MEDLINE/PubMed, Scopus, LILACS, Cochrane Library, and Scielo databases were searched.

STUDY SELECTION

Studies comparing calories and nutrient intake among elderly people diagnosed with sarcopenia and people without sarcopenia were included.

DATA ANALYSIS

Mean differences and 95% confidence intervals (CIs) were calculated, and heterogeneity was assessed using I2 test.

RESULTS

A total of 23 studies fulfilled the inclusion criteria. The average number of calories and nutrients ingested were significantly lower in elderly study participants with sarcopenia compared with those without sarcopenia. The meta-analyses showed that the average number of calories ingested (n = 19 studies; mean difference, -156.7 kcal; 95%CI, -194.8 to -118.7) were significantly lower in those with sarcopenia than in elderly participants without sarcopenia. Compared to those without sarcopenia, elderly people with sarcopenia consumed lower amounts of proteins; carbohydrates; saturated fatty acids; vitamins A, B12, C, and D; and minerals such as calcium, magnesium, sodium, and selenium.

CONCLUSIONS

The evidence so far available suggests a difference in caloric, macronutrient (ie, proteins, carbohydrates, saturated fatty acids), and micronutrient (ie calcium, magnesium, sodium, selenium, and vitamins A, B12, C, and D) intake among the elderly with and without sarcopenia. Additional studies are needed to define the best interventions to improve the consumption of calories and nutrients by the aging population.

Sarcopenia, Low Handgrip Strength, and Low Absolute Muscle Mass Predict Long-Term Mortality in Older Hospitalized Patients: An Observational Inception Cohort Study

OBJECTIVE

Sarcopenia is highly prevalent in hospitalized older patients and associated with short-term mortality. This study aimed to investigate whether sarcopenia and its measures handgrip strength (HGS) and muscle mass at hospital admission were associated with long-term mortality in a cohort of hospitalized older patients.

DESIGN

Observational, prospective, longitudinal inception cohort study.

SETTING AND PARTICIPANTS

Academic teaching hospital; patients age ≥70 years admitted to the internal medicine, acute admission, trauma, or orthopedic wards.

METHODS

HGS and muscle mass were measured at admission using a hand dynamometer and bioelectrical impedance analysis. Sarcopenia was determined based on the European Working Group on Sarcopenia in Older People definition. HGS and muscle mass (skeletal muscle mass index, appendicular lean mass, relative skeletal muscle mass) were expressed as sex-specific tertiles. The associations of sarcopenia, HGS, and muscle mass with mortality (during a follow-up of 3.4-4.1 years) were analyzed using Cox regression, adjusted for age, sex, comorbidity, and weight or height. Associations of HGS and muscle mass were stratified by sex.

RESULTS

Out of 363 patients [mean age: 79.6 years (standard deviation: 6.4), 49.9% female] 49% died. Probable sarcopenia (prevalence of 53.7%) and sarcopenia (prevalence of 20.8%) were significantly associated with long-term mortality [hazard ratio (HR) 1.53, 95% confidence interval (CI) 1.08‒2.17 and 1.71 95% CI 1.12‒2.61, respectively]. Low HGS, skeletal muscle mass index, and appendicular lean mass were associated with a higher mortality risk (lowest tertile vs highest tertile: HR 2.660, 95% CI 1.40‒5.05; HR 1.95, 95% CI 1.06‒3.58 and HR 1.99 (95% CI 1.12‒3.53) in male patients. No statistically significant associations of relative muscle mass with mortality were found.

CONCLUSIONS AND IMPLICATIONS

Sarcopenia and its measures (low HGS and low absolute muscle mass at admission) predict long-term mortality in older hospitalized patients.

Type-2 muscle fiber atrophy is associated with sarcopenia in elderly men with hip fracture

Sarcopenia is a common geriatric syndrome and can lead to falls and fragility fractures. It is associated with a decline of muscle fiber numbers and size. Muscle biopsies of the vastus lateralis muscle were taken from thirty-two patients with hip fracture (18 women and 14 men; mean age: 82.2 ± 6.2 years). Serial cross sections of skeletal muscle were labeled with myosin heavy chain slow (fiber type-1) and fast (fiber type-2) antibodies in order to measure the size, ratio and percentage of mixed fiber types. The presence of sarcopenia was defined according to the EWGSOP2 criteria by using BIA and handgrip strength measurement. Sarcopenia was identified in 5 patients (3 women and 2 men), probable-sarcopenia in 11 patients (4 women and 7 men). Significant differences in fiber diameter were found for fiber type-2 in men but not in women. Only 1-3% mixed fiber types were found in sarcopenic patients, indicating a final stage where reinnervation is not possible to occur anymore. Muscle fiber type-2 atrophy seems to be a histological marker for sarcopenia in men.

Sarcopenia Induced by Chronic Liver Disease in Mice Requires the Expression of the Bile Acids Membrane Receptor TGR5

Sarcopenia is a condition of muscle dysfunction, commonly associated with chronic liver disease (CLD), characterized by a decline in muscle strength, the activation of the ubiquitin-proteasome system (UPS), and oxidative stress. We recently described a murine model of CLD-induced sarcopenia by intake of hepatotoxin 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC), which presents an increase in plasma bile acids (BA). BA induced skeletal muscle atrophy through a mechanism dependent on the Takeda G protein-coupled receptor 5 (TGR5) receptor. In the present study, we evaluated the role of TGR5 signaling in the development of sarcopenia using a model of DDC-induced CLD in C57BL6 wild-type (WT) mice and mice deficient in TGR5 expression (TGR5^−/− mice). The results indicate that the decline in muscle function and contractibility induced by the DDC diet is dependent on TGR5 expression. TGR5 dependence was also observed for the decrease in fiber diameter and sarcomeric proteins, as well as for the fast-to-slow shift in muscle fiber type. UPS overactivation, indicated by increased atrogin-1/MAFbx (atrogin-1) and muscle RING-finger protein-1 (MuRF-1) protein levels and oxidative stress, was abolished in tibialis anterior muscles from TGR5^−/− mice. Our results collectively suggest that all sarcopenia features induced by the DDC-supplemented diet in mice are dependent on TGR5 receptor expression.

SARS-CoV-2/Renin-Angiotensin System: Deciphering the Clues for a Couple with Potentially Harmful Effects on Skeletal Muscle

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) has produced significant health emergencies worldwide, resulting in the declaration by the World Health Organization of the coronavirus disease 2019 (COVID-19) pandemic. Acute respiratory syndrome seems to be the most common manifestation of COVID-19. A high proportion of patients require intensive care unit admission and mechanical ventilation (MV) to survive. It has been well established that angiotensin-converting enzyme type 2 (ACE2) is the primary cellular receptor for SARS-CoV-2. ACE2 belongs to the renin–angiotensin system (RAS), composed of several peptides, such as angiotensin II (Ang II) and angiotensin (1-7) (Ang-(1-7)). Both peptides regulate muscle mass and function. It has been described that SARS-CoV-2 infection, by direct and indirect mechanisms, affects a broad range of organ systems. In the skeletal muscle, through unbalanced RAS activity, SARS-CoV-2 could induce severe consequences such as loss of muscle mass, strength, and physical function, which will delay and interfere with the recovery process of patients with COVID-19. This article discusses the relationship between RAS, SARS-CoV-2, skeletal muscle, and the potentially harmful consequences for skeletal muscle in patients currently infected with and recovering from COVID-19.

Role of Oxidative Stress in Hepatic and Extrahepatic Dysfunctions during Nonalcoholic Fatty Liver Disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is a pathology that contains a broad liver dysfunctions spectrum. These alterations span from noninflammatory isolated steatosis until nonalcoholic steatohepatitis (NASH), a more aggressive form of the disease characterized by steatosis, inflammatory status, and varying liver degrees fibrosis. NAFLD is the most prevalent chronic liver disease worldwide. The causes of NAFLD are diverse and include genetic and environmental factors. The presence of NASH is strongly associated with cirrhosis development and hepatocellular carcinoma, two conditions that require liver transplantation. The liver alterations during NAFLD are well described. Interestingly, this pathological condition also affects other critical tissues and organs, such as skeletal muscle and even the cardiovascular, renal, and nervous systems. Oxidative stress (OS) is a harmful state present in several chronic diseases, such as NAFLD. The purpose of this review is to describe hepatic and extrahepatic dysfunctions in NAFLD. We will also review the influence of OS on the physiopathological events that affect the critical function of the liver and peripheral tissues.

Apitherapy for Age-Related Skeletal Muscle Dysfunction (Sarcopenia): A Review on the Effects of Royal Jelly, Propolis, and Bee Pollen

The global pandemic of sarcopenia, skeletal muscle loss and weakness, which prevails in up to 50% of older adults is increasing worldwide due to the expansion of aging populations. It is now striking young and midlife adults as well because of sedentary lifestyle and increased intake of unhealthy food (e.g., western diet). The lockdown measures and economic turndown associated with the current outbreak of Coronavirus Disease 2019 (COVID-19) are likely to increase the prevalence of sarcopenia by promoting sedentarism and unhealthy patterns of eating. Sarcopenia has multiple detrimental effects including falls, hospitalization, disability, and institutionalization. Although a few pharmacological agents (e.g., bimagrumab, sarconeos, and exercise mimetics) are being explored in different stages of trials, not a single drug has been approved for sarcopenia treatment. Hence, research has focused on testing the effect of nutraceuticals, such as bee products, as safe treatments to prevent and/or treat sarcopenia. Royal jelly, propolis, and bee pollen are common bee products that are rich in highly potent antioxidants such as flavonoids, phenols, and amino acids. These products, in order, stimulate larval development into queen bees, promote defenses of the bee hive against microbial and environmental threats, and increase royal jelly production by nurse bees. Thanks to their versatile pharmacological activities (e.g., anti-aging, anti-inflammatory, anticarcinogenic, antimicrobial, etc.), these products have been used to treat multiple chronic conditions that predispose to muscle wasting such as hypertension, diabetes mellitus, cardiovascular disorder, and cancer, to name a few. They were also used in some evolving studies to treat sarcopenia in laboratory animals and, to a limited degree, in humans. However, a collective understanding of the effect and mechanism of action of these products in skeletal muscle is not well-developed. Therefore, this review examines the literature for possible effects of royal jelly, bee pollen, and propolis on skeletal muscle in aged experimental models, muscle cell cultures, and humans. Collectively, data from reviewed studies denote varying levels of positive effects of bee products on muscle mass, strength, and function. The likely underlying mechanisms include amelioration of inflammation and oxidative damages, promotion of metabolic regulation, enhancement of satellite stem cell responsiveness, improvement of muscular blood supply, inhibition of catabolic genes, and promotion of peripheral neuronal regeneration. This review offers suggestions for other mechanisms to be explored and provides guidance for future trials investigating the effects of bee products among people with sarcopenia.

Prevalence of probable sarcopenia in community-dwelling older Swiss people - a cross-sectional study

BACKGROUND

The European Working Group on Sarcopenia in Older People has recently defined new criteria for identifying "(probable) sarcopenia" (EWGSOP2). However, the prevalence of probable sarcopenia, defined by these guidelines, has not been determined extensively, especially in the oldest old. This study aims to determine the prevalence of probable sarcopenia in older, community-living people and its association with strength-related determinants.

METHODS

Handgrip strength and reported determinants (age, height, weight, osteoarthritis of hands, medications, fall history, physical activity, activities of daily living (ADL) and global cognitive function) were collected in a cross-sectional study of 219 community-living Swiss people (75 years and over). Probable sarcopenia was estimated based on cut-off values for handgrip strength as recommended by EWGSOP2. Spearman correlations, binary-regression analyses and contingency tables were used to explore relationships between variables.

RESULTS

The prevalence of probable sarcopenia in women (n = 137, age 84.1 ± 5.7 years) and men (n = 82, age 82.6 ± 5.2 years) was 26.3 and 28.0%, respectively. In women, probable sarcopenia correlated positively with age and falls (r_s range 0.332-0.195, p < .05), and negatively with weight, cognition, physical activity, using stairs regularly, participating in sports activities and ADL performance (r_s range = - 0.141 - -0.409, p < .05). The only significant predictor of probable sarcopenia at the multivariate level was ADL performance (Wald(1) = 5.51, p = .019). In men, probable sarcopenia was positively correlated with age (r_s = 0.33, p < .05) and negatively with physical activity, participation in sports and ADL performance (r_s range - 0.221 - - 0.353, p < .05). ADL performance and age (Wald(1) = 4.46, p = .035 and Wald(1) = 6.30, p = .012) were the only significant predictors at the multivariate level. Men and women with probable sarcopenia were 2.8 times more likely to be dependent in ADL than those without.

CONCLUSION

Probable sarcopenia affected one in every four community-living, oldest old people and was independently associated with impaired ADL performance in both sexes. This highlights the importance of detection of handgrip strength in this age group in clinical practice. Although prospective studies are required, independence in ADL might help to protect against probable sarcopenia.

Psychological Climacteric Symptoms and Attitudes toward Menopause among Emirati Women

Menopause is an inevitable developmental event that women encounter at an age of 42–54 years. The drop of estrogen levels that accompanies cessation of menstruation is associated with multiple vasomotor, physical, neuropsychological, and sexual symptoms, which may hamper quality of life. This study aimed to examine the severity of psychological symptoms and their correlates among peri- and postmenopausal Emirati women (N = 60, mean age = 54.88 ± 6 years). Participants were interviewed using the Menopause-Specific Quality of Life (MENQOL) and attitudes toward menopause scale (ATMS). In four path analysis models, vasomotor symptoms, weight gain, and fatigue had significant direct effects on symptoms of anxiety, depression (only weight gain and fatigue), and psychological distress. Fatigue significantly mediated the effects of vasomotor symptoms and weight gain on symptoms of anxiety, depression (only vasomotor symptoms), psychological distress, and memory problems. These models explained 47.6%, 44.5%, 56.6%, and 29.1% of the variances in anxiety, depression, psychological distress, and memory problems, respectively. Participants with more severe menopausal symptoms expressed more negative attitudes toward menopause though regression analysis revealed that only vasomotor symptoms could significantly contribute to ATMS scores. In conclusion, psychological distress is widespread among menopausal women, and it is associated with vasomotor symptoms, fatigue, and change of body composition (obesity). Psychological symptoms, along with vasomotor symptoms, express a key link to negative attitudes toward menopause. Therefore, interventional strategies that target psychological distress may promote coping with midlife transition and improve mental health among menopausal women.

Prevalencia de dinapenia (disminución de la fuerza), sarcopenia y posibles biomarcadores en rehabilitación cardíaca

Introducción: la relación entre dinapenia y sarcopenia da como resultado un aumento adicional en el riesgo de morbimortalidad en la población general, con un incremento progresivo de acuerdo con la edad. A partir de los 30 años debido a la disminución de la masa muscular y de la fuerza, se afecta la capacidad de ejercicio, la calidad de vida y el estado de ánimo. Objetivo: determinar la prevalencia de dinapenia y sarcopenia en los pacientes en rehabilitación cardíaca de un hospital colombiano, con mediciones de la fuerza y de los marcadores bioquímicos. Métodos: estudio de corte transversal en mayores de 40 años en rehabilitación cardíaca con controles al menos una vez por semana. La medición de la fuerza se realizó con dinamómetro de mano, la masa muscular con impedanciómetro bipolar y velocidad de la marcha con la prueba de caminata de 6 metros. Se tomaron mediciones de hormona de crecimiento (GH), testosterona libre, somatomedina IGF-1 y cortisol. Resultados: la disminución de la fuerza muscular fue prevalente en hombres (n=15, 19.4%; mujeres n=5, 10%). La prevalencia de dinapenia fue 15,7% y sarcopenia 0%. Los resultados obtenidos fueron GH 0.27 (0.08-1.18), testosterona 5.9 (0.3-8.5), IGF-1 126 (95.5-169) cortisol 13.9 (11.2-18.4). Las patologías más frecuentes de los pacientes del programa fueron infarto del miocardio, angioplastia e implantación de stent. Conclusiones: la prevalencia de dinapenia fue 15.7%. No se encontró diferencia alguna de los marcadores bioquímicos en los pacientes con y sin dinapenia.

Reliability and Validity of SARC-F Questionnaire to Assess Sarcopenia Among Vietnamese Geriatric Patients

Background

The SARC-F questionnaire has been developed as a rapid diagnostic test that can be used to screen for sarcopenia.

Aim

To investigate the reliability and validity of the Vietnamese version of SARC-F as a screening tool for sarcopenia in older patients in Vietnam.

Methods

A cross-sectional study was conducted in older people attending the outpatient clinics of the National Geriatric Hospital in Vietnam. Muscle mass (using dual-energy X-ray absorptiometry), handgrip strength and gait speed were assessed. SARC-F was validated against the three standard criteria for sarcopenia: the Foundation for the National Institutes of Health (FNIH), Asia Working Group for Sarcopenia (AWGS 2019) and European Working Group on Sarcopenia in Older People (EWGSOP2).

Results

There were 764 participants (mean age 71.5 ± 8.9 years). The Vietnamese SARC-F questionnaire had a good internal consistency (Cronbach’s alpha 0.85). The prevalence of sarcopenia was 49.2% according to SARC-F and 48.3%, 61.1% and 52.6% according to FNIH, AWGS 2019 and EWGSOP2, respectively. The sensitivity and specificity of SARC-F in identifying sarcopenia were 67.1% and 66.7% (for FINH), 66.7% and 67.1% (for AWGS 2019), and 64.9% and 68.2% (for EWGSOP2). The AUCs of SARC-F were 0.71–0.72 against the three sarcopenia criteria.

Conclusion

The Vietnamese version of SARC-F questionnaire has acceptable diagnostic value for sarcopenia. SARC-F could be used as an initial screening for sarcopenia in hospital clinics.

Protective Effect of Angiotensin 1-7 on Sarcopenia Induced by Chronic Liver Disease in Mice

Sarcopenia associated with chronic liver disease (CLD) is one of the more common extrahepatic features in patients with these pathologies. Among the cellular alterations observed in the muscle tissue under CLD is the decline in the muscle strength and function, as well as the increased fatigue. Morphological changes, such as a decrease in the fiber diameter and transition in the fiber type, are also reported. At the molecular level, sarcopenia for CLD is characterized by: (i) a decrease in the sarcomeric protein, such as myosin heavy chain (MHC); (ii) an increase in the ubiquitin–proteasome system markers, such as atrogin-1/MAFbx1 and MuRF-1/TRIM63; (iii) an increase in autophagy markers, such as LC3II/LC3I ratio. Among the regulators of muscle mass is the renin-angiotensin system (RAS). The non-classical axis of RAS includes the Angiotensin 1–7 [Ang-(1-7)] peptide and its receptor Mas, which in skeletal muscle has anti-atrophic effect in models of muscle wasting induced by immobilization, lipopolysaccharide, myostatin or angiotensin II. In this paper, we evaluated the effect of Ang-(1-7) on the sarcopenia by CLD in a murine model induced by the 5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) hepatotoxin administered through diet. Our results show that Ang-(1-7) administration prevented the decline of the function and strength of muscle and increased the fatigue detected in the DDC-fed mice. Besides, we observed that the decreased fiber diameter and MHC levels, as well as the transition of fiber types, were all abolished by Ang-(1-7) in mice fed with DDC. Finally, Ang-(1-7) can decrease the atrogin-1 and MuRF-1 expression as well as the autophagy marker in mice treated with DDC. Together, our data support the protective role of Ang-(1-7) on the sarcopenia by CLD in mice.

Quantification of skeletal muscle mass: sarcopenia as a marker of overall health in children and adults

Sarcopenia is defined as the loss of muscle mass or function and has been associated with increased morbidity and mortality in a variety of diseased populations. Sarcopenia results from a higher rate of muscle protein degradation compared to protein synthesis and is an important marker of metabolic status related to nutrition and physical activity. The diagnosis of sarcopenia is accomplished by clinical assessment demonstrating decreased muscle function and radiographic confirmation of decreased muscle mass, via dual X-ray absorptiometry, bioelectric impedance or cross-sectional imaging with CT or MRI. However, normative data for skeletal muscle mass are lacking, especially for children and young adults. Additionally, studies of skeletal muscle mass by cross-sectional imaging in children are scarce. Here, we review the concept of sarcopenia with an emphasis on its relevance in the pediatric population.

Influence of sarcopenia in major pancreatic surgery. A systematic review of the literature

Post-operative morbidity of pancreatectomies occurs in up to 40-50% of patients, even in modern series. There is a need to find a simple scale in order to identify patients with increased risk of developing major post-operative complications after pancreatic resections. Many studies have been published on sarcopenia and surgical outcomes. Aspects of sarcopenia are presented, along with a systematic review using PRISMA guidelines, in order to search for articles about sarcopenia and pancreatic surgery. The impact of sarcopenia on morbidity and mortality in pancreatic resections is still unclear. The studies presented have been carried out over long periods of time, and many of them compare patients with different diseases. There are also different definitions of sarcopenia, and this can influence the results, as some of the reviewed articles have already shown. It is necessary to unify criteria, both in the definition and in the cut-off values. Prospective studies and consensus on sarcopenia diagnosis should be achieved.

Inflammaging as a common ground for the development and maintenance of sarcopenia, obesity, cardiomyopathy and dysbiosis

Sarcopenia, obesity and their coexistence, obese sarcopenia (OBSP) as well as atherosclerosis-related cardio-vascular diseases (ACVDs), including chronic heart failure (CHF), are among the greatest public health concerns in the ageing population. A clear age-dependent increased prevalence of sarcopenia and OBSP has been registered in CHF patients, suggesting mechanistic relationships. Development of OBSP could be mediated by a crosstalk between the visceral and subcutaneous adipose tissue (AT) and the skeletal muscle under conditions of low-grade local and systemic inflammation, inflammaging. The present review summarizes the emerging data supporting the idea that inflammaging may serve as a mutual mechanism governing the development of sarcopenia, OBSP and ACVDs. In support of this hypothesis, various immune cells release pro-inflammatory mediators in the skeletal muscle and myocardium. Subsequently, the endothelial structure is disrupted, and cellular processes, such as mitochondrial activity, mitophagy, and autophagy are impaired. Inflamed myocytes lose their contractile properties, which is characteristic of sarcopenia and CHF. Inflammation may increase the risk of ACVD events in a hyperlipidemia-independent manner. Significant reduction of ACVD event rates, without the lowering of plasma lipids, following a specific targeting of key pro-inflammatory cytokines confirms a key role of inflammation in ACVD pathogenesis. Gut dysbiosis, an imbalanced gut microbial community, is known to be deeply involved in the pathogenesis of age-associated sarcopenia and ACVDs by inducing and supporting inflammaging. Dysbiosis induces the production of trimethylamine-N-oxide (TMAO), which is implicated in atherosclerosis, thrombosis, metabolic syndrome, hypertension and poor CHF prognosis. In OBSP, AT dysfunction and inflammation induce, in concert with dysbiosis, lipotoxicity and other pathophysiological processes, thus exacerbating sarcopenia and CHF. Administration of specialized, inflammation pro-resolving mediators has been shown to ameliorate the inflammatory manifestations. Considering all these findings, we hypothesize that sarcopenia, OBSP, CHF and dysbiosis are inflammaging-oriented disorders, whereby inflammaging is common and most probably the causative mechanism driving their pathogenesis.

Muscle health in Hispanic women. REDLINC VIII

Objectives: This study aimed to evaluate muscle strength and related factors in Hispanic women.Methods: We studied 593 women between 40 and 89 years old. The women were asked about personal and clinical information. The following instruments were applied: dynamometer (strength), Short Physical Performance Battery (physical performance), SARC-F (sarcopenia), International Physical Activity Questionnaire (physical activity), Menopause Rating Scale (quality of life), 36-item Short Form (general health), and Frailty (Fried's criteria).Results: Low muscle strength rises from 7.1% of women in their 40s to 79.4% in their 80s. Physical performance is low in 0.5% of the first group and rises to 60.5% in the second. The risk of sarcopenia increases significantly from 6.7% in younger women to 58.1% in older women. Frailty, which affects less than 1% of women under age 60 years, increases to 39.5% in their 80s. Sedentary lifestyle rises from 26% to 68.3%. Fragility impairs the quality of life and the perception of health (p < 0.0001). The deterioration of different tests of muscle function is significantly associated with age >70 years (OR 5-20) and with osteoarthritis (OR 4-9). Menopause before the age of 45 years increases the risk of sarcopenia (odds ratio 2.2; 95% confidence interval 1.2-4.0).Conclusion: With aging there is a decrease in muscle strength and an increase in frailty. This entails a decrease in the quality of life.

Prognostic value of radiologically determined sarcopenia prior to treatment in urologic tumors: A meta-analysis

OBJECTIVE

Increasing evidence suggests that radiologically determined sarcopenia prior to treatment can serve as a prognostic marker in various tumors. However, there are conflicting conclusions about the prognostic role of sarcopenia in urological tumors. We performed a meta-analysis to assess the association between radiologically determined sarcopenia before treatment and survival outcomes in urological tumors.

METHODS

A systematically literature search in PubMed, Cochrane databases, and EMBASE was performed. We estimated hazard ratios (HRs) for overall survival (OS) and cancer-specific survival (CSS). Hazard ratios (HR) with 95% confidence interval (CI) were calculated using STATA 12.0 software.

RESULTS

A total of 16 studies enrolling 2264 patients with urologic tumors were included in our meta-analysis. Among these studies, 13 studies with 1941 patients explored the association between sarcopenia and OS, and 10 studies with 1790 patients investigated the relationship between sarcopenia and OS. The synthesized result suggested that sarcopenia was significantly associated with poor OS (Fixed-effect model, HR 1.73, 95% CI: 1.48-2.01, P <.05; heterogeneity: P = .064; I = 40.5%), and poor CSS (Fixed-effect model, HR: 1.85, 95% CI: 1.51-2.28, P <.05, heterogeneity: P = .053; I = 46.2%).

CONCLUSION

This meta-analysis showed that sarcopenia was associated with poor OS and CSS, suggesting that sarcopenia may serve as a promising prognostic marker in urologic cancer patients. Considering several limitations in our study, in the future more high-quality studies on this topic should be conducted to confirm our findings.

Sarcopenia: revised European consensus on definition and diagnosis

Background

in 2010, the European Working Group on Sarcopenia in Older People (EWGSOP) published a sarcopenia definition that aimed to foster advances in identifying and caring for people with sarcopenia. In early 2018, the Working Group met again (EWGSOP2) to update the original definition in order to reflect scientific and clinical evidence that has built over the last decade. This paper presents our updated findings.

Objectives

to increase consistency of research design, clinical diagnoses and ultimately, care for people with sarcopenia.

Recommendations

sarcopenia is a muscle disease (muscle failure) rooted in adverse muscle changes that accrue across a lifetime; sarcopenia is common among adults of older age but can also occur earlier in life. In this updated consensus paper on sarcopenia, EWGSOP2: (1) focuses on low muscle strength as a key characteristic of sarcopenia, uses detection of low muscle quantity and quality to confirm the sarcopenia diagnosis, and identifies poor physical performance as indicative of severe sarcopenia; (2) updates the clinical algorithm that can be used for sarcopenia case-finding, diagnosis and confirmation, and severity determination and (3) provides clear cut-off points for measurements of variables that identify and characterise sarcopenia.

Conclusions

EWGSOP2's updated recommendations aim to increase awareness of sarcopenia and its risk. With these new recommendations, EWGSOP2 calls for healthcare professionals who treat patients at risk for sarcopenia to take actions that will promote early detection and treatment. We also encourage more research in the field of sarcopenia in order to prevent or delay adverse health outcomes that incur a heavy burden for patients and healthcare systems.

Impact of Atrial Fibrillation on Postoperative Adverse Outcomes of Surgical Patients With Knee Endoprosthetic Surgery

BACKGROUND

Atrial fibrillation/flutter (AF) is associated with increased mortality, thromboembolism, heart failure, and adverse perioperative outcomes. We aimed to investigate the impact of AF on adverse in-hospital outcomes of hospitalized patients who underwent knee endoprosthetic surgery (KES).

METHODS

The nationwide German inpatient sample of the years 2005-2015 was used for this analysis. Patients who underwent KES were identified based on the surgical and interventional procedural codes (surgery and procedure code [Operationen-und Prozedurenschlüssel] 5-822), and patients were further stratified by AF (International Classification of Diseases and Related Health Problems code I48). We compared patients with and without AF who underwent KES as well as survivors vs nonsurvivors among patients with AF. Logistic regression models were used to investigate the impact of AF as a predictor for adverse in-hospital outcomes.

RESULTS

Overall, 1,642,875 hospitalized surgical patients (65.4% females, 49.5% aged >70 years) were included in the analysis. Of these, 93,748 patients (5.7%) were diagnosed with AF. Overall, 0.1% of the patients who underwent KES and 0.6% of the patients who underwent KES with additional AF died during in-hospital stay. All-cause death (risk ratio 5.97 [95% confidence interval {CI} 5.41-6.58], P < .001) and adverse in-hospital events (risk ratio 2.62 [95% CI 2.50-2.74], P < .001) occurred both more often in patients with AF compared to those without. AF was an important predictor for in-hospital death (odds ratio 2.09 [95% CI 1.88-2.32], P < .001) and adverse in-hospital events (odds ratio 1.76 [95% CI 1.68-1.85], P < .001) in patients who underwent KES independent of age, sex, and comorbidities.

CONCLUSION

In patients who underwent KES, AF is associated with increased in-hospital mortality and adverse in-hospital outcomes. Pneumonia, pulmonary embolism, shock, myocardial infarction, intracerebral bleeding, and stroke were the key complications promoting in-hospital death.