Sarcopenia Is Recognized as an Independent Condition by an International Classification of Disease, Tenth Revision, Clinical Modification (ICD-10-CM) Code

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.

Sarcopenia-a geriatric pandemic : A narrative review

With growing life expectancy, the prevalence of frailty and sarcopenia will continuously increase during the next decades. Geographical differences have been described, and depending on the population studied, sarcopenia is evident in 10% of community-dwelling people, increasing up to 40 to 50% among those living in nursing homes. Sarcopenia is a complex age-related process of multifactorial pathogenesis, influenced by lifestyle, nutrition, biological processes during aging, and also immunological and endocrine mechanisms. For diagnostic criteria, physical parameters (muscle mass measurement) and functional aspects (muscle strength, gait speed, physical performance) are required. In routine clinical care, screening patients using the SARC‑F questionnaire is recommended by recent guidelines of the European Workgroup for Sarcopenia.

Lower serum FT3 within the reference range is associated with mortality for older adults over 80 years of age with sarcopenia

OBJECTIVE

Thyroid hormones stimulate myogenesis and muscle contraction and regulate skeletal muscle cell metabolism. However, the association between thyroid hormone levels and mortality in sarcopenic older adults remains elusive. The aim of this study was to investigate the relationship between thyroid hormones and all-cause mortality in people over 80 years of age with sarcopenia.

METHODS

This study was performed on 264 sarcopenic patients aged 80 years and older. Serum levels of thyroid hormone, including free triiodothyronine (FT3), free thyroxine (FT4), and thyroid stimulating hormone (TSH) were tested to evaluate thyroid status. Sarcopenia was defined using the criteria of the European Working Group on Sarcopenia in Older People. Mortality data were available for up to 38 months of follow-up. The correlation between FT3 and calf circumference (CC) or handgrip strength (HGS) was determined by Pearson correlation analysis. Kaplan-Meier analysis was used to compare the differences between FT3 tertile groups. Cox regression was used to analyze the mortality risk ratio of patients with different FT3 tertiles.

RESULTS

During the follow-up period, 88 older adults died. Non-Survivors had lower serum FT3 levels (3.7 ± 0.5 vs. 3.9 ± 0.7, P = 0.001) than the Survivor. Serum FT3 was positively associated with CC and HGS (r = 0.29, P < 0.001, r = 0.21, P = 0.002, respectively). The Kaplan-Meier curve analysis demonstrated a difference in mortality among the FT3 tertile groups (log-rank test, χ² = 11.83, P = 0.003). The high FT3 group had lower mortality compared with the low FT3 group (the adjusted HRs were 0.63 (95%CI: 0.41-0.96 P = 0.031).

CONCLUSION

Lower FT3 within the reference range is associated with higher mortality in adults over 80 years with sarcopenia and euthyroid. Routine assessment of FT3 may be an easy way to identify high-risk older adults with sarcopenia.

Anti-tumor necrosis factor-α is potentially better than tumor necrosis factor-α as the biomarker for sarcopenia: Results from the I-Lan longitudinal aging study

Tumor necrosis factor (TNF)-α is a proinflammatory cytokine involved in the pathogenesis of sarcopenia, but its short half-life and inconsistent reproducibility limit the potential of TNF-α to be an ideal sarcopenia biomarker. Anti-TNF-α, a natural consequent autoantibody to TNF-α, is an indicator of relatively prolonged TNF-α exposure, has more stable concentrations than TNF-α and should be a better alternative as a biomarker of sarcopenia. Data from 484 participants from the I-Lan Longitudinal Aging Study were used for this study, and sarcopenia was defined by the Asian Working Group for Sarcopenia 2019 consensus. Plasma levels of anti-TNF-α were determined by a sandwich ELISA approach, and levels of TNF-α were determined by an immunoassay. Compared to nonsarcopenic participants, 43 sarcopenic participants had higher levels of anti-TNF-α (0.73 ± 0.19 vs. 0.79 ± 0.25 OD, p = 0.045). Plasma levels of anti-TNF-α were positively correlated with TNF-α (r = 0.24, p < 0.001), and plasma levels of anti-TNF-α were positively correlated with adiposity (r = 0.16, p < 0.001) and negatively correlated with lean body mass (r = -0.14, p = 0.003). Individuals with increasing levels of anti-TNF-α had higher odds of being sarcopenic (OR 5.4, 95 % CI: 1.1-25.8, p = 0.035), and these associations were stronger among women and younger adults. An association between TNF-α and sarcopenia was noted only in middle-aged adults (OR 6.2, 95 % CI: 1.8-21.7, p = 0.004). Plasma anti-TNF-α levels were positively correlated with TNF-α and were significantly associated with sarcopenia. Anti-TNF-α may be a more appropriate biomarker than TNF-α for sarcopenia, but further investigations are needed to confirm its roles in sarcopenia diagnosis and treatment response evaluation.

Recent sarcopenia definitions-prevalence, agreement and mortality associations among men: Findings from population-based cohorts

BACKGROUND

The 2019 European Working Group on Sarcopenia in Older People (EWGSOP2) and the Sarcopenia Definitions and Outcomes Consortium (SDOC) have recently proposed sarcopenia definitions. However, comparisons of the performance of these approaches in terms of thresholds employed, concordance in individuals and prediction of important health-related outcomes such as death are limited. We addressed this in a large multinational assembly of cohort studies that included information on lean mass, muscle strength, physical performance and health outcomes.

METHODS

White men from the Health Aging and Body Composition (Health ABC) Study, Osteoporotic Fractures in Men (MrOS) Study cohorts (Sweden, USA), the Hertfordshire Cohort Study (HCS) and the Sarcopenia and Physical impairment with advancing Age (SarcoPhAge) Study were analysed. Appendicular lean mass (ALM) was ascertained using DXA; muscle strength by grip dynamometry; and usual gait speed over courses of 2.4-6 m. Deaths were recorded and verified. Definitions of sarcopenia were as follows: EWGSOP2 (grip strength <27 kg and ALM index <7.0 kg/m2 ), SDOC (grip strength <35.5 kg and gait speed <0.8 m/s) and Modified SDOC (grip strength <35.5 kg and gait speed <1.0 m/s). Cohen's kappa statistic was used to assess agreement between original definitions (EWGSOP2 and SDOC). Presence versus absence of sarcopenia according to each definition in relation to mortality risk was examined using Cox regression with adjustment for age and weight; estimates were combined across cohorts using random-effects meta-analysis.

RESULTS

Mean (SD) age of participants (n = 9170) was 74.3 (4.9) years; 5929 participants died during a mean (SD) follow-up of 12.1 (5.5) years. The proportion with sarcopenia according to each definition was EWGSOP2 (1.1%), SDOC (1.7%) and Modified SDOC (5.3%). Agreement was weak between EWGSOP2 and SDOC (κ = 0.17). Pooled hazard ratios (95% CI) for mortality for presence versus absence of each definition were EWGSOP2 [1.76 (1.42, 2.18), I2 : 0.0%]; SDOC [2.75 (2.28, 3.31), I2 : 0.0%]; and Modified SDOC [1.93 (1.54, 2.41), I2 : 58.3%].

CONCLUSIONS

There was low prevalence and poor agreement among recent sarcopenia definitions in community-dwelling cohorts of older white men. All indices of sarcopenia were associated with mortality. The strong relationship between sarcopenia and mortality, regardless of the definition, illustrates that identification of appropriate management and lifecourse intervention strategies for this condition is of paramount importance.

Sarcopenia and COVID-19 Outcomes

Coronavirus disease 2019 (COVID-19) spread rapidly and became a severe global public health threat. Older adults have a high risk of COVID-19 and its associated mortality. Sarcopenia has emerged as a predictor of poor outcomes in COVID-19 patients, including lengthy hospital stays, mortality, intensive care unit admission, need for invasive mechanical ventilation, and poor rehabilitation outcomes. Chronic inflammation, immune dysfunction, respiratory muscle dysfunction, and swallowing dysfunction may underlie the association between sarcopenia and the poor outcomes of COVID-19 patients. Interleukin 6 receptor blockers (tocilizumab or sarilumab) are recommended for treating patients with severe COVID-19, and their therapeutic effects on sarcopenia are of great interest. This review aimed to analyze the current reports on the association between sarcopenia and COVID-19 and provide an update on the contribution of sarcopenia to the severity and adverse outcomes of COVID-19 and its underlying mechanisms. We also aimed to explore the different screening tools for sarcopenia concurrent with COVID-19, and advocate for early diagnosis and treatment of sarcopenia. Given that the fight against the COVID-19 pandemic may be long-term, further research into understanding the effects of sarcopenia in patients infected with the Omicron variant is necessary.

The Role of Sarcopenia in Overactive Bladder in Adults in the United States: Retrospective Analysis of NHANES 2011-2018

PURPOSE

To investigate the association between sarcopenia and overactive bladder (OAB) in a United States adult population from 2011 to 2018, and whether sarcopenia can predict the risk of OAB.

MATERIALS AND METHODS

We analyzed data from the 2011-2018 National Health and Nutrition Examination Survey in a cross-sectional study(NHANES) of 8746 participants, of whom 1213 were diagnosed with OAB, we analyzed correlations by sex, age, race, education level, marital status, household income-to-poverty ratio, hypertension, diabetes, strenuous work activity, moderate work activity, strenuous recreational activity, moderate recreational activity, blood urea nitrogen, creatinine, and uric acid levels using restricted cubic spline plots of dose-response curves, univariate and multivariate Logistic regression. Models based on sex, age, education, household income to poverty ratio, hypertension, diabetes, sarcopenia index, and cotinine were developed and evaluated using Nomogram, calibration curves, receiver operating characteristic curves, and clinical decision curves.

RESULTS

Of the 1213 OAB patients, 388 (32.0%) were male and 825 (68.0%) were female. Univariate and multivariate Logistic regression analysis showed that sarcopenia index was negatively correlated with the prevalence of OAB (OR=0.084, 95% CI, 0.056 - 0.130, P <0.001;OR=0.456, 95%CI, 0.215-0.968, P= 0.0041). Dose curve analysis of the sarcopenia index and prevalence of OAB showed that the prevalence of OAB decreased significantly with increasing sarcopenia index. Sarcopenia was positively correlated with OAB (OR=2.400, 95%CI, 2.000 - 2.800, P <0.001;OR=1.46, 95%CI, 1.096 -1.953, P = 0.010). In addition, our model shows that sarcopenia can predict the prevalence of OAB (AUC = 0.750) and has some clinical decision-making implications.

CONCLUSION

Sarcopenia is positively associated with the risk of OAB in United States adults and can be used as a predictor of OAB prevalence.

The prevalence of low muscle mass associated with obesity in the USA

BACKGROUND

Sarcopenia is defined as age-related low muscle mass and function, and can also describe the loss of muscle mass in certain medical conditions, such as sarcopenic obesity. Sarcopenic obesity describes loss of muscle and function in obese individuals; however, as sarcopenia is an age-related condition and obesity can occur in any age group, a more accurate term is obesity with low lean muscle mass (OLLMM). Given limited data on OLLMM (particularly in those aged < 65 years), the purpose of this study was to estimate the prevalence of OLLMM in adults aged ≥ 20 years in the USA.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018 and 1999-2006 were used. OLLMM was defined as an appendicular lean mass, adjusted for body mass index (BMI), cut-off point < 0.789 for males and < 0.512 for females, measured by dual-energy X-ray absorptiometry (DXA). DXA was only measured in individuals 20-59 years old in NHANES 2017-2018; we therefore utilized logistic regression models to predict OLLMM from NHANES 1999-2006 for those aged ≥ 60 years. The prevalence of OLLMM was estimated overall, and by sex, age, race/ethnicity, and clinical subgroup (high BMI, prediabetes, type 2 diabetes mellitus [T2DM], non-alcoholic fatty liver disease [NAFLD] with fibrosis, or post-bariatric surgery). Prevalence estimates were extrapolated to the USA population using NHANES sampling weights.

RESULTS

We estimated that, during 2017-2018, 28.7 million or 15.9% of the USA population had OLLMM. The prevalence of OLLMM was greater in older individuals (8.1%, aged 20-59 years vs 28.3%, aged ≥ 60 years), highest (66.6%) in Mexican-American females aged ≥ 60 years, and lowest (2.6%) in non-Hispanic Black males aged 20-59 years. There was a higher prevalence of OLLMM in adults with prediabetes (19.7%), T2DM (34.5%), NAFLD with fibrosis (25.4%), or post-bariatric surgery (21.8%), compared with those without each condition.

CONCLUSIONS

Overall, the burden of OLLMM in the USA is substantial, affecting almost 30 million adults. The prevalence of OLLMM increased with age, and among those with prediabetes, T2DM, NAFLD with fibrosis, or post-bariatric surgery. A unified definition of OLLMM will aid diagnosis and treatment strategies.

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.

Elevated CD47 is a hallmark of dysfunctional aged muscle stem cells that can be targeted to augment regeneration

In aging, skeletal muscle strength and regenerative capacity decline, due in part to functional impairment of muscle stem cells (MuSCs), yet the underlying mechanisms remain elusive. Here, we capitalize on mass cytometry to identify high CD47 expression as a hallmark of dysfunctional MuSCs (CD47hi) with impaired regenerative capacity that predominate with aging. The prevalent CD47hi MuSC subset suppresses the residual functional CD47lo MuSC subset through a paracrine signaling loop, leading to impaired proliferation. We uncover that elevated CD47 levels on aged MuSCs result from increased U1 snRNA expression, which disrupts alternative polyadenylation. The deficit in aged MuSC function in regeneration can be overcome either by morpholino-mediated blockade of CD47 alternative polyadenylation or antibody blockade of thrombospondin-1/CD47 signaling, leading to improved regeneration in aged mice, with therapeutic implications. Our findings highlight a previously unrecognized age-dependent alteration in CD47 levels and function in MuSCs, which underlies reduced muscle repair in aging.

Is age-related sarcopenia a real concern for my developing country?

Ageing is a distinctive feature of living organisms. With the modernization of human societies, including the development of science, technology and education, expected life expectancy at birth is being extended. This allows novel health-related conditions to gain particular interest amongst the field experts. Along comes sarcopenia, an age-related condition of global proportions that effects all populations, societies and countries. Several international working groups have been trying to identify the more appropriate and applicable sarcopenia definition and diagnostic criteria to follow. Contrary to the initial muscle mass-related context, the shift of attention to muscle strength by the revised European Working Group in Sarcopenia for Older People (EWGSOP2) was ground-breaking and potentially game-changing. The suggested diagnostic algorithm by the EWGSOP2 for case finding, diagnosing and quantifying the severity of cases further facilitated the applicability on clinical practices. Since being directly related to the ageing process, sarcopenia presents an issue of growing concern particularly within the high-income and developed world regions that are generally characterized with an increased life expectancy. In contrast, the developing world and their generally lower life expectancy do not always have sarcopenia amongst the top targeted health-related concerns. In such cases, the expected life expectancy and the populations' quality of life do not necessarily present an issue of major interest. Other serious medical concerns of acute state often eclipse the need for long-term health-related investments, shifting the interest towards only direct interventions and short-term planning. In conclusion, the emerging of sarcopenia as a serious age-related concern is finding care providers and healthcare systems from lower and middle-income countries (LMICs) unprepared. For the time being, it needs to be introduced and promoted in the developing world as a condition with direct life-threatening implications. Simple and creative forms of approach should be ideated and implemented in both scientific and clinical contexts (by researchers and care providers, respectively). The best practice to address this situation would be by empowering intradisciplinary and interdisciplinary collaborations, as well as facilitating interconnections between researches, healthcare practitioners and clients. This should help establish sarcopenia as a serious age-related condition that needs a multidisciplinary and multidimensional approach.

Determination of skeletal muscle mass by aspartate aminotransferase / alanine aminotransferase ratio, insulin and FSH in Chinese women with sarcopenia

BACKGROUND

Sarcopenia is an age-related skeletal muscle disorder that involves a loss of muscle mass or strength and physiological function. Skeletal muscle deteriorates in both quantity and quality. The endocrine system is an important regulator of muscle metabolism. Therefore, we aimed to explore the relationship between biochemical markers and muscle mass in sarcopenia.

METHODS

We used the AWGS 2014 as the diagnostic criteria for sarcopenia, considering both the loss in muscle mass, muscle strength and physical performance. A total of 2837 elderly female participants over 50 years of age from the West China Health and Aging Trend (WCHAT) study were included. Insulin, glucose, 25(OH)VD, procalcitonin, alanine aminotransferase, aspartate aminotransferase, total protein, prealbumin, albumin, thyroid-stimulating hormone, free triiodothyronine, free tetraiodothyronine, triglycerides, cholesterol, high-density lipoprotein, very low-density lipoprotein, cortisol, and follicle-stimulating hormone were measured. Based on the findings of univariate analysis, multivariate regression and receiver operating characteristic (ROC) curves were established.

RESULTS

Participants with sarcopenia had significantly lower free triiodothyronine, insulin, total protein, albumin, prealbumin, albumin/prealbumin ratio (A/G), alanine aminotransferase, triglycerides, and very low-density lipoprotein concentrations (P < 0.05). Compared with those without sarcopenia, those with sarcopenia had significantly higher free tetraiodothyronine, cortisol, follicle-stimulating hormone (FSH), aspartate aminotransferase/alanine aminotransferase ratio (AST/ALT), and high-density lipoprotein concentrations (P < 0.05). Insulin (OR = 0.854), FSH (OR = 1.016), and the AST/ALT ratio (OR = 1.819) were independent risk factors for low muscle mass (P < 0.001). The AUC of insulin was the highest, followed by the AST/ALT ratio and FSH (0.691, 0.671, and 0.634, respectively), and the AUC of the mixture of the above three reached 0.736.

CONCLUSION

In this cross-sectional study of elderly Chinese females aged over 50 years from the WCHAT, FSH, insulin, and AST/ALT ratio were associated with sarcopenia and risk factors for low muscle mass.

Effect of flavonoids on skeletal muscle mass, strength and physical performance in middle-aged and older adults with or without Sarcopenia: A meta-analysis of randomized controlled trials

The role of flavonoids in regulating the synthesis and function of skeletal muscles is increasingly recognized. However, randomized controlled trials have yielded inconsistent results on the influence of flavonoids on human muscular parameters. Therefore, we performed a meta-analysis to evaluate the possible effects of flavonoids on sarcopenia-related parameters in middle-aged and elderly people. Eligible literature and randomized controlled trials reports have been extensively searched from PubMed, Cochrane Library, Web of Science, and EMBASE databases until April 2022. A total of 20 articles involving 796 participants were available for the meta-analysis. There were significant benefits for participants in appendicular muscle mass gain (SMD = 0.29; 95% CI: 0.07, 0.52; P = 0.01) and 6-min walk distance (SMD = 0.37; 95% CI: 0.01, 0.73; P = 0.05). A subgroup analysis indicated that flavonoid significantly improves appendicular muscle mass (SMD = 0.50; 95% CI: 0.21, 0.80; P < 0.01) and Timed-Up and Go test (SMD = −0.47; 95% CI: −0.85, −0.09; P = 0.02) in Sarcopenia population. Our results provide insight into the effects of flavonoids on skeletal muscle mass and gait speed for those without exercise. However, there was no significant improvement in the subjects' muscle strength.

Association of Micronutrients and Handgrip Strength in Korean Older Population: A Cross-Sectional Study

Sarcopenia is characterized by the loss of skeletal muscle mass, strength, and physical performance. Dynapenia and kratopenia are described as the loss of muscle strength and power. Nutritional intake status is one of the factors affecting the prevention of an age-related muscle decline such as sarcopenia, dynapenia, or kratopenia in older populations. This study aimed to investigate the association between the intake of micronutrients and handgrip strength in 1254 individuals (546 men and 708 women) of the Korean older population from the most recent dataset. They were analyzed and divided into two groups: a LHS group with low handgrip strength (<28 kg for men and <18 kg for women) and a normal group with normal handgrip strength. Logistic regression analysis was performed to estimate the odds ratios (ORs) and 95% confidence intervals (Cis) of the associations between micronutrient intakes and low handgrip strength in Korean older population by gender. Among micronutrients, insufficient potassium intake showed a significant association with low handgrip strength for men (OR: 3.159, 95% CI: 1.164−8.578) and women (OR: 2.793, 95% CI: 1.380−5.654) aged ≥65 years, respectively (p = 0.005 for men, p = 0.024 for women), as a result of adjusting for all confounding factors that could affect low handgrip strength. In conclusion, potassium intake among micronutrients in Korean older populations with low handgrip strength might need continuous monitoring for the intervention or prevention of dynapenia or sarcopenia.

Association of peripheral neuropathy with skeletal muscle mass and function in type two diabetes mellitus patients: A cross-sectional study

BACKGROUND & OBJECTIVE

Diabetic peripheral neuropathy (DPN) is considered to be a risk factor for development of sarcopenia. Therefore, our study aimed to detect the association between peripheral neuropathy with skeletal muscle mass and function in type two diabetes mellitus (T2DM) patients.

METHODS

A total of 176 participants, ≥45 years were included in the study. Out of 176, 60 were healthy volunteers, 60 had T2DM without neuropathy, 56 had T2DM with neuropathy. In all the participants peripheral nerve function was assessed by nerve conduction studies (Common peroneal and Sural nerve) and sarcopenia parameters were evaluated according to the Asian Working Group for Sarcopenia (AWGS) criteria.

RESULTS

The present study suggested that diabetic peripheral neuropathy (DPN) was associated with decline in muscle mass, which was found only in men. Our study showed a positive correlation between appendicular skeletal muscle index (ASMI) and common peroneal nerve amplitude and sural nerve amplitude with r=0.527, p<0.05; r=0.847, p<0.001 respectively. Furthermore, in multiple linear regression analyses, we found a positive relationship between ASMI and sural nerve amplitude after adjustment for confounders like age, duration of diabetes, and HbA1C (B=0.739; p<0.001).

CONCLUSION

As DPN patients are more prone to developing sarcopenia, and periodic assessment of skeletal muscle mass and function is warranted to initiate early lifestyle interventions in these patients, which will improve their quality of life.

Effect of Ishige okamurae extract on musculoskeletal biomarkers in adults with relative sarcopenia: Study protocol for a randomized double-blind placebo-controlled trial

Introduction

Sarcopenia is a phenomenon in which skeletal muscle mass decreases with age, causing many health problems. Many studies have been conducted to improve sarcopenia nutritionally. Ishige okamura (IO) is a genus of brown algae and plays a role in anti-diabetes, anti-obesity, and myogenesis. However, the effect of IO extract (IOE) on human muscle strength and mass is unclear. Therefore, we will examine the impact and safety of consumption of IOE for 12 weeks on muscle strength and mass in middle-aged and old-aged adults with relatively low skeletal muscle mass.

Materials and methods

A randomized controlled trial is conducted on 80 adults aged 50–80. A total of 80 participants will be enrolled in this study. Participants assign IOE-taking group (n = 40) and placebo taking group (n = 40). At a baseline and 12 weeks after treatment, the following parameters of the participants are checked: knee extension strength, handgrip strength, body composition, laboratory tests, dietary recall, physical activity, and EQ-5D-5L.

Discussion

The present study will be the first randomized, double-blind placebo-controlled trial to examine the efficacy and tolerability of IOE supplementation in adults with relatively low muscle mass. The nutritional intake and physical activity that might influence muscle strength and mass will be considered as covariates for transparency of results. The results of this study will provide clinical evidence for sarcopenia patients with nutrient treatment.

Clinical Trial Registration

www.clinicaltrials.gov/, Identifier: NCT04617951.

Ultrasound and magnetic resonance imaging as diagnostic tools for sarcopenia in immune-mediated rheumatic diseases (IMRDs)

Sarcopenia is characterized by loss of muscle mass, altered muscle composition, fat and fibrous tissue infiltration, and abnormal innervation, especially in older individuals with immune-mediated rheumatic diseases (IMRDs). Several techniques for measuring muscle mass, strength, and performance have emerged in recent decades. The portable dynamometer and gait speed represent the most frequently used tools for the evaluation of muscle strength and physical efficiency, respectively. Aside from dual-energy, X-ray, absorptiometry, and bioelectrical impedance analysis, ultrasound (US) and magnetic resonance imaging (MRI) techniques appear to have a potential role in evaluating muscle mass and composition. US and MRI have been shown to accurately identify sarcopenic biomarkers such as inflammation (edema), fatty infiltration (myosteatosis), alterations in muscle fibers, and muscular atrophy in patients with IMRDs. US is a low-cost, easy-to-use, and safe imaging method for assessing muscle mass, quality, architecture, and biomechanical function. This review summarizes the evidence for using US and MRI to assess sarcopenia.

Dynapenic-abdominal obesity as an independent risk factor for chronic kidney disease in postmenopausal women: a population-based cohort study

OBJECTIVE

Low muscle strength and obesity lead to a higher risk of chronic kidney disease (CKD). Perimenopause is associated with a natural decline in muscle strength and an increase in visceral adiposity. Dynapenic obesity, which is the coexistence of low muscle strength and obesity, is expected to synergistically increase the prevalence of CKD in postmenopausal women. The aim of this study was to determine combined associations of dynapenia and obesity with CKD in postmenopausal women.

METHODS

This study used data from the Korean National Health and Nutrition Examination Survey, 2016 to 2019. The study included 4,525 postmenopausal women aged 42 to 80 years that were classified into four groups based on waist circumference (≥85 cm) and hand grip strength (<18 kg): normal, dynapenic, obese, or dynapenic-obese. According to the Kidney Disease: Improving Global Outcomes, we defined CKD as an estimated glomerular filtration rate <60 mL/min per 1.73 m2. Complex sample logistic regression models were conducted to determine the relationships among coexistence of dynapenia, abdominal obesity, and the risk of CKD.

RESULTS

Dynapenic-abdominal obese group displayed lower estimated glomerular filtration rate levels than other groups (P < 0.05 for all data). The prevalence rates of CKD were 15.5%, 7.8%, 6.2%, and 2.4% in the dynapenic-abdominal obese, dynapenic, abdominal obese, and normal groups, respectively (P < 0.001). Complex sample logistic regression analyses, after adjusting for age, height, health behaviors, and comorbidities, showed that the odds ratio for CKD with respect to dynapenic-abdominal obesity was 1.82 (95% confidence interval, 1.19-2.79) and to abdominal obesity was 1.54 (95% confidence interval, 1.07-2.22) than in the normal group.

CONCLUSIONS

This study demonstrated that dynapenic-abdominal obesity, as determined by low handgrip strength and high waist circumference values, was associated with increased risk of CKD in postmenopausal women.

Reversibility of sarcopenia by Ishige okamurae and its active derivative diphloroethohydroxycarmalol in female aging mice

With the rapid increase in the elderly population worldwide, the number of people with sarcopenia has also increased significantly, and this disease is emerging as a medical and social issue. The development of pharmaceutics targeting sarcopenia is limited owing to the occurrence of side effects, and exercise therapy also has a limited scope of application. Therefore, it is necessary to develop safe and biocompatible agents to treat age-related sarcopenia. Ishige okamurae (IO), an edible brown alga, and its active substance, diphloroethohydroxycarmalol (DPHC), have been reported to have various physiological functions, including skeletal muscle regeneration ability. However, this effect has not been verified in an in vivo aging model. As an aging model, the oral IO extracts and DPHC supplemented 14-month-old female C57BL/6J mice were compared to the young group in this study; the mice model showed a substantial restoration of physical exercise ability with the imbalance of famine hormone and senescence-associated secretary phenotypes compared with those in young mice. Regarding the lean mass increase in aging mice following IO extract and DPHC administration, the muscular characteristics and molecular alterations in the gastrocnemius and soleus muscles, which are sensitive to the damage that occurs during the aging process, were significantly improved. Collectively, the current study reveals that the natural agent IO extract and its derivative DPHC can reverse sarcopenia that occurs during the process of aging by improving the imbalance of muscle regeneration in vivo.

Interprofessional Treatment of Malnutrition and Sarcopenia by Dietitians and Physiotherapists: Exploring Attitudes, Interprofessional Identity, Facilitators, Barriers, and Occurrence

Purpose

Malnutrition and sarcopenia require dietetic and physiotherapy interventions. In this study, we aimed to compare interprofessional identity of dietitians and physiotherapists, as well as attitudes towards, facilitators and barriers for, and occurrence of interprofessional treatment of malnutrition and sarcopenia by both professions.

Methods

A cross-sectional online survey was distributed from December 4, 2021 until January 31, 2022 through an international online network platform for professionals (LinkedIn). Practitioners working as dietitian or physiotherapist in a healthcare setting were eligible for participation. Outcome measures concerned perceptions regarding shared problem domains, interprofessional treatment, attitudes towards interprofessional treatment, interprofessional identity, facilitators, and barriers. A Chi²-test, Mann–Whitney U-test, and Spearman’s Rho correlation were calculated.

Results

Data from 53 physiotherapists and 48 dietitians were included. Malnutrition is considered a shared problem domain by both professions (U = 1248.000; p = 0.858). While sarcopenia is treated by both professions (U = 1260.000; p = 0.927), physiotherapists consider sarcopenia more often a shared problem domain compared to dietitians (U = 1003.000; p = 0.044). Attitudes towards interprofessional treatment were mostly positive (73%, n = 35 and 87%, n = 46 respectively). Interprofessional identity of dietitians was lower compared to physiotherapists (median = 4.0 versus median = 4.3 respectively; U = 875.000, p = 0.007). This was explained by lower interprofessional belonging (median = 4.0 versus median = 4.8 respectively; U = 771.000, p < 0.001) and lower interprofessional commitment (median = 4.0 versus median = 4.3 respectively; U = 942.500, p = 0.023). Interprofessional identity was correlated with efficient means of communication (r = 0.30, p = 0.003) and bureaucracy (r = −0.21, p = 0.034). Other barriers reported included available time, financial compensation, interprofessional knowledge, and obtaining extra care. Most reported facilitators concerned role clarity, clarity of expertise, and willingness of others to collaborate.

Conclusion

Dietitians and physiotherapists have different interprofessional identities, but both are advocates of interprofessional treatment. Both professions mostly treat malnutrition and sarcopenia individually and have different perceptions regarding sarcopenia as shared problem domain. Facilitators were mainly related to clarity and commitment while barriers were mainly related to resources.

Network pharmacology-based analysis of the effects of puerarin on sarcopenia

Background

With the acceleration of population aging, sarcopenia will place a heavy burden on families and society. Thus, effective treatments urgently need to be developed to slow down the development of sarcopenia. This study adopted a network pharmacological approach to explore the possible mechanisms of puerarin in treating sarcopenia.

Methods

The potential therapeutic targets of puerarin were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) database, while the targets of sarcopenia were obtained from the GeneCards, DisGeNET, Online Mendelian Inheritance in Man (OMIM), and Therapeutic Target Database (TTD) databases. The protein-protein interaction (PPI) network was generated by BisoGenet, and core targets were identified by a topological analysis. To determine the potential targeting pathways, the core targets were further imported into the Metascape platform for the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The results were visualized using an online bioinformatics tool.

Results

We identified 53 targets for puerarin and 129 targets for sarcopenia. A total of 206 core targets, which were considered potential therapeutic targets, were identified from the merged PPI network. Further, the GO and KEGG analyses revealed that the functions of the core targets and related pathways were mainly associated with the cell cycle, apoptosis, protein synthesis, and proteolysis.

Conclusions

Puerarin has the potential to treat sarcopenia through the regulation of the cell cycle, apoptosis, and protein homeostasis. Our study has laid a foundation for further studies on drug development and pharmacological experiments in the treatment of sarcopenia.

Clinical implications of severe sarcopenia in Japanese patients with acute heart failure

AIM

Sarcopenia is a geriatric condition characterized by progressive loss of skeletal muscle mass and function. The definition and diagnosis of sarcopenia is inconsistent between different populations and is still evolving. Herein, we investigated the prevalence and clinical implications of severe sarcopenia using the Asian Working Group for Sarcopenia (AWGS) 2019 criteria in Japanese patients with acute heart failure (HF).

METHODS

Overall, 272 patients admitted for acute HF were evaluated for sarcopenia using the AWGS 2019 criteria.

RESULTS

There were 46 patients with severe sarcopenia, accounting for approximately 75% of patients who were diagnosed as having sarcopenia. A Kaplan-Meier analysis showed that patients with severe sarcopenia had a higher incidence of cardiac death or rehospitalization for HF 1 year post-discharge than those with non-severe sarcopenia or without sarcopenia (log-rank P = 0.006). A multivariate Cox regression analysis showed that severe sarcopenia was independently correlated with the occurrence of cardiac death or rehospitalization for HF after adjusting for other prognostic factors (hazard ratio 2.580, 95% confidence interval: 1.404-4.740, P = 0.002).

CONCLUSIONS

Severe sarcopenia constituted most sarcopenia diagnoses using the AWGS 2019 cut-off values, and was independently associated with 1-year incidence of cardiac death or rehospitalization for HF post-discharge in Japanese patients with acute HF. The assessment of sarcopenia may provide useful information for HF management. Geriatr Gerontol Int 2022; 22: 477-482.

Characterization of the Skeletal Muscle Proteome in Undernourished Old Rats

Aging is associated with a progressive loss of skeletal muscle mass and function termed sarcopenia. Various metabolic alterations that occur with aging also increase the risk of undernutrition, which can worsen age-related sarcopenia. However, the impact of undernutrition on aged skeletal muscle remains largely under-researched. To build a deeper understanding of the cellular and molecular mechanisms underlying age-related sarcopenia, we characterized the undernutrition-induced changes in the skeletal muscle proteome in old rats. For this study, 20-month-old male rats were fed 50% or 100% of their spontaneous intake for 12 weeks, and proteomic analysis was performed on both slow- and fast-twitch muscles. Proteomic profiling of undernourished aged skeletal muscle revealed that undernutrition has profound effects on muscle proteome independently of its effect on muscle mass. Undernutrition-induced changes in muscle proteome appear to be muscle-type-specific: slow-twitch muscle showed a broad pattern of differential expression in proteins important for energy metabolism, whereas fast-twitch muscle mainly showed changes in protein turnover between undernourished and control rats. This first proteomic analysis of undernourished aged skeletal muscle provides new molecular-level insight to explain phenotypic changes in undernourished aged muscle. We anticipate this work as a starting point to define new biomarkers associated with undernutrition-induced muscle loss in the elderly.

Association between dietary intake of branched-chain amino acids and sarcopenia and its components: a cross-sectional study

There is no previous study that investigated the association between dietary intake of total and individual branched-chain amino acids (BCAAs) and odds of sarcopenia. The present study aimed to examine the association between dietary intake of BCAAs and sarcopenia and its components among Iranian adults. The data for this cross-sectional study was collected in 2011 among 300 older people (150 men and 150 female) with aged ≥ 55 years. We used a Block-format 117-item food frequency questionnaire (FFQ) to evaluate usual dietary intakes. BCAAs intake was calculated by summing up the amount of valine, leucine and isoleucine intake from all food items in the FFQ. The European Sarcopenia Working Group (EWGSOP) definition was used to determine sarcopenia and its components. Mean age of study participants was 66.8 years and 51% were female. Average intake of BCAAs was 12.8 ± 5.1 g/day. Prevalence of sarcopenia and its components was not significantly different across tertile categories of total and individual BCAAs intake. We found no significant association between total BCAAs intake and odds of sarcopenia (OR for comparison of extreme tertiles 0.48, 95% CI 0.19–1.19, P-trend = 0.10) and its components (For muscle mass 0.83, 95% CI 0.39–1.77, P-trend = 0.63; for hand grip strength 0.81, 95% CI 0.37–1.75, P-trend: 0.59; for gait speed 1.22, 95% CI 0.58–2.57, P-trend = 0.56). After adjusting for potential confounders, this non-significant relationship did not alter. In addition, we did not find any significant association between individual BCAAs intake and odds of sarcopenia or its components. We found no significant association between dietary intakes of BCAAs and sarcopenia in crude model (OR 0.60; 95% CI 0.29–1.26). After controlling for several potential confounders, the result remained insignificant (OR 0.48; 95% CI 0.19–1.19). In this cross-sectional study, no significant association was observed between dietary intakes of total and individual BCAAs and odds of sarcopenia and its components.

Can Biological Drugs Diminish the Risk of Sarcopenia in Psoriatic Patients?

Sarcopenia and psoriasis are different inflammatory diseases that share common comorbidities (e.g., cardiovascular diseases, metabolic syndrome, obesity, autoimmune diseases, depression). Psoriasis is a dermatosis involving the skin, joints, and nails. Its estimated prevalence is 2–4%, and the possibility of progression to psoriatic arthritis reaches 6–42%. Sarcopenia is defined as reduced muscle strength, muscle quantity, and physical performance due to non-ageing related causes. It affects up to 10% of the general population. We conducted a review of the literature to provide up-to-date information about the risk of sarcopenia in psoriasis and to identify risk factors that increase this risk. The search of the literature allowed us to include 51 publications, but only five cross-sectional studies provided quantitative results on the rates of sarcopenia in psoriasis. The prevalence of sarcopenia in psoriasis varied from 9.1% to 61.7%. This wide range was caused by different definitions of sarcopenia and different cut-off values across studies. Prognostic factors include lean mass and fat mass. Further research based on the European Working Group on Sarcopenia in Older People guidelines is required. Such studies should include not only muscle mass and strength but also other factors that may influence the occurrence of sarcopenia and inflammatory markers.

Forecasting Healthy Life Expectancy Among Chilean Community-Dwelling Older Adults With and Without Sarcopenia

BACKGROUND

Sarcopenia is an important risk factor for disability and dependency at old age. The prevalence of sarcopenia among the Chilean older population is high.

OBJECTIVE

To estimate life expectancy, healthy life expectancy and unhealthy life expectancy among sarcopenic and non-sarcopenic older adults from Santiago, Chile.

METHODS

A sample of 1,897 community-dwelling older adults aged 60 years or more, living in Santiago, was observed between 5-15 years. Disability was defined as the unhealthy state, assessed through self-reported difficulties in activities of daily living. Sarcopenia was determined via HTSMayor software. Total and marginal life expectancies were estimated using the Interpolated Markov Chain method "IMaCh".

RESULTS

At 60 years, estimated life expectancy for sarcopenic and non-sarcopenic older adults was similar (22.7 and 22.5 years, respectively). The proportion of years to be lived with disability was three times greater in sarcopenic adults, compared to non-sarcopenic people. This difference was observed up to 80 years. Non-sarcopenic women had a higher proportion of years to be lived with disabilities compared to non-sarcopenic men of the same age, but this proportion was higher among sarcopenic men, compared to sarcopenic women until 70 years of age.

DISCUSSION

People with sarcopenia expect to live a higher proportion of years with disabilities. Sarcopenic men until 70 years expected to live a higher proportion of years with disability, compared to sarcopenic women. Monitoring sarcopenia among older people may help to identify individuals with higher risk of disability onset. Future research should focus on disentangling the mechanisms explaining sex differences.

Sarcopenia: An Age-Related Multifactorial Disorder

Sarcopenia is an emerging clinical entity characterized by a gradual decline in skeletal muscle mass and strength that accompanies the normal aging process. It has been noted that sarcopenia is associated with various adverse health outcomes in the geriatric population like prolonged hospital admission, disability, poor quality of life, frailty, and mortality. Factors involved in the development of age-related sarcopenia include anorexia, alteration in the hormone levels, decreased neural innervation, low blood flow to the muscles, cytokine dysregulation, altered mitochondrial activity, genomic instability, intracellular proteolysis, and insulin resistance. Understanding the mechanism may help develop efficient preventive and therapeutic strategies which can improve the quality of life in elderly individuals. Thus, the objective of the present article is to review the literature regarding the mechanism involved in the development of sarcopenia in aged individuals.

Pathway-based metabolomics study of sarcopenia-related traits in two US cohorts

We aimed to validate two metabolites, aspartic acid and glutamic acid, which were associated with sarcopenia-related traits, muscle mass and strength, in our previous untargeted metabolomics study and to identify novel metabolites from five metabolic pathways involving these two metabolites. We included a discovery cohort of 136 white women aged 20-40 years (used for the previous untargeted metabolomics analysis) and a validation cohort of 174 subjects aged ≥ 60 years, including men and women of white and black. A targeted LC-MS assay successfully detected 12 important metabolites from these pathways. Aspartic acid was associated with muscle mass and strength in the discovery cohort, but not in the validation cohort. However, glutamic acid was associated with these sarcopenia traits in both cohorts. Additionally, N-acetyl-L-aspartic acid and carnosine were the newly identified metabolites that were associated with muscle strength in the discovery and validation cohorts, respectively. We did not observe any significant sex and race differences in the associations of these metabolites with sarcopenia traits in the validation cohort. Our findings indicated that glutamic acid might be consistently associated with sarcopenia-related traits across age, sex, and race. They also suggested that age-specific metabolites and metabolic pathways might be involved in muscle regulation.

Osteosarcopenia, the co-existence of osteoporosis and sarcopenia, is associated with social frailty in older adults

BACKGROUND

Osteosarcopenia is a newly described, aging-associated condition. Social frailty is an important condition whose prevalence may have risen by physical distancing during the coronavirus disease 2019 pandemic. However, the relationship between these two remains unclear.

AIMS

To examine the association between osteosarcopenia and social frailty.

METHODS

This cross-sectional study was conducted using data from outpatients visiting general geriatric hospital frailty clinics. Bone mineral density (BMD) and muscle mass were measured using dual X-ray absorptiometry. Osteoporosis was defined as a BMD of < 70% of the young adult mean, according to the Japan Osteoporosis Society. Sarcopenia was diagnosed as per the Asian Working Group for Sarcopenia 2019 recommendation. Osteosarcopenia was defined as the co-existence of osteoporosis and sarcopenia. We defined social frailty using a questionnaire comprising four items: general resources, social resources, social behavior, and basic social needs. Ordinal logistic regression analysis was performed with social frailty status and osteosarcopenia as the dependent and independent variables, respectively.

RESULTS

We included 495 patients (mean age = 76.5 ± 7.2 years) in the analysis; of these, 58.2% were robust and 17.2%, 13.5%, and 11.1% had osteoporosis alone, sarcopenia alone, and osteosarcopenia, respectively. Social frailty prevalence increased stepwise from 8.0% in robust patients to 11.8%, 17.9%, and 29.1% among those with osteoporosis alone, sarcopenia alone, and osteosarcopenia, respectively (P < 0.001). Logistic regression analysis revealed that only osteosarcopenia was significantly associated with social frailty (pooled odds ratio: 2.117; 95% confidence interval: 1.104-4.213).

DISCUSSION

Comprehensive assessment of osteosarcopenia and social frailty is needed for disability prevention in older adults.

Relationship between Low Muscle Strength, and Protein Intake: A Preliminary Study of Elderly Patients with Hip Fracture

Background: The purpose of the present study was to assess the daily protein uptake and its relationship with sarcopenia, as defined by the Asian Working Group for Sarcopenia (AWGS), among elderly patients with hip fractures.Methods: Forty-seven elderly patients with hip fractures were enrolled in this retrospective observational study. The main outcome measures included protein uptake, muscle mass, and grip strength for sarcopenia in elderly patients. Sarcopenia was diagnosed according to AWGS. Wholebody densitometry was used to measure skeletal muscle mass, and muscle strength was evaluated using handgrip testing.Results: Of 47 patients with hip fractures (12 men and 35 women), 37 (79%) patients exhibited insufficient protein intake (range, 0.01-0.588 g/kg/day), and 10 (21%) patients exhibited excessive protein intake (range, 1.215-2.121 g/kg/day). The mean daily protein intake was 56.5 g (range, 7.2–136.0 g). Prevalence of low muscle strength (handgrip strength <18 kg in women and <26 kg in men) was detected in 13 (37%) women and 8 (67%) men (P=0.076). Sarcopenia (lower muscle mass and lower muscle strength) was detected in 9 (26%) women and 6 (50%) men (P=0.119). Although lower protein intake was marginally associated with sarcopenia (P=0.189), it was significantly associated with lower grip strength (P=0.042).Conclusions: The present study demonstrated that insufficient protein intake in elderly patients with hip fractures was common, and lower protein intake was significantly associated with lower muscle strength.

The impact of sarcopenia on low back pain and quality of life in patients with osteoporosis

PURPOSE

Osteoporosis combined with sarcopenia contributes to a high risk of falling, fracture, and even mortality. However, sarcopenia's impact on low back pain and quality of life (QOL) in patients with osteoporosis is still unknown. The purpose of this study is to investigate low back pain and QOL in osteoporosis patients with sarcopenia.

METHODS

We assessed 100 ambulatory patients who came to our hospital for osteoporosis treatment. Low back pain was evaluated using the Visual Analogue Scale (VAS) with 100 being an extreme amount of pain and 0 no pain. The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) score was used to assess QOL after adjustment for age, history of vertebral fracture, and adult spinal deformity. Differences in low back pain intensity assessed by VAS between groups were evaluated by the Willcoxon rank-sum test. Covariance analysis was used to assess QOL. All data are expressed as either median, interquartile range, or average, standard error.

RESULTS

Patients were classified into the sarcopenia group (n = 32) and the non-sarcopenia group (n = 68). Low back pain intensity assessed by VAS was significantly higher in the sarcopenia group than in the non-sarcopenia group (33.0 [0-46.6] vs. 8.5 [0-40.0]; p < 0.05). The subscales of the JOABPEQ for low back pain were significantly lower in the sarcopenia group than in the non-sarcopenia group (65.0 ± 4.63 vs. 84.0 ± 3.1; p < 0.05).

CONCLUSION

In this cross-sectional study, sarcopenia affected low back pain and QOL in ambulatory patients with osteoporosis. Sarcopenia may exacerbate low back pain and QOL.

Gait characteristics in community-dwelling older persons with low skeletal muscle mass and low physical performance

Background

Demographic changes in the western world entail new clinical approaches and challenges in older persons. Low skeletal muscle mass and low physical performance in older persons are both predisposing conditions for disability and obtaining knowledge in this cohort is essential.

Aim

The primary aim of the study was to analyze a broader spectrum of gait characteristics within this specific population and differentiate them across different test conditions.

Methods

Two centers participating at the SPRINTT project with hi-tech gait analysis available conducted a cross-sectional descriptive study on N = 115 community-dwelling older persons with low muscle mass and physical performance.

Reference values of 13 gait parameters were collected across different conditions: usual gait speed, fast gait speed, and usual gait speed while simultaneously naming animals.

Results and discussion

This study shows the first spatio-temporal reference values in a community-dwelling older population composed of individuals with low skeletal muscle mass and low physical performance. In comparison to the normative spatio-temporal gait parameters in older persons reported in the literature, this population showed some differences. The mean gait speed was lower than 1 m/s, considered as a cutoff for vulnerable community-dwelling individuals, which corresponds to a greater risk of falls, hospitalization, and mortality. The stride length variability was higher, exposing to a greater risk of falling, and was also associated with a higher risk of developing cognitive decline.

Conclusion

This study represents the first step in the development of quantitative reference values in community-dwelling older persons with low physical performance and low skeletal muscle mass.

A reliable and robust method for the upper thigh muscle quantification on computed tomography: toward a quantitative biomarker for sarcopenia

Background

We aimed to evaluate the feasibility of the upper thigh level as a landmark to measure muscle area for sarcopenia assessment on computed tomography (CT).

Methods

In the 116 healthy subjects who performed CT scans covering from mid-abdomen to feet, the skeletal muscle area in the upper thigh level at the inferior tip of ischial tuberosity (SMA_UT), the mid-thigh level (SMA_MT), and L3 inferior endplate level (SMA_L3) were measured by two independent readers. Pearson correlation coefficients between SMA_UT, SMA_MT, and SMA_L3 were calculated. Inter-reader agreement between the two readers were evaluated using intraclass correlation coefficient (ICC) and Bland-Altman plots with 95% limit of agreement (LOA).

Results

In readers 1 and 2, very high positive correlations were observed between SMA_UT and SMA_MT (r = 0.91 and 0.92, respectively) and between SMA_UT and SMA_L3 (r = 0.90 and 0.91, respectively), while high positive correlation were observed between SMA_MT and SMA_L3 (r = 0.87 and 0.87, respectively). Based on ICC values, the inter-reader agreement was the best in the SMA_UT (0.999), followed by the SMA_L3 (0.990) and SMA_MT (0.956). The 95% LOAs in the Bland-Altman plots indicated that the inter-reader agreement of the SMA_UT (− 0.462 to 1.513) was the best, followed by the SMA_L3 (− 9.949 to 7.636) and SMA_MT (− 12.105 to 14.605).

Conclusion

Muscle area measurement at the upper thigh level correlates well with those with the mid-thigh and L3 inferior endpoint level and shows the highest inter-reader agreement. Thus, the upper thigh level might be an excellent landmark enabling SMA_UT as a reliable and robust biomarker for muscle area measurement for sarcopenia assessment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05032-2.

Open-Ended Transmission Coaxial Probes for Sarcopenia Assessment

We developed a handheld, side-by-side transmission-based probe for interrogating tissue to diagnose sarcopenia—a condition largely characterized by muscle loss and replacement by fat. While commercial microwave reflection-based probes exist, they can only be used in a lab for a variety of applications. The penetration depth of these probes is only in the order of 0.3 mm, which does not even traverse the skin layer, and minor motion of the coaxial feedlines can completely dismantle the calibration. Our device builds primarily on the transmission-based concept that allows for substantially greater signal penetration depth operating over a very broad bandwidth. Additional features were integrated to further improve the penetration, optimize the geometry for a more focused planar excitation, and juxtapose the coaxial apertures for more controlled interrogation. The larger coaxial apertures further increased the penetration depth while retaining the broadband performance. Three-dimensional printing technology made it possible for the apertures to be compressed into ellipses for interrogation in a near-planar geometry. Finally, fixed side-by-side positioning provided repeatable and reliable performance. The probes were also not susceptible to multipath signal corruption due to the close proximity of the transmitting and receiving apertures. The new concept worked from 100 MHz to over 8 GHz and could sense property changes as deep as 2–3 cm. While the signal changes due to deeper feature aberrations were more subtle than for signals emanating from the skin and subcutaneous fat layers, the large property contrast between muscle and fat is a sarcopenic indication that helps to distinguish even the deepest objects. This device has the potential to provide needed specificity information about the relevant underlying tissue.

Prevalence of Sarcopenia and Its Association with Quality of Life, Postural Stability, and Past Incidence of Falls in Postmenopausal Women with Osteoporosis: A Cross-Sectional Study

In this cross-sectional analysis of 61 postmenopausal osteoporosis patients who regularly visited an osteoporosis outpatient clinic, we aimed to clarify the prevalence of sarcopenia and its related clinical factors. Of 61 patients (mean age 77.6 ± 8.1 years), 24 (39.3%) had osteosarcopenia and 37 (60.7%) had osteoporosis alone. Age, nutritional status, and the number of prescribed drugs were associated with the presence of sarcopenia (p = 0.002, <0.001, and 0.001, respectively), while bone mineral density (BMD) and % young adult mean BMD were not (p = 0.119 and 0.119, respectively). Moreover, patients with osteosarcopenia had lower quality of life (QOL) scores, greater postural instability, and a higher incidence of falls in the past year than patients with osteoporosis alone. In contrast, BMD status showed no correlation with the nutritional status, QOL score, postural instability, or incidence of falls in the past year. In conclusion, the incidence of sarcopenia was relatively high among postmenopausal osteoporosis female patients in an osteoporosis outpatient clinic. Our results suggest that in addition to routine BMD evaluation, assessment and management of sarcopenia may be promoted at osteoporosis outpatient clinics to limit the risk of falls and prevent consequent fragility fractures in osteoporosis patients.

Impact of Sarcopenia and Myosteatosis in Non-Cirrhotic Stages of Liver Diseases: Similarities and Differences across Aetiologies and Possible Therapeutic Strategies

Sarcopenia is defined as a loss of muscle strength, mass and function and it is a predictor of mortality. Sarcopenia is not only a geriatric disease, but it is related to several chronic conditions, including liver diseases in both its early and advanced stages. Despite the increasing number of studies exploring the role of sarcopenia in the early stages of chronic liver disease (CLD), its prevalence and the relationship between these two clinical entities are still controversial. Myosteatosis is characterized by fat accumulation in the muscles and it is related to advanced liver disease, although its role in the early stages is still under researched. Therefore, in this narrative review, we firstly aimed to evaluate the prevalence and the pathogenetic mechanisms underlying sarcopenia and myosteatosis in the early stage of CLD across different aetiologies (mainly non-alcoholic fatty liver disease, alcohol-related liver disease and viral hepatitis). Secondly, due to the increasing prevalence of sarcopenia worldwide, we aimed to revise the current and the future therapeutic approaches for the management of sarcopenia in CLD.

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.

Calf Circumference and All-Cause Mortality: A Systematic Review and Meta-Analysis Based on Trend Estimation Approaches

OBJECTIVES

To perform a systematic review and meta-analysis and quantify the associations of total mortality with calf circumference (CC) in adults 18 years and older via combining various analyses based on empirical dichotomic CC, continuous CC, and dose-response CC.

METHODS

We conducted a systematic search of relevant studies in PubMed, EMBASE, Cochrane Library, and Web of Science published through April 12, 2022. This systematic review includes longitudinal observational studies reporting the relationships of total mortality with CC. We calculated the pooled relative risk (RR) and 95% confidence interval (CI) of total mortality with CC per 1 cm for each study and combined the values using standard meta-analysis approaches. Newcastle-Ottawa scale (NOS), Grading of Recommendations, Assessment, Development and Evaluations approach (GRADE), and the Instrument for assessing the Credibility of Effect Modification Analyses (ICEMAN) were assessed for meta-analyses.

RESULTS

Our analysis included a total of 37 cohort studies involving 62,736 participants, across which moderate heterogeneity was observed (I2=75.7%, P<0.001), but no publication bias was found. Study quality scores ranged from 6 to 9 (mean 7.7), with only three studies awarded a score of 6 (fair quality). We observed an inverse trend between total death risk and CC per 1 cm increase (RR, 0.95, 95% CI, 0.94-0.96; P<0.001; GRADE quality=high). Only a very slight difference was found among residents of nursing homes (6.9% mortality risk reduction per one cm CC increase), community-dwellers (5.4%), and those living in hospitals (4.8%), respectively (P for meta-regression=0.617). Low credible subgroup difference was found based on the ICEMAN tool.

CONCLUSIONS

Calf circumference is a valid anthropometric measure for mortality risk prediction in a community, nursing home, or hospital.

Association of SARC-F Score and Rockwood Clinical Frailty Scale with CT-Derived Muscle Mass in Patients with Aortic Aneurysms

OBJECTIVES

Patients with aortic aneurysms (AA) are often co-morbid and susceptible to frailty. Low core muscle mass has been used as a surrogate marker of sarcopenia and indicator of frailty. This study aimed to assess association between core muscle mass with sarcopenia screening tool SARC-F and Clinical Frailty Scale (CFS) in patients with AA.

METHODS

Prospective audit of patients in pre-operative aortic clinic between 01/07/2019-31/01/2020 including frailty assessment using Rockwood CFS and sarcopenia screening using SARC-F questionnaire. Psoas and sartorius muscle area were measured on pre-operative CT scans and adjusted for height. Association was assessed using Spearman's rank correlation coefficient.

RESULTS

Of 84 patients assessed, median age was 75 years [72,82], 84.5% were men, 65.5% were multimorbid and 63.1% had polypharmacy. Nineteen percent were identified as frail (CFS score >3) and 6.1% positively screened for sarcopenia (SARC-F score 4 or more). Median psoas area (PMA) at L3 was 5.6cm2/m2 [4.8,6.6] and L4 was 7.4cm2/m2 [6.3,8.6]. Median sartorius area (SMA) was 1.8 cm2/m2 [1.5,2.2]. CFS demonstrated weak but statistically significant negative correlation with height-adjusted PMA at L3 (r=-0.25, p=0.034) but not at L4 (r=-0.23, p=0.051) or with SMA (r=-0.22, p=0.065). No association was observed between SARC-F score and PMA or SMA (L3 PMA r=-0.015, p=0.9; L4 PMA r=-0.0014, p= 0.99; SMA r=-0.051, p=0.67).

CONCLUSION

CFS showed higher association with CT-derived muscle mass than SARC-F. Comprehensive pre-operative risk-stratification tools which incorporate frailty assessment and body composition analysis may assist in decision making for surgery and allow opportunity for pre-habilitation.

Comparative Analysis on the Effects of Sarcopenia following Primary Total Knee Arthroplasty: A Retrospective Matched-Control Analysis

Despite the high incidence of sarcopenia in the orthopaedic community, studies evaluating the influence of sarcopenia following primary total knee arthroplasty (TKA) are limited. Therefore, the purpose of this study is to determine if sarcopenic patients undergoing primary TKA have higher rates of (1) in-hospital lengths of stay (LOS); (2) medical complications; (3) implant-related complications; (4) fall risk; (5) lower extremity fracture risk; and (6) costs of care. Sarcopenia patients were matched to controls in a 1:5 ratio according to age, sex, and medical comorbidities. The query yielded 90,438 patients with (n = 15,073) and without (n = 75,365) sarcopenia undergoing primary TKA. Primary outcomes analyzed included: in-hospital LOS, 90-day medical complications, 2-year implant-related complications, fall risk, lower extremity fracture risk, and costs of care. A p-value of less than 0.05 was considered statistically significant. Patients with sarcopenia undergoing primary TKA had greater in-hospital LOS (4 vs. 3 days, p < 0.0001). Sarcopenic patients were also found to have increased incidence and odds of 90-day medical complications (2.9 vs. 1.1%; odds ratio [OR] = 2.83, p < 0.0001), falls (0.9 vs. 0.3%; OR = 3.54, p < 0.0001), lower extremity fractures (1.0 vs. 0.2%; OR = 5.54, p < 0.0001), and reoperation (0.9 vs. 0.5%; OR = 1.87, p < 0.0001). Additionally, sarcopenic patients had greater 2-year implant-related complications (4.3 vs. 2.4%; OR = 1.80, p < 0.0001), as well as day of surgery ($52,900 vs. 48,248, p < 0.0001), and 90-day ($68,303 vs. $57,671, p < 0.0001) costs compared with controls. This analysis of over 90,000 patients demonstrates that patients with sarcopenia undergoing primary TKA have greater in-hospital LOS, increased odds of 90-day medical complications, falls, lower extremity fractures, and reoperations. Additionally, sarcopenia was associated with greater 2-year implant-related complications, day of surgery costs, and 90-day costs. The study is useful as it can allow orthopaedic surgeons to properly educate these patients of the potential complications which may occur following their surgery.

Sarcopenia affects activities of daily living recovery and hospitalization costs in older adults in convalescent rehabilitation wards

PURPOSE

This study aimed to investigate the impact of sarcopenia on activities of daily living (ADL) recovery and hospitalization costs in older patients admitted to convalescent rehabilitation wards.

METHODS

This prospective cohort study included 104 patients aged ≥ 65 years who were admitted to convalescent rehabilitation wards. The primary outcome was ADL recovery as evaluated by the Functional Independence Measure (FIM) efficiency during hospitalization, and the secondary outcome was hospital-related costs. Univariate and multivariate analyses were performed to identify whether sarcopenia was associated with FIM-motor efficiency and hospitalization costs.

RESULTS

Among the patients, 68.3% were females, and the mean age was 82.3 ± 8.3 years. The prevalence of sarcopenia was 73.1%. The FIM-motor efficiency score was significantly lower in patients with sarcopenia (median 0.38; interquartile range 0.27-0.52) than in those without sarcopenia (median 0.55; interquartile range 0.34-0.87) (P = 0.009). Hospitalization costs were higher in patients with sarcopenia (32,813 ± 15,184 dollars) than in those without sarcopenia (26,879 ± 10,248 dollars) (P = 0.058). Multivariate analysis showed that sarcopenia was independently associated with FIM-motor efficiency (standardized β =  - 0.236, P = 0.014, R2 = 0.40) and hospitalization costs (standardized β = 0.15, P = 0.027, R2 = 0.70) after adjusting for confounding factors.

CONCLUSION

We found that sarcopenia reduces the FIM-motor efficiency and increases direct hospitalization costs in older patients admitted to convalescent rehabilitation wards. Therefore, it is necessary to design interventions to prevent sarcopenia and improve the efficiency of ADL recovery and reduce direct hospitalization cost.

Diagnosis of sarcopenia by evaluating skeletal muscle mass by adjusted bioimpedance analysis validated with dual-energy X-ray absorptiometry

BACKGROUND

This study aimed to adjust and cross-validate skeletal muscle mass measurements between bioimpedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) for the screening of sarcopenia in the community and to estimate the prevalence of sarcopenia in Hong Kong.

METHODS

Screening of sarcopenia was provided to community-dwelling older adults. Appendicular skeletal muscle mass (ASM) was evaluated by BIA (InBody 120 or 720) and/or DXA. Handgrip strength and/or gait speed were assessed. Diagnosis of sarcopenia was based on the 2019 revised Asian Working Group for Sarcopenia cut-offs. Agreement analysis was performed to cross-validate ASM measurements by BIA and DXA. Multiple regression was used to explore contribution of measured parameters in predicting DXA ASM from BIA.

RESULTS

A total of 1587 participants (age = 72 ± 12 years) were recruited; 1065 participants were screened by BIA (InBody 120) with 18 followed up by DXA, while the remaining 522 participants were assessed by the BIA (InBody 720) and DXA. The appendicular skeletal muscle mass index (ASMI) evaluated by BIA showed a mean difference of 2.89 ± 0.38 kg/m² (InBody 120) and 2.97 ± 0.45 kg/m² (InBody 720) against DXA gold standard. A significant overestimation of muscle mass was measured by BIA compared with DXA (P < 0.005). BIA data were adjusted using prediction equation and mean difference reduced to -0.02 ± 0.31 kg/m² in cross-validation. Prevalence of sarcopenia in older adults ≥65 ranged from 39.4% (based on ASMI by DXA) to 40.8% (based on predicted DXA ASMI from BIA). Low ASMI by DXA was found in 68.5% of the older adults screened. The percentage of older adults exhibited low handgrip strength ranged from 31.3% to 56%, while 49% showed low gait speed.

CONCLUSIONS

Bioimpedance analysis was found to overestimate skeletal muscle mass compared with DXA. With adjustment equations, BIA can be used as a quick and reliable tool for screening sarcopenia in community and clinical settings with limited access to better options.

Allulose Attenuated Age-Associated Sarcopenia via Regulating IGF-1 and Myostatin in Aged Mice

SCOPE

Allulose is shown to increase the muscle weight in diet-induced obese mice. However, there are no studies on the effects of allulose in age-associated sarcopenia. This study aims to elucidate the mechanisms of action for allulose in age associated by analyzing the transcriptional patterns in aged mice.

METHODS AND RESULTS

The 48-week-old mice are fed with AIN-93diet containing allulose for 12 weeks. Allulose supplementation increases the muscle mass and grip strength in aged mice. Allulose increases the insulin-like growth factor 1 (IGF-1) and its downstream factor expressions which 40 are related protein synthesis, while inhibits the myostatin expression related protein degradation. In mRNA-seq analysis, allulose supplementation significantly decreases in Adiponectin, Adipsin, cell death inducing DFFA like effector (CIDEC), Haptoglobin, Neuroglobin, and stearoyl-CoA desaturase-1 (SCD1) and increases in cytokine-inducible SH2-containing protein (CISH) and ceramide synthase 1 (CerS1) that are regulate protein turn over in gastrocnemius. Also, allulose alleviates autophagy in muscle with regulated mammalian target of rapamycin (mTOR) signaling pathway and increases the anti-oxidant enzyme activity.

CONCLUSION

These findings suggest that allulose improves the age-associated sarcopenia with enhancing antioxidant properties by altering mRNA and protein expression.

Mechanisms Linking the Gut-Muscle Axis With Muscle Protein Metabolism and Anabolic Resistance: Implications for Older Adults at Risk of Sarcopenia

Aging is associated with a decline in skeletal muscle mass and function-termed sarcopenia-as mediated, in part, by muscle anabolic resistance. This metabolic phenomenon describes the impaired response of muscle protein synthesis (MPS) to the provision of dietary amino acids and practice of resistance-based exercise. Recent observations highlight the gut-muscle axis as a physiological target for combatting anabolic resistance and reducing risk of sarcopenia. Experimental studies, primarily conducted in animal models of aging, suggest a mechanistic link between the gut microbiota and muscle atrophy, mediated via the modulation of systemic amino acid availability and low-grade inflammation that are both physiological factors known to underpin anabolic resistance. Moreover, in vivo and in vitro studies demonstrate the action of specific gut bacteria (Lactobacillus and Bifidobacterium) to increase systemic amino acid availability and elicit an anti-inflammatory response in the intestinal lumen. Prospective lifestyle approaches that target the gut-muscle axis have recently been examined in the context of mitigating sarcopenia risk. These approaches include increasing dietary fiber intake that promotes the growth and development of gut bacteria, thus enhancing the production of short-chain fatty acids (SCFA) (acetate, propionate, and butyrate). Prebiotic/probiotic/symbiotic supplementation also generates SCFA and may mitigate low-grade inflammation in older adults via modulation of the gut microbiota. Preliminary evidence also highlights the role of exercise in increasing the production of SCFA. Accordingly, lifestyle approaches that combine diets rich in fiber and probiotic supplementation with exercise training may serve to produce SCFA and increase microbial diversity, and thus may target the gut-muscle axis in mitigating anabolic resistance in older adults. Future mechanistic studies are warranted to establish the direct physiological action of distinct gut microbiota phenotypes on amino acid utilization and the postprandial stimulation of muscle protein synthesis in older adults.

Osteosarcopenia, an Asymmetrical Overlap of Two Connected Syndromes: Data from the OsteoSys Study

Osteoporosis and sarcopenia are two chronic conditions, which widely affect older people and share common risk factors. We investigated the prevalence of low bone mineral density (BMD) and sarcopenia, including the overlap of both conditions (osteosarcopenia) in 572 older hospitalized patients (mean age 75.1 ± 10.8 years, 78% women) with known or suspected osteoporosis in this prospective observational multicenter study. Sarcopenia was assessed according to the revised definition of the European Working Group on Sarcopenia in Older People (EWGSOP2). Low BMD was defined according to the World Health Organization (WHO) recommendations as a T-score < -1.0. Osteosarcopenia was diagnosed when both low BMD and sarcopenia were present. Low BMD was prevalent in 76% and the prevalence of sarcopenia was 9%, with 90% of the sarcopenic patients showing the overlap of osteosarcopenia (8% of the entire population). Conversely, only few patients with low BMD demonstrated sarcopenia (11%). Osteosarcopenic patients were older and frailer and had lower BMI, fat, and muscle mass, handgrip strength, and T-score compared to nonosteosarcopenic patients. We conclude that osteosarcopenia is extremely common in sarcopenic subjects. Considering the increased risk of falls in patients with sarcopenia, they should always be evaluated for osteoporosis.