Definition Of Sarcopenia Research Articles

Comparison of the 2010 and 2019 diagnostic criteria for sarcopenia by the European Working Group on Sarcopenia in Older People (EWGSOP) in two cohorts of Swedish older adults

BackgroundThe operational definition of sarcopenia has been updated (EWGSOP2) and apply different cut-off points compared to previous criteria (EWGSOP1). Therefore, we aim to compare the sarcopenia prevalence and the association with mortality and dependence in activities of daily living using the 2010 (EWGSOP1 and 2019 (EWGSOP2 operational definition, applying cut-offs at two levels using T-scores.MethodsTwo birth cohorts, 70 and 85-years-old (n = 884 and n = 157, respectively), were assessed cross-sectionally (57% women). Low grip strength, low muscle mass and slow gait speed were defined below − 2.0 and − 2.5 SD from a young reference population (T-score). Muscle mass was defined as appendicular lean soft tissue index by DXA. The EWGSOP1 and EWGSOP2 were applied and compared with McNemar tests and Cohen’s kappa. All-cause mortality was analyzed with the Cox-proportional hazard model.ResultsSarcopenia prevalence was 1.4–7.8% in 70-year-olds and 42–62% in 85 years-old’s, depending on diagnostic criteria. Overall, the prevalence of sarcopenia was 0.9–1.0 percentage points lower using the EWGSOP2 compared to EWGSOP1 when applying uniform T-score cut-offs (P < 0.005). The prevalence was doubled (15.0 vs. 7.5%) using the − 2.0 vs. -2.5 T-scores with EWGSOP2 in the whole sample. The increase in prevalence when changing the cut-offs was 5.7% (P < 0.001) in the 70-year-olds and 17.8% (P < 0.001) in the 85-year-olds (EWGSP2). Sarcopenia with cut-offs at − 2.5 T-score was associated with increased mortality (hazard ratio 2.4–2.8, P < 0.05) but not at T-score − 2.0.ConclusionsThe prevalence of sarcopenia was higher in 85-year-olds compared to 70-year-olds. Overall, the differences between the EWGSOP1 and EWGSOP2 classifications are small. Meaningful differences between EWGSOP1 and 2 in the 85-year-olds could not be ruled out. Prevalence was more dependent on cut-offs than on the operational definition.

Comparisons and Impacts of the Basic Components of Sarcopenia Definition and Their Pairwise Combinations in Gastric Cancer: A Large-Scale Study in a Chinese Population.

Background and Aims: Sarcopenia is negatively associated with clinical outcomes. However, the definitions of sarcopenia are inconsistent across international consensuses. Thus, the purpose of this study is to compare the impact of the basic definition components of sarcopenia and their combinations in post-operative complications and overall survival, aiming to find the best sarcopenia definition to stratify the prognosis in an Asian population.Methods: A total of 1,307 patients who underwent curative surgery for gastric cancer from July 2014 to May 2019 were prospectively included. The basic sarcopenia components were measured pre-operatively, including low skeletal muscle mass index (LSMI), low skeletal muscle radiodensity (LSMD), low handgrip strength (LHGS), and low gait speed (LGS). Among them, LSMI and LSMD were measured using a CT post-processing software, LHGS was measured using an electronic hand dynamometer, and LGS was represented by a 6-m walk speed.Results: For the single basic component, the muscle function parameters (LHGS or LGS) but not the muscle composition parameters (LSMI or LSMD) showed associations with post-operative complications and mortality. For the combination of the basic combinations, all statistically significant combinations included at least one muscle function parameter. The combination of muscle composition (LSMI or LSMD) and muscle function (LHGS or LGS) had a significantly higher area under the curve in the prediction of post-operative complications compared with the combinations of two muscle function parameters (LSMI plus LSMD) or two muscle composition parameters (LHGS plus LGS).Conclusions: Compared with muscle composition parameters (LSMI and LSMD), muscle function parameters (LHGS and LGS) are better predictors of post-operative complications and overall survival, which should be considered as the principal determinant in the sarcopenia definition. The definition of sarcopenia consists of muscle function (LHGS or LGS) and muscle composition (LSMI or LSMD) separately, which is better than the combination of the two muscle function parameters (LHGS plus LGS) or two muscle composition parameters (LSMI plus LSMD).

Ishii test for screening sarcopenia: performance in community-dwelling older adults.

Sarcopenia is associated with an increased likelihood of major adverse health outcomes. Therefore, screening and early and timely identification of sarcopenia are essential. EWGSOP2 (European Working Group on Sarcopenia in Older People2) suggests Ishii screening test for formal-case findings. We aimed to define the diagnostic value of the Ishii screening test, which estimates the probability of sarcopenia using an equation-derived score based on three variables (age, grip strength, and calf circumference) in Turkish older adults. Older adults aged > = 60 who applied to a geriatric outpatient clinic were included in the study. The recommendation of the EWGSOP2 for the definition of sarcopenia was followed. The probability of sarcopenia was estimated by using a score chart of Ishii. Performance of Ishii screening test was analyzed by using sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The receiver-operating characteristic (ROC) analysis was performed to determine the area under the curve (AUC). We included 1635 patients with the mean age of 74.7 ± 7.0. The prevalence of probable sarcopenia was 11.9%. The prevalence of confirmed sarcopenia according to height2 was 0.7%. The prevalence of severe sarcopenia was 0.3% in total. Against diagnoses of probable sarcopenia, confirmed sarcopenia, and severe sarcopenia, the sensitivity values of the Ishii screening test were 84%, 100%, and 100%; the specificity values were 86.1%, 83.9%, and 84.6%, respectively. PPV values were 44.9%, 4.2%, 2.1%; NPV were 97.6%, 100%, 100%, and the AUC values were 0.933, 0.961, and 0.959, respectively. Our results suggest that the Ishii screening test is a successful screening and maybe a candidate diagnostic test for sarcopenia.

Between-study differences in grip strength: a comparison of Norwegian and Russian adults aged 40-69years.

BackgroundIdentifying individuals with low grip strength is an initial step in many operational definitions of sarcopenia. As evidence indicates that contemporaneous Russian populations may have lower mean levels of grip strength than other populations in northern Europe, we aimed to: compare grip strength in Russian and Norwegian populations by age and sex; investigate whether height, body mass index, education, smoking status, alcohol use and health status explain observed differences and; examine implications for case‐finding low muscle strength.MethodsWe used harmonized cross‐sectional data on grip strength and covariates for participants aged 40–69 years from the Russian Know Your Heart study (KYH) (n = 3833) and the seventh survey of the Norwegian Tromsø Study (n = 5598). Maximum grip strength (kg) was assessed using the same protocol and device in both studies. Grip strength by age, sex and study was modelled using linear regression and between‐study differences were predicted from these models. Sex‐specific age‐standardized differences in grip strength and in prevalence of low muscle strength were estimated using the European population standard of 2013.ResultsNormal ranges of maximum grip strength in both studies combined were 33.8 to 67.0 kg in men and 18.7 to 40.1 kg in women. Mean grip strength was higher among Tromsø than KYH study participants and this difference did not vary markedly by age or sex. Adjustment for covariates, most notably height, attenuated between‐study differences but these differences were still evident at younger ages. For example, estimated between‐study differences in mean grip strength in fully adjusted models were 2.2 kg [95% confidence interval (CI) 1.4, 3.1] at 40 years and 1.0 kg (95% CI 0.5, 1.5) at 65 years in men (age × study interaction P = 0.09) and 1.1 kg (95% CI 0.4, 1.9) at age 40 years and −0.2 kg (95% CI −0.7, 0.3) at 65 years in women (age × study interaction P < 0.01).ConclusionsWe found between‐study differences in mean grip strength that are likely to translate into greater future risk of sarcopenia and poorer prospects of healthy ageing for Russian than Norwegian study participants. For example, the average Russian participant had a similar level of grip strength to a Norwegian participant 7 years older. Our findings suggest these differences may have their origins in childhood highlighting the need to consider interventions in early life to prevent sarcopenia.

Sarcopenia and malnutrition in relation to mortality in hospitalised patients in geriatric care - predictive validity of updated diagnoses.

The definition of sarcopenia was recently updated by the European Working Group on Sarcopenia (EWGSOP2), and consensus criteria for the diagnosis of malnutrition have been presented by the Global Leadership Initiative on Malnutrition (GLIM). The aim of this study was to investigate prevalence and mortality related to categorisation of patients according to these definitions in a geriatric hospital setting. Fifty-six consecutive geriatric inpatients (84y (SD 7.3), 68% women) underwent test of handgrip strength (HGS) and five-rise chair stand test (5CST). Muscle mass and fat free mass (FFM) were evaluated by Dual X-ray Absorptiometry (DXA). Calf circumference (CC) was recorded. Probable sarcopenia was defined, according to EWGSOP2, as low HGS (<27/16kg for men/women) and/or 5CST >15s; sarcopenia was confirmed when coupled with low appendicular skeletal muscle index (ASMI <7.0 and<5.5kg/m2 (m/w)). Malnutrition was defined according to GLIM as weight loss >5% (past 6mo); BMI <20/22kg/m2 (<70/>70y); and FFM-index <17/15kg/m2 (m/w) combined with reduced food intake and/or disease burden/inflammatory condition. Alternatively, CC<31cm was used as a proxy for low muscle mass for both sarcopenia and malnutrition. One- and two-year mortality was registered. All participants displayed probable sarcopenia; 46% and 20% were sarcopenic depending on whether muscle mass was estimated by DXA or CC. Malnutrition according to the GLIM criteria was prevalent in 64% or 60% (muscle mass by DXA or CC, respectively). Nine in ten with sarcopenia were also malnourished. Twenty-six participants (46%) died within two years. Sarcopenia defined by CC<31cm, but not by DXA, was associated with increased mortality; e.g. 2-y mortality HR was 3.19 (95% CI 1.31-7.75). Similarly, malnutrition according to GLIM related to increased 1-y mortality (HR 4.83, 95% CI 1.04-22.39) when DXA was used for muscle mass estimation. All of the participants with CC<31cm were categorised as both sarcopenic and malnourished. In this small set of well-characterised geriatric inpatients all displayed probable sarcopenia. Prevalence of sarcopenia (EWGSOP2) and malnutrition (GLIM) was 20-46% and 60-64%, respectively. Both conditions related to mortality. CC<31cm hold promises to be an acceptable alternative for DXA as a proxy for low muscle mass.

Understanding of sarcopenia: from definition to therapeutic strategies.

Sarcopenia refers to the gradual loss of skeletal muscle mass and function along with aging and is a social burden due to growing healthcare cost associated with a super-aging society. Therefore, researchers have established guidelines and tests to diagnose sarcopenia. Several studies have been conducted actively to reveal the cause of sarcopenia and find an economic therapy to improve the quality of life in elderly individuals. Sarcopenia is caused by multiple factors such as reduced regenerative capacity, imbalance in protein turnover, alteration of fat and fibrotic composition in muscle, increased reactive oxygen species, dysfunction of mitochondria and increased inflammation. Based on these mechanisms, nonpharmacological and pharmacological strategies have been developed to prevent and treat sarcopenia. Although several studies are currently in progress, no treatment is available yet. This review presents the definition of sarcopenia and summarizes recent understanding on the detailed mechanisms, diagnostic criteria, and strategies for prevention and treatment.

Ultrasound assessment of sarcopenia in patients with rheumatoid arthritis.

To evaluate the efficacy of ultrasound (US) as a diagnostic tool for sarcopenia in patients with rheumatoid arthritis (RA). Female RA patients aged >50 years and matched controls were cross-sectionally assessed. Sarcopenia was diagnosed based on the 2019-updated Asian Working Group for Sarcopenia definition. The cross-sectional area (CSA) and echo intensity (EI) of the biceps brachii, rectus femoris, and EI of the vastus lateralis were examined bilaterally. Correction for subcutaneous fat and calculation of the recorrected EI (rcEI) were performed. We performed logistic regression using both muscle rcEI and CSA with receiver operating curve analysis to evaluate the discriminative performance per muscle group. Seventy-eight consecutive RA patients and 15 age-and sex-matched controls were assessed. Sarcopenia was diagnosed in 34 RA patients (43.6%). The rcEI of examined muscles were significantly higher, whereas CSA were significantly lower in sarcopenic RA patients than in non-sarcopenic patients and matched controls. The combined discriminative performance of rcEI and CSA was superior to those of rcEI or CSA alone. This study suggests the use of US for the diagnosis of sarcopenia in RA patients. The diagnostic performance increases when both echogenicity and CSA are considered together rather than individually.

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

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. systematic review and meta-analysis. community-dwelling older people. 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. 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. 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.

Assessment of sarcopenia in patients with fibromyalgia

Fibromyalgia is a chronic disorder characterized by persistent widespread musculoskeletal pain. Patients with fibromyalgia have reduced physical activity and increased sedentary rate. The age-associated reduction of skeletal muscle mass and function is called sarcopenia. The European Working Group on Sarcopenia in Older People developed a practical clinical definition and consensus diagnostic criteria for sarcopenia. Loss of muscle function is common in fibromyalgia and in the elderly. The goal of this study is to determine whether the reduction of muscle function in fibromyalgia is related to sarcopenia according to the European Working Group on Sarcopenia in Older People criteria. Forty-five patients with fibromyalgia and thirty-nine healthy control female subjects were included. All the participants were assessed by Fibromyalgia Impact Questionnaire and SARC-F questionnaire. Muscle mass was evaluated by bioimpedance analysis, muscle strength by handgrip strength test and physical performance with the Short Physical Performance Battery. Fibromyalgia Impact Questionnaire and SARC-F scores were statistically significantly higher in the fibromyalgia group than in the control group, showing severe disease and a higher risk of sarcopenia in the fibromyalgia group (p < 0.001). Muscle strength and physical performance were statistically significantly lower in the group with fibromyalgia than in the control group (p < 0.001). There was no statistical difference between fibromyalgia and control groups regarding skeletal muscle mass (p = 0.263). Our study demonstrated a significant reduction in muscle function in fibromyalgia patients without any loss of muscle mass. Loss of muscle function without decrease in muscle mass is called dynapenia.

Prevalence and Risk Factors of Sarcopenia among Older Adults Aged ≥65 Years Admitted to Daycare Centers of Taiwan: Using AWGS 2019 Guidelines.

Sarcopenia is a geriatric syndrome which is likely to cause disability, body unbalance, and mortality and thus can lead to heavy healthcare expenditure and caregiver burden. Although some studies have addressed the prevalence of sarcopenia for older adults, there are limited studies conducted in daycare centers. The present study aimed to (i) estimate the prevalence of sarcopenia and (ii) explore associated factors of sarcopenia and standing balance among older adults admitted to daycare centers in Taiwan. The cross-sectional study collected data on demographics, health status, handgrip strength, gait speed (GS), skeletal muscle mass, Taiwan-Mini Nutritional Assessment Short-Form (TW-MNA-SF), and Short Physical Performance Battery from daycare centers in northern Taiwan. The definition of sarcopenia followed the Asian Working Group for Sarcopenia 2019 guidelines. Among 173 participants ≥65 year-old, 50.9% had confirmed sarcopenia, 47.4% possible sarcopenia, and 1.7% normal. Results showed that calf circumference, TW-MNA-SF, dementia, and body mass index (BMI) were associated with sarcopenia. Moreover, BMI, GS, and sarcopenia were associated factors of standing balance. The study estimated a high prevalence of sarcopenia in daycare centers and identified some significant factors of sarcopenia and standing balance. Early nutritional and physiotherapy interventions could benefit older adults to prevent sarcopenia or unbalance.

Sarcopenia Is Associated with Mortality in Adults: A Systematic Review and Meta-Analysis

Background: Sarcopenia can predispose individuals to falls, fractures, hospitalization, and mortality. The prevalence of sarcopenia depends on the population studied and the definition used for the diagnosis. Objective: This systematic review and meta-analysis aimed to investigate the association between sarcopenia and mortality and if it is dependent on the population and sarcopenia definition. Methods: A systematic search was conducted in MEDLINE, EMBASE, and Cochrane from 1 January 2010 to 6 April 2020 for articles relating to sarcopenia and mortality. Articles were included if they met the following criteria – cohorts with a mean or median age ≥18 years and either of the following sarcopenia definitions: Asian Working Group for Sarcopenia (AWGS and AWGS2019), European Working Group on Sarcopenia in Older People (EWGSOP and EWGSOP2), Foundation for the National Institutes of Health (FNIH), International Working Group for Sarcopenia (IWGS), or Sarcopenia Definition and Outcomes Consortium (SDOC). Hazard ratios (HR) and odds ratios (OR) were pooled separately in meta-analyses using a random-effects model, stratified by population (community-dwelling adults, outpatients, inpatients, and nursing home residents). Subgroup analyses were performed for sarcopenia definition and follow-up period. Results: Out of 3,025 articles, 57 articles were included in the systematic review and 56 in the meta-analysis (42,108 participants, mean age of 49.4 ± 11.7 to 86.6 ± 1.0 years, 40.3% females). Overall, sarcopenia was associated with a significantly higher risk of mortality (HR: 2.00 [95% CI: 1.71, 2.34]; OR: 2.35 [95% CI: 1.64, 3.37]), which was independent of population, sarcopenia definition, and follow-up period in subgroup analyses. Conclusions: Sarcopenia is associated with a significantly higher risk of mortality, independent of population and sarcopenia definition, which highlights the need for screening and early diagnosis in all populations.

Differences among Three Skeletal Muscle Mass Indices in Predicting Non-Alcoholic Fatty Liver Disease: Korean Nationwide Population-Based Study.

Recent studies have investigated the relationship between sarcopenia and non-alcoholic fatty liver disease (NAFLD); however, there is no unified definition of sarcopenia. Thus, we aimed to investigate the differences among three skeletal muscle mass indices (SMI) in predicting NAFLD. This study included 8133 adults from the 2008–2010 Korea National Health and Nutrition Survey. SMI was calculated as appendicular skeletal muscle mass divided by height-square (hSMI), weight (wSMI), or body mass index (bSMI). The presence of NAFLD was defined by using the NAFLD-liver fat score. On the receiver operating characteristic curve analysis, the predictive power of wSMI for NAFLD was significantly higher than those of hSMI and bSMI in men (wSMI vs. hSMI, p = 0.003; wSMI vs. bSMI, p < 0.001). In women, the predictive power of hSMI was only significantly higher than that of bSMI (p = 0.023), and other predictive powers were not significantly different. In addition, hSMI was correlated with insulin resistance and NAFLD-liver fat score in the opposite direction to wSMI and bSMI in both men and women. Among the three definitions of SMI, wSMI showed the highest diagnostic performance for predicting NAFLD in men, suggesting the importance of defining sarcopenia for its association with specific diseases.

The 30-s chair stand test can be a useful tool for screening sarcopenia in elderly Japanese participants

BackgroundLow muscle strength has been focused on as an essential characteristic of sarcopenia, and the 30-s chair stand test (CS-30) could be a particularly useful test for assessing muscle strength. While it is speculated to be a beneficial tool for the assessment of sarcopenia, this remains to be verified. In this study, we examined the reliability and optimal diagnostic score of the CS-30 for assessing sarcopenia in elderly Japanese participants.MethodsThis cross-sectional study included 678 participants (443 females and 235 males) who underwent the test for sarcopenia as per the Asian Working Group for Sarcopenia (AWGS) 2019, the CS-30 test, and the isometric knee-extension muscle strength test. ROC analysis was used to estimate the optimal CS-30 scores at which sarcopenia was detected.ResultsCS-30 scores were positively associated with sarcopenia (OR: 0.88; 95% CI:0.82–0.93). The AUC of the CS-30 for sarcopenia definition were 0.84 (p < 0.001) for females and 0.80 (p < 0.001) for males. The optimal number of stands in the CS-30 that predicted sarcopenia was 15 for females (sensitivity, 76.4%; specificity, 76.8%) and 17 for males (sensitivity, 75.0%; specificity, 71.7%).ConclusionsThe CS-30 was found to be a reliable test for sarcopenia screening in the elderly Japanese population.

Assessment of uremic sarcopenia in dialysis patients: An update.

Uremic sarcopenia, which is highly prevalent in dialysis patients, leads to an increased risk of adverse outcomes, such as poor quality of life, falls, fracture, hospitalization, and even mortality. Therefore, early detection of uremic sarcopenia is crucial for administering quick and adequate multidisciplinary therapy to improve clinical outcomes. This review updates the current information about uremic sarcopenia assessment in chronic dialysis patients. We discuss the methods of assessing skeletal muscle mass, strength, and physical performance. We also discuss surrogate markers derived from serum and dialysate creatinine, in addition to emerging screening tools. The prevalence, clinical relevance, and impact of uremic sarcopenia on survival are reviewed and we discuss the limitations and challenges in applying the current working definition of sarcopenia based on the senior population to dialysis patients. The review shows that dialysis patients with skeletal muscle weakness or poor physical performance, either with or without low skeletal muscle mass, should undergo multidisciplinary therapy, included nutritional counseling, lifestyle modification, and exercise intervention, to mitigate the detrimental effects of uremic sarcopenia.

Sarcopenia in patients following stroke: an overlooked problem.

Our aim was to investigate the prevalence of sarcopenia in stroke patients, the relationship between sarcopenia detected with different low muscle mass (LMM) adjustment methods, and between stroke-related parameters. Eighty-one patients with chronic stroke who underwent inpatient rehabilitation were included. Spasticity was evaluated by modified Ashworth scale, Brunnstrom staging approach was used for motor function evaluation, physical independence was evaluated using Barthel Index, quality-of-life was evaluated by EQ-5D-3L, and the Cumulative Illness Rating Scale was used to measure multimorbidity. Muscle strength was evaluated by handgrip strength, muscle quantity through a bioelectric impedance analysis, and physical performance by gait speed and short physical performance battery. LMM was calculated through two different methods: Skeletal muscle mass (SMM)/height2, and SMM/BMI. For the definition of sarcopenia, we followed the EWGSOP2 recommendation. Associated sarcopenia factors were predicted by multivariate binary logistic regression analysis. The prevalence of probable sarcopenia was 32.1%. The prevalence of confirmed/sarcopenia when LMM was adjusted for BMI was higher than when adjusted for height2 (16 and 1.2%, respectively). Age was significantly higher in those with probable sarcopenia (P = 0.006). Stroke duration was shorter in those with probable or confirmed sarcopenia (P = 0.004, P < 0.001, respectively). EQ-5D-3L scores were significantly lower in those with confirmed sarcopenia (P = 0.050). The strongest associated factor with confirmed sarcopenia was stroke duration (OR: 0.77; 95% CI, 0.618-0.965). This study suggests that prevalence of sarcopenia after a stroke is significantly high. LMM adjusted for BMI comes in front as the adjustment method for LMM after a stroke.

Sarcopenia: What Is the Origin of This Aging-Induced Disorder?

We here review the loss of muscle function and mass (sarcopenia) in the framework of human healthspan and lifespan, and mechanisms involved in aging. The rapidly changing composition of the human population will impact the incidence and the prevalence of aging-induced disorders such as sarcopenia and, henceforth, efforts to narrow the gap between healthspan and lifespan should have top priority. There are substantial knowledge gaps in our understanding of aging. Heritability is estimated to account for only 25% of lifespan length. However, as we push the expected lifespan at birth toward those that we consider long-lived, the genetics of aging may become increasingly important. Linkage studies of genetic polymorphisms to both the susceptibility and aggressiveness of sarcopenia are still missing. Such information is needed to shed light on the large variability in clinical outcomes between individuals and why some respond to interventions while others do not. We here make a case for the concept that sarcopenia has a neurogenic origin and that in manifest sarcopenia, nerve and myofibers enter into a vicious cycle that will escalate the disease progression. We point to gaps in knowledge, for example the crosstalk between the motor axon, terminal Schwann cell, and myofiber in the denervation processes that leads to a loss of motor units and muscle weakness. Further, we argue that the operational definition of sarcopenia should be complemented with dynamic metrics that, along with validated biomarkers, may facilitate early preclinical diagnosis of individuals vulnerable to develop advanced sarcopenia. We argue that preventive measures are likely to be more effective to counter act aging-induced disorders than efforts to treat manifest clinical conditions. To achieve compliance with a prescription of preventive measures that may be life-long, we need to identify reliable predictors to design rational and convincing interventions.

The Optimal Definition of Sarcopenia for Predicting Postoperative Pneumonia after Esophagectomy in Patients with Esophageal Cancer.

Esophageal cancer (EC) is associated with malnutrition in the vast majority of patients, and this often leads to sarcopenia, which is characterised by loss of skeletal muscle mass (SMM). Although sarcopenia could be one of the risk factors for postoperative pneumonia (PP), the optimal definition of sarcopenia using skeletal muscle mass index (SMI) by bioelectrical impedance analysis (BIA) remains unknown for predicting PP after esophagectomy in patients with EC. Therefore, this study aimed to identify high-risk patients for PP after esophagectomy through evaluating SMI by BIA and set an appropriate cut-off value for this purpose. A total of 73 patients with EC who underwent subtotal esophagectomy with lymph node dissection at Osaka City University Hospital between 2017 and 2019 were reviewed retrospectively. The association between PP and perioperative factors including SMI by BIA were analysed. When SMI was lower than the cut-off values proposed by two study groups (Asian Working Group for Sarcopenia (AWGS) and original European Working Group on Sarcopenia in Older People (EWGSOP)) or SMM was less than 90% of standard, the patient was diagnosed with sarcopenia. Receiver operating characteristic analysis was performed to set the appropriate cut-off value of SMI, and a new criterion (modified EWGSOP) was formulated by using the value. Clinicopathological factors and postoperative complications between sarcopenia and non-sarcopenia groups were compared, which were classified by four different criteria: (1) AWGS, (2) original EWGSOP, (3) < 90% standard and (4) modified EWGSOP criteria. Nine patients (12.3%) were with PP grade III or higher. Total SMI as well as body mass index (BMI), transthyretin and % vital capacity (%VC) were found to be significantly associated with PP (Clavien-Dindo grade ≥ III). BMI, total and appendicular SMI of sarcopenic patients were found to be lower than those of non-sarcopenic patients. Low serum albumin and %VC were significantly associated with sarcopenia defined by modified EWGSOP criteria. The rate of PP was significantly higher in sarcopenic patients when the original and modified EWGSOP criteria were used (p = 0.0079 and 0.0015, respectively). A multivariate analysis revealed that sarcopenic state by modified EWGSOP criteria was the significant independent predictive factor of PP [p = 0.0031, hazard ratio (HR) = 10.1; 95% confidential interval (CI): 2.12-76.9]. Preoperative sarcopenia by modified EWGSOP criteria could be the best indicator using BIA for predicting PP after esophagectomy in patients with EC.

What Cut-Point in Gait Speed Best Discriminates Community-Dwelling Older Adults With Mobility Complaints From Those Without? A Pooled Analysis From the Sarcopenia Definitions and Outcomes Consortium.

Cut-points to define slow walking speed have largely been derived from expert opinion. Study participants (13 589 men and 5043 women aged ≥65years) had walking speed (m/s) measured over 4-6 m (mean ± SD: 1.20 ± 0.27 m/s in men and 0.94 ± 0.24 m/s in women.) Mobility limitation was defined as any self-reported difficulty with walking approximately 1/4 mile (prevalence: 12.6% men, 26.4% women). Sex-stratified classification and regression tree (CART) models with 10-fold cross-validation identified walking speed cut-points that optimally discriminated those who reported mobility limitation from those who did not. Among 5043 women, CART analysis identified 2 cut-points, classifying 4144 (82.2%) with walking speed ≥0.75 m/s, which we labeled as "fast"; 478 (9.5%) as "intermediate" (walking speed ≥0.62 m/s but <0.75 m/s); and 421 (8.3%) as "slow" (walking speed <0.62 m/s). Among 13 589 men, CART analysis identified 3 cut-points, classifying 10 001 (73.6%) with walking speed ≥1.00 m/s ("very fast"); 2901 (21.3%) as "fast" (walking speed ≥0.74 m/s but <1.00 m/s); 497 (3.7%) as "intermediate" (walking speed ≥0.57 m/s but <0.74 m/s); and 190 (1.4%) as "slow" (walking speed <0.57 m/s). Prevalence of self-reported mobility limitation was lowest in the "fast" or "very fast" (11% for men and 19% for women) and highest in the "slow" (60.5% in men and 71.0% in women). Rounding the 2 slower cut-points to 0.60 m/s and 0.75 m/s reclassified very few participants. Cut-points in walking speed of approximately 0.60 m/s and 0.75 m/s discriminate those with self-reported mobility limitation from those without.

Definition and Diagnosis of Sarcopenia

高齢化の進行とともに，加齢に伴って増加する疾患，病態の重要性が高くなっている．加齢とともに骨格筋量は減少するが，骨格筋量とともに歩行速度や握力など機能的な低下も認められる．このような加齢に伴う骨格筋の機能低下がサルコペニアと定義されたが，サルコペニアは，日常生活活動（ADL）の低下，フレイル，転倒・骨折，入院，施設入所，死亡などの危険因子であり，その診断基準も2010年から2014年にかけて欧米およびアジアで確立してきた．その後，EWGSOPは2018年診断基準の改訂を発表し，続いてAWGSも2019年10月に診断基準を改訂した．さまざまな診療科において高齢化とともにサルコペニアの診断・治療の重要性は高まっており，治療の質向上や健康寿命延伸のためガイドラインに応じたサルコペニアの管理が必要である．

Prevalence of Sarcopenia and its Association with Antirheumatic Drugs in Middle-Aged and Older Adults with Rheumatoid Arthritis: A Systematic Review and Meta-analysis

To examine the prevalence of sarcopenia and its association with antirheumatic drugs in adults with rheumatoid arthritis (RA). This review was registered on PROSPERO and followed PRISMA guidelines. Electronic databases were searched for studies reporting on the prevalence of sarcopenia in adults with RA using any muscle index (muscle mass, strength and/or physical performance) and cutpoints as recommended by established criteria (EWGSOP1/2, AWGS, FNIH, SDOC). The secondary objective was to investigate the relationship between RA, antirheumatic drugs, and sarcopenia. Among 2240 middle-aged and older adults with RA (mean age: 47.7 ± 5.5 to 75.0 ± 6.2years, 83.8% women), the pooled prevalence of low muscle mass/sarcopenia was 30.2% [95% confidence interval (CI) 24.2-36.2%; 16 studies; I2: 89.2%]. Sub-group analysis showed a non-significant higher prevalence of low muscle mass alone (32.6%, 95% CI 25.0-40.3%; I2: 87.9%) versus consensus definitions of sarcopenia (25.4%, 95% CI 15.4-35.3%; I2: 91.2%, p = 0.255). In adults with RA, corticosteroid use was positively associated with sarcopenia [odds ratio (OR) 1.46, 95% CI 0.94-2.29, 7 studies; I2: 47.5%] while conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) was inversely associated (OR 0.70, 95% CI 0.52-0.94; 6 studies: I2: 0.00%) with this muscle disease. No association was found for biological/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) (OR 0.83, 95% CI 0.54-1.30; 6 studies: I2: 47.6%). Sarcopenia is a common comorbidity of RA, and as such, clinicians should screen for this muscle disease in adults with RA. Further longitudinal studies are needed to understand the role of antirheumatic drugs (particularly type, dosing, and duration) in the development of sarcopenia.