Sarcopenia

Development of a community intervention combining social media-based health education plus exercise programme (SHEEP) to improve muscle function among young-old adults with possible sarcopenia: Co-design approach

OBJECTIVES

There is no precedent for the use of social media in preventing sarcopenia. The aim of this study is to develop a social media-based intervention programme for the young-old population in the community in China to improve their awareness and behaviours regarding sarcopenia prevention.

STUDY DESIGN

Using guidelines for developing complex interventions, this study was divided into two main phases: a co-development phase and a preliminary test phase. Both were carried out in Changsha, China. The development phase employed co-design methodology with relevant stakeholders, including two rounds of consultation with patient and public involvement (12 members) and two rounds of focus groups (30 participants); this was followed by the three-week preliminary test phase (22 participants).

MAIN OUTCOME MEASURES

This study evaluated the consultation with patient and public involvement, and mainly collected qualitative data from the two rounds of focus group interviews and a final semi-structured interview following the preliminary test, so as to explore the participants' experiences, comments, and suggestions for revising the social media-based intervention. Handgrip strength was also evaluated.

RESULTS

The health education included seven videos of 4-6 min each related to sarcopenia, including information on the concept, influencing factors, adverse effects, manifestations, screening methods, and preventions. The exercise video consisted of four types of training (warm-up, aerobic, resistance, and flexibility training) and lasted 30 min, with a suggested engagement of at least 3 days/week. The specific contents and "dosage" of the final intervention were unanimously favourable to the diverse stakeholders involved (older adults with possible sarcopenia, experts, researchers). After the preliminary test, an improvement in handgrip strength was observed, from M15.92±SD5.22 kg to M19.13±SD5.44 kg (T = -5.44, P < 0.001). Subgroup analysis revealed that this improvement was evident in both men and women.

CONCLUSIONS

The social media-based intervention was universally endorsed by the participants and showed indications of a positive influence on sarcopenia. A feasibility study is now needed.

Beef peptides mitigate skeletal muscle atrophy in C2C12 myotubes through protein degradation, protein synthesis, and the oxidative stress pathway

This study aimed to investigate the potential of beef peptides (BPs) in mitigating muscle atrophy induced by dexamethasone (DEX) with underlying three mechanisms in vitro (protein degradation, protein synthesis, and the oxidative stress pathway). Finally, the anti-atrophic effect of BPs was enhanced through purification and isolation. BPs were generated using beef loin hydrolyzed with alcalase/ProteAX/trypsin, each at a concentration of 0.67%, followed by ultrafiltration through a 3 kDa cut-off. BPs (10-100 μg mL-1) dose-dependently counteracted the DEX-induced reductions in myotube diameters, differentiation, fusion, and maturation indices (p < 0.05). Additionally, BPs significantly reduced FoxO1 protein dephosphorylation, thereby suppressing muscle-specific E3 ubiquitin ligases such as muscle RING-finger containing protein-1 and muscle atrophy F-box protein in C2C12 myotubes at concentrations exceeding 25 μg mL-1 (p < 0.05). BPs also enhanced the phosphorylation of protein synthesis markers, including mTOR, 4E-BP1, and p70S6K1, in a dose-dependent manner (p < 0.05) and increased the mRNA expression of antioxidant enzymes. Fractionated peptides derived from BPs, through size exclusion and polarity-based fractionation, also demonstrated enhanced anti-atrophic effects compared to BPs. These peptides downregulated the mRNA expression of primary muscle atrophy markers while upregulated that of antioxidant enzymes. Specifically, peptides GAGAAGAPAGGA (MW 924.5) and AFRSSTKK (MW 826.4) were identified from fractionated peptides of BPs. These findings suggest that BPs, specifically the peptide fractions GAGAAGAPAGGA and AFRSSTKK, could be a potential strategy to mitigate glucocorticoid-induced skeletal muscle atrophy by reducing the E3 ubiquitin ligase activity.

Plasma microRNA signature associated with skeletal muscle wasting in post-menopausal osteoporotic women

BACKGROUND

Skeletal muscle mass wasting almost invariably accompanies bone loss in elderly, and the coexistence of these two conditions depends on the tight endocrine crosstalk existing between the two organs, other than the biomechanical coupling. Since the current diagnostics limitation in this field, and given the progressive population aging, more effective tools are needed. The aim of this study was to identify circulating microRNAs (miRNAs) as potential biomarkers for muscle mass wasting in post-menopausal osteoporotic women.

METHODS

One hundred seventy-nine miRNAs were assayed by quantitative real-time polymerase chain reaction in plasma samples from 28 otherwise healthy post-menopausal osteoporotic women (73.4 ± 6.6 years old). The cohort was divided in tertiles based on appendicular skeletal muscle mass index (ASMMI) to better highlight the differences on skeletal muscle mass (first tertile: n = 9, ASMMI = 4.88 ± 0.40 kg·m-2; second tertile: n = 10, ASMMI = 5.73 ± 0.23 kg·m-2; third tertile: n = 9, ASMMI = 6.40 ± 0.22 kg·m-2). Receiver operating characteristic (ROC) curves were calculated to estimate the diagnostic potential of miRNAs. miRNAs displaying a statistically significant fold change ≥ ±1.5 and area under the curve (AUC) > 0.800 (P < 0.05) between the first and third tertiles were considered. A linear regression model was applied to estimate the association between miRNA expression and ASMMI in the whole population, adjusting for body mass index, age, total fat (measured by total-body dual-energy X-ray absorptiometry [DXA]) and bone mineral density (measured by femur DXA). Circulating levels of adipo-myokines were evaluated by bead-based immunofluorescent assays and enzyme-linked immunosorbent assays.

RESULTS

Five miRNAs (hsa-miR-221-3p, hsa-miR-374b-5p, hsa-miR-146a-5p, hsa-miR-126-5p and hsa-miR-425-5p) resulted down-regulated and two miRNAs (hsa-miR-145-5p and hsa-miR-25-3p) were up-regulated in the first tertile (relative-low ASMMI) compared with the third tertile (relative-high ASMMI) (fold change ≥ ±1.5; P-value < 0.05). All the corresponding ROC curves had AUC > 0.8 (P < 0.05). Two signatures hsa-miR-126-5p, hsa-miR-146a-5p and hsa-miR-425-5p; and hsa-miR-126-5p, hsa-miR-146a-5p, hsa-miR-145-5p and hsa-miR-25-3p showed the highest AUC, 0.914 (sensitivity = 77.78%; specificity = 100.00%) and 0.901 (sensitivity = 88.89%; specificity = 100.00%), respectively.

CONCLUSIONS

In this study, we identified, for the first time, two miRNA signatures, hsa-miR-126-5p, hsa-miR-146a-5p and hsa-miR-425-5p; and hsa-miR-126-5p, hsa-miR-146a-5p, hsa-miR-145-5p and hsa-miR-25-3p, specifically associated with muscle mass wasting in post-menopausal osteoporotic women.

Dynapenia and sarcopenia: association with the diagnosis, duration and complication of type 2 diabetes mellitus in ELSA-Brasil

Sarcopenia (the loss of muscle mass, strength and skeletal muscle function) increases mortality and the risk of hospitalization in the older population. Although it is known that older adults with type 2 diabetes mellitus (T2DM) have a higher risk of dynapenia and sarcopenia, few studies have investigated these conditions in middle-aged populations. The objective of this study was to investigate whether T2DM, its duration, the presence of albuminuria, and glycemic control are associated with sarcopenia and its components in adults. The cross-sectional analysis was based on data from visit 2 of the Brazilian Longitudinal Study of Adult Health (2012-2014). The 2018 European Working Group on Sarcopenia in Older People criteria were used to define dynapenia, low appendicular muscle mass (LAMM), and sarcopenia (absent/probable/confirmed). The explanatory variables were: T2DM; duration of T2DM; T2DM according to the presence of albuminuria; and glycemic control (HbA1C < 7%) among people with T2DM. A total of 12,132 participants (mean age = 55.5, SD: 8.9 years) were included. The odds ratio for LAMM was greater among those with T2DM, T2DM duration from 5 to 10 years, and T2DM without albuminuria. Chances of dynapenia were higher among those with T2DM, T2DM duration > 10 years, and T2DM with and without albuminuria. The variables T2DM, T2DM ≥ 10 years, and T2DM with albuminuria increased the odds of probable sarcopenia, and T2DM duration from 5 to 10 years increased the odds of confirmed sarcopenia. The results support the importance of frequently monitoring the musculoskeletal mass and strength of individuals with T2DM to prevent sarcopenia and related outcomes.

The Current Landscape of Pharmacotherapies for Sarcopenia

Sarcopenia is a skeletal muscle disorder characterized by progressive and generalized decline in muscle mass and function. Although it is mostly known as an age-related disorder, it can also occur secondary to systemic diseases such as malignancy or organ failure. It has demonstrated a significant relationship with adverse outcomes, e.g., falls, disabilities, and even mortality. Several breakthroughs have been made to find a pharmaceutical therapy for sarcopenia over the years, and some have come up with promising findings. Yet still no drug has been approved for its treatment. The key factor that makes finding an effective pharmacotherapy so challenging is the general paradigm of standalone/single diseases, traditionally adopted in medicine. Today, it is well known that sarcopenia is a complex disorder caused by multiple factors, e.g., imbalance in protein turnover, satellite cell and mitochondrial dysfunction, hormonal changes, low-grade inflammation, senescence, anorexia of aging, and behavioral factors such as low physical activity. Therefore, pharmaceuticals, either alone or combined, that exhibit multiple actions on these factors simultaneously will likely be the drug of choice to manage sarcopenia. Among various drug options explored throughout the years, testosterone still has the most cumulated evidence regarding its effects on muscle health and its safety. A mas receptor agonist, BIO101, stands out as a recent promising pharmaceutical. In addition to the conventional strategies (i.e., nutritional support and physical exercise), therapeutics with multiple targets of action or combination of multiple therapeutics with different targets/modes of action appear to promise greater benefit for the prevention and treatment of sarcopenia.

Prevalence of sarcopenia and its association with clinical outcomes in heart failure: An updated meta-analysis and systematic review

BACKGROUND

Sarcopenia is thought to be strongly associated with heart failure, but meta-analyses with sufficient samples are still lacking to accurately address its clinical situation.

HYPOTHESIS

Sarcopenia has a high prevalence in patients with heart failure and is closely related to adverse clinical outcomes.

METHODS

Relevant databases were systematically searched in October 2021 and updated in July 2022. The data with high heterogeneity were combined with random effects model.

RESULTS

Twenty-one studies with 68,556 HF patients were included. The combined prevalence of sarcopenia in HF patients was 31%. Subgroup analysis found that the prevalence of sarcopenia in HF patients was 35% in Asia, 31% in Europe, 25% in the Americas, 31% in people aged ≥65 years, 25% in people with age <65 years, 28% in HF with reduced ejection fraction (HFrEF) patients and 18% in HF with preserved ejection fraction (HFpEF) patients. In addition, our analysis shows that sarcopenia in patients with HF is associated with an increased risk of poor prognosis, with a combined hazard ratio [HR] of 1.64 (95% confidence interval [CI] = 1.20-5.25), sarcopenia was also associated with poor outcomes in HFrEF patients with pooled HR of 2.77 (95% CI = 1.29-5.95). However, it was not associated with poor outcomes in HFpEF patients with pooled HR of 1.61 (95% CI = 0.82-3.16).

CONCLUSIONS

The prevalence of sarcopenia is high in HF patients, and patients with HF, particularly those with reduced ejection fraction, are at high risk of adverse outcomes from sarcopenia. Therefore, early identification and intervention for sarcopenia were beneficial for improving the prognosis of HF patients.

Pre-sarcopenia is associated with health-related quality of life in patients with primary Sjögren's syndrome

OBJECTIVES

Primary Sjögren's syndrome leads to pain and fatigue that may cause impaired muscle function and muscle mass. This study aimed to determine the presence of pre-sarcopenia and to clarify associated factors with pre-sarcopenia in primary Sjögren's syndrome patients.

METHOD

This cross-sectional study recruited 49 patients with primary Sjögren's syndrome and 49 age- and gender-matched healthy controls. Sarcopenia was assessed according to European Working Group on Sarcopenia in Older People in 2018 (EGSWOP2) criteria by evaluating muscle mass, gait speed, and grip strength. Physical function was also assessed with five times sit-to-stand (FTSTS) test. Quality of life (QoL), psychological symptoms, and nutritional status were evaluated using Sarcopenia Quality of Life (SarQoL) questionnaire, Hospital Anxiety and Depression Scale (HADS), and Mini Nutritional Assessment Long Form (MNA-LF), respectively.

RESULTS

Pre-sarcopenia was detected in 28.5% of patients with primary Sjögren's syndrome and 6.1% of healthy controls (p = 0.006). Patients with pre-sarcopenia were older and had worse scores in terms of depression, QoL, pain scores, grip strength, and gait speed compared with those without pre-sarcopenia. The SarQoL scores and grip strength were significantly correlated with gait speed, pain, FTSTS test, and depression. Logistic regression analyses identified that the independent predictive factor for pre-sarcopenia was QoL (OR: 0.79, 95% CI: 0.65-0.95; p = 0.015).

CONCLUSIONS

Maintaining adequate muscle mass and muscle function in patients with primary Sjögren's syndrome may contribute toward improving health-related QoL. Also, controlling depression and malnutrition risk may help to reduce the risk of development of sarcopenia. Key Points • Pre-sarcopenia is detected in 28.4% of the patients with primary Sjögren's syndrome which is higher than healthy controls. • Pre-sarcopenia is associated with health-related quality of life in primary Sjögren's syndrome. • Psychological symptoms and low physical performance are more common in pre-sarcopenic patients.

The impact of sarcopenia on survival and treatment tolerance in patients with head and neck cancer treated with chemoradiotherapy

BACKGROUND

Sarcopenia appears to be a negative prognostic factor for poor survival outcomes and worse treatment tolerance in patients with head-and-neck squamous cell carcinoma (HNSCC). We evaluated sarcopenia's impact on overall survival (OS), disease-free survival (DFS) and chemo-radiation tolerance in patients with head-and-neck cancer (HNC) treated with chemoradiotherapy (CRT) from a monocentric observational study.

METHODS

We identified patients with HNC treated by CRT between 2009 and 2018 with pretreatment imaging using positron emission tomography-computed tomography scans (PET/CT). Sarcopenia was measured using the pretreatment PET/CT at the L3 vertebral body using previously published methods. Clinical variables were retrospectively retrieved.

RESULTS

Of 216 patients identified, 54 patients (25.47%) met the criteria for sarcopenia. These patients had a lower mean body mass index before treatment (21.92 vs. 25.65 cm/m² , p < 0.001) and were more likely to have a history of smoking (88.89% vs. 71.52%, p = 0.01), alcohol use (55.56% vs. 38.61%, p = 0.03) and positive human papilloma virus status (67.74% vs. 41.75%, p = 0.011). At 3 years of follow-up, OS and DFS were 75% and 70% versus 82% and 85% for sarcopenic and non-sarcopenic patients, respectively (p = 0.1 and p = 0.00015). On multivariate analysis, sarcopenia appeared as a pejorative factor on DFS (hazard ratio 2.174, p = 0.0001) in the overall cohort. Sarcopenic patients did not require more chemotherapy and radiation-treatment interruptions and did not suffer from more chemo-induced and radiation-induced grade 3-4 toxicities than their non-sarcopenic counterparts.

CONCLUSION

Sarcopenia in HNSCC patients is an independent adverse prognostic factor for DFS after definitive chemoradiotherapy.

The effect of computed tomography parameters on sarcopenia and myosteatosis assessment: a scoping review

Computed tomography (CT) is a valuable assessment method for muscle pathologies such as sarcopenia, cachexia, and myosteatosis. However, several key underappreciated scan imaging parameters need consideration for both research and clinical use, specifically CT kilovoltage and the use of contrast material. We conducted a scoping review to assess these effects on CT muscle measures. We reviewed articles from PubMed, Scopus, and Web of Science from 1970 to 2020 on the effect of intravenous contrast material and variation in CT kilovoltage on muscle mass and density. We identified 971 articles on contrast and 277 articles on kilovoltage. The number of articles that met inclusion criteria for contrast and kilovoltage was 11 and 7, respectively. Ten studies evaluated the effect of contrast on muscle density of which nine found that contrast significantly increases CT muscle density (arterial phase 6-23% increase, venous phase 19-57% increase, and delayed phase 23-43% increase). Seven out of 10 studies evaluating the effect of contrast on muscle area found significant increases in area due to contrast (≤2.58%). Six studies evaluating kilovoltage on muscle density found that lower kilovoltage resulted in a higher muscle density (14-40% increase). One study reported a significant decrease in muscle area when reducing kilovoltage (2.9%). The use of contrast and kilovoltage variations can have dramatic effects on skeletal muscle analysis and should be considered and reported in CT muscle analysis research. These significant factors in CT skeletal muscle analysis can alter clinical and research outcomes and are therefore a barrier to clinical application unless better appreciated.

The impact of geriatric nutritional risk index on esophageal squamous cell carcinoma patients with neoadjuvant therapy followed by esophagectomy

Background

The Geriatric Nutritional Index (GNRI) has been indicated as a nutritional index which is highly associated with complications and mortality in older hospitalized patients. Moreover, early studies had suggested that GNRI is a potential prognostic indicator for some malignances. However, the prognostic value of GNRI in esophageal squamous cell carcinoma (ESCC) patients underwent neoadjuvant therapy followed by esophagectomy remains elusive.

Materials and methods

This retrospective study incorporated 373 patients with ESCC who had underwent neoadjuvant therapy followed by radical esophagectomy at West China Hospital of Sichuan University between April 2011 and September 2021. The GNRI formula was: 1.489 × albumin (g/dl) + 41.7 × current weight/ideal weight. Patients were classified as GNRI-low (GNRI < 98.7) or GNRI high (GNRI ≥ 98.7). The association between GNRI and clinical survival status were assessed utilizing Kaplan-Meier methods and Cox regression analysis.

Results

Three hundred and seventy three patients were retrospectively included in this study. 80 (21.5%) and 293 (78.5%) patients had been divided into the GNRI-low and GNRI-high groups respectively. Pathological T stage and the rate of nodal metastasis were significantly higher in the GNRI low group than in the GNRI high group (P = 0.003 and P = 0.001, respectively) among the examined demographic parameters. Furthermore, GNRI was significantly correlated with postoperative complications, patients with lower GNRI had a higher postoperative complication rate as compared with GNRI high group [Odds ratio: 2.023; 95% confidence interval (CI): 1.208–3.389; P = 0.007]. Univariate analysis of 5-year overall survival (OS) and disease-free survival (DFS) found that the rate of survival was considerably lower in the GNRI-low group than in the GNRI-high group (P < 0.001). However, multivariate analysis demonstrated that GNRI was not an independent risk factor.

Conclusion

In patients with ESCC, low GNRI exhibited a poor nutritional indicator and related to postoperative complications after neoadjuvant therapy. Intensive follow-up after surgery should be performed for ESCC patients with low GNRI.

The combination of sarcopenia and biochemical factors can predict the survival of hepatocellular carcinoma patients receiving transarterial chemoembolization

Background

Transarterial chemoembolization(TACE) is the suggested treatment for hepatocellular carcinoma (HCC) not amenable to curative treatments. We investigated the role of sarcopenia on overall survival in HCC patients receiving TACE and proposed a new prognostic scoring system incorporating sarcopenia.

Materials and methods

We retrospectively analyzed 260 HCC patients who received TACE between 2010 and 2015. Total psoas muscle was measured on a cross-sectional CT image before the first TACE session. Sarcopenia was defined by the pre-determined sex-specific cutoff value. We assessed the impact of sarcopenia and other biochemical factors on the overall survival and compared the new scoring system with other prognostic scoring systems.

Results

One hundred and thirty patients (50%) were classified as sarcopenia before the first TACE. They were older with a higher male tendency and a significantly lower body mass index (BMI). Cox regression multivariate analysis demonstrated that sarcopenia, multiple tumors, maximal tumor diameter≥ 5cm, major venous thrombosis, sarcopenia, AFP ≥ 200 ng/ml, and albumin<3.5mg/dL were independent poor prognostic factors for overall survival in HCC patients receiving TACE. Our scoring system comprising these factors outperformed other major scoring systems in terms of predicting survival after TACE.

Conclusion

The current study demonstrated that sarcopenia was an independent prognostic factor for HCC undergoing TACE therapy. Our newly developed scoring system could effectively predict patient survival after TACE. Physicians could, based on the current score model, carefully select candidate patients for TACE treatment in order to optimize their survival. Further studies are warranted to validate our findings.

Muscle Strength and Balance as Mediators in the Association between Physical Activity and Health-Related Quality of Life in Community-Dwelling Older Adults

Lower extremity muscle strength (LEMS) and body balance (BB) are essential for older adults to maintain an upright posture and autonomously perform their basic activities of daily living. This study aimed to examine whether LEMS and BB mediate the relationship between physical activity (PA) and health-related quality of life (HRQoL) in a large sample of community-dwelling older adults. This is a cross-sectional study carried out with 802 individuals, 401 males and 401 females (69.8 ± 5.6 years), residents of the Autonomous Region of Madeira, Portugal. PA and HRQoL were assessed by the Baecke Questionnaire and e SF-36, respectively. LEMS was assessed by the Senior Fitness Test and BB by the Fullerton Advance Balance (FAB). The serial mediation pathway model pointed out that LEMS and BB partially mediated the association between PA and HRQoL in approximately 39.6% and 47%, respectively. The total variance in HRQoL explained by the entire model was 98%. Our findings may indicate the role that LEMS and BB play in the relationship between PA and HRQoL in the older population.

Modulation of Neuroendocrine and Immunological Biomarkers Following Rehabilitation in Sarcopenic Patients

This study aimed to investigate if rehabilitation could down-regulated sarcopenia-associated inflammation by modulating the crosstalk between the neuroendocrine and immune systems, with the aim of ameliorating quality of life of sarcopenic subjects. A total of 60 sarcopenic patients (49 females and 11 males; median age 74.5, interquartile range 71–79), undergoing a personalized rehabilitation program, have been recruited and subjected to: (1) functional and physical evaluation (Short Physical Performance Battery (SPPB), Barthel Index and Tinetti Test); (2) pro-inflammatory IL-1β, TNF-α, IL-6, IL-18, and anti-inflammatory IL-10 cytokines plasmatic level measures; and (3) norepinephrine, epinephrine, dopamine, and serotonin neurotransmitter level evaluation at time of enrollment (T0) and once rehabilitation was concluded (1 month, T1). Rehabilitation combined a balance and strength training program with two daily sessions that were fine-tuned and personalized according to the ability of the patient. The results showed a significant increase at T1 in the plasmatic levels of IL-10 (p = 0.018) and of norepinephrine (p = 0.016)), whereas the concentration of IL-18 was significantly reduced (p = 0.012). Notably, changes in norepinephrine were positively correlated with clinical improvements (Tinetti and Barthel scores, p ≤ 0.0001; SPPB scores, p = 0.0002). These results show that efficient rehabilitation induces a reduction of inflammation, suggesting that this effect could be mediated by a modulation of the neuro-immune axis that results in an increase of norepinephrine.

Randomised Controlled Trial of Fish Oil Supplementation on Responsiveness to Resistance Exercise Training in Sarcopenic Older Women

This study aims to investigate the effects of fish oil supplementation on the muscle adaptive response to resistance exercise training, physical performance and serum levels of inflammatory cytokines in sarcopenic older women. A randomised, double-blind, placebo-controlled trial is performed with thirty-four sarcopenic women (2010 European Consensus of Sarcopenia), aged ≥ 65 years. The participants are allocated into the following two groups: Exercise and Fish Oil (EFO) and Exercise and Placebo (EP). Both groups undertook a resistance exercise programme over 14 weeks. All participants are instructed to ingest 4 g/day of food supplements; the EP group received sunflower oil capsules, and the EFO group, fish oil capsules. The cross-sectional area (CSA) of the quadriceps muscle is calculated using magnetic resonance imaging (MRI). The strength of the lower limbs is measured using isokinetic dynamometry. Both groups show improvements in CSA and strength after the intervention. Changes in EFO are significantly greater compared with EP for muscle strength (peak torque, 19.46 Nm and 5.74 Nm, respectively, p < 0.001). CSA increased after the intervention in both groups (EFO; 6.11% and EP; 2.91%), although there is no significant difference between the groups (p = 0.23). There are no significant intra-group, inter-group or time differences in any of the cytokines measured. The use of fish oil supplementation potentiates the neuromuscular response to the anabolic stimulus from training, increasing muscle strength and physical performance in sarcopenic older women.

GNRI And Conut Scores: Simple Predictors of Sarcopenia in Metastatic Colorectal Cancer Patients

OBJECTIVE

To evaluate the correlation between sarcopenia and inflammation- and nutrition-based markers in metastatic colorectal cancer (mCRC) patients.

MATERIALS AND METHODS

Age, body mass index (BMI), neutrophil/lymphocyte ratio (NLR), modified Glasgow prognostic score (mGPS), prognostic nutrition index (PNI), cachexia index (CIn), skeletal muscle index (SMI), controlling nutritional status (CONUT) score, and geriatric nutritional risk index (GNRI) were evaluated in 185 patients. Ideal cut-off values for the GNRI score were determined with the ROC curve analysis, and the patients were divided into two groups as low and high GNRI. Sarcopenia was diagnosed using CT scanning, the gold standard method. Univariate and multivariate Cox proportional hazard analyses were done based on the above-listed parameters to assess the correlation between sarcopenia and changes in immuno-nutrition and inflammatory response. Kaplan-Meier analysis was also done to evaluate survival.

RESULTS

Univariate analysis of the 185 patients based on the EGWSOP 2018 threshold values showed correlation between the presence of sarcopenia and male gender, diagnosed colon cancer, history of metastasectomy, BMI < 24, high mGPS score, PNI score ≥ 45, high CONUT score, and low GNRI score (p < 0.05). In multivariate analysis, low GNRI (HR: 2.40; 95% CI: 1.03-5.544; p = 0.040), and high-CONUT scores (HR: 2.01; 95% CI: 1.06-3.73; p = 0.029) were identified as independent prognostic factors for the presence of sarcopenia.

CONCLUSION

GNRI and CONUT scores are elementary and practical predictors for sarcopenia, a condition which is associated with poor outcomes in mCRC patients.

Effects of resistance training on body composition and physical function in elderly patients with osteosarcopenic obesity: a systematic review and meta-analysis

Osteosarcopenic obesity (OSO) is a complex disease commonly seen in the elderly. We found that resistance training may improve bone mineral density, skeletal muscle mass, and body fat percentage in patients with OSO. Therefore, resistance training is beneficial for elderly OSO patients and is worth being promoted.

PURPOSE

Investigate effects of resistance training on body composition and physical function in elderly osteosarcopenic obesity (OSO) patients.

METHODS

PubMed, Web of Science, Embase, Cochrane Library, Medline, SinoMed, CNKI, and Wanfang Database were searched from inception until October 13, 2021.Two independent researchers extracted the key information from each eligible study. The methodological quality of included studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. The Cochrane Risk of Bias Tool was used to assess the risk of bias. Grading of Recommendations Assessment Development and Evaluation (GRADE) was used to evaluate the quality of the outcomes. Sensitivity analysis indicated the stability of the results. Statistical analysis was performed using Review Manager 5.3.

RESULTS

Four randomized controlled studies meeting the inclusion criteria were included, with 182 participants. Twelve weeks of resistance training improved bone mineral density (BMD, mean difference (MD) = 0.01 g/cm², 95% confidence interval (CI): 0.001, 0.02, P = 0.03, I² = 0%), skeletal muscle mass (SMM, MD = 1.19 kg, 95% CI: 0.50, 1.89, P = 0.0007, I² = 0%), Z score, timed chair rise test (TCR), and body fat percentage (BFP, MD =  - 1.61%, 95% CI: - 2.94, - 0.28, P = 0.02, I² = 50%) but did not significantly affect skeletal muscle mass index (SMI, MD = 0.20 kg/m², 95% CI: - 0.25, 0.64, P = 0.38, I² = 0%) or gait speed (GS).

CONCLUSIONS

Resistance training is a safe and effective intervention that can improve many parameters, including BFP, SMM, and Z score, among OSO patients and is a good option for elderly individuals to improve their physical fitness.

Prevalence and prognostic value of preexisting sarcopenia in patients with mechanical ventilation: a systematic review and meta-analysis

Background

Sarcopenia is defined as age-related loss of muscle mass, strength, and/or function in the context of aging. Mechanical ventilation (MV) is one of the most frequently used critical care technologies in critically ill patients. The prevalence of preexisting sarcopenia and the clinical impact of its prognostic value on patients with MV are unclear. This review sought to identify the prevalence and prognostic value of preexisting sarcopenia on MV patient health outcomes.

Methods

Relevant studies were identified by searching MEDLINE, Embase, and the Cochrane library and were searched for all articles published as of December 2021. The prevalence of sarcopenia was determined using the authors' definitions from the original studies. Comparisons were made between patients who did and did not have sarcopenia for prognostic outcomes, including mortality, the number of days of MV, the length of intensive care unit stay, and the length of hospital stay. Odds ratios (ORs) and weighted mean differences with 95% confidence intervals (CIs) were used for pooled analyses of the relationships between sarcopenia and prognostic outcomes.

Results

The initial search identified 1333 studies, 17 of which met the eligibility criteria for the quantitative analysis, including 3582 patients. The pooled prevalence was 43.0% (95% CI 34.0–51.0%; I² = 96.7%). The pooled analyses showed that sarcopenia was related to increased mortality (OR 2.13; 95% CI 1.70, 2.67; I² = 45.0%), longer duration of MV (MD = 1.22; 95% CI 0.39, 2.05; I² = 97.0%), longer days of ICU stay (MD = 1.31; 95% CI 0.43, 2.19; I² = 97.0%), and hospital stay (MD 2.73; 95% CI 0.58, 4.88; I² = 98.0%) in patients with MV.

Conclusion

The prevalence of sarcopenia is relatively high in patients with MV, and it will have a negative impact on the prognosis of patients. However, further, large-scale, high-quality prospective cohort studies are required.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04015-y.

Sarcopenia and Myosteatosis Are Associated with Neutrophil to Lymphocyte Ratio but Not Glasgow Prognostic Score in Colorectal Cancer Patients

Cancer patients commonly present sarcopenia, myosteatosis, and systemic inflammation, which are risk factors of poor survival. In this study, sarcopenia and myosteatosis were defined from preoperative body computed tomography scans of 222 colorectal cancer (CRC) patients and analyzed in relation to tumor and patient characteristics, markers of systemic inflammation (modified Glasgow prognostic score (mGPS), neutrophil−lymphocyte ratio (NLR), serum levels of C-reactive protein (CRP), albumin, and 13 cytokines, and survival. Of the systemic inflammation markers, sarcopenia and/or myosteatosis associated with elevated NLR (p = 0.005) and low albumin levels (≤35 g/L) (p = 0.018), but not with mGPS or serum cytokine levels. In addition, myosteatosis was associated with a proximal tumor location (p = 0.039), serrated tumor subtype (p < 0.001), and severe comorbidities (p = 0.004). Multivariable analyses revealed that severe comorbidities and serrated histology were independent predictors of myosteatosis, and older age and elevated NLR were independent indicators of sarcopenia. Myosteatosis associated with shorter overall survival in univariable analysis (HR 1.959, 95% CI 1.24−3.10, p = 0.004) but not in multivariable analysis (p = 0.075). We conclude that sarcopenia and myosteatosis were associated with inflammatory marker NLR, but not with mGPS. Moreover, patients with serrated CRC may have an increased risk of myosteatosis. Myosteatosis or sarcopenia were not independent predictors of patient survival.

Higher Abdominal Adiposity Is Associated With Lower Muscle Strength in Chilean Adults

Handgrip strength (HGS) is a well-established indicator of muscle strength and a reasonable clinical predictor of metabolic health and diseases. This study explores the association between relative muscular strength and abdominal obesity (AO) in healthy Chilean adults. A convenience sample was recruited (n = 976) between 2018 and 2020. The HGS was determined by dynamometry. The anthropometry (weight, height, waist, and mid-arm circumference) and physical activity were also measured. The relative HGS (RHGS) was calculated by dividing the maximum HGS of the dominant hand by the body mass index. The AO was defined as a waist circumference (WC) >88 cm for women, and >102 cm for men. From the sample, 52.6% were women, 56.4% had excessive weight, and 42.7% had AO. The absolute and RHGS were greater in men compared to women (p < 0.001) and were decreased with age in both sexes. We observed a moderate negative correlation between WC and RHGS (rho = −0.54, and rho = −0.53, for men and women, respectively). The RHGS was lower in individuals with AO, independent of age and sex (p < 0.05). For each cm increase in WC, the odds of low RHGS (<25th percentile) increased by 12 and 9% for men and women, respectively. The AO is related to higher odds for low RHGS (OR: 1.72; 95% CI: 1.23–2.41). In our sample of healthy adults, a higher AO was associated with a lower muscle strength measured by dynamometry.

Vitamin D Supplementation Improves Handgrip Strength in Postmenopausal Women: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

In postmenopausal women, vitamin D deficiency (as defined by the circulating level of 25(OH)D being below 20 ng/ml (50 nmol/L)) is a regular occurrence. The effect of vitamin D supplementation on the muscle function of postmenopausal women has been controversial. This systematic review and meta-analysis of randomized controlled trials (RCTs) examines and summarizes the effects of vitamin D supplementation on the muscular strength and mobility of postmenopausal women.

METHODS

RCTs that met the inclusion criteria for this study were identified by searching PubMed, EMBASE, and the Cochrane Library. Postmenopausal women who were included in the study were exposed to RCTs assessing the effectiveness of vitamin D supplements. Meta-analysis data were extracted by two independent reviewers and screened for methodological quality. RCTs that did not meet the minimum requirement for assessment were excluded. In the meta-analysis, the effect size (weighted mean differences, WMD) of handgrip strength (HGS) and timed-up and go test (TUG) with a 95% confidence interval (CI) was obtained to compare reported results across the included RCTs.

RESULTS

A total of 19 trials were included in this systematic review, among which 13 trials were eligible for the meta-analysis. In the 13 included studies, supplementing with vitamin D produced a weighted mean difference of 0.876 kg (95% CI = 0.180 to 1.571, P = 0.014, I² = 68.5%) for HGS, a measurement of muscle strength. However, an insignificant decrease of 0.044 s was observed after analyzing the TUG (95% CI = -0.979 to 0.892, P = 0.927, I² = 95%). According to subgroup analysis, vitamin D supplementation increased HGS in patients over the age of 60 (P = 0.001), in those without calcium supplementation (P = 0.032), and in those whose baseline vitamin D level was greater than 75 nmol/L (30 ng/ml) (P = 0.003).

CONCLUSIONS

Taking into account the studies in this systematic review, vitamin D supplementation improved muscle strength in postmenopausal women. However, an insignificant result was demonstrated in terms of mobility after vitamin D supplementation.

The Risk of Presarcopenia Is Increased Among Female Patients With Primary Sjögren's Syndrome

OBJECTIVES

Sarcopenia is a progressive and generalized loss of muscle mass and function. The aim of this study was to evaluate the frequency of sarcopenia among patients with primary Sjögren's syndrome (SS) and the factors related with sarcopenia.

METHODS

Forty-four female patients with primary SS and 44 female control subjects were included in this cross-sectional study between February and August 2019. Sarcopenia was evaluated by the handgrip test, Skeletal Muscle Mass Index, and gait speed test.

RESULTS

Eleven patients (25.0%) had presarcopenia in the SS group and 2 (4.5%) in the control group (p = 0.007). Compared with control subjects, SS patients had lower results of hand grip and gait speed tests (p = 0.005 and p < 0.001, respectively). According to the Mini Nutritional Assessment Short Form, patients with presarcopenia had higher risk of malnutrition compared with patients without sarcopenia (p = 0.043). Patients with presarcopenia had higher scores in the European League Against Rheumatism Sjögren's Syndrome Patient-Reported Index pain domain and patient visual analog scale for global disease activity compared with patients without sarcopenia (p = 0.044 and p = 0.036, respectively). In multivariate regression analysis, European League Against Rheumatism Sjögren's Syndrome Patient-Reported Index pain was associated with hand grip strength (p = 0.016, R2 = 0.13) and Mini Nutritional Assessment Short Form was associated with Skeletal Muscle Mass Index (p = 0.005).

CONCLUSIONS

Risk of sarcopenia is increased in patients with SS. Pain and malnutrition may contribute to presarcopenia. Evaluating pain and patient's global disease activity may help physicians to determine patients with increased risk of sarcopenia. Controlling disease activity and pain and preventing malnutrition may reduce the risk of development of sarcopenia.

Oyster Hydrolysates Attenuate Muscle Atrophy via Regulating Protein Turnover and Mitochondria Biogenesis in C2C12 Cell and Immobilized Mice

Sarcopenia, also known as skeletal muscle atrophy, is characterized by significant loss of muscle mass and strength. Oyster (Crassostrea gigas) hydrolysates have anti-cancer, antioxidant, and anti-inflammation properties. However, the anti-sarcopenic effect of oyster hydrolysates remains uninvestigated. Therefore, we prepared two different oyster hydrolysates, namely TGPN and PNY. This study aimed to determine the anti-muscle atrophy efficacy and molecular mechanisms of TGPN and PNY on both C2C12 cell lines and mice. In vitro, the TGPN and PNY recovered the dexamethasone-induced reduction in the myotube diameters. In vivo, TGPN and PNY administration not only improved grip strength and exercise endurance, but also attenuated the loss of muscle mass and muscle fiber cross-sectional area. Mechanistically, TGPN and PNY increased the expression of protein synthesis-related protein levels via phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of the rapamycin pathway, and reduced the expression of protein degradation-related protein levels via the PI3K/Akt/forkhead box O pathway. Also, TGPN and PNY stimulated NAD-dependent deacetylase sirtuin-1(SIRT1), peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α), nuclear respiratory factor 1,2, mitochondrial transcription factor A, along with mitochondrial DNA content via SIRT1/PGC-1α signaling. These findings suggest oyster hydrolysates could be used as a valuable natural material that inhibits skeletal muscle atrophy via regulating protein turnover and mitochondrial biogenesis.

Association between biomarkers of bone health and osteosarcopenia among Iranian older people: The Bushehr Elderly Health (BEH) program

Background

Osteosarcopenia is referred to as co-incidence of osteoporosis/osteopenia and sarcopenia which is defined as a geriatric syndrome with a significant prevalence that increases morbidity and mortality. There are some relevant factors that can show an increased risk of incidence of osteosarcopenia.

Aim

We aimed to consider the association of bone turnover markers such as Osteocalcin (OC), C-terminal cross-linked telopeptide (CTX), Tartrate Resistant acid Phosphatase (TRAP), Bone Alkaline Phosphatase (BALP) and also other factors like vitamin D, calcium, phosphorous, and ALP with osteosarcopenia in elderly.

Methods

We carried out a cross-sectional study on a random sample including 400 elder participants of Bushehr Elderly Health (BEH) study, in Iran. Osteopenia/ osteoporosis was defined as a T-score ≤ -1.0 standard deviation below the mean values of a young healthy adult. We defined sarcopenia as low muscle strength (handgrip strength<26 kg for men and <18 kg for women) with reduced skeletal muscle mass [Skeletal muscle index (SMI) < 7.0 kg/m² for male and <5.4 kg/m² for female]. Osteosarcopenia was considered as the presence of both osteopenia/osteoporosis and sarcopenia. We estimated the age-standardized prevalence of osteosarcopenia for men and women, separately. We used multivariable logistic regression to address the factors associated with osteosarcopenia.

Results

The results showed that there was a statistically significant difference in OC), CTX, TRAP were between the osteosarcopenia (-) and osteosarcopenia (+) groups. No statistically significant difference was observed in BALP, vitamin D, calcium, phosphorous, and ALP between the compared groups.

In the multivariable logistic regression model, OC and CTX were associated with increased likelihood of osteosarcopenia [adjusted OR= 1.023(1.002-1.045 for OC, 4.363(1.389-15.474 for CTX)]. Furthermore, TRAP increases the odds of osteosarcopenia in crude model [OR= 1.333 (1.070- 1.660)].

Conclusions

We observed the association between bone turnover markers particularly OC, CTX and osteosarcopenia. Given the rapid growth of the aging population, we should focus on geriatric diseases such as musculoskeletal disorders. Bone turnover markers maybe improve the early diagnosis, screening and assess the response to therapies in people with osteosarcopenia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02608-w.

Effects of daily 1,000-IU vitamin D-fortified milk intake on skeletal muscle mass, power, physical function and nutrition status in Japanese

An intervention study was conducted to investigate the effects of daily 1,000-IU vitamin D-fortified milk intake on skeletal muscle mass, power, physical function and nutrition status in 26 healthy people and 8 older adults living in a nursing home. The serum 25-hydroxyvitamin D [25(OH)D] level was 13.4 ± 0.8 ng / mL and it markedly increased to 29.6 ± 0.9 ng / mL after daily 1000-IU vitamin D-fortified milk intake for 6 months. Handgrip strength (kg) also significantly increased in the 21-50 years and total groups, and male subjects, and the timed up and go test significantly improved in the 21-50 years and total groups, and female subjects after 6-month vitamin D intake. However, there were no significant differences between baseline and post-treatment in the Barthel Index (BI), walking speed (m / sec) or skeletal muscle mass (kg, % of BW, kg / m2). Therefore, the present study suggested that vitamin D-fortified milk intake is effective at improving muscle strength and physical function in Japanese, although further studies are needed, particularly for older adults. J. Med. Invest. 68 : 249-255, August, 2021.

Effects of Vitality Acupunch exercise on functional fitness and activities of daily living among probable sarcopenic older adults in residential facilities

PURPOSE

To test the effects of a Vitality Acupunch exercise program on the functional fitness and the ability to perform the activities of daily living (ADL) among older adults with probable sarcopenia in residential facilities.

DESIGN

This was a cluster-randomized controlled trial. A total of 12 long-term care facilities randomly assigned to the intervention and control groups with 1:1 allocation ratio. Among them, 114 older adults with probable sarcopenia participated at baseline and were allocated to either the intervention or control group according to the facility where they resided in. Of these, 103 older adults completed the study.

METHODS

The intervention group (n = 52) underwent the Vitality Acupunch exercise program three times a week, each lasting 40 min, for 6 months while the control group (n = 51) performed its routine daily activities.

FINDINGS

The functional fitness and ADL of the intervention group significantly improved at each time point (all p < 0.001), while the control group showed a significant decreasing trend. Except the lower limb muscular endurance, the functional fitness and ADL of the intervention group significantly improved compared to the control group at T1, and the improvements were still significant at T2.

CONCLUSIONS

Functional fitness and the ability to perform ADL in older adults with probable sarcopenia were significantly improved after receiving the Vitality Acupunch exercises.

CLINICAL RELEVANCE

An exercise that integrates the meridian theory and exercise concepts effectively improves functional fitness in probable sarcopenic older adults.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov (NCT04504786). The trial was first posted on August 7, 2020. This part of the data was collected from August 2020 to March 2021.

Sarcopenia, immune-mediated rheumatic diseases, and nutritional interventions

Introduction

Sarcopenia is defined by a loss of muscle mass and function associated with mortality, decreased physical performance, falls, and disability. Since chronic inflammation and decreased physical activity are risk factors for developing sarcopenia, it is critical to assess the role of sarcopenia in immune-mediated rheumatic diseases (IMRDs). Moreover, nutritional interventions are emerging as key modifiable and affordable options to improve physical performance in sarcopenia.

Objective

The aim of this review is to critically summarize current information on the evidence linking nutritional interventions and sarcopenia in IMRDs.

Methods

The search and selection of articles was performed in Medline, Dimensions.ai, Google Scholar, Cochrane Library, Epistemonikos, and Trip Database. The results were clustered into three areas: sarcopenia and IMRDs, sarcopenia and biological disease-modifying antirheumatic drugs (bDMARDs), and nutritional interventions for sarcopenia.

Findings

Several cross-sectional studies have shown a higher prevalence of sarcopenia in IMRDs, such as rheumatoid arthritis. Although not fully established, evidence linking sarcopenia and other IMRDs (ankylosing spondylitis and systemic sclerosis) has been also described. For secondary sarcopenia prevention and treatment, bDMARDs’ administration proved efficacy in patients with rheumatoid arthritis. Furthermore, there is growing evidence linking nutrition to the prevention and treatment of sarcopenia. Evidence linking unfavourable results in nutritional risk assessment, insufficient intake of protein, vitamin D, antioxidant nutrients, and long-chain polyunsaturated fatty acids and sarcopenia have been reported.

Conclusion

Given that sarcopenia and IMRDs have strong links, further research is needed to improve patient care.

Osteosarcopenic obesity in cardiovascular patients. Controversial and open issues

See “Inflammaging in the pathogenesis of chronic non-communicable diseases”, Kim O. T. in Opinion of invited editor, pp. 54-55.

The study of osteosarcopenic obesity (OSO) in patients with cardiovascular diseases (CVDs) in recent years has caused a dis-cussion on common pathogenesis of atherosclerosis, obesity, progressive loss of skeletal and muscle mass. Are these processes independent age-related conditions or comorbidities with common links of pathogenesis? The aim of this review was to analyze studies on OSO in patients with CVDs. We used following electronic databases: PubMed, Clinical Trials, Google Scholar, www.elibrary.ru. Based on this analysis, modern ideas on the etiology, epidemiology and pathogenesis of OSO in elderly and senile patients with atherosclerosis were described. The authors concluded that absence of standards for OSO diagnosis and inadequate clinical suspicion of specialists during routine examination is one of the main causes of its insufficient detection in elderly patients with CVDs. The results of analyzed studies allow us to consider the OSO and atherosclerotic changes as a single link of cardiovascular continuum. Eliminating the negative effect of chronic inflammation on human body should be considered as a key mechanism in the treatment of OSO and atherosclerosis. However, more research is needed in this area.

Exercise Experiences of Older Adults with Diabetes and Sarcopenia: A Phenomenological Study

Sarcopenia is a common and progressive skeletal muscle condition, often described as an intermediate stage in the development of frailty and disability in patients with diabetes. This can be improved through physical activity and exercise. This descriptive phenomenological study explored the exercise experiences of older adults with diabetes and sarcopenia. Individual interviews were conducted following semi-structured interview guidelines, and narratives were analyzed using Giorgi's method. Data saturation was achieved after interviewing 14 purposively sampled older patients with diabetes and sarcopenia. The study identified three main themes: encountering difficulty during exercise, recognizing the advantages of exercise, and constructing a suitable exercise model. While older adults with diabetes and sarcopenia may encounter difficulty during exercise, they also experience positive feedback from exercise. Understanding the limitations of older adults, individualizing exercise models based on their exercise experiences, and providing appropriate interventions and necessary emotional support can effectively prevent diabetes and sarcopenia.

Lipophorin receptor 1 (LpR1) in Drosophila muscle influences life span by regulating mitochondrial aging

Sarcopenia is a syndrome characterized by progressive loss of muscle mass and function during aging. Although mitochondrial dysfunction and related metabolic defects precede age-related changes in muscle, their contributions to muscle aging are still not well known. In this study, we used a Drosophila model to investigate the role of lipophorin receptors (LpRs), a Drosophila homologue of the mammalian very low-density lipoprotein receptor (VLDLR), in mitochondrial dynamics and muscle aging. Muscle-specific knockdown of LpR1 or LpR2 resulted in mitochondrial dysfunction and reduced proteostasis, which contributed to muscle aging. Activation of AMP-activated protein kinase (AMPK) ameliorated muscle dysfunction induced by LpR1 knockdown. These results suggest that LpR1/VLDLR is a novel key target that modulates age-dependent lipid remodeling and muscle homeostasis.

T-Score and Handgrip Strength Association for the Diagnosis of Osteosarcopenia: A Systematic Review and Meta-Analysis

BACKGROUND

Osteosarcopenia is a recently identified condition caused by the coexistence of osteoporosis and sarcopenia that affects the frail elderly population, leading to an increased risk of falls and fractures. Given the recent socio-economic interest associated with osteosarcopenia, the aim of this meta-analysis is to provide an overview of the factors potentially involved in its pathogenesis, assessing its population type, prevalence, and associated variables.

METHODS

A comprehensive systematic search for relevant studies, published from 2015 to 2020, was performed by using PubMed, EMBASE, and Cochrane databases. We analysed the variables of age, vitamin D, handgrip, and T-score in four different groups: healthy, osteopenic-osteoporotic, sarcopenic, and osteosarcopenic.

RESULTS

A total of 6504 patients from 16 studies were included in the final meta-analysis. The analysis of the individual variables reveals a statistically significant correlation between the handgrip test data and T-score (p < 0.001).

CONCLUSIONS

The correlation between T-score values and handgrip strength suggests a new potential parameter in the development of predictive models that could be used in clinical practice, highlighting its importance for the diagnosis of osteosarcopenia.

Sarcopenia and mortality in different clinical conditions: A meta-analysis

OBJECTIVES

Sarcopenia is recognized to be a health problem which is as serious as obesity, but its relevance to mortality is unclear. We conducted a meta-analysis of cohort studies on lean mass and mortality in populations with different health conditions.

METHODS

In this study, a systematic search of PubMed, Cochrane Library and Embase was performed for cohort studies published before Dec 20, 2017 which examined the relationship between lean mass and mortality. We included studies reporting lean mass measurement by dual-energy X-ray absorptiometry, bioimpedance analysis or computed tomography, as continuous (per standard deviation [SD] decrease) or binary variables (using sarcopenia cutoffs). We excluded studies which used muscle mass surrogates, anthropometric measurement of muscle, rate of change in muscle mass, and sarcopenia defined by composite criteria. The primary study outcome was all-cause mortality. Pooled hazard ratio estimates were calculated using a random effects model.

RESULTS

A total of 9602 articles were identified from the systematic search, and 188 studies with 98 468 participants from 34 countries were included in the meta-analysis. Of the 68 studies included in the present meta-analysis, the pooled HR was 1.36 and 1.74 for every SD decrease in lean mass and in people with low lean mass (cutoffs), respectively. Significant associations were also observed in elderly and all disease subgroups, irrespective of the measurement modalities.

CONCLUSIONS

Lower lean mass is robustly associated with increased mortality, regardless of health conditions and lean mass measurement modalities. This meta-analysis highlighted low lean mass as a key public health issue.

Effect of Sarcopenia Status on Disability Incidence Among Japanese Older Adults

OBJECTIVES

The updated definition of sarcopenia by the European Working Group on Sarcopenia in Older People (EWGSOP2) recommends both low muscle mass and quality to diagnose sarcopenia; concurrent poor physical performance is considered indicative of severe sarcopenia; however, the relationship between the revised definition and disability incidence among Japanese older adults is unclear. Therefore, we aimed to examine the associations between EWGSOP2-defined sarcopenia and disability incidence among community-dwelling older Japanese adults.

DESIGN

Nationwide study.

SETTING AND PARTICIPANTS

We included 4561 individuals aged ≥65 years and enrolled in the National Center for Geriatrics and Gerontology-Study of Geriatric Syndromes (NCGG-SGS).

METHODS

Skeletal muscle mass was assessed using a bioimpedance analysis device; handgrip strength and walking speed were measured as physical performance indicators. We used the Asian Working Group for Sarcopenia cutoffs to define low muscle mass and poor physical performance. We stratified all participants into nonsarcopenia, sarcopenia, and severe sarcopenia groups. Disability incidence was prospectively determined over 49 months using data extracted from the Japanese long-term care insurance system.

RESULTS

The prevalence of sarcopenia and severe sarcopenia was 3.4% and 1.7%, respectively. Participants with any form of sarcopenia were at a higher risk of disability [hazard ratio (HR) 1.78, 95% confidence interval (CI) 1.27-2.49]. Although participants with severe sarcopenia showed a higher risk of disability (HR 2.00, 95% CI 1.32-3.02), there was no significant disability risk in the sarcopenia group (HR 1.54, 95% CI 0.97-2.46). Grip strength (HR 0.96, 95% CI 0.94-0.98) and walking speed (HR 0.19, 95% CI 0.12-0.30) negatively correlated with disability incidence.

CONCLUSIONS AND IMPLICATIONS

Severe sarcopenia, involving low muscle mass and poor physical performance, might increase disability risk in older adults, as opposed to low muscle mass alone. Further studies are needed to determine whether sarcopenia without poor physical performance increases disability risk.

Bimagrumab vs Optimized Standard of Care for Treatment of Sarcopenia in Community-Dwelling Older Adults: A Randomized Clinical Trial

IMPORTANCE

The potential benefit of novel skeletal muscle anabolic agents to improve physical function in people with sarcopenia and other muscle wasting diseases is unknown.

OBJECTIVE

To confirm the safety and efficacy of bimagrumab plus the new standard of care on skeletal muscle mass, strength, and physical function compared with standard of care alone in community-dwelling older adults with sarcopenia.

DESIGN, SETTING, AND PARTICIPANTS

This double-blind, placebo-controlled, randomized clinical trial was conducted at 38 sites in 13 countries among community-dwelling men and women aged 70 years and older meeting gait speed and skeletal muscle criteria for sarcopenia. The study was conducted from December 2014 to June 2018, and analyses were conducted from August to November 2018.

INTERVENTIONS

Bimagrumab 700 mg or placebo monthly for 6 months with adequate diet and home-based exercise.

MAIN OUTCOMES AND MEASURES

The primary outcome was the change in Short Physical Performance Battery (SPPB) score after 24 weeks of treatment. Secondary outcomes included 6-minute walk distance, usual gait speed, handgrip strength, lean body mass, fat body mass, and standard safety parameters.

RESULTS

A total of 180 participants were recruited, with 113 randomized to bimagrumab and 67 randomized to placebo. Among these, 159 participants (88.3%; mean [SD] age, 79.1 [5.3] years; 109 [60.6%] women) completed the study. The mean SPPB score increased by a mean of 1.34 (95% CI, 0.90 to 1.77) with bimagrumab vs 1.03 (95% CI, 0.53 to 1.52) with placebo (P = .13); 6-minute walk distance increased by a mean of 24.60 (95% CI, 7.65 to 41.56) m with bimagrumab vs 14.30 (95% CI, -4.64 to 33.23) m with placebo (P = .16); and gait speed increased by a mean of 0.14 (95% CI, 0.09 to 0.18) m/s with bimagrumab vs 0.11 (95% CI, 0.05 to 0.16) m/s with placebo (P = .16). Bimagrumab was safe and well-tolerated and increased lean body mass by 7% (95% CI, 6% to 8%) vs 1% (95% CI, 0% to 2%) with placebo, resulting in difference of 6% (95% CI, 4% to 7%) (P < .001).

CONCLUSIONS AND RELEVANCE

This randomized clinical trial found no significant difference between participants treated with bimagrumab vs placebo among older adults with sarcopenia who had 6 months of adequate nutrition and light exercise, with physical function improving in both groups. Bimagrumab treatment was safe, well-tolerated, increased lean body mass, and decreased fat body mass. The effects of sarcopenia, an increasing cause of disability in older adults, can be reduced with proper diet and exercise.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02333331; EudraCT number: 2014-003482-25.

Effect of Aerobic Exercise Training and Deconditioning on Oxidative Capacity and Muscle Mitochondrial Enzyme Machinery in Young and Elderly Individuals

Mitochondrial dysfunction is thought to be involved in age-related loss of muscle mass and function (sarcopenia). Since the degree of physical activity is vital for skeletal muscle mitochondrial function and content, the aim of this study was to investigate the effect of 6 weeks of aerobic exercise training and 8 weeks of deconditioning on functional parameters of aerobic capacity and markers of muscle mitochondrial function in elderly compared to young individuals. In 11 healthy, elderly (80 ± 4 years old) and 10 healthy, young (24 ± 3 years old) volunteers, aerobic training improved maximal oxygen consumption rate by 13%, maximal workload by 34%, endurance capacity by 2.4-fold and exercise economy by 12% in the elderly to the same extent as in young individuals. This evidence was accompanied by a similar training-induced increase in muscle citrate synthase (CS) (31%) and mitochondrial complex I–IV activities (51–163%) in elderly and young individuals. After 8 weeks of deconditioning, endurance capacity (−20%), and enzyme activity of CS (−18%) and complex I (−40%), III (−25%), and IV (−26%) decreased in the elderly to a larger extent than in young individuals. In conclusion, we found that elderly have a physiological normal ability to improve aerobic capacity and mitochondrial function with aerobic training compared to young individuals, but had a faster decline in endurance performance and muscle mitochondrial enzyme activity after deconditioning, suggesting an age-related issue in maintaining oxidative metabolism.

DNA methylation across the genome in aged human skeletal muscle tissue and muscle-derived cells: the role of HOX genes and physical activity

Skeletal muscle tissue demonstrates global hypermethylation with age. However, methylome changes across the time-course of differentiation in aged human muscle derived cells, and larger coverage arrays in aged muscle tissue have not been undertaken. Using 850K DNA methylation arrays we compared the methylomes of young (27 ± 4.4 years) and aged (83 ± 4 years) human skeletal muscle and that of young/aged heterogenous muscle-derived human primary cells (HDMCs) over several time points of differentiation (0, 72 h, 7, 10 days). Aged muscle tissue was hypermethylated compared with young tissue, enriched for; pathways-in-cancer (including; focal adhesion, MAPK signaling, PI3K-Akt-mTOR signaling, p53 signaling, Jak-STAT signaling, TGF-beta and notch signaling), rap1-signaling, axon-guidance and hippo-signalling. Aged cells also demonstrated a hypermethylated profile in pathways; axon-guidance, adherens-junction and calcium-signaling, particularly at later timepoints of myotube formation, corresponding with reduced morphological differentiation and reductions in MyoD/Myogenin gene expression compared with young cells. While young cells showed little alterations in DNA methylation during differentiation, aged cells demonstrated extensive and significantly altered DNA methylation, particularly at 7 days of differentiation and most notably in focal adhesion and PI3K-AKT signalling pathways. While the methylomes were vastly different between muscle tissue and HDMCs, we identified a small number of CpG sites showing a hypermethylated state with age, in both muscle tissue and cells on genes KIF15, DYRK2, FHL2, MRPS33, ABCA17P. Most notably, differential methylation analysis of chromosomal regions identified three locations containing enrichment of 6–8 CpGs in the HOX family of genes altered with age. With HOXD10, HOXD9, HOXD8, HOXA3, HOXC9, HOXB1, HOXB3, HOXC-AS2 and HOXC10 all hypermethylated in aged tissue. In aged cells the same HOX genes (and additionally HOXC-AS3) displayed the most variable methylation at 7 days of differentiation versus young cells, with HOXD8, HOXC9, HOXB1 and HOXC-AS3 hypermethylated and HOXC10 and HOXC-AS2 hypomethylated. We also determined that there was an inverse relationship between DNA methylation and gene expression for HOXB1, HOXA3 and HOXC-AS3. Finally, increased physical activity in young adults was associated with oppositely regulating HOXB1 and HOXA3 methylation compared with age. Overall, we demonstrate that a considerable number of HOX genes are differentially epigenetically regulated in aged human skeletal muscle and HDMCs and increased physical activity may help prevent age-related epigenetic changes in these HOX genes.

Physical activity and sarcopenia in older adults

BACKGROUND

Sarcopenia is prevalent in ever growing older adult populations.

AIM

The aim of this study was to quantify the association between physical activity (PA), sedentary time (SED), cardiorespiratory fitness (CRF), and strength (STR) with sarcopenia in community-dwelling older adults using a standard definition of sarcopenia.

METHOD

This cross-sectional study examined a large group of older adults (n = 304) who provided a broad range of health, lifestyle, and socioeconomic variables. PA was assessed using a pedometer worn for 7 days. SED was assessed by survey. CRF was assessed by 400-m walk test performance. Strength (STR) was assessed by one-repetition maximum chest and leg press. The European Working Group on Sarcopenia in Older People (EWGSOP) definition defined 10.9% (n = 33) as sarcopenic.

RESULTS

PA, CRF, and STR were significantly associated with sarcopenia components (muscle mass, muscle strength, and muscle function). The upper two-thirds of CRF had significantly lower odds of having sarcopenia, whereas the strongest third of STR was associated with lower odds of sarcopenia. All exposure variables had significant odds ratios associated with at least one component of sarcopenia. Joint analyses indicated additional benefit may be gained from being both active (≥ 5000 daily steps) and fit (top two-thirds), active and strong (top two-thirds), and fit and strong.

DISCUSSION

Overall, objectively measured PA, CRF, and STR, and self-reported SED, are associated with sarcopenia and its components.

CONCLUSION

Therefore, older adults who are physically active, maintain higher levels of cardiorespiratory fitness, upper and lower body strength, and avoid sedentary time may have significantly lower odds of sarcopenia.

Prognostic role of pre-sarcopenia and body composition with long-term outcomes in obstructive colorectal cancer: a retrospective cohort study

Background

The clinical significance of pre-sarcopenia in colorectal cancer obstruction has not yet been described. The present study aimed to determine the short- and long-term oncologic impacts of pre-sarcopenia in obstructive colorectal cancer.

Methods

We retrospectively analyzed 214 patients with obstructive colon cancer between January 2004 and December 2013. Initial staging computed tomography (CT) scans identified pre-sarcopenia and visceral obesity by measuring the muscle and visceral fat areas at the third lumbar vertebra level. Both short-term postoperative and long-term oncologic outcomes were analyzed.

Results

Among all 214 patients, 71 (33.2%) were diagnosed with pre-sarcopenia. Pre-sarcopenia had a negative oncologic impact in both disease-free survival (DFS) and overall survival (OS), (hazard ratio [HR] = 1.86, 95% confidence interval [CI] 1.04–3.13, p = 0.037, and HR = 1.92, CI 1.02–3.60, p = 0.043, respectively). Visceral adiposity, body mass index (BMI), and neutrophil-lymphocyte ratio (NLR) did not significantly impact DFS and OS.

Conclusion

Pre-sarcopenia is a clinical factor significantly associated with OS and DFS but not with short-term complications in obstructive colorectal cancer. In future, prospective studies should incorporate body composition data in patient risk assessments and oncologic prediction tools.

The external phenotype of aging

Aging is widely studied as a physiological process. Segmental aging can also occur prematurely in Mendelian disorders, and these can act this way as excellent sources of information, specifically for the underlying mechanisms. Adequate recognition of such aging characteristics in Mendelian disorders needs a well-defined phenotype of aging. Here the external phenotype of aging is described that can be recognized in the consulting room without major additional studies. Existing definitions of the signs and symptoms in Elements of Morphology or Human Phenotype Ontology are added or a new definition is suggested if none is available.

Preserved Capacity for Adaptations in Strength and Muscle Regulatory Factors in Elderly in Response to Resistance Exercise Training and Deconditioning

Aging is related to an inevitable loss of muscle mass and strength. The mechanisms behind age-related loss of muscle tissue are not fully understood but may, among other things, be induced by age-related differences in myogenic regulatory factors. Resistance exercise training and deconditioning offers a model to investigate differences in myogenic regulatory factors that may be important for age-related loss of muscle mass and strength. Nine elderly (82 ± 7 years old) and nine young, healthy persons (22 ± 2 years old) participated in the study. Exercise consisted of six weeks of resistance training of the quadriceps muscle followed by eight weeks of deconditioning. Muscle biopsy samples before and after training and during the deconditioning period were analyzed for MyoD, myogenin, insulin-like growth-factor I receptor, activin receptor IIB, smad2, porin, and citrate synthase. Muscle strength improved with resistance training by 78% (95.0 ± 22.0 kg) in the elderly to a similar extent as in the young participants (83.5%; 178.2 ± 44.2 kg) and returned to baseline in both groups after eight weeks of deconditioning. No difference was seen in expression of muscle regulatory factors between elderly and young in response to exercise training and deconditioning. In conclusion, the capacity to gain muscle strength with resistance exercise training in elderly was not impaired, highlighting this as a potent tool to combat age-related loss of muscle function, possibly due to preserved regulation of myogenic factors in elderly compared with young muscle.

The effect of vitamin D on sarcopenia depends on the level of physical activity in older adults

OBJECTIVE

Sarcopenia in older adults is closely related to vitamin D deficiency and reduced levels of physical activity, but little has been reported on the interaction between physical activity and the positive effects of vitamin D. The purpose of this study was to explore the interactive effect of vitamin D and physical activity on muscle mass and function through animal experiments and population surveys.

METHODS

Male 4-week-old C57BL/6J mice were fed different purified diets: a vitamin D-deficient diet (with increased calcium and phosphorus to prevent the effects of abnormal mineral levels on muscle) or a 1,25-dihydroxyvitamin D3 (1,25D)-supplemented diet. After 24 weeks on the assigned diets, the mice were immobilized. The level of skeletal muscle atrophy in the mice was determined by grip strength, gastrocnemius (GA) muscle mass and muscle fiber cross-sectional area (CSA); additionally, the protein expression levels of FOXO3a and the E3 ubiquitin ligases MuRF1 and MAFbx were detected. A cross-sectional study included data from 4139 older adults (64.9% women, 67.9 ± 6.7 years) as part of a survey in Shenyang, Northeast China. The associations of serum 25(OH)D3 and physical activity with timed up and go test (TUG) performance, handgrip strength, calf circumference, and body muscle mass were assessed by a linear regression analysis that was adjusted for covariates.

RESULTS

In activity-limited mice, vitamin D deficiency accelerated the decrease in GA muscle weight, muscle fiber CSA, and grip strength and increased the protein expression of MuRF1, MAFbx, and FOXO3a (all P < 0.05). In addition, 1,25D supplementation may inhibit the grip-strength reduction induced by limited activity (P = 0.069). Serum 25(OH)D3 and physical activity were linearly related to TUG time (P < 0.001) and handgrip strength (P < 0.05) after adjustment for sex, age, body mass index (BMI), education level, smoking status, and serum calcium level. Serum 25(OH)D3 and physical activity had interactive effects on TUG (P < 0.001) and handgrip strength (P < 0.05) but not calf circumference or body muscle mass in older adults.

CONCLUSIONS

The effect of vitamin D on muscle strength and physical performance depends on physical activity level in the elderly. It is recommended that older adults strive to avoid both physical inactivity and vitamin D deficiency. Because physical inactivity and vitamin D deficiency may exacerbate muscle atrophy, the biological mechanism may involve synergistic effects of vitamin D and physical activity on the promotion of muscle protein ubiquitination and degradation.

Cell-autonomous and non-autonomous roles of daf-16 in muscle function and mitochondrial capacity in aging C. elegans

Sarcopenia, defined as the loss of skeletal muscle mass and strength, contributes to disability and health-related conditions with aging. In vitro studies indicate that age-related mitochondrial dysfunction could play a central role in the development and progression of sarcopenia, but because of limitations in the methods employed, how aging affects muscle mitochondrial function in vivo is not fully understood. We use muscle-targeted fluorescent proteins and the ratiometric ATP reporter, ATeam, to examine changes in muscle mitochondrial mass and morphology, and intracellular ATP levels in C. elegans. We find that the preserved muscle function in aging daf-2 mutants is associated with higher muscle mitochondrial mass, preserved mitochondrial morphology, and higher levels of intracellular ATP. These phenotypes require the daf-16/FOXO transcription factor. Via the tissue-specific rescue of daf-16, we find that daf-16 activity in either muscle or neurons is sufficient to enhance muscle mitochondrial mass, whereas daf-16 activity in the muscle is required for the enhanced muscle function and mobility of the daf-2 mutants. Finally, we show through the use of drugs known to enhance mitochondrial activity that augmenting mitochondrial function leads to improved mobility during aging. These results suggest an important role for mitochondrial function in muscle aging.

Relative Handgrip Strength Diminishes the Negative Effects of Excess Adiposity on Dependence in Older Adults: A Moderation Analysis

The adverse effects of fat mass on functional dependence might be attenuated or worsened, depending on the level of muscular strength. The aim of this study was to determine (i) the detrimental effect of excess adiposity on dependence in activities of daily living (ADL), and (ii) whether relative handgrip strength (HGS) moderates the adverse effect of excess adiposity on dependence, and to provide the threshold of relative HGS from which the adverse effect could be improved or worsened. A total of 4169 participants (69.3 ± 7.0 years old) from 244 municipalities were selected following a multistage area probability sampling design. Measurements included anthropometric/adiposity markers (weight, height, body mass index, waist circumference, and waist-to-height ratio (WHtR)), HGS, sarcopenia “proxy” (calf circumference), and ADL (Barthel Index scale). Moderation analyses were performed to identify associations between the independent variable (WHtR) and outcomes (dependence), as well as to determine whether relative HGS moderates the relationship between excess adiposity and dependence. The present study demonstrated that (i) the adverse effect of having a higher WHtR level on dependence in ADL was moderated by relative HGS, and (ii) two moderation thresholds of relative HGS were estimated: 0.35, below which the adverse effect of WHtR levels on dependency is aggravated, and 0.62, above which the adverse effect of fat on dependency could be improved. Because muscular strength represents a critically important and modifiable predictor of ADL, and the increase in adiposity is inherent in aging, our results underscore the importance of an optimal level of relative HGS in the older adult population.

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

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

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

BACKGROUND

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

AIM

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

DESIGN

Cross-sectional study.

SETTING

Division of Physical and Rehabilitation Medicine.

POPULATION

We studied 350 women with subacute hip fracture.

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL REHABILITATION IMPACT

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

Age-related decrease in muscle satellite cells is accompanied with diminished expression of early growth response 3 in mice

Skeletal muscle regeneration is mostly dependent on muscle satellite cells. Proper muscle regeneration requires enough number of satellite cells. Recent studies have suggested that the number of satellite cells in skeletal muscle declines as we age, leading to the impairment of muscle regeneration in older population. Our earlier study demonstrated that zinc finger transcription factor early growth response 3 (Egr3) plays an important role for maintaining the number of myoblasts, suggesting that age-related decrease in muscle satellite cell should be associated with the expression levels of Egr3. The aim of this study was to investigate whether aging would alter the Egr3 expression in satellite cells. A couple groups of male C57BL/6J mice were examined in this study: young (3 Mo) and old (17 Mo). Immunohistochemical staining showed that the satellite cell number decreased in normal and injured muscles of old mice. In fluorescence-activated cell sorting-isolated muscle satellite cells from normal and injured muscles, the mRNA expression of Egr3 was significantly decreased with age regardless of injury. In harmony with these results, Pax7 mRNA levels also decreased in the satellite cells from old mice. Alternatively, inhibition of Egr3 expression by shRNA decreased Pax7 protein expression in cultured myoblasts. These results suggest that Egr3 is associated with the age-related decline of muscle satellite cells in older population. Also, Egr3 might be implicated in the regulation of Pax7. Therefore, the loss of Egr3 expression may elucidate attenuated MSCs function and muscle regeneration in older age.

Recent Issues on Body Composition Imaging for Sarcopenia Evaluation

Recently, sarcopenia has garnered renewed interest. Sarcopenia is a disease characterized by decreased skeletal muscle mass and strength/function, which can impair the quality of life and increase physical disability, adverse metabolic effects, and mortality. Imaging tools for evaluating and diagnosing sarcopenia have developed rapidly. Radiologists should be aware of sarcopenia and its clinical implications. We review current knowledge about sarcopenia, its pathophysiological impact, and advantages and disadvantages of methods for evaluation of sarcopenia focusing on body composition imaging modalities such as whole-body dual-energy X-ray absorptiometry, CT, and MRI. Controversial issues are discussed, including the lack of consensus and standardization of the disease definition, imaging modality, measurement methods, and diagnostic cutoff points.

Gait speed as a mediator of the effect of sarcopenia on dependency in activities of daily living

BACKGROUND

Sarcopenia in older adults is strongly associated with an increase in dependency in activities of daily living (ADL) and with a decline in gait speed. Interestingly, gait speed has been shown to independently predict mortality. In this context, our study aimed to explore the mediator role of gait speed on the relationship between sarcopenia and dependency in ADL.

METHODS

A cross-sectional study was conducted in Colombia, 19 705 older adults with a mean age of 70 years, 55.6% women, 16.1% with sarcopenia, and 14.7% mild, moderate, or severe dependency in ADL, according to 'SABE Survey 2015'. Sarcopenia was assessed by calf circumference and ADL dependence through the Barthel Index. Gait speed was measured over a distance of 3 m. The association between sarcopenia condition and gait speed and dependency level was analysed by linear regression adjusted by covariates. To examine whether gait speed mediated the association between sarcopenia and dependence components of physical function, simple mediation models were generated using ordinary least squares with the macro PROCESS version 3.2, adjusted for age, sex, and body mass index (BMI).

RESULTS

Significant differences (P < 0.05) were found in gait speed and dependency in ADL between the sarcopenia and non-sarcopenia groups after adjusting for age, sex, and BMI. BMI was significantly higher in the non-sarcopenia group whereas dependency was significantly higher in the sarcopenia group (19.6% vs. 13.8%). Results from mediation model regression analysis indicated a significant and direct detrimental effect of sarcopenia on dependency in ADL (β = -0.05; P < 0.001), and a significant indirect effect of gait speed on the direct effect (-0.009 to -0.004).

CONCLUSIONS

The negative effect of sarcopenia on functional dependence was mediated by the gait speed. Therefore, gait speed may positively influence the detrimental effect of sarcopenia for dependency, after adjusting for age, gender, and BMI. Consequently, physical exercise should be promoted and focused to circumvent the gait speed decline associated with age in older people with sarcopenia.