Sarcopenia: designing phase IIB trials

Wearable Fabric System for Sarcopenia Detection

Sarcopenia has been a serious concern in the context of an increasingly aging global population. Existing detection methods for sarcopenia are severely constrained by cumbersome devices, the necessity for specialized personnel, and controlled experimental environments. In this study, we developed an innovative wearable fabric system based on conductive fabric and flexible sensor array. This fabric system demonstrates remarkable pressure-sensing capabilities, with a high sensitivity of 18.8 kPa-1 and extraordinary stability. It also exhibits excellent flexibility for wearable applications. By interacting with different parts of the human body, it facilitates the monitoring of various physiological activities, such as pulse dynamics, finger movements, speaking, and ambulation. Moreover, this fabric system can be seamlessly integrated into sole to track critical indicators of sarcopenia patients, such as walking speed and gait. Clinical evaluations have shown that this fabric system can effectively detect variations in indicators relevant to sarcopenia patients, proving that it offers a straightforward and promising approach for the diagnosis and assessment of sarcopenia.

Steatosarcopenia: A New Terminology for Clinical Conditions Related to Body Composition Classification

Body composition analysis focuses on measuring skeletal muscle mass and total body fat. The loss of muscle function and mass is related to clinical conditions such as frailty, increased risk of falls, and prolonged hospitalizations. Despite the relevance of the definition of sarcopenic obesity, there is still a gap in the monitoring of patients who have the combination of sarcopenia and myosteatosis, regardless of the presence of obesity. Therefore, we propose a new nomenclature, steatosarcopenia, a condition characterized by the loss of mass or skeletal muscle strength and performance associated with the excessive deposition of ectopic reserve fat in muscle tissue, in the same individual, not necessarily related to excess fat total body mass. A greater understanding of this condition may assist in developing strategies for preventing and treating metabolic diseases.

Sarcopenia and Dinapenia in Patients with Ulcerative Colitis (Cross-Sectional Observational Study)

Background. Sarcopenia is a generalised, progressive decline in skeletal muscle mass, strength and performance leading to reduced quality of life, increased risk of falls, hospitalisation and mortality. Primary sarcopenia results from age-related changes in muscle tissue. In certain cases, sarcopenia develops secondary as a consequence of diseases including ulcerative colitis (UC), which is associated with a systemic inflammatory process, malabsorption syndrome, restriction of patients’ physical activity and nutrient deficiencies. The term “dynapenia” or “probable sarcopenia” has been proposed to describe the decrease in muscle strength. Studies have demonstrated that muscle strength is a more relevant marker for predicting adverse outcomes because its measurement is more practical, whereas muscle mass is technically difficult to measure. Aims — to increase the effectiveness of the diagnosis of dinapenia, to assess the prevalence and risk factors of its formation in patients with UC. Methods. A single-centre, observational cross-sectional study included 80 UC patients. To identify factors associated with the development of dinapenia, patients with dinapenia were compared with patients without dinapenia. The investigated parameters in patients: sex, age, body mass index, peculiarities of the course of the disease, ongoing treatment, concomitant pathology, peculiarities of nutrition, nutritional deficiency, malabsorption syndrome, bad habits, psychological stress and sleep duration, physical activity, laboratory indicators of inflammation, myokine-adipokine profile. Statistical parameters were calculated using Statistica 10.0.1011.0 programme. Results. Dinapenia is present in 32.5% of UC patients. Risk factors for the formation of dinapenia in UC patients include female sex (p = 0.0003); nutritional insufficiency (p = 0.021); low physical activity (p = 0.010); artificial feeding in infancy (p = 0.024); inflammation, namely C-reactive protein, autoantibodies of class G against double-stranded DNA (p = 0.006; p = 0.002 respectively). Patients with UC with dinapenia significantly more often gave a positive answer to the questionnaire question “Does daily activity cause you a lot of stress?” (p = 0.048). In the group of UC patients with dinapenia, the level of cortisol in evening saliva was significantly higher than in the comparison group (p = 0.005). Conclusions. Sarcopenia and UC are multifactorial conditions with common developmental mechanisms that can burden each other. Dynamometry is not technically difficult and is justified from an economic point of view. The timely detection of dinapenia and its correction will additionally affect the mechanisms of UC pathogenesis in order to improve the quality of life and prognosis of patients.

Gouqi-derived nanovesicles (GqDNVs) inhibited dexamethasone-induced muscle atrophy associating with AMPK/SIRT1/PGC1α signaling pathway

With the increasing trend of global aging, sarcopenia has become a significant public health issue. Goji berry, also known as "Gou qi zi" in China, is a traditional Chinese herb that can enhance the structure and function of muscles and bones. Otherwise, previous excellent publications illustrated that plant-derived exosome-like nanoparticles can exert good bioactive functions in different aging or disease models. Thus, we issued the hypothesis that Gouqi-derived nanovesicles (GqDNVs) may also have the ability to improve skeletal muscle health, though the effect and its mechanism need to be explored. Hence, we have extracted GqDNVs from fresh berries of Lycium barbarum L. (goji) and found that the contents of GqDNVs are rich in saccharides and lipids. Based on the pathway annotations and predictions in non-targeted metabolome analysis, GqDNVs are tightly associated with the pathways in metabolism. In muscle atrophy model mice, intramuscular injection of GqDNVs improves the cross-sectional area of the quadriceps muscle, grip strength and the AMPK/SIRT1/PGC1α pathway expression. After separately inhibiting AMPK or PGC1α in C2C12 cells with dexamethasone administration, we have found that the activated AMPK plays the chief role in improving cell proliferation induced by GqDNVs. Furthermore, the energy-targeted metabolome analysis in the quadriceps muscle demonstrates that the GqDNVs up-regulate the metabolism of amino sugar and nucleotide sugar, autophagy and oxidative phosphorylation process, which indicates the activation of muscle regeneration. Besides, the Spearman rank analysis shows close associations between the quality and function of skeletal muscle, metabolites and expression levels of AMPK and SIRT1. In this study, we provide a new founding that GqDNVs can improve the quality and function of skeletal muscle accompanying the activated AMPK/SIRT1/PGC1α signaling pathway. Therefore, GqDNVs have the effect of anti-aging skeletal muscle as a potential adjuvant or complementary method or idea in future therapy and research.

Sarcopenia Among Older People in the Philippines: A Scoping Review

Aims: This review aimed to identify and map the evidence about sarcopenia among older Filipinos. Methods: Studies about sarcopenia among Filipinos aged 60 and above were included. All studies regardless of type, setting, language, and timeframe were reviewed. The Cochrane Library, Cumulative Index of Nursing and Allied Health, Embase, PubMed, and Health Research and Development Information Network were searched. The study was conducted per an a priori protocol and utilized the Joanna Briggs Institute guidance for scoping reviews. Results: From the 87 records identified, 20 studies published from 2013 to 2023 were eligible (≥ 5424 participants). The studies were varied; 11 cross-sectional, 2 conference lectures, 2 consensus reports, 1 meta-analysis, cohort study, case series, posthoc analysis, and continuing education. As to setting, 11 studies were conducted in the hospital and 4 in the community. On the level of prevention, 5 studies addressed the primary level, 10 studies secondary, and 2 studies both tertiary and secondary. The studies focused on: sarcopenia in a specific group (13 studies), consensus (4 studies), and education (3 studies). Conclusions: Sarcopenia studies among older Filipinos were limited. Most were hospital-based and involved patients with comorbidities. Some studies used sarcopenia assessment guidelines with Filipino normative references. Sarcopenia impacts the overall well-being of older Filipinos; hence more studies and health promotion programs are necessary.

All you need to know about sarcopenia: a short guide for an internal medicine physician in questions and answers

Sarcopenia is associated with social, economic, and individual burdens, including loss of independence, poor quality of life, and disability. In a short period of time, ideas about sarcopenia transformed from geriatric syndrome to disease. Initially, sarcopenia was considered in the context of gradual age-related deterioration in the functioning of all physiological systems. Over the years, it became clear that it can develop a second time, as a consequence of various diseases and pathological conditions.

To date, there have been no generally accepted diagnostic criteria for sarcopenia. There are several tests and tools available for screening sarcopenia, the choice of which depends on physical capabilities of the patient, capabilities of the medical institution, and the purpose for which it is detected (research or clinical practice).

From the point of view of human health, sarcopenia increases the risk of falls and fractures; impairs the ability to perform daily activities; is associated with the progression of major diseases and cognitive impairments; leads to movement disorders; contributes to a decrease in the quality of life, loss of independence or a need for long-term care. The presence of sarcopenia increases both the risk of hospitalization and hospitalization costs.

The aim of the literature review is to provide an analysis of up-to-date information on the causes, pathogenesis, screening, diagnosis, treatment, and consequences of sarcopenia, myosteatosis, and sarcopenic obesity. The search for literature containing information on relevant studies was conducted in PubMed and Google Scholar by the following keywords: sarcopenia, dynapenia, myosteatosis, sarcopenic obesity, nutritional status, malnutrition.

Diagnostic performance of SARC-F and SARC-CalF in screening for sarcopenia in older adults in Northern Brazil

To compare the performance of SARC-F and SARC-CalF as screening tools for sarcopenia. Cross-sectional study with a convenience sample of 312 community-dwelling older people. Sarcopenia was defined as low handgrip strength (HGS) or low gait speed (GS ≤ 0.8 m/s). HGS was measured by dynamometry and GS by the 4-m walking speed test. For HGS, six criteria (C) were used to identify sarcopenia in men/women: C_I: < 27 kg/16 kg; C_II: < 35.5 kg/20.0 kg; C_III: grip over body mass index < 1.05/< 0.79; C_IV: grip strength over total body fat < 1.66/< 0.65; C_V: grip over bodyweight < 0.45/< 0.34; C_VI: < 27 kg/16 kg and low skeletal muscle mass index (SMMI); C_I and C_VI defined according to the European Working Group on sarcopenia in older people and the rest according to the sarcopenia definition and outcomes Consortium. For sarcopenia screening, the SARC-F (≥ 4 points) and the SARC-CalF (≥ 11 points) were used. The kappa analysis revealed no agreement between the SARC-F and the various criteria for the identification of sarcopenia in men. The same lack of agreement was observed in women with some exceptions: C_I = 0.161 ± 0.074, p = 0.020; GS = 0.209 ± 0.076, p = 0.003. Concerning the Cohen's kappa between the SARC-Calf and the reference criteria of sarcopenia, the following coefficients were observed as significant for women: C_I = 0.201 ± 0.069, p = 0.003; C_II = 0.186 ± 0.064, p = 0.005; GS = 0.273 ± 0.068, p = 0.0001; and for men: C_II = 0.139 ± 0.053, p = 0.021; GS = 0.223 ± 0.099, p = 0.011. ROC curves revealed the SARC-Calf with acceptable discrimination and reasonable sarcopenia predictive capacity considering a cutoff value of 10.5 in both men (AUC: 67.5%, p = 0.022; Se = 52.9%; Sp = 76.8%) and women (AUC: 72.4%, p < 0.001; Se = 63%; Sp = 68.5%) concerning GS. The SARC-CalF performed better than the SARC-F for screening sarcopenia in the population ≥ 60 years of age in the Amazonas, measured through walking slowness.

Prevalence of sarcopenia in patients older than 75 years admitted for hip fracture

BACKGROUND

Hip fracture in the population aged 75 years and older is one of the most disabling pathologies. Likewise, disease related malnutrition (DRM) and sarcopenia are two frequent diagnoses in this age group, whose prevalence may be increased in patients with hip fracture.

AIMS

To determine the prevalence of malnutrition and/or sarcopenia in patients admitted for hip fracture and evaluate the existence of malnutrition related to disease and sarcopenia, and the differences between the sarcopenic and non-sarcopenic group.

METHODS

186 patients aged 75 years or over, hospitalised for hip fracture from March 2018 to June 2019 were included. Demographic, nutritional and biochemical variables were collected. Nutritional screening was carried out with the Mini-Nutritional Assessment (MNA), the presence of DRM was established with The Global Leadership Initiative on Malnutrition (GLIM) criteria. For sarcopenia screening, the Strength, Assistance with walking, Rising from a chair, Climbing stairs and Falls (SARC-F) was used and the diagnosis of sarcopenia was made using the criteria from the European Working Group on Sarcopenia in Older People (EWGSOP) reviewed in 2019 (EWGSOP2). Muscle strength was determined by hand-grip strength, body composition by measurement of bioelectrical impedance.

RESULTS

The mean age was 86.2 years, most of the patients were women (81.7%). 37.1% of patients were at nutritional risk (MNA 17-23.5) and 16.7% were malnourished (MNA < 17). 72.4% of women and 79.4% of men, were diagnosed with DRM. 77.6% of the women and 73.5% of the men had low muscle strength. The appendicular muscle mass index was below the cut-off points for sarcopenia in 72.4% of the women and 79.4% of the men. Patients with sarcopenia had a lower body mass index, older age, poorer previous functional status and higher disease burden. The relationship between weight loss and hand grip strength (HGS) was significant (p = 0.007).

CONCLUSIONS

53.8% of patients admitted for hip fracture present malnutrition or are at risk after screening with MNA. Sarcopenia and DRM affects at least three out of four patients older than 75 years admitted for hip fracture. Older age, worse functional status, lower body mass index and high number of comorbidities, are associated with these two entities. There is a relationship between DRM and sarcopenia.

Which intervention is more effective in improving sarcopenia in older adults? A systematic review with meta-analysis of randomized controlled trials

This systematic review aims, however, to determine which intervention is more effective. The skeletal muscle index (SMI), handgrip, and gait speed were used as indicators of improvement, and these effects were compared across six subgroups: combined intervention versus exercise; nutrition or control group; exercise versus nutrition; and exercise or nutrition versus control group. Out of 1596 articles, 32 studies (3063 older adults) were selected and meta-analyzed. Comparing the combined intervention with a control group, the WMD was 0.20 kg/m², 1.56 kg, and 0.08 m/s for SMI, handgrip, and gait speed, respectively, all of which showed a statistically significant improvement. When a combined intervention was compared with exercise and nutrition, the former resulted in improvements in handgrip (WMD 0.38 kg) and gait speed (WMD 0.12 m/s). On comparing exercise and nutrition, there was an improvement in gait speed (0.12 m/s) with exercise alone. On comparing exercise with a control group, only handgrip (WMD 1.74 kg) and gait speed (WMD 0.11 m/s) showed improvement, whereas in the nutrition versus the control group, only the handgrip (WMD 0.90 kg) improved. Although exercise and nutritional therapy together demonstrated improved muscle strength, exercise is recommended for the improvement of physical performance.

Gene Ontology (GO)-Driven Inference of Candidate Proteomic Markers Associated with Muscle Atrophy Conditions

Skeletal muscle homeostasis is essential for the maintenance of a healthy and active lifestyle. Imbalance in muscle homeostasis has significant consequences such as atrophy, loss of muscle mass, and progressive loss of functions. Aging-related muscle wasting, sarcopenia, and atrophy as a consequence of disease, such as cachexia, reduce the quality of life, increase morbidity and result in an overall poor prognosis. Investigating the muscle proteome related to muscle atrophy diseases has a great potential for diagnostic medicine to identify (i) potential protein biomarkers, and (ii) biological processes and functions common or unique to muscle wasting, cachexia, sarcopenia, and aging alone. We conducted a meta-analysis using gene ontology (GO) analysis of 24 human proteomic studies using tissue samples (skeletal muscle and adipose biopsies) and/or biofluids (serum, plasma, urine). Whilst there were few similarities in protein directionality across studies, biological processes common to conditions were identified. Here we demonstrate that the GO analysis of published human proteomics data can identify processes not revealed by single studies. We recommend the integration of proteomics data from tissue samples and biofluids to yield a comprehensive overview of the human skeletal muscle proteome. This will facilitate the identification of biomarkers and potential pathways of muscle-wasting conditions for use in clinics.

Exercise and Nutrition Strategies for Combating Sarcopenia and Type 2 Diabetes Mellitus in Older Adults

Medical and technology development have drastically the improved quality of life and, consequently, life expectancy. Nevertheless, the more people who enter the third-age, the more geriatric syndromes expand in the elderly. Sarcopenia and Type 2 diabetes mellitus (T2DM) are common diseases among the elderly and the literature has extensively studied these two diseases separately. Recent evidence, however, revealed that there is a bidirectional relationship between sarcopenia and T2DM. The aims of the present review were: (1) to present diet and exercise interventions for the management of sarcopenia and T2DM and (2) identify which diet and exercise interventions can be used simultaneously in order to effectively deal with these two disorders. Exercise and a balanced diet are used as effective countermeasures for combating sarcopenia and T2DM in older adults based on their bidirectional relationship. Lifestyle changes such as exercise and a balanced diet seem to play an important role in the remission of the diseases. Results showed that chronic exercise can help towards glycemic regulation as well as decrease the incidence rate of muscle degradation, while diet interventions which focus on protein or amino acids seem to successfully treat both disorders. Despite the fact that there are limited studies that deal with both disorders, it seems that a combined exercise regime (aerobic and resistance) along with protein intake > 1gr/kg/d is the safest strategy to follow in order to manage sarcopenia and T2DM concurrently.

Pyroptosis and Sarcopenia: Frontier Perspective of Disease Mechanism

With global ageing, sarcopenia, as an age-related disease, has brought a heavy burden to individuals and society. Increasing attention has been given to further exploring the morbidity mechanism and intervention measures for sarcopenia. Pyroptosis, also known as cellular inflammatory necrosis, is a kind of regulated cell death that plays a role in the ageing progress at the cellular level. It is closely related to age-related diseases such as cardiovascular diseases, Alzheimer’s disease, osteoarthritis, and sarcopenia. In the process of ageing, aggravated oxidative stress and poor skeletal muscle perfusion in ageing muscle tissues can activate the nod-like receptor (NLRP) family to trigger pyroptosis. Chronic inflammation is a representative characteristic of ageing. The levels of inflammatory factors such as TNF-α may activate the signaling pathways of pyroptosis by the NF-κB-GSDMD axis, which remains to be further studied. Autophagy is a protective mechanism in maintaining the integrity of intracellular organelles and the survival of cells in adverse conditions. The autophagy of skeletal muscle cells can inhibit the activation of the pyroptosis pathway to some extent. A profound understanding of the mechanism of pyroptosis in sarcopenia may help to identify new therapeutic targets in the future. This review article focuses on the role of pyroptosis in the development and progression of sarcopenia.

From the Bench to the Bedside: Branched Amino Acid and Micronutrient Strategies to Improve Mitochondrial Dysfunction Leading to Sarcopenia

With extended life expectancy, the older population is constantly increasing, and consequently, so too is the prevalence of age-related disorders. Sarcopenia, the pathological age-related loss of muscle mass and function; and malnutrition, the imbalance in nutrient intake and resultant energy production, are both commonly occurring conditions in old adults. Altered nutrition plays a crucial role in the onset of sarcopenia, and both these disorders are associated with detrimental consequences for patients (e.g., frailty, morbidity, and mortality) and society (e.g., healthcare costs). Importantly, sarcopenia and malnutrition also share critical molecular alterations, such as mitochondrial dysfunction, increased oxidative stress, and a chronic state of low grade and sterile inflammation, defined as inflammageing. Given the connection between malnutrition and sarcopenia, nutritional interventions capable of affecting mitochondrial health and correcting inflammageing are emerging as possible strategies to target sarcopenia. Here, we discuss mitochondrial dysfunction, oxidative stress, and inflammageing as key features leading to sarcopenia. Moreover, we examine the effects of some branched amino acids, omega-3 PUFA, and selected micronutrients on these pathways, and their potential role in modulating sarcopenia, warranting further clinical investigation.

How do we define and measure sarcopenia? A meta-analysis of observational studies

OBJECTIVE

this study aimed to investigate how sarcopenia has been defined and measured in the literature reporting its prevalence, and how different definitions and measurement tools can affect prevalence estimates.

DESIGN

systematic review and meta-analysis.

SETTING AND PARTICIPANTS

community-dwelling older people.

METHODS

meta-analysis of data collected from observational studies. We performed an electronic search in five databases to identify studies reporting the prevalence of sarcopenia. We used descriptive statistics to present data pertaining sarcopenia definition and measurement tools, and the quality-effects model for meta-analysis of pooled prevalence.

RESULTS

we found seven different operational definitions for sarcopenia and a variety of tools applied to assess the sarcopenic markers; muscle mass, muscle strength and physical performance. The prevalence of sarcopenia varied between the definitions with general estimates ranging from 5% based on the European Working Group on Sarcopenia in Older People (EWGSOP1) criterion to 17% with the International Working Group on Sarcopenia. According to the tool used to assess muscle mass, strength and physical performance, prevalence values also varied within definitions extending from 1 to 7%, 1 to 12% and 0 to 22%, respectively.

CONCLUSION AND IMPLICATIONS

the criteria used to define sarcopenia, as well as the measurement tools applied to assess sarcopenic markers have influence in the prevalence of sarcopenia. The establishment of a unique definition for sarcopenia, the use of methods that guarantee an accurate evaluation of muscle mass and the standardisation of measurement tools are necessary to allow a proper diagnosis and comparison of sarcopenia prevalence among populations.

Sex Differences in Adaptations in Muscle Strength and Size Following Resistance Training in Older Adults: A Systematic Review and Meta-analysis

BACKGROUND

Reductions in muscle size and strength occur with aging. These changes can be mitigated by participation in resistance training. At present, it is unknown if sex contributes to differences in adaptation to resistance training in older adults.

OBJECTIVE

The aim of this systematic review was to determine if sex differences are apparent in adaptations to resistance training in older adults.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

Web of Science; Science Direct; SPORTDiscus; CINAHL; and MEDLINE were searched from inception to June 2020.

ELIGIBILITY CRITERIA

Studies where males and females older than 50 years of age performed identical resistance training interventions and had outcome measures of muscle strength or size.

RESULTS

We initially screened 5337 studies. 30 studies (with 41 comparison groups) were included in our review (1410 participants; 651 males, 759 females). Mean study quality was 14.7/29 on a modified Downs and Black checklist, considered moderate quality. Females gained more relative lower-body strength than males (g = - 0.21 [95% CI - 0.33, - 0.10], p = 0.0003) but there were no differences in relative change for upper-body strength (g = - 0.29 [95% CI - 0.62, 0.04], p = 0.08) or relative muscle size (g = 0.10 [95% CI - 0.04, 0.23], p = 0.16). Males gained more absolute upper-body strength (g = 0.48 [95% CI 0.09, 0.88], p = 0.016), absolute lower-body strength (g = 0.33 [95% CI 0.19, 0.47], p < 0.0001), and absolute muscle size (g = 0.45 [95% CI 0.23, 0.66], p < 0.0001).

CONCLUSION

Our results indicate that sex differences in adaptations to resistance training are apparent in older adults. However, it is evident that the interpretation of sex-dependent adaptations to resistance training is heavily influenced by the presentation of the results in either an absolute or relative context.

STUDY REGISTRATION

Open Science Framework (osf.io/afn3y/).

Sarcopenic obesity and function in women with subacute hip fracture: a short-term prospective study

BACKGROUND

The prognostic role exerted by the concurrent presence of sarcopenia and obesity after hip fracture has not been elucidated.

AIM

To assess the effect of sarcopenic obesity on ability to function in women with subacute hip fracture.

DESIGN

Short-term prospective study.

SETTING

Rehabilitation hospital.

POPULATION

Women with subacute hip fracture.

METHODS

At admission, grip strength, by a Jamar dynamometer, and body composition by dual-energy x-ray absorptiometry were assessed. Sarcopenia was defined according to the criteria released by the European Working Group for Sarcopenia in Older People in 2019, with both grip strength < 16kg and appendicular lean mass (aLM) < 15kg. Alternatively, aLM/(height)2 < 5.5kg/m2 was substituted for aLM < 15kg to confirm sarcopenia in the women with grip strength < 16kg. Obesity was diagnosed with fat mass exceeding 40% of total body mass. Function was assessed by the Barthel index.

RESULTS

We assessed 183 of 200 women. Sarcopenic women had lower Barthel index scores assessed at the end of subacute inpatient rehabilitation (U=300,0; z=-4.3; P<0.001) and lower Batrhel index effectiveness (U=310,0; z=-4.2; P<0.001) than non-sarcopenic women. Conversely, we found no significant differences in function between obese and non-obese women. The concurrent presence of sarcopenia and obesity did not worsen the functional prognosis versus the presence of isolated sarcopenia. After adjustment for Barthel index scores before rehabilitation, age, hip-fracture type and cognitive impairment, sarcopenia was significantly associated with Barthel index scores (P=0.001) and Barthel index effectiveness (P<0.001), whereas obesity was not. The results did not materially change when aLM/(height)2 < 5.5kg/m2 was substituted for aLM <15kg to confirm sarcopenia in the women whose handgrip strength was < 16kg.

CONCLUSIONS

The concurrent presence of obesity did not worsen the negative prognostic role of sarcopenia in the short-term recovery of ability to function after hip fracture in women.

CLINICAL REHABILITATION IMPACT

In women with subacute hip fracture, sarcopenia but not obesity should be assessed to contribute to the prediction of the short-term functional outcome.

Body composition, adipokines, FGF23-Klotho and bone in kidney transplantation: Is there a link?

BACKGROUND

Kidney transplantation-associated mineral and bone disorder (KT-MBD) still represents a black box on the long-term due to scarce available data. We aimed to investigate the impact of non-classical bone regulating factors (body composition, adipokines, inflammatory markers, fibroblast growth factor 23-FGF23 and α-Klotho) in long-standing kidney transplant (KT) recipients compared to the general population.

METHODS

Our cross-sectional study, enrolling 59 KT patients and age, sex and body mass index-matched healthy general population volunteers, assessed the predictive role of the body composition, serum adipokines (leptin, adiponectin, resistin), inflammatory markers (erythrocyte sedimentation rate, C-reactive protein) and parathyroid hormone (PTH)-FGF23/α-Klotho axis upon bone mineral density (BMD) and osteocalcin, using correlation and linear multiple regression.

RESULTS

The 59 KT recipients (mean transplantation span of 57.7 ± 7.2 months) had similar body composition but significantly lower BMD (p < 0.01) compared to the general population group. Total lean mass was independently associated with BMD in both groups. In KT patients, age, time spent on dialysis and PTH were the main negative independent predictors of BMD, after adjusting for possible confounders. Resistin and α-Klotho also negatively predicted lumbar bone density (p < 0.001), while adiponectin and α-Klotho positively predicted osteocalcin levels (p < 0.001) in KT recipients, independently of inflammatory markers. No significant associations were found between FGF23 and bone parameters in any of the groups.

CONCLUSIONS

Age, PTH, time on dialysis and lean mass are among the main bone density predictors in long-standing KT patients. The bone impact of adipokine dysregulation and of α-Klotho merits further investigations in KT-MBD. Preserving lean mass for improved bone outcomes should be part of KT-MBD management on the long-term.

Sarcopenic obesity: research advances in pathogenesis and diagnostic criteria

Sarcopenic obesity (SO) refers to an obesity disease accompanied by low skeletal muscle quality, strength and/or function, which is more common in the elderly and seriously affects their quality of life and can lead to falls, unstable walking, balance disorders and fractures in the elderly. The increase in aging populations and the various health problems and medical costs associated with SO have aroused widespread concern in society. However, the pathogenesis of SO has not been fully clarified and the diagnostic criteria are not uniform, meaning that there are inconsistent data on the prevalence of SO and the potential correlation between SO and health outcomes. Therefore, we review the research progress on delineating the pathogenesis and diagnostic criteria of SO, to assist in the early diagnosis and evaluation of SO and subsequent interventions.

Update on the ESCEO recommendation for the conduct of clinical trials for drugs aiming at the treatment of sarcopenia in older adults

BACKGROUND

In 2016, an expert working group was convened under the auspices of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) and formulated consensus recommendations for the conduct of clinical trials for drugs to prevent or treat sarcopenia.

AIMS

The objective of the current paper is to provide a 2020 update of the previous recommendations in accordance with the evidence that has become available since our original recommendations.

METHODS

This paper is based on literature reviews performed by members of the ESCEO working group and followed up with face to face meetings organized for the whole group to make amendments and discuss further recommendations.

RESULTS

The randomized placebo-controlled double-blind parallel-arm drug clinical trials should be the design of choice for both phase II and III trials. Treatment and follow-up should run at least 6 months for phase II and 12 months for phase III trials. Overall physical activity, nutrition, co-prescriptions and comorbidity should be recorded. Participants in these trials should be at least 70-years-old and present with a combination of low muscle strength and low physical performance. Severely malnourished individuals, as well as bedridden patients, patients with extremely limited mobility or individuals with physical limitations clearly attributable to the direct effect of a specific disease, should be excluded. Multiple outcomes are proposed for phase II trials, including, as example, physical performance, muscle strength and mass, muscle metabolism and muscle-bone interaction. For phase III trials, we recommend a co-primary endpoint of a measure of functional performance and a Patient Reported Outcome Measure.

CONCLUSION

The working group has formulated consensus recommendations on specific aspects of trial design, and in doing so hopes to contribute to an improvement of the methodological robustness and comparability of clinical trials. Standardization of designs and outcomes would advance the field by allowing better comparison across studies, including performing individual patient-data meta-analyses, and different pro-myogenic therapies.

Exercise-Induced Autophagy Suppresses Sarcopenia Through Akt/mTOR and Akt/FoxO3a Signal Pathways and AMPK-Mediated Mitochondrial Quality Control

Exercise training is one of the most effective interventional strategies for sarcopenia in aged people. Nevertheless, the underlying mechanisms are not well recognized. Increasing studies have reported abnormal regulation of autophagy in aged skeletal muscle. Our current study aims to explore the efficiency of exercise interventions, including treadmill exercise, resistance exercise, alternating exercise with treadmill running and resistance exercise, and voluntary wheel running, on 21-month-old rats with sarcopenia and to detect the underlying mechanisms. Results showed the declined mass of gastrocnemius muscle with deficient autophagy and excessive apoptosis as a result of up-regulated Atrogin-1 and MuRF1, declined Beclin1 level and LC3-II/LC3-I ratio, accumulated p62, increased Bax, and reduced Bcl-2 levels, and also exhibited a defective mitochondrial quality control due to declined PGC-1α, Mfn2, Drp1, and PINK1 levels. However, 12-week exercise interventions suppressed the decline in mass loss of skeletal muscle, accompanied by down-regulated Atrogin-1 and MuRF1, increased Beclin1 level, improved LC3-II/LC3-I ratio, declined p62 level, and reduced Bax and increased Bcl-2 level, as well as enhanced mitochondrial function due to the increased PGC-1α, Mfn2, Drp1, and PINK1 levels. Moreover, exercise interventions also down-regulated the phosphorylation of Akt, mTOR, and FoxO3a, and up-regulated phosphorylated AMPK to regulate the functional status of autophagy and mitochondrial quality control. Therefore, exercise-induced autophagy is beneficial for remedying sarcopenia by modulating Akt/mTOR and Akt/FoxO3a signal pathways and AMPK-mediated mitochondrial quality control, and resistance exercise exhibits the best interventional efficiency.

Elevated Plasma Growth and Differentiation Factor 15 Is Associated With Slower Gait Speed and Lower Physical Performance in Healthy Community-Dwelling Adults

BACKGROUND

Growth and differentiation factor 15 (GDF-15) has been associated with obesity, muscle wasting, and cachexia. The receptor for GDF-15 was recently identified in the brainstem and regulates food intake and metabolism. The relationship of plasma GDF-15 with the age-associated decline of muscle mass and strength, gait speed, and physical performance in adults has not been well characterized.

METHODS

Plasma GDF-15, grip strength, 6-m gait speed, 400-m walking test time, lower extremity physical performance score, appendicular lean mass, and fat mass were measured in 194 healthy adult participants, aged 22-93 years, of the Baltimore Longitudinal Study of Aging.

RESULTS

Plasma GDF-15 concentrations increased with age (p < .001) and were higher in whites compared with blacks and Asians (p = .04). Adults with higher plasma GDF-15 had slower 6-m gait speed, longer 400-m walking time, and lower physical performance score in multivariable analyses adjusting for age and race. Plasma GDF-15 was not associated with grip strength, appendicular lean mass, or fat mass.

CONCLUSIONS

Elevated plasma GDF-15 is associated with slower gait speed, higher 400-m walking time, and lower physical performance in very healthy community-dwelling adults. The relationship between plasma GDF-15 and sarcopenia-related outcomes may be stronger in the population not selected to be healthy, and this hypothesis should be tested in a representative population.

Whey for Sarcopenia; Can Whey Peptides, Hydrolysates or Proteins Play a Beneficial Role?

As the human body ages, skeletal muscle loses its mass and strength. It is estimated that in 10% of individuals over the age of 60, this muscle frailty has progressed to sarcopenia. Biomarkers of sarcopenia include increases in inflammatory markers and oxidative stress markers and decreases in muscle anabolic markers. Whey is a high-quality, easily digested dairy protein which is widely used in the sports industry. This review explores the evidence that whey protein, hydrolysates or peptides may have beneficial effects on sarcopenic biomarkers in myoblast cell lines, in aged rodents and in human dietary intervention trials with the older consumer. A daily dietary supplementation of 35 g of whey is likely to improve sarcopenic biomarkers in frail or sarcopenia individuals. Whey supplementation, consumed by an older, healthy adult certainly improves muscle mTOR signaling, but exercise appears to have the greatest benefit to older muscle. In vitro cellular assays are central for bioactive and bioavailable peptide identification and to determine their mechanism of action on ageing muscle.

Hypovitaminosis D and Aging: Is There a Role in Muscle and Brain Health?

The older-adult population is constantly increasing, hence aging and mechanisms leading to aging are a topic raising increasing interest. Hypovitaminosis D is common amongst old patients and has been proposed as causative of several chronic diseases. Here we review the role of hypovitaminosis D and vitamin D supplementation in sarcopenia and dementia, from bench to bedside.

Sarcopenia, osteoporosis and the burden of prevalent vertebral fractures: a cross-sectional study of 350 women with hip fracture

BACKGROUND

The concurrent presence of sarcopenia and osteoporosis may enhance fracture risk.

AIM

The aim of this study was to evaluate the association between sarcopenia, osteoporosis, or the concurrent presence of both the conditions (osteosarcopenia) and the burden (number and severity) of vertebral fractures in women with hip fracture.

DESIGN

Cross-sectional study.

SETTING

Division of Physical and Rehabilitation Medicine.

POPULATION

We studied 350 women with subacute hip fracture.

METHODS

Lateral radiographs of the spine were taken 18.2±4.5 days after fracture occurrence and the Spine Deformity Index (SDI) was calculated. Body composition was assessed by dual-energy X-ray absorptiometry. Low muscle mass was identified with appendicular lean mass <15.02 kg and low bone mineral density with a femoral T-Score <-2.5.

RESULTS

The presence of sarcopenia (P=0.033) and osteoporosis (P=0.032) was associated with the SDI scores independently of each other and independently of age, percentage of body fat and hip-fracture type. The 350 women were categorized into 3 groups according to the absence of both osteoporosis and sarcopenia (N.=25), presence of either osteoporosis or sarcopenia (N.=95) or presence of osteosarcopenia (N.=230). We found a significant difference in SDI scores across the 3 groups: χ2 (2, N.=350) = 15.29; P<0.001. The categorization of the 350 women into the 3 groups was associated with the SDI scores (P=0.001) independently of age, percentage of body fat and hip-fracture type.

CONCLUSIONS

Both osteoporosis and sarcopenia were independently associated with the burden of prevalent vertebral fractures in women with hip fracture. The concurrent presence of sarcopenia and osteoporosis was associated with a higher SDI Score than the presence of only one of the 2 conditions.

CLINICAL REHABILITATION IMPACT

Subjects with both low bone mass and low muscle mass should be considered at particularly high risk for vertebral fractures. Interventions targeting both the components of the muscle-bone unit, including exercise, nutrition, and possibly new medications, should be investigated to optimize fracture prevention.

Cardiac cachexia in cats with congestive heart failure: Prevalence and clinical, laboratory, and survival findings

BACKGROUND

Cardiac cachexia is common in people and dogs with congestive heart failure (CHF). However, the prevalence and effects of cardiac cachexia in cats are unknown.

OBJECTIVES

To determine the prevalence of cachexia and its associations with clinical laboratory and survival data in cats with CHF.

ANIMALS

One hundred twenty-five cats with CHF.

METHODS

Medical records of cats evaluated during a 40-month period were retrospectively reviewed to identify cats with cardiac cachexia using 7 different definitions. Clinical, laboratory, and survival data were compared between cats with and without cachexia.

RESULTS

Prevalence of cachexia ranged from 0 to 66.7% for the 7 definitions, with a prevalence of 41.6% using muscle condition score (MCS). Cats with cachexia (determined by MCS) were older (P < .001), more likely to have pleural effusion (P = .003), had significantly higher blood urea nitrogen (P < .001) and neutrophil concentrations (P = .01), and significantly lower body condition score (P < .001), body weights (P < .001), hematocrit (P = .007), and hemoglobin concentrations (P = .009). Survival time for cats with cachexia (determined by MCS) was significantly shorter than for cats without cachexia (P = .03). Cats that were underweight (P = .002) and cats with dilated cardiomyopathy (DCM) also had shorter survival times (P = .04).

CONCLUSIONS AND CLINICAL IMPORTANCE

The association between cachexia and reduced survival time emphasizes the importance of identifying and addressing this common problem in cats with CHF.

How do we define and measure sarcopenia? Protocol for a systematic review

BACKGROUND

The loss of muscle mass is a natural aging consequence. A reduction of muscle mass that surpasses the physiological rate is considered the key factor responsible for the development of a geriatric syndrome called sarcopenia. However, a new understanding of the importance of muscle quality over quantity is rising; as a result, different definitions for sarcopenia has been used. Due to the negative impact on elder's health and quality of life, the number of research investigating the causes, prevalence, and management of sarcopenia is increasing, although a consensus on sarcopenia definition is still missing. This systematic review will assess observational studies reporting the presence of sarcopenia aiming to verify how sarcopenia is defined, the diagnosis criteria, and the tools used for assessment. In addition, we will investigate the influence of the definition and diagnostic tools on the prevalence rate.

METHODS

Keywords related to the condition, population, and type of study will be combined to build a search strategy for each of the following databases MEDLINE, EMBASE, CINAHL (Cumulative Index to Nursing and Allied Health Literature), Web of Science, and Google Scholar. Two independent reviewers will analyze the retrieved papers for eligibility and the methodological quality of eligible studies. The definition of sarcopenia and diagnostic tools used in each study and the prevalence estimates will be extracted. Descriptive statistics will be used to report the definitions of sarcopenia, diagnostic tools, and whether these influence or not, the prevalence rates.

DISCUSSION

Sarcopenia is receiving greater attention in geriatrics research in recent years. Therefore, it is important to investigate how this condition is defined in the literature and whether these definitions can interfere with the reported estimates devoting more efforts on the topic. The results of this study can help to determine the most used definitions of sarcopenia reported in the literature, its strengths and limitations, and open a discussion about a need for a more valid, easy, and suitable one.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015020832.

Populations and outcome measures used in ongoing research in sarcopenia

BACKGROUND

Sarcopenia research may be hampered by the heterogeneity of populations and outcome measures used in clinical studies.

AIM

The aim of this study was to describe the inclusion/exclusion criteria and outcome measures used in ongoing research in sarcopenia.

METHODS

All active intervention studies registered in the World Health Organization with the keyword sarcopenia were included. Study design, type of intervention, inclusion/exclusion criteria and outcome measures were registered and classified.

RESULTS

In April 2014, 151 studies on sarcopenia were registered in the WHO database. One hundred twenty-three were intervention studies. Most trials (94.3 %) were single centre and randomized (93.5 %), 51.2 % were double blind. Nutritional interventions (36.6 %), physical exercise (12.2 %) or both (19.5 %) were the most common interventions tested. Only 54.4 % included subjects of both genders, and 46.3 % had an upper age limit. Definition of the target populations was heterogeneous, with 57.7 % including healthy subjects and none using recent definitions of sarcopenia. Lifestyle and the degree of physical activity of subjects were not described or considered in most cases (79.7 %). Subjects with cardiovascular, neuropsychiatric or metabolic disorders and those with physical disability were usually excluded. Muscle mass and muscle strength were the primary outcome variables in 28.5 and 29.5 % of studies and physical performance in 19.5 %, but only 4.1 % used the three variables used the three of them. An additional 26.8 % used biological outcome variables. Little information and agreement existed in the way muscle and physical performance parameters were measured.

CONCLUSIONS

We found a large heterogeneity in trial design, definition of populations and outcome measures in present research.

Physical activity, diet quality, and mortality among sarcopenic older adults

BACKGROUND

It is unknown if physical activity and good diet quality modify the risk of poor outcomes, such as mortality, among older adults with sarcopenia.

AIM

To examine if physical activity and good diet quality modify the risk of poor outcomes, such as mortality, among older adults with sarcopenia.

METHODS

A population-based cohort study among 1618 older adults with sarcopenia from the Third National Health and Nutrition Survey (NHANES III; 1988-1994). Sarcopenia was defined by the European Working Group on Sarcopenia in Older People. Physical activity was self-reported, and classified as sedentary (0 bouts per week), physically inactive (1-4 bouts per week), and physically active (≥5 bouts per week). Diet quality was assessed with the healthy eating index (a scale of 0-100 representing adherence to federal dietary recommendations), and classified as poor (<51), fair (51-80), and good (>80) diet quality.

RESULTS

Compared to participants who were sedentary, those who were physically inactive were 16 % less likely to die [HR 0.84 (95 % CI 0.64-1.09)], and those who were physically active were 25 % less likely to die [HR 0.75 (95 % CI 0.59-0.97); P _trend = 0.026]. Compared to participants with poor diet quality, those with fair diet quality were 37 % less likely to die [HR 0.63 (95 % CI 0.47-0.86)], and those with good diet quality were 45 % less likely to die [HR 0.55 (95 % CI 0.37-0.80); P _trend = 0.002].

CONCLUSIONS

Participation in physical activity and consumption of a healthy diet correspond with a lower risk of mortality among older adults with sarcopenia. Randomized trials are needed in this population.

Physical frailty and sarcopenia (PF&S): a point of view from the industry

We have observed over the last 15 years a wide debate both in the medical scientific community and in the public health arena on the definition and operationalization of frailty, typically a geriatric condition, and in particular of physical frailty linked to sarcopenia. Because physical frailty in its initial phase can still be reversed, fighting sarcopenia in elderly persons has the potential to slow or halt progressive decline towards disability and dependency. Quite recently, regulators focused attention on frailty as an indicator of biological age to be measured to characterize elderly patients before their inclusion in clinical trials. A European guidance regarding most adapted evaluation instruments of frailty is currently under public consultation. Does the regulatory initiative imply we should now consider frailty, and particularly physical frailty, primarily as an important risk factor for adverse events and poor response, or mainly as a clinical tool helping the physician to opt for one therapeutic pathway or another? Or is physical frailty above all a specific geriatric condition deserving an effective and innovative therapeutic approach with the objective to curb the incidence of its most common result, e.g., mobility disability? Pharmaceutical industry developers consider both faces of the coin very relevant. We agree with regulators that better characterization of subpopulations, not only in elderly patients, can improve the benefit risk ratio of medicines. At the same time, we believe it is in the public health interest to develop novel drugs indicated for specific geriatric conditions, like osteoporosis in the 1990s and sarcopenia today. We consider it an important therapeutic goal to effectively delay mobility disability and to extend the active, independent, and healthy life years of aging people. The "Sarcopenia and Physical fRailty IN older people: multi-componenT Treatment strategies" (SPRINTT) collaborative project under IMI is paving the way for adapted methodologies to study the change of physical frailty and sarcopenia in at-risk older persons and to adequately characterize the population that needs to be treated.

Melatonin as a Potential Agent in the Treatment of Sarcopenia

Considering the increased speed at which the world population is aging, sarcopenia could become an epidemic in this century. This condition currently has no means of prevention or treatment. Melatonin is a highly effective and ubiquitously acting antioxidant and free radical scavenger that is normally produced in all organisms. This molecule has been implicated in a huge number of biological processes, from anticonvulsant properties in children to protective effects on the lung in chronic obstructive pulmonary disease. In this review, we summarize the data which suggest that melatonin may be beneficial in attenuating, reducing or preventing each of the symptoms that characterize sarcopenia. The findings are not limited to sarcopenia, but also apply to osteoporosis-related sarcopenia and to age-related neuromuscular junction dysfunction. Since melatonin has a high safety profile and is drastically reduced in advanced age, its potential utility in the treatment of sarcopenic patients and related dysfunctions should be considered.

Recommendations for the conduct of clinical trials for drugs to treat or prevent sarcopenia

Purpose

Sarcopenia is an age-related muscle condition which is frequently a precursor of frailty, mobility disability and premature death. It has a high prevalence in older populations and presents a considerable social and economic burden. Potential treatments are under development but, as yet, no guidelines support regulatory studies for new drugs to manage sarcopenia. The objective of this position paper is therefore to suggest a set of potential endpoints and target population definitions to stimulate debate and progress within the medico-scientific and regulatory communities.

Methods

A multidisciplinary expert working group was hosted by the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis, which reviewed and discussed the recent literature from a perspective of clinical experience and guideline development. Relevant parallels were drawn from the development of definition of osteoporosis as a disease and clinical assessment of pharmaceutical treatments for that indication.

Results

A case-finding decision tree is briefly reviewed with a discussion of recent prevalence estimations of different relevant threshold values. The selection criteria for patients in regulatory studies are discussed according to the aims of the investigation (sarcopenia prevention or treatment) and the stage of project development. The possible endpoints of such studies are reviewed and a plea is made for the establishment of a core outcome set to be used in all clinical trials of sarcopenia.

Conclusions

The current lack of guidelines for the assessment of new therapeutic treatments for sarcopenia could potentially hinder the delivery of effective medicines to patients at risk.

Electronic supplementary material

The online version of this article (doi:10.1007/s40520-015-0517-y) contains supplementary material, which is available to authorized users.

The impact of sleep on age-related sarcopenia: Possible connections and clinical implications

Sarcopenia is a geriatric condition that comprises declined skeletal muscle mass, strength and function, leading to the risk of multiple adverse outcomes, including death. Its pathophysiology involves neuroendocrine and inflammatory factors, unfavorable nutritional habits and low physical activity. Sleep may play a role in muscle protein metabolism, although this hypothesis has not been studied extensively. Reductions in duration and quality of sleep and increases in prevalence of circadian rhythm and sleep disorders with age favor proteolysis, modify body composition and increase the risk of insulin resistance, all of which have been associated with sarcopenia. Data on the effects of age-related slow-wave sleep decline, circadian rhythm disruptions and obstructive sleep apnea (OSA) on hypothalamic-pituitary-adrenal (HPA), hypothalamic-pituitary-gonadal (HPG), somatotropic axes, and glucose metabolism indicate that sleep disorder interventions may affect muscle loss. Recent research associating OSA with the risk of conditions closely related to the sarcopenia process, such as frailty and sleep quality impairment, indirectly suggest that sleep can influence skeletal muscle decline in the elderly. Several protein synthesis and degradation pathways are mediated by growth hormone (GH), insulin-like growth factor-1 (IGF-1), testosterone, cortisol and insulin, which act on the cellular and molecular levels to increase or reestablish muscle fiber, strength and function. Age-related sleep problems potentially interfere intracellularly by inhibiting anabolic hormone cascades and enhancing catabolic pathways in the skeletal muscle. Specific physical exercises combined or not with nutritional recommendations are the current treatment options for sarcopenia. Clinical studies testing exogenous administration of anabolic hormones have not yielded adequate safety profiles. Therapeutic approaches targeting sleep disturbances to normalize circadian rhythms and sleep homeostasis may represent a novel strategy to preserve or recover muscle health in older adults. Promising research results regarding the associations between sleep variables and sarcopenia biomarkers and clinical parameters are required to confirm this hypothesis.

Presarcopenia and sarcopenia in hip-fracture women: prevalence and association with ability to function in activities of daily living

BACKGROUND AND AIMS

Sarcopenia staging systems have been proposed, but little is known on their application in hip-fracture patients. Our aim was to assess the prevalence of presarcopenia and sarcopenia and their association with ability to function in activities of daily living in hip-fracture women.

METHODS

We investigated white women (N = 138 of 149) who were consecutively admitted to a rehabilitation hospital because of their first hip fracture. In each woman, we measured appendicular lean mass (aLM) by dual-energy X-ray absorptiometry, at a median of 18 days after hip fracture occurrence. On the same day, we assessed grip strength with a handheld dynamometer. Functional autonomy was assessed by the Barthel Index. We used the European Working Group on Sarcopenia in Older People (EWGSOP) definition to calculate the prevalence of presarcopenia and sarcopenia, taking into account both aLM/height(2) and handgrip strength. Gait speed was not considered, because of the recent hip fracture.

RESULTS

Twenty-three (17 %) of the 138 women fulfilled the diagnostic criteria for presarcopenia whereas 80 (58 %) were sarcopenic. The women with presarcopenia were younger, healthier and with higher Barthel Index scores (median 65 vs. 55; interquartile range 60-75 and 50-60, respectively; p < 0.001) than those with sarcopenia. Significant differences in Barthel Index scores at the time of assessment (but not at the end of the rehabilitation course) persisted after multiple adjustments (p < 0.001).

CONCLUSIONS

The prevalence of presarcopenia and sarcopenia was high in hip-fracture women. Presarcopenic women had higher ability to function in activities of daily living than sarcopenic women.

Abnormal myofiber morphology and limb dysfunction in claudication

BACKGROUND

Peripheral artery disease (PAD), which affects an estimated 27 million people in Europe and North America, is caused by atherosclerotic plaques that limit blood flow to the legs. Chronic, repeated ischemia in the lower leg muscles of PAD patients is associated with loss of normal myofiber morphology and myofiber degradation. In this study, we tested the hypothesis that myofiber morphometrics of PAD calf muscle are significantly different from normal calf muscle and correlate with reduced calf muscle strength and walking performance.

METHODS

Gastrocnemius biopsies were collected from 154 PAD patients (Fontaine stage II) and 85 control subjects. Morphometric parameters of gastrocnemius fibers were determined and evaluated for associations with walking distances and calf muscle strength.

RESULTS

Compared with control myofibers, PAD myofiber cross-sectional area, major and minor axes, equivalent diameter, perimeter, solidity, and density were significantly decreased (P < 0.005), whereas roundness was significantly increased (P < 0.005). Myofiber morphometric parameters correlated with walking distances and calf muscle strength. Multiple regression analyses demonstrated myofiber cross-sectional area, roundness, and solidity as the best predictors of calf muscle strength and 6-min walking distance, whereas cross-sectional area was the main predictor of maximum walking distance.

CONCLUSIONS

Myofiber morphometrics of PAD gastrocnemius differ significantly from those of control muscle and predict calf muscle strength and walking distances of the PAD patients. Morphometric parameters of gastrocnemius myofibers may serve as objective criteria for diagnosis, staging, and treatment of PAD.

Reproducibility of jumping mechanography and traditional measures of physical and muscle function in older adults

SUMMARY

Improved approaches to assess functional change over time are needed to optimally reduce fall/fracture risk; jumping mechanography (JM) may be one such methodology. In this study, JM parameters were more reproducible than traditional functional tests. JM may be better able to demonstrate efficacy of interventions to mitigate sarcopenia.

INTRODUCTION

Jumping mechanography (JM), a tool using maximal countermovement jumps performed on a force plate, may more reliably assess muscle function than traditional methods. The purpose of this study was to examine JM retest reliability in older adults compared with commonly used muscle and physical function assessments.

METHODS

Community-dwelling individuals age≥70 years performed physical and muscle function assessments including the short physical performance battery (SPPB), grip strength, and JM on multiple occasions over 3 months. JM parameters included body weight-corrected peak power and jump height. Appendicular lean mass was measured by dual energy x-ray (DXA). Mixed effects linear regression models were used to estimate between- and within-person variability summarized as intra-class correlation coefficients (ICC).

RESULTS

Ninety-seven individuals (49 females, 48 males, mean age 80.7 years) participated. All testing was well tolerated; no participant sustained injury. Jump power, height, and grip strength were greater (p<0.0001) in men than women. Grip strength, jump power, and height had excellent ICCs (0.95, 0.93, and 0.88, respectively); chair rise, SPPB score, and gait speed had lower ICCs (0.81, 0.77, and 0.76, respectively).

CONCLUSION

In older adults, JM has excellent retest reliability, is stable over time, and can be performed safely. JM retest reliability was comparable to grip strength and possibly better than SPPB and gait speed. JM is a promising tool for muscle function assessment in older adults. Comparison of this approach with traditional assessment tools in longitudinal interventional studies is needed.

Assessing sarcopenic prevalence and risk factors in residential aged care: methodology and feasibility

BACKGROUND

Sarcopenia is a significant geriatric syndrome with both health care expenditure and personal burden. Most recently, the European Working Group in Sarcopenia in Older Adults has established a consensus definition and assessment criteria for sarcopenia that includes a below-normal muscle mass and muscle function (either or both of below-normal muscle strength and physical performance). Using these criteria, work is needed to identify the prevalence and risk factors among the old, and those most susceptible to sarcopenia, the very old. This manuscript describes the recruitment and data collection methodology, and direct burden to participants, among a very old cohort residing in a residential aged care (RAC) setting.

METHODS

Eleven RAC facilities participated in the study. Potential participants were identified by the facility service manager and then randomised into the study. All participants gave self or substitute decision maker consent. Participants undertook a single one on one assessment that included measures of sarcopenia, functional capacity, cognitive and nutritional health, falls, activity, facility and hospital history, physical activity and assessment burden. A sub-study of physical activity and sedentary behaviours measured by activPAL3™ inclinometer was also conducted.

RESULTS

Of 709 residents, 328 were ineligible to participate. Two hundred and seventy-three residents were randomised to the study and 102 gave informed or substitute decision maker consent. Participants were 84.5 ± 8.2 years of age and had been in care for 1,204.2 ± 1,220.1 days. The groups need for care was high (Aged Care Funding Instrument score of 2.6 ± 1.7) and they had a below-normal functional (Short Physical Performance Battery summery score of 3.5 ± 2.4). The larger percentage of participants had no depression and normal cognitive capacity. A total of 33 residents participated in the activPAL study. Each assessment took an average of 27.0 ± 7.0 min, with a low assessment burden reported by participants.

CONCLUSIONS

The successful assessment of sarcopenia and physical activity in a RAC setting is labour intensive to establish, but feasible to conduct. Low recruitment numbers and the restrictive exclusion criteria, may have limited the accuracy of this work. However, this work is a primary step in establishing the level of sarcopenia and its risk factors for those in end-of-life care.

Techniques for the diagnosis of sarcopenia

Sarcopenia is an age-related process of skeletal muscle loss associated with declining physical performance, highly prevalent among older subjects, with a negative prognostic effect on falls, disability and mortality risk. Modern approaches to sarcopenia case finding and diagnosis are based on physical performance measures, while assessment of muscle mass represents the second diagnostic step. Muscle mass can be quantified at different levels of body composition, with a complexity increasing from atomic detection to anatomic measure. In the choice of measuring method, different factors have to be taken into account, including validity, simplicity, cost and specific purpose (clinical versus research). Some methods, such as MRI and CT, have high validity but are complex and costly. Bioelectrical impedance analysis is inexpensive and easy to perform in most settings, being the preferred method for clinical practice. Dual energy X-ray absorptiometry has intermediate cost and complexity with good reproducibility, and is more reliable for research setting. Other methods, such as administration of tritium (D3)-marked creatine and measurement of urinary D3-creatinine, are still in a preclinical phase of development. For all methods the issue of normative data does exist and needs to be solved, in order to reliably identify homogeneous populations with sarcopenia, to be targeted in clinical practice and intervention studies.

Sarcopenia and the analysis of body composition

Reduction of lean mass is a primary body composition change associated with aging. Because many factors contribute to lean mass reduction, the problem has been given various names depending on the proposed cause, such as "age-related sarcopenia," "dynapenia," "myopenia," "sarcopenic obesity," or simply "sarcopenia." There is currently no consensus on how to best diagnose the reduction of lean mass and its consequences on health. We propose that simple body composition methods can be used to indirectly evaluate sarcopenia, provided that those techniques are validated against the "quality of lean" criterion that associates muscle mass and metabolic function with the components of fat-free mass. Promising field methods include the use of stable isotopes for the evaluation of water compartments and new approaches to bioelectrical impedance analysis, which is also associated with the monitoring of water homeostasis.

Prevalence of sarcopenia and associated risk factors by two diagnostic criteria in community-dwelling older men: the São Paulo Ageing & Health Study (SPAH)

Sarcopenia is an aging syndrome that can be characterized by many criteria adjusted or not by fat mass. This study suggested that the optimal criteria should be selected according to body mass index (BMI) in older men and identified age, BMI, race, smoking, physical activity, hip bone mineral density (BMD) as risk factors for this syndrome.

INTRODUCTION

This study aims to analyze the prevalence of sarcopenia and associated risk factors using appendicular skeletal mass (ASM)/height(2) and ASM adjusted for total fat mass criteria in older men from community.

METHODS

Three hundred ninety-nine men were included and answered a questionnaire about lifestyle and medical history. Individuals were classified by their BMI using the classification adjusted by age. Body composition and bone mineral density were measured by dual X-ray absorptiometry. Sarcopenia was classified according to both criteria. Logistic regression models were used to analyze risk factors associated with sarcopenia.

RESULTS

The mean BMI was 26.46 kg/m(2): 12.5 % underweight, 43.6 % normal, and 43.9 % overweight/obese. Fifty-four (13.5 %) were considered sarcopenic by ASM/height(2) and 79 (19.8 %) by ASM adjusted for fat (p = 0.001). Fifty-one (12.8 %) individuals had discordant sarcopenia classification: 13 were classified only by ASM/height(2) and 38 only by ASM adjusted for fat. Of the 13 subjects classified as sarcopenic only by ASM/height(2), 84.6 % (11/13) were underweight and solely one (7.7 %) was considered overweight/obese. In contrast, of those 38 older men classified as sarcopenic only by ASM adjusted for fat, none were underweight and 53 % (20/38) were overweight/obese. Subjects classified as sarcopenic according to both criteria had the same risk factors in the final model analyses (age, BMI, race, smoking, physical activity, hip BMD; p < 0.05).

CONCLUSION

This study suggested that the optimal criteria for sarcopenia should be selected according to BMI in community-dwelling older men.

Myostatin--the holy grail for muscle, bone, and fat?

Myostatin, a member of the transforming growth factor beta (TGF-β) superfamily, was first described in 1997. Since then, myostatin has gained growing attention because of the discovery that myostatin inhibition leads to muscle mass accrual. Myostatin not only plays a key role in muscle homeostasis, but also affects fat and bone. This review will focus on the impact of myostatin and its inhibition on muscle mass/function, adipose tissue and bone density/geometry in humans. Although existing data are sparse, myostatin inhibition leads to increased lean mass and 1 study found a decrease in fat mass and increase in bone formation. In addition, myostatin levels are increased in sarcopenia, cachexia and bed rest whereas they are increased after resistance training, suggesting physiological regulatory of myostatin. Increased myostatin levels have also been found in obesity and levels decrease after weight loss from caloric restriction. Knowledge on the relationship of myostatin with bone is largely based on animal data where elevated myostatin levels lead to decreased BMD and myostatin inhibition improved BMD. In summary, myostatin appears to be a key factor in the integrated physiology of muscle, fat, and bone. It is unclear whether myostatin directly affects fat and bone, or indirectly via muscle. Whether via direct or indirect effects, myostatin inhibition appears to increase muscle and bone mass and decrease fat tissue-a combination that truly appears to be a holy grail. However, at this time, human data for both efficacy and safety are extremely limited. Moreover, whether increased muscle mass also leads to improved function remains to be determined. Ultimately potential beneficial effects of myostatin inhibition will need to be determined based on hard outcomes such as falls and fractures.

What's in a name revisited: should osteoporosis and sarcopenia be considered components of "dysmobility syndrome?"

Sarcopenia and osteoporosis are age-related declines in the quantity and quality of muscle and bone respectively, with shared pathogeneses and adverse health consequences. Both absolute and relative fat excess, i.e., obesity and sarcopenic obesity, contribute to disability, falls, and fractures. Rather than focusing on a single component, i.e., osteoporosis, sarcopenia, or obesity, we realized that an opportunity exists to combine clinical factors, thereby potentially allowing improved identification of older adults at risk for disability, falls, and fractures. Such a combination could be termed dysmobility syndrome, analogous to the approach taken with metabolic syndrome. An arbitrary score-based approach to dysmobility syndrome diagnosis is proposed and explored in a small cohort of older adults. Further evaluation of such an approach in large population-based and prospective studies seems warranted.

Mitochondrial dysfunction and sarcopenia of aging: from signaling pathways to clinical trials

Sarcopenia, the age-related loss of muscle mass and function, imposes a dramatic burden on individuals and society. The development of preventive and therapeutic strategies against sarcopenia is therefore perceived as an urgent need by health professionals and has instigated intensive research on the pathophysiology of this syndrome. The pathogenesis of sarcopenia is multifaceted and encompasses lifestyle habits, systemic factors (e.g., chronic inflammation and hormonal alterations), local environment perturbations (e.g., vascular dysfunction), and intramuscular specific processes. In this scenario, derangements in skeletal myocyte mitochondrial function are recognized as major factors contributing to the age-dependent muscle degeneration. In this review, we summarize prominent findings and controversial issues on the contribution of specific mitochondrial processes - including oxidative stress, quality control mechanisms and apoptotic signaling - on the development of sarcopenia. Extramuscular alterations accompanying the aging process with a potential impact on myocyte mitochondrial function are also discussed. We conclude with presenting methodological and safety considerations for the design of clinical trials targeting mitochondrial dysfunction to treat sarcopenia. Special emphasis is placed on the importance of monitoring the effects of an intervention on muscle mitochondrial function and identifying the optimal target population for the trial. This article is part of a Directed Issue entitled: Molecular basis of muscle wasting.

Body composition, muscle strength, and physical function of patients with Bethlem myopathy and Ullrich congenital muscular dystrophy

OBJECTIVE

To determine the contributions of body mass, adiposity, and muscularity to physical function and muscle strength in adult patients with Bethlem myopathy (BM) and Ullrich congenital muscular dystrophy (UCMD).

MATERIALS AND METHODS

Evaluation involved one UCMD and 7 BM patients. Body composition was determined by body mass index (BMI) and dual-energy-X-ray-absorptiometry (DXA), muscle strength by dynamometry, physical function by the distance walked in 6 minutes (6MWD), forced vital capacity (FVC) by a spirometer.

RESULTS

Six participants were of normal weight and 2 overweight based on BMI; all were sarcopenic based on appendicular fat free mass index (AFFMI); and 7 were sarcopenic obese based on AFFMI and % fat mass. Average muscle strength was reduced below 50% of normal. The 6MWD was in BM patients 30% less than normal. FVC was reduced in 4 of the BM patients. Muscle strength had a good correlation with the physical function variables. Correlation between muscle strength and BMI was poor; it was very high with AFFMI. AFFMI was the best single explicator of muscle strength and physical function.

CONCLUSION

Muscle mass determined by DXA explains most of the variability of the measures of muscle strength and physical function in patients with BM and UCMD.

Designing pharmaceutical trials for sarcopenia in frail older adults: EU/US Task Force recommendations

An international task force of academic and industry leaders in sarcopenia research met on December 5, 2012 in Orlando, Florida to develop guidelines for designing and executing randomized clinical trials of sarcopenia treatments. The Task Force reviewed results from previous trials in related disease areas to extract lessons relevant to future sarcopenia trials, including practical issues regarding the design and conduct of trials in elderly populations, the definition of appropriate target populations, and the selection of screening tools, outcome measures, and biomarkers. They discussed regulatory issues, the challenges posed by trials of different types of interventions, and the need for standardization and harmonization. The Task Force concluded with recommendations for advancing the field toward better clinical trials.

Sarcopenia and osteopenia among 70-80-year-old home-dwelling Finnish women: prevalence and association with functional performance

This study showed that the prevalence of sarcopenia (low muscle mass and performance) among 70-80-year-old home-dwelling Finnish women is very low, while every third woman has WHO-based osteopenia (low bone mass). Muscle mass and derived indices of sarcopenia were not significantly related to measures of functional ability.

INTRODUCTION

This study aims to determine the prevalence of sarcopenia and osteopenia among four hundred nine 70-80-year-old independently living Finnish women. The study compared consensus diagnostic criteria for age-related sarcopenia recently published by the European Working Group on Sarcopenia in Older People (EWGSOP) and the International Working Group on Sarcopenia (IWG) and assessed their associations with functional ability.

METHODS

Femoral bone mineral density and body composition were measured with dual-energy X-ray absorptiometry. Skeletal muscle mass index (SMI), gait speed, and handgrip strength were used for sarcopenia diagnosis. Independent samples t tests determined group differences in body composition and functional ability according to recommended diagnostic cutpoints. Scatter plots were used to illustrate the correlations between the outcome measures used for diagnosis.

RESULTS

Prevalence of sarcopenia was 0.9 and 2.7 % according to the EWGSOP and IWG, respectively. Thirty-six percent of the women had WHO-based osteopenia. Women with higher gait speed had significantly lower body weight and fat mass percentage, higher lean mass percentage, and better functional ability. Women with a low SMI weighed significantly less, with no significant differences in other outcome measures. SMI, gait speed, and grip strength were significantly correlated.

CONCLUSIONS

Our study suggests that when using consensus definitions, sarcopenia is infrequent among older home-dwelling women while every third woman has osteopenia. In clinical practice, attention should be paid to the decline in functional ability rather than focusing on low muscle mass alone.