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

Applicability of the masseter muscle as a nutritional biomarker

Nutritional assessment is feasible with computed tomography anthropometry. The abdominal muscle at the L3 vertebra is a well-known nutritional biomarker for predicting the prognosis of various diseases, especially sarcopenia. However, studies on nutritional assessment of the brain using computed tomography are still scarce. This study aimed to investigate the applicability of the masseter muscle as a nutritional biomarker.Patients who underwent simultaneous brain and abdominopelvic computed tomography in the emergency department was retrospectively analyzed. We assessed their masseter muscle 2 cm below the zygomatic arch and abdominal muscle at L3 via computed tomography anthropometry. The skeletal muscle index, prognostic nutritional index, and other nutritional biomarkers were assessed for sarcopenia using the receiver operating characteristic curve analysis.A total of 314 patients (240 men and 72 women) were analyzed (mean age, 50.24 years; mean areas of the masseter and abdominal muscles, 1039.6 and 13478.3 mm, respectively). Masseter muscle areas significantly differed in sarcopenic, obese, and geriatric patients (P < .001). The areas under the curve of the masseter muscle in sarcopenic, geriatric, and obese patients were 0.663, 0.686, and 0.602, respectively. Multivariable linear regression analysis showed a correlation with the abdominal muscle area, weight, and age.The masseter muscle, analyzed via computed tomography anthropometry, showed a statistically significant association with systemic nutritional biomarkers, and its use as a nutritional biomarker would be feasible.

Sarcopenia and Back Muscle Degeneration as Risk Factors for Back Pain: A Comparative Study

Study Design

Case-control study.

Purpose

To investigate the independent associations of back pain with sarcopenia and with back muscle degeneration, and to introduce a new risk index for back muscle degeneration.

Overview of Literature

The Asian Working Group for Sarcopenia recommends diagnosis using handgrip strength, gait speed, and skeletal muscle mass. However, these criteria do not strongly reflect back muscle degeneration.

Methods

Patients who completed a questionnaire on back-pain between October 2016 and October 2017 were enrolled in this study. Appendicular skeletal muscle index (ASMI), cross-sectional area (CSA) index, fatty infiltration (FI) rate of the paraspinal muscles, and lumbar extensor strength index (LESI) were measured and compared between no back-pain and back-pain group. Correlations between LESI and ASMI, CSA index, and FI rate were analyzed. The back-pain group was further divided according to ASMI into sarcopenia and non-sarcopenia subgroups and by our newly developed back muscle degeneration risk index based on correlation coefficients between LESI and CSA index, FI rate. Differences in ASMI, CSA index, FI rate, LESI, and Visual Analog Scale (VAS) score between subgroups were analyzed.

Results

The ASMI, CSA index, FI rate, and LESI differed significantly between back-pain and pain-free groups. The LESI demonstrated the strongest correlation with FI rate. There were no significant differences in VAS score and back muscle degeneration index in the back-pain group when divided according to the presence of sarcopenia. However, there was a significant difference in VAS score between back-pain patients when classified according to high and low back muscle degeneration risk index.

Conclusions

We suggest that the degree of back pain is more strongly associated with back muscle degeneration than with sarcopenia. This back muscle degeneration risk index, reflecting both back muscle morphology and function, could be a useful parameter for evaluation of back pain and muscle degeneration.

Oral Management in Rehabilitation Medicine: Oral Frailty, Oral Sarcopenia, and Hospital-Associated Oral Problems

Oral health is a crucial but often neglected aspect of rehabilitation medicine. Approximately 71% of hospitalized rehabilitation patients and 91% of hospitalized acute care patients have impaired oral health. Poor oral condition in hospitalized patients can be attributed to factors such as age, physical dependency, cognitive decline, malnutrition, low skeletal muscle mass and strength, and multimorbidity. Another major factor is a lack of knowledge and interest in oral problems among health care workers. Recently, new concepts have been proposed, such as oral frailty, oral sarcopenia, and hospital-associated oral problems. Oral frailty, the accumulation of a slightly poor status of oral conditions and function, strongly predicts physical frailty, dysphagia, malnutrition, need for long-term care, and mortality in community-dwelling older adults. Oral sarcopenia refers to sarcopenia associated with oral conditions and function, although its definition has not yet been fully discussed. Hospital-associated oral problems are caused by disease, disease treatment, surgery, endotracheal intubation, poor self-care abilities, lack of care by medical staff, drugs, and iatrogenic factors during hospitalization. Furthermore, oral problems have negative impacts on rehabilitation outcomes, which include functional recovery, length of hospital stay, discharge home, and in-hospital mortality. Oral health management provided by dental hygienists improves not only oral status and function, swallowing function, and nutritional status but also activities of daily living, discharge home, and in-hospital mortality in post-acute rehabilitation. Oral rehabilitation, promotion, education, and medical-dental collaboration can be effective interventions for oral problems and therefore are necessary to improve rehabilitation outcomes.

SARC-F as a Useful Tool for Screening Sarcopenia in Elderly Patients with Hip Fractures

BACKGROUND

SARC-F is recommended as a sarcopenia screening tool and comprised of five assessment items: strength, assistance walking, rising from a chair, climbing stairs, and falls.

OBJECTIVE

The purpose of this study was to assess whether the SARC-F questionnaire in elderly patients with hip fractures was a valid screening tool for sarcopenia by comparison of the results with criteria from the Europe, Asia, and international working groups.

MEASUREMENTS

115 men and woman with hip fractures were assessed. The SARC-F self-reported questionnaire scores range from 0 to 10 and a score ≥ 4 defines sarcopenia. These survey questions were used to calculate the SARC-F score. Measurements, including appendicular muscle mass, were taken using dual-energy X-ray and grip strength using a dynamometer. Classification using the SARC-F score was compared using the consensus panel criteria from the international, European, and Asian sarcopenia working groups. The performance of all four methods was compared by examining the predictive ability using a ROC curve.

RESULTS

A total of 115 subjects were included and the sarcopenia prevalence rate (SARC-F score ≥ 4) was 63.5 percent. The sensitivity, specificity, positive predictive value, negative predictive value PPV with the EWGSOP-2 criteria in Older People as the reference standard were 95.35 %, 56.94 %, 56.94%, 95.35%, and 71.3%, respectively. In addition, we found similar results for sensitivity and specificity as studies using the EWGSOP and AWGS criteria.

CONCLUSIONS

The SARC-F questionnaire is a useful screening tool for elderly patients with hip fractures. This finding supports the recommendation of SARC-F as a screening tool for sarcopenia from the EWGSOP2.

Validation of the Danish SARC-F in Hospitalized, Geriatric Medical Patients

OBJECTIVES

Validation of the Danish version of the SARC-F (Strength, Assistance in walking, Rise from a chair, Climb stairs, and Falls) for hospitalized geriatric medical patients, compared against the original EWGSOP (European Working Group on Sarcopenia in Older People) and revised EWGSOP2 definition for sarcopenia. Additionally, investigation of the ability of SARC-F to individually identify low strength/function and muscle mass.

DESIGN

Cross-sectional analysis of data from an RCT.

SETTING

Hospital, Medical Department.

PARTICIPANTS

122 geriatric medical patients (65.6% women) ≥ 70 years of age with mixed medical conditions.

MEASUREMENTS

SARC-F screening, diagnostic assessment of sarcopenia (hand-grip strength, muscle mass measured by dual-frequency bio-impedance analysis, and 4-m usual gait speed).

RESULTS

The prevalence of risk of sarcopenia (SARC-F ≥ 4) was 48.3%, while it was diagnosed in 65.8% and 21.7%, with EWGSOP and EWGSOP2, respectively. The sensitivity, specificity, positive predictive value, negative predictive value according to EWGSOP were 50.0 %, 53.7 %, 67.2% and 36.1%, while they were 53.8 %, 53.2 %, 24.1% and 80.6%, according to EWGSOP2 (all participants). The ability of SARC-F to predict reduced strength, function, and muscle mass was modest. There was a significant negative linear, yet weak, relationship between total SARC-F score and hand-grip strength (R2=0.033) and 4-m gait speed (R2=0.111), but not muscle mass (R2=0.004).

CONCLUSION

SARC-F does not seem to be a suitable screening tool for identifying and excluding non-sarcopenic geriatric patients. Furthermore, the SARC-F score was more strongly correlated with reduced muscle strength and physical function than with low muscle mass.

Prevalence of sarcopenic obesity in adults with end-stage knee osteoarthritis

OBJECTIVE

To identify the prevalence of sarcopenic obesity, a phenotype of low muscle mass and high adiposity, in adults with end-stage knee osteoarthritis (OA). Various diagnostic criteria, including assessment of muscle/fat mass, muscle strength and physical function, were used to identify patients with and without sarcopenic obesity, and to compare outcomes of pain, function and quality of life.

DESIGN

Cross-sectional clinical study including adults with a body mass index (BMI) ≥30 kg/m² and knee OA. Body composition was measured by dual-energy X-ray absorptiometry (DXA). Assessments included gait speed, handgrip strength, six minute walk test, and self-reported pain, physical function, and health-related quality of life using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and EuroQol Foundation (EQ-5D).

RESULTS

151 adults (59% female) aged 65.1 ± 7.9 years, mean BMI 37.1 ± 5.5 kg/m², were included. Prevalence of sarcopenic obesity using diagnostic cut-offs of appendicular skeletal muscle mass (ASM) relevant to height², weight and BMI varied from 1.3% (95% confidence interval (CI): 0.2-4.7%) to 14.6% (9.4-21.2%) and 27.2% (20.2-35%), respectively. A combined diagnostic approach including low ASM with either low strength or low function yielded a prevalence of 8.6% (4.7-14.3%). Sarcopenic obesity influenced walking speed, endurance, strength, and patient-reported difficulty with self-care activities, regardless of diagnostic approach.

CONCLUSION

Prevalence of sarcopenic obesity varied depending on diagnostic criteria. Given the impact of this condition and OA on physical function, we suggest a combined diagnostic approach be used to clarify expected prevalence and enable early clinical identification and management of sarcopenic obesity in patients with knee OA.

Sarcopenia disease in Iran: an overview

BACKGROUND

Sarcopenia is a geriatric disease with adverse clinical outcomes, high rate of mortality and a major challenge to healthy elderly. This study aimed to undertake a survey to identify gaps and highlight strengths in sarcopenia research in order to progress research in this area for the next years in Iran.

METHODS

This study included all studies published from the beginning until the first of 2019 in national and international journals by Iranian authors conducted in the field of sarcopenia. The databases including MEDLINE (via PubMed), Web of Science and SCOPUS were used as the sources of information. All relevant available academic studies, including review articles, original articles, case reports, conference abstracts, and letters were included in the analysis.

FINDINGS

A total of 48 articles obtained and then categorized into six groups. These groups were; about Pathophysiology, Epidemiology of sarcopenia, Screening of sarcopenia, Nutrition, Physical activity and Association of Sarcopenia and Other Diseases that briefly findings of each study had been described. These findings showed that the prevalence of sarcopenia was 16.5% to 32.5%, using different definitions. A study developed and validated a screening model for identifying people with sarcopenia. Lifestyle changes such as diet can be appropriate strategies for the prevention of sarcopenia and also, physical activity is considered to be one of the few effective strategies to improve sarcopenia and prevent its outcomes, especially if in combination with appropriate nutritional supplementation. Sarcopenia is associated with adverse outcomes and other serious areas such as metabolic disorders, cancers, cardiovascular diseases, nephrology, gastroenterology, psychiatry, other geriatric diseases (such as osteoporosis, etc) and death. Some studies about these areas have been done in Iran.

CONCLUSIONS

By this study, we found that studies on sarcopenia, the gaps of sarcopenia research in Iran, and highlighted the research priorities for future works. The outcome of the present research is to ultimately improve the health, quality of life and well-being of sarcopenic people.

[Diagnosis and prevalence of sarcopenia in long-term care homes: EWGSOP2 versus EWGSOP1]

Introduction

Background: the definition and methodology recommended for the diagnosis of sarcopenia has been changing. The mostly applied consensus is the one published by the European Working Group in Older People in 2010 (EWGSOP1), which was updated in 2019 (EWGSOP2). Objectives: assessing the prevalence of sarcopenia in institutionalized older adults using the EWGSOP2 algorithm and comparing these results with the EWGSOP1 algorithm results. Methods: in order to diagnose sarcopenia, muscle mass was assessed using an impedanciometer, muscle strength with a dynamometer and walking speed over a four-meter course. For the comparison of the results, a sensitivity and specificity analysis were performed with the version 20 of SPSS. Results: according to the EWGSOP2, 60.1% of the participants had sarcopenia and 58.1% had severe sarcopenia, results with no statistical differences when they are compared to the results according to the EWGSOP1 (63% had sarcopenia and 61.2%, severe sarcopenia). Neither were statistical differences found when comparing subjects with low muscle mass according to the formulas suggested by both consensus, while there were differences when comparing subjects with low muscle strength due to the variation of cut-off points. Conclusions: the prevalence of sarcopenia in institutionalized older adults is high, being remarkable that the majority of the participants had low muscle strength and low physical performance. The utilization of the methodology proposed by the EWGSOP2 did not have influence in the results of prevalence of sarcopenia obtained when the EWGSOP1 recommendations were applied.

Disease-Related Malnutrition and Sarcopenia as Determinants of Clinical Outcome

BACKGROUND

Disease-related malnutrition (DRM) and sarcopenia are common complications in chronic or severe disease, with a prevalence in general patient population of 20-50% and 0.1-85.4%, respectively. In many patient populations, malnutrition and sarcopenia are present in parallel and often manifest clinically through a combination of decreased nutrient intake, inflammation, and decreased body weight, along with a decrease in muscle mass, strength, and/or physical function, resulting in a clinical condition termed malnutrition-sarcopenia syndrome.

SUMMARY

DRM and sarcopenia are associated with increases in all-cause mortality, morbidity, length of hospital stay, and functional impairments (including disabilities and fractures) that lead to a loss of independence and higher costs. Different mortality rates are reported in malnourished patients and well-nourished patients after hospitalization, and higher mortality is the most common complication in patients with sarcopenia. Sarcopenia is a predictor of cancer survival in patients with gastrointestinal, respiratory, and urothelial cancer, and is also related to worse outcomes in patients with liver failure, intestinal insufficiency, and intestinal failure. Length of hospital stay has been found to be longer in DRM and sarcopenic patients in several studies. Prolonged hospitalization due to higher complication rates is often accompanied by demographic changes, resulting in higher hospital and health insurance costs. There are more frequent readmissions by patients with sarcopenia than nonsarcopenic patients. In addition, postoperative complications, duration of hospital stay, and costs increase with advancing sarcopenia stage. A significantly higher complication rate is also reported for DRM, leading to delayed mobilization, lower values in health-related quality of life and more adverse events. DRM is independently associated with poorer clinical outcomes in intensive care unit patients. Muscle dysfunction, as reflected by a decreased handgrip strength, is a well-known consequence of DRM and a good marker of immediate postoperative complications. Most of these outcomes have potential direct or indirect effects on hospital and health care costs, both for the patient and the society at large.

KEY MESSAGES

Consistent and robust data show DRM and sarcopenia are clinically relevant. They are an increasing problem with relevant medical consequences as well as socioeconomic implications.

Sarcopenia: A Time for Action. An SCWD Position Paper

The term sarcopenia was introduced in 1988. The original definition was a "muscle loss" of the appendicular muscle mass in the older people as measured by dual energy x-ray absorptiometry (DXA). In 2010, the definition was altered to be low muscle mass together with low muscle function and this was agreed upon as reported in a number of consensus papers. The Society of Sarcopenia, Cachexia and Wasting Disorders supports the recommendations of more recent consensus conferences, i.e. that rapid screening, such as with the SARC-F questionnaire, should be utilized with a formal diagnosis being made by measuring grip strength or chair stand together with DXA estimation of appendicular muscle mass (indexed for height2). Assessments of the utility of ultrasound and creatine dilution techniques are ongoing. Use of ultrasound may not be easily reproducible. Primary sarcopenia is aging associated (mediated) loss of muscle mass. Secondary sarcopenia (or disease-related sarcopenia) has predominantly focused on loss of muscle mass without the emphasis on muscle function. Diseases that can cause muscle wasting (i.e. secondary sarcopenia) include malignant cancer, COPD, heart failure, and renal failure and others. Management of sarcopenia should consist of resistance exercise in combination with a protein intake of 1 to 1.5 g/kg/day. There is insufficient evidence that vitamin D and anabolic steroids are beneficial. These recommendations apply to both primary (age-related) sarcopenia and secondary (disease related) sarcopenia. Secondary sarcopenia also needs appropriate treatment of the underlying disease. It is important that primary care health professionals become aware of and make the diagnosis of age-related and disease-related sarcopenia. It is important to address the risk factors for sarcopenia, particularly low physical activity and sedentary behavior in the general population, using a life-long approach. There is a need for more clinical research into the appropriate measurement for muscle mass and the management of sarcopenia. Accordingly, this position statement provides recommendations on the management of sarcopenia and how to progress the knowledge and recognition of sarcopenia.

Promoting mobility and healthy aging in men: a narrative review

Maintaining mobility is an important aspect of health and well-being in older men. This literature review describes several modifiable and nonmodifiable risk factors impacting bone, muscle, and joint health. Exercise and nutritional interventions may help to prevent the progressive deterioration in bones, muscles, and joints impacting mobility in later life. Limitations in mobility are increasingly recognized as a major public health problem due to an aging population and growing number of older individuals affected by disabling comorbidities. Despite increasing numbers and debilitating consequences, there are no guidelines providing recommendations on strategies to maintain mobility for healthy aging among older men. This narrative review aims to fill this literature gap. PubMed, Scopus, and Google Scholar databases were searched using predefined search terms. Primary studies, exploratory analyses, cross-sectional surveys, meta-analyses, evidence-based clinical reviews, and guidelines from nationally recognized societies focusing on mobility in older men and key elements including bone, muscle and joint health, and balance were selected. Several modifiable and nonmodifiable risk factors have been reported in the literature that impact bone, muscle, and joint health and predispose older men to falls and fractures. The most common conditions impacting bones, muscles, and joints are osteoporosis, sarcopenia, and osteoarthritis, respectively. In addition to being key contributors to disability in the elderly, these conditions are all associated with a higher mortality risk. Although more studies are required, current evidence supports the use of various nonpharmacological (mainly exercise and nutrition) and/or pharmacological treatment modalities to help prevent and/or reverse these conditions. Incorporating lifestyle interventions involving exercise and nutrition at a younger age can help prevent the age-related, progressive deterioration in bones, muscles, and joints that can reduce mobility in later life. Established barriers to physical activities (e.g., poor health, social isolation) in men are important to consider for optimizing outcomes.

Pharmacological Interventions for Treatment of Sarcopenia: Current Status of Drug Development for Sarcopenia

Sarcopenia, the loss of skeletal muscle mass and function with age, was first recognized as a disease in the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) (M62.84) and has recently attracted attention as aged populations increase. However, the diagnostic criteria for sarcopenia remain controversial and there are as yet no US Food and Drug Administration-approved medications for sarcopenia. Given that both intrinsic and extrinsic factors contribute to sarcopenia onset and development, understanding the mechanism of sarcopenia is important for the development of therapeutic strategies. In this review, we described a variety of drugs for sarcopenia under investigation, including myostatin/ActR2 signaling inhibitors, exercise mimetics, anabolic hormones, and natural compounds. However, the combination of non-drug therapies with exercise and nutritional supplements are also needed as more easily accessible intervention strategies against sarcopenia rather than pharmacological treatments alone. Many approaches to develop therapeutic methods to overcome sarcopenia may lead to healthy aging.

Reliable and robust method for abdominal muscle mass quantification using CT/MRI: An explorative study in healthy subjects

Background

Quantification of abdominal muscle mass by cross-sectional imaging has been increasingly used to diagnose sarcopenia; however, the technical method for quantification has not been standardized yet. We aimed to determine an optimal method to measure the abdominal muscle area.

Methods

Among 50 consecutive subjects who underwent abdominal CT and MRI for possible liver donation, total abdominal muscle area (TAMA) and total psoas muscle area (TPA) at the L3 inferior endplate level were measured by two blinded readers. Inter-scan agreement between CT and MRI and inter-reader agreement between the two readers were evaluated using intraclass correlation coefficient (ICC) and within-subject coefficient of variation (WSCV). To evaluate the effect of measurement level, one reader measured TAMA and TPA at six levels from the L2 to L4 vertebral bodies.

Results

TAMA was a more reliable biomarker than TPA in terms of inter-scan agreement (ICC: 0.928 vs. 0.788 for reader 1 and 0.853 vs. 0.821 for reader 2, respectively; WSCV: 8.3% vs. 23.4% for reader 1 and 10.4% vs. 22.3% for reader 2, respectively) and inter-reader agreement (ICC: 0.986 vs. 0.886 for CT and 0.865 vs. 0.669 for MRI, respectively; WSCV: 8.2% vs. 16.0% for CT and 11.6% vs. 29.7% for MRI, respectively). In terms of the measurement level, TAMA did not differ from the L2_inf to L4_inf levels, whereas TPA increased with a decrease in measurement level.

Conclusions

TAMA is a better biomarker than TPA in terms of inter-scan and inter-reader agreement and robustness to the measurement level. CT was a more reliable imaging modality than MRI. Our results support the use of TAMA measured by CT as a standard biomarker for abdominal muscle area measurement.

Factors Associated with Sarcopenia and 7-Year Mortality in Very Old Patients with Hip Fracture Admitted to Rehabilitation Units: A Pragmatic Study

Background: Admitted bedridden older patients are at risk of the development of sarcopenia during hospital stay (incident sarcopenia). The objective of this study was to assess the factors associated with sarcopenia (incident and chronic) and its impact on mortality in older people with hip fracture. Methods: A multicenter, pragmatic, prospective observational study was designed. Older subjects with hip fracture admitted to two rehabilitation units were included. Sarcopenia was assessed at admission and at discharge according to the revised EWGSOP (European Working Group on Sarcopenia in Older People) consensus definition. The mortality was evaluated after 7 years of follow-up. Results: A total of 187 subjects (73.8% women) age 85.2 ± 6.3 years were included. Risk factors associated to incident and chronic sarcopenia were undernutrition (body mass index—BMI and Mini Nutritional Assessment−Short Form—MNA-SF), hand-grip strength and skeletal muscle index. During follow-up 114 patients died (60.5% sarcopenic vs. 39.5% non-sarcopenic, p = 0.001). Cox regression analyses showed that factors associated to increased risk of mortality were sarcopenia (HR: 1.67, 95% CI 1.11–2.51) and low hand-grip strength (HR: 1.76, 95% CI 1.08–2.88). Conclusions: Older patients with undernutrition have a higher risk of developing sarcopenia during hospital stay, and sarcopenic patients have almost two times more risk of mortality than non-sarcopenic patients during follow-up after hip fracture.

The Influence of Omega-3 Fatty Acids on Skeletal Muscle Protein Turnover in Health, Disuse, and Disease

Ingestion of omega-3 fatty acids is known to exert favorable health effects on a number of biological processes such as improved immune profile, enhanced cognition, and optimized neuromuscular function. Recently, data have emerged demonstrating a positive influence of omega-3 fatty acid intake on skeletal muscle. For instance, there are reports of clinically-relevant gains in muscle size and strength in healthy older persons with omega-3 fatty acid intake as well as evidence that omega-3 fatty acid ingestion alleviates the loss of muscle mass and prevents decrements in mitochondrial respiration during periods of muscle-disuse. Cancer cachexia that is characterized by a rapid involuntary loss of lean mass may also be attenuated by omega-3 fatty acid provision. The primary means by which omega-3 fatty acids positively impact skeletal muscle mass is via incorporation of eicosapentaenoic acid (EPA; 20:5n−3) and docosahexaenoic acid (DHA; 22:6n−3) into membrane phospholipids of the sarcolemma and intracellular organelles. Enrichment of EPA and DHA in these membrane phospholipids is linked to enhanced rates of muscle protein synthesis, decreased expression of factors that regulate muscle protein breakdown, and improved mitochondrial respiration kinetics. However, exactly how incorporation of EPA and DHA into phospholipid membranes alters these processes remains unknown. In this review, we discuss the interaction between omega-3 fatty acid ingestion and skeletal muscle protein turnover in response to nutrient provision in younger and older adults. Additionally, we examine the role of omega-3 fatty acid supplementation in protecting muscle loss during muscle-disuse and in cancer cachexia, and critically evaluate the molecular mechanisms that underpin the phenotypic changes observed in skeletal muscle with omega-3 fatty acid intake.

The Role of the Molecular Clock in Promoting Skeletal Muscle Growth and Protecting against Sarcopenia

The circadian clock has a critical role in many physiological functions of skeletal muscle and is essential to fully understand the precise underlying mechanisms involved in these complex interactions. The importance of circadian expression for structure, function and metabolism of skeletal muscle is clear when observing the muscle phenotype in models of molecular clock disruption. Presently, the maintenance of circadian rhythms is emerging as an important new factor in human health, with disruptions linked to ageing, as well as to the development of many chronic diseases, including sarcopenia. Therefore, the aim of this review is to present the latest findings demonstrating how circadian rhythms in skeletal muscle are important for maintenance of the cellular physiology, metabolism and function of skeletal muscle. Moreover, we will present the current knowledge about the tissue-specific functions of the molecular clock in skeletal muscle.

ICD-10-CM extension with ICD-9 diagnosis codes to support integrated access to clinical legacy data

INTRODUCTION

ICD is currently the most widely used terminology to code diagnosis and procedures. The transition from ICD-9-CM to ICD-10-CM became effective on October 1, 2015 in US and many other countries. Projects that use this codification for research purposes, requires advanced methods to exploit data with both versions of ICD. Although the General Equivalence Mappings (GEMs), provided by the Centers for Medicare and Medicaid Services, might help to overcome these challenges, their direct use as translation mappings is not possible, mostly due to the further specificity of ICD-10-CM concepts.

OBJECTIVE

We propose a methodology to generate an extended version of ICD-10-CM with selected ICD-9-CM diagnosis codes.

METHODS

The extension was generated using the GEMs relations between concepts of both terminologies and the hierarchical relations of ICD-10-CM.

RESULTS

This extended ICD-10-CM, together with modifications to the mapping of ICD-9-CM concepts that were not inserted, allows the generation of an improved translation of legacy data, raising the number of 1-to-1 correspondences by +13.81%.

CONCLUSION

The extended ICD-10-CM enables the accurate integration of ICD-9-CM and ICD-10-CM diagnosis data into a single terminology. With such analysis of data possible without having to specify both ICD-9-CM and ICD-10-CM separately for each query.

Geographical differences in osteoporosis, obesity, and sarcopenia related traits in white American cohorts

It has been reported that geographical variation influences bone mineral density (BMD), obesity, and sarcopenia related traits in other countries. However, there is lack of similar studies in the US population. In this study, we compared data from three US study cohorts to evaluate geographical variations of BMD and body composition. BMD, fat mass and lean mass were collected from Dual-energy X-ray absorptiometry machine. ANCOVA and Chi-square tests were used to compare the differences between BMDs, obesity and sarcopenia related traits from different regional sites (Omaha, Kansas City and Baton Rouge/New Orleans). Eta-squared was used to measure the effect sizes of these differences. A total of 11,315 Caucasians from our previous three study cohorts were compared. There was no significant geographical difference in BMD for males or females under the criteria of p-values < 0.05 and effect size η² > 0.01. There were significant geographical differences with medium effect size (p-value < 0.001, 0.01 < η² < 0.14) for whole body fat mass percentage and index of low muscle mass. For Caucasians in the United States, there is no significant geographical effect found on BMD. The obesity and sarcopenia related traits are significantly different between the three study cohorts.

Association between dietary nutrient intake and sarcopenia in the SarcoPhAge study

BACKGROUND

It has been suggested that a balanced nutritional intake may be useful in preventing or even reversing sarcopenia.

AIM

To describe cross-sectional associations between dietary nutrient intake and sarcopenia.

METHODS

Subjects recruited from the SarcoPhAge study population completed a food frequency questionnaire. The micronutrient and macronutrient intake was evaluated in both sarcopenic and non-sarcopenic participants. The Nutritional Belgian Recommendations of 2016 were used, i.e., adequate intake and estimated average requirement (EAR). For micronutrients, the prevalence of insufficient intake was estimated as the proportion of subjects whose intake was below the EAR.

RESULTS

A total of 331 subjects (mean age of 74.8 ± 5.9 years, 58.9% women) had complete data and were included in this study. Among them, 51 were diagnosed with sarcopenia (15.4%). In the fully adjusted model, analyses revealed that sarcopenic subjects consumed significantly lower amounts of two macronutrients (proteins, lipids) and five micronutrients (potassium, magnesium, phosphorus, iron, and vitamin K) than non-sarcopenic subjects (all p values < 0.005). A significantly increased prevalence of insufficiency was found for sarcopenic subjects compared to non-sarcopenic subjects for potassium, magnesium, iron, calcium and vitamins E and C (all p values < 0.005). The prevalence of sarcopenic subjects who were also below the Nutritional Belgian Recommendations for protein and lipids was significantly higher than that of non-sarcopenic subjects.

DISCUSSION AND CONCLUSIONS

Sarcopenic subjects seem to consume significantly reduced amounts of many micronutrients and macronutrients compared to non-sarcopenic subjects. These results suggest that a poorly balanced diet may be associated with sarcopenia and poor musculoskeletal health, although prospective studies are needed to confirm these findings.

Current pharmacotherapies for sarcopenia

Introduction: Sarcopenia, the age-related loss of skeletal muscle mass and function, is a global health problem that contributes to the development of physical disability, morbidity and mortality in the ageing population. Sarcopenia is now recognised in many countries as a muscle disease with an ICD-10-CM Diagnosis Code for billing care related to this condition, despite no FDA-approved treatments being currently available. Areas covered: This review highlights the current state of knowledge regarding the biological mechanisms contributing to the age-related loss of muscle mass and function and provides a summary of existing and emerging pharmacotherapies in clinical trials for sarcopenia. Expert opinion: While understanding of the pathophysiology of sarcopenia has progressed, rigorous preclinical studies that better inform clinical trials are needed to accelerate drug discovery and identify safe and effective treatments. Few drugs have been developed specifically for sarcopenia and many have failed to meet clinically relevant outcomes related to strength and physical performance. The multifactorial complexity of sarcopenia means that tailored, personalised treatments are more likely to be required than just a single intervention.

Sarcopenia Is Associated with Cognitive Impairment Mainly Due to Slow Gait Speed: Results from the Korean Frailty and Aging Cohort Study (KFACS)

Sarcopenia and cognitive impairment may share common risk factors and pathophysiological pathways. We examined the association between impairments in specific cognitive domains and sarcopenia (and its defining components) in community-dwelling older adults. We analyzed 1887 patients who underwent cognitive function tests and dual-energy X-ray absorptiometry from the baseline data of adults aged 70-84 years obtained from the Korean Frailty and Aging Cohort Study. Those with disability in activities of daily living, dementia, severe cognitive impairment, Parkinson's disease, musculoskeletal complaints, neurological disorders, or who were illiterate were excluded. Cognitive function was assessed using the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet, the Frontal Assessment Battery. For sarcopenia, we used the diagnostic criteria of the Asian Working Group for Sarcopenia. The prevalence of sarcopenia was 9.6% for men and 7.6% for women. Sarcopenia (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.04-2.99) and slow gait speed (OR 2.58, 95% CI 1.34-4.99) were associated with cognitive impairment in men. Only slow gait speed (OR 1.88, 95% CI 1.05-3.36) was associated with cognitive impairment in women. Sarcopenia is associated with cognitive impairment mainly due to slow gait speed. Our results suggested that cognitive impairment domains, such as processing speed and executive function, are associated with sarcopenia-related slow gait speed.

Short-Term Exercise Training Inconsistently Influences Basal Testosterone in Older Men: A Systematic Review and Meta-Analysis

Background: The age-associated decrease in testosterone is one mechanism suggested to accelerate the aging process in males. Therefore, approaches to increase endogenous testosterone may be of benefit. The aim of this paper was to undertake a Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA)-accordant meta-analysis concerning the effect of exercise on total (TT), bioavailable (bio-T), free (free-T), and salivary (sal-T) testosterone in older males. Methods: Databases were searched up to and including 20th February 2018 for the terms "testosterone AND exercise AND aging AND males," "testosterone AND exercise AND old AND males," "testosterone AND training AND aging AND males," and "testosterone AND training AND old AND males". From 1259 originally identified titles, 22 studies (randomized controlled trials; RCTs; n = 9, and uncontrolled trials; UCTs; n = 13) were included which had a training component, participants ≥60 years of age, and salivary or serum testosterone as an outcome measure. Meta-analyses were conducted on change to testosterone following training using standardized difference in means (SDM) and random effects models. Results: The overall SDM for endurance training, resistance training, and interval training was 0.398 (95% CI = 0.034-0.761; P = 0.010), -0.003 (95% CI = -0.330-0.324; P = 0.986), and 0.283 (95% CI = 0.030-0.535; P = 0.028), respectively. Resistance training exhibited a qualitative effect of hormone fraction whereby free-T resulted in the greatest SDM (0.253; 95% CI = -0.043-0.549; P = 0.094), followed by TT (0.028; 95% CI = -0.204-0.260; P = 0.813), and resistance training negatively influenced bio-T (-0.373; 95% CI = -0.789-0.042; P = 0.078). Due to the small number of studies, subgroup analysis was not possible for endurance training and interval training studies. Conclusions: Data from the present investigation suggests that resistance training does not significantly influence basal testosterone in older men. Magnitude of effect was influenced by hormone fraction, even within the same investigation. Aerobic training and interval training did result in small, significant increases in basal testosterone. The magnitude of effect is small but the existing data are encouraging and may be an avenue for further research.

Association Between the Results of the Timed Up-and-Go Test Adjusted for Disease Severity and Sarcopenia in Patients with Chronic Obstructive Pulmonary Disease: a Pilot Study

OBJECTIVES

Loss of muscle mass and/or physical performance, a condition commonly known as sarcopenia, is prevalent in chronic obstructive pulmonary disease (COPD) and is associated with adverse outcomes. The aim of this study was to investigate the association between functional performance and sarcopenia in COPD patients classified by disease severity according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria.

METHODS

The study was a cross-sectional observational and the sample size consisted of 35 COPD patients (69.24±1.54 years, 20 men). Physical performance was assessed with the timed up-and-go (TUG) test. Sarcopenia was assessed according to the European Working Group on Sarcopenia in Older People criteria.

RESULTS

The frequency of sarcopenia was 20% and was more prevalent among individuals classified with greater disease severity, GOLD III, n=4 patients (23%) and GOLD IV, n=3 patients (27%), p=0.83. The mean time to complete the TUG test was 11.66±4.78 s. Binary logistic regression revealed an association between the TUG test and sarcopenia adjusted by disease severity (OR=1.55, 95% CI: 1.03-8.23, p=0.04).

CONCLUSION

Our findings showed that worse performance in the TUG test leads to a substantial increase in the chance of COPD patients presenting sarcopenia.

Sarcopenia and hospital-related outcomes in the old people: a systematic review and meta-analysis

AIM

This systematic review was conducted to explore the associations between sarcopenia, hospitalization and length of stay in the old people.

METHODS

Pubmed, Embase, Medline and Cochrane Central Register of Controlled Trails from January 2009 to October 2017 were searched in this review. We included prospective studies, which had the clear definition of sarcopenia and reported the hospitalization or length of stay as one of outcomes. Adjusted Odd ratios (aORs), hazard ratios (aHRs) or relative risks (aRRs) extracted from the studies were combined to synthesize pooled effect measures. Heterogeneity, and methodological quality were assessed using I² statistic and Newcastle-Ottawa scale, respectively.

RESULTS

Nine studies were included in this review. Of these, 8 studies with 4174 individuals reported results for hospitalization, 3 studies involving 6276 old people in the community reported results for length of stay. Sarcopenia was significantly associated with future hospitalization (RR 1.40, 95% CI 1.04-1.89, p = 0.029; data from 8 studies). A subgroup analysis showed the associations between sarcopenia and readmission in hospitalized old patients that were statistically significant (RR 1.75, 95% CI 1.01-3.03, p = 0.044; data from 8 studies). However, this association were not found in the community-dwelling older subjects (RR 1.08, 95% CI 0.74-1.57, p = 0.688; data from 8 studies), uncertain in nursing home residents. The association of sarcopenia and length of stay was not statistically significant (OR 1.21, 95% CI 0.90-1.63, p = 0.20; data from 8 studies) in community-dwelling residents.

CONCLUSIONS

This systematic review demonstrates that sarcopenia is a significant predictor of readmission in old inpatients, but not associated with hospitalization or length of stay in community-dwelling old adults.

Sarcopenia Is Related to Mortality in the Acutely Hospitalized Geriatric Patient

BACKGROUND

Sarcopenia is defined as low skeletal muscle mass with poor physical performance, representing a strong prognostic factor for mortality in older people. Although highly prevalent in hospitalized geriatric patients, it is unknown whether sarcopenia can also predict mortality in these patients.

OBJECTIVE

To determine the association between sarcopenia according the criteria of the European Working Group on Sarcopenia in Older People (EWGSOP), International Working Group on Sarcopenia (IWGS), Special Interest Group of Sarcopenia, Cachexia and Wasting Disorders (SIG) and Foundation for the National Institutes of Health (FNIH) and 2-year mortality in acutely hospitalized geriatric patients.

DESIGN

81 patients (84±5 y) admitted to the acute geriatric ward participated in this study. Body composition assessment (bio-impedance, Maltron Bioscan 920-II) and physical performance tests were performed, and mortality information was retrieved through patient files.

RESULTS

Prevalence rates of sarcopenia were 51% (EWGSOP), 75% (IWGS), 69% (SIG), and 27% (FNIH). Based on Cox proportional hazard ratio (HR) analysis, 2-year mortality was significantly higher in sarcopenic patients versus non-sarcopenic patients when using the EWGSOP (2-y: HR 4.310; CI-95%:2.092-8.850; P<0.001) and FNIH criteria (2-y: HR 3.571; CI-95%:1.901-6.711; P<0.001). Skeletal muscle mass index, fat mass index, body mass index, phase angle and gait speed were significantly lower in the geriatric patients who deceased after 2 years versus those who were still alive. Cox proportional HR analyses showed that higher phase angle (HR 0.678; CI-95%:0.531- 0.864; P=0.002) and higher fat mass index (HR 0.839; CI-95%:0.758-0.928; P=0.001) significantly reduced 2-y mortality probability. Combining sarcopenia criteria and separate patient characteristics finally resulted in a model in which HRs for sarcopenia (EWGSOP and FNIH) as well as phase angle significantly predicted mortality probability.

CONCLUSION

Sarcopenia is prevalent in acutely hospitalized geriatric patients and is associated with significantly higher 2-year mortality according the EWGSOP and FNIH criteria.

Reduced physical activity in young and older adults: metabolic and musculoskeletal implications

BACKGROUND

Although the health benefits of regular physical activity and exercise are well established and have been incorporated into national public health recommendations, there is a relative lack of understanding pertaining to the harmful effects of physical inactivity. Experimental paradigms including complete immobilization and bed rest are not physiologically representative of sedentary living. A useful 'real-world' approach to contextualize the physiology of societal downward shifts in physical activity patterns is that of short-term daily step reduction.

RESULTS

Step-reduction studies have largely focused on musculoskeletal and metabolic health parameters, providing relevant disease models for metabolic syndrome, type 2 diabetes (T2D), nonalcoholic fatty liver disease (NAFLD), sarcopenia and osteopenia/osteoporosis. In untrained individuals, even a short-term reduction in physical activity has a significant impact on skeletal muscle protein and carbohydrate metabolism, causing anabolic resistance and peripheral insulin resistance, respectively. From a metabolic perspective, short-term inactivity-induced peripheral insulin resistance in skeletal muscle and adipose tissue, with consequent liver triglyceride accumulation, leads to hepatic insulin resistance and a characteristic dyslipidaemia. Concomitantly, various inactivity-related factors contribute to a decline in function; a reduction in cardiorespiratory fitness, muscle mass and muscle strength.

CONCLUSIONS

Physical inactivity maybe particularly deleterious in certain patient populations, such as those at high risk of T2D or in the elderly, considering concomitant sarcopenia or osteoporosis. The effects of short-term physical inactivity (with step reduction) are reversible on resumption of habitual physical activity in younger people, but less so in older adults. Nutritional interventions and resistance training offer potential strategies to prevent these deleterious metabolic and musculoskeletal effects.

IMPACT

Individuals at high risk of/with cardiometabolic disease and older adults may be more prone to these acute periods of inactivity due to acute illness or hospitalization. Understanding the risks is paramount to implementing countermeasures.

Recent Progress in Sarcopenia Research: a Focus on Operationalizing a Definition of Sarcopenia

PURPOSE OF REVIEW

To discuss recent progress in sarcopenia research and to highlight controversies in the field particularly around reaching consensus on a definition of sarcopenia.

RECENT FINDINGS

Accordingly, this review begins with a discussion of the increasing awareness of this condition; briefly describes evolving definitions of sarcopenia; suggests a framework for consistent terminology for sarcopenia; discusses outstanding issues in the definition of sarcopenia; and reviews the association between sarcopenia and adverse outcome in older adults. In addition, the role of sarcopenia in other diseases is discussed. The field of sarcopenia continues to hold considerable promise and work continues to resolve outstanding concerns in this field with a unifying consensus definition on the horizon.

Protein Intake Recommendation for Korean Older Adults to Prevent Sarcopenia: Expert Consensus by the Korean Geriatric Society and the Korean Nutrition Society

Sarcopenia, a common clinical syndrome in older adults, is defined as decreased muscle mass, strength, and physical performance. Since sarcopenia is associated with the incidence of functional decline, falls, and even mortality in older adults, researchers and health care providers have been keen to accumulate clinical evidence to advocate the screening and prevention of sarcopenia progression in older adults. The factors that may accelerate the loss of muscle mass and function include chronic diseases, inactivity, and deficiency in appropriate nutritional support. Among these, nutritional support is considered an initial step to delay the progression of muscle wasting and improve physical performance in community-dwelling older adults. However, a nationwide study suggested that most Korean older adults do not consume sufficient dietary protein to maintain their muscle mass. Furthermore, considering age-associated anabolic resistance to dietary protein, higher protein intake should be emphasized in older adults than in younger people. To develop a dietary protein recommendation for older adults in Korea, we reviewed the relevant literature, including interventional studies from Korea. From these, we recommend that older adults consume at least 1.2 g of protein per kg of body weight per day (g/kg/day) to delay the progression of muscle wasting. The amount we recommend (1.2 g/kg/day) is 31.4% higher than the previously suggested recommended daily allowance (i.e., 0.91 g/kg/day) for the general population of Korea. Also, evidence to date suggests that the combination of exercise and nutritional support may enhance the beneficial effects of protein intake in older adults in Korea. We found that the current studies are insufficient to build population-based guidelines for older adults, and we call for further researches in Korea.

A Distinct Pattern of Circulating Amino Acids Characterizes Older Persons with Physical Frailty and Sarcopenia: Results from the BIOSPHERE Study

Physical frailty and sarcopenia (PF&S) are hallmarks of aging that share a common pathogenic background. Perturbations in protein/amino acid metabolism may play a role in the development of PF&S. In this initial report, 68 community-dwellers aged 70 years and older, 38 with PF&S and 30 non-sarcopenic, non-frail controls (nonPF&S), were enrolled as part as the "BIOmarkers associated with Sarcopenia and Physical frailty in EldeRly pErsons" (BIOSPHERE) study. A panel of 37 serum amino acids and derivatives was assayed by UPLC-MS. Partial Least Squares⁻Discriminant Analysis (PLS-DA) was used to characterize the amino acid profile of PF&S. The optimal complexity of the PLS-DA model was found to be three latent variables. The proportion of correct classification was 76.6 ± 3.9% (75.1 ± 4.6% for enrollees with PF&S; 78.5 ± 6.0% for nonPF&S). Older adults with PF&S were characterized by higher levels of asparagine, aspartic acid, citrulline, ethanolamine, glutamic acid, sarcosine, and taurine. The profile of nonPF&S participants was defined by higher concentrations of α-aminobutyric acid and methionine. Distinct profiles of circulating amino acids and derivatives characterize older people with PF&S. The dissection of these patterns may provide novel insights into the role played by protein/amino acid perturbations in the disabling cascade and possible new targets for interventions.

Evaluation of the Responsiveness of the SarQoL® Questionnaire, a Patient-Reported Outcome Measure Specific to Sarcopenia

INTRODUCTION

The Sarcopenia Quality of Life (SarQoL®) questionnaire was developed to provide a patient-reported outcome measure specific to sarcopenia. Its psychometric properties indicate that it is a valid and reliable instrument. However, until now, its ability to detect change over time has not been examined. Therefore, the objective of this study is to evaluate the responsiveness (also known as sensitivity to change) of the SarQoL® questionnaire in a prospective, longitudinal cohort of community-dwelling, older, sarcopenic subjects.

METHODS

Sarcopenic subjects from the SarcoPhAge (Sarcopenia and Physical impairment with advancing Age) study were included. Responsiveness was evaluated with nine pre-specified hypotheses on the correlation between the evolution of the SarQoL® scores after a 2-year interval and the evolution of the scores on the Short Form-36 (SF-36) and the Euroqol 5-dimension (EQ-5D) questionnaires. This technique considers responsiveness to be a form of longitudinal validity. Additionally, standardized response means were also calculated to compare the quantity of change measured by the different questionnaires.

RESULTS

A total of 42 sarcopenic subjects were included. The median age of the sample was 72.9 (68.9-78.8) years, 59.5% were female, and the mean body mass index was 23.3 (20.4-25.7) kg/m2. A good responsiveness was observed, as evidenced by the confirmation of eight out of nine hypotheses, well above the 75% confirmation threshold. The standardized response mean of the Overall SarQoL® score was significantly higher than those of the SF-36 Physical Component Summary (p = 0.005), the EQ-5D Utility Index (p < 0.001) and the Euroqol visual analogue scale (p = 0.003).

CONCLUSION

The first data available on the ability of the SarQoL® questionnaire to detect change over time indicates that the questionnaire has good responsiveness. This, together with the previously established psychometric properties, confirms that the SarQoL® questionnaire is a relevant instrument for the assessment of quality of life in sarcopenic populations.

Effects of branched-chain amino acids and vitamin D supplementation on physical function, muscle mass and strength, and nutritional status in sarcopenic older adults undergoing hospital-based rehabilitation: A multicenter randomized controlled trial

AIM

To investigate the effects of branched-chain amino acids and vitamin D supplementation on physical function, muscle strength, muscle mass, and nutritional status in sarcopenic older adults undergoing hospital-based rehabilitation.

METHODS

We carried out an 8-week, multicenter, randomized, controlled, blinded outcome, two-cohort parallel group intervention trial of sarcopenic older adults undergoing in-hospital rehabilitation. The eligibility criteria included older adults (aged ≥65 years) with low muscle strength (handgrip strength) and low muscle mass (calf circumference) according to the cut-off values for older Asians. The intervention group received branched-chain amino acids and vitamin D supplementation, whereas the control group did not. Both groups underwent low-intensity resistance training in addition to the post-acute rehabilitation program. The primary outcome of physical function (Functional Independence Measure-motor scores), and the secondary outcomes of muscle strength (handgrip strength), muscle mass (calf circumference) and nutritional status (body mass index) were measured at baseline and at the end of the intervention.

RESULTS

Finally, a total of 68 patients were analyzed (intention-to-treat analysis): 35 in the intervention group and 33 in the control group. Functional Independence Measure-motor scores increased significantly in both groups over time (P < 0.05). However, no treatment-by-time effects were observed (median estimated difference 2.4, 95% confidence interval -1.2 to 7.1). Handgrip strength, calf circumference and body mass index increased significantly in both groups over time (P < 0.05), with significantly greater improvements in the intervention group (P = 0.041, 0.033 and 0.035, respectively).

CONCLUSIONS

We showed that an 8-week intervention of branched-chain amino acids and vitamin D supplementation with low-intensity resistance training improves muscle-related outcomes in sarcopenic older adults undergoing hospital-based rehabilitation (UMIN000006238). Geriatr Gerontol Int 2019; 19: 12-17.

The "BIOmarkers associated with Sarcopenia and PHysical frailty in EldeRly pErsons" (BIOSPHERE) study: Rationale, design and methods

Sarcopenia, the progressive and generalised loss of muscle mass and strength/function, is a major health issue in older adults given its high prevalence and burdensome clinical implications. Over the years, this condition has been endorsed as a marker for discriminating biological from chronological age. However, the absence of a unified operational definition has hampered its full appreciation by healthcare providers, researchers and policy-makers. In addition to this unsolved debate, the complexity of musculoskeletal ageing represents a major challenge to the identification of clinically meaningful biomarkers. Here, we illustrate the advantages of biomarker discovery procedures in muscle ageing based on multivariate methodologies as an alternative approach to traditional single-marker strategies. The rationale, design and methods of the "BIOmarkers associated with Sarcopenia and PHysical frailty in EldeRly pErsons" (BIOSPHERE) study are described as an application of a multi-marker strategy for the development of biomarkers for the newly operationalised Physical Frailty & Sarcopenia condition.

Sarcopenia

Sarcopenia is defined as a combination of low muscle mass with low muscle function. The term was first used to designate the loss of muscle mass and performance associated with aging. Now, recognized causes of sarcopenia also include chronic disease, a physically inactive lifestyle, loss of mobility, and malnutrition. Sarcopenia should be differentiated from cachexia, which is characterized not only by low muscle mass but also by weight loss and anorexia. Sarcopenia results from complex and interdependent pathophysiological mechanisms that include aging, physical inactivity, neuromuscular compromise, resistance to postprandial anabolism, insulin resistance, lipotoxicity, endocrine factors, oxidative stress, mitochondrial dysfunction, and inflammation. The prevalence of sarcopenia ranges from 3% to 24% depending on the diagnostic criteria used and increases with age. Among patients with rheumatoid arthritis 20% to 30% have sarcopenia, which correlates with disease severity. Sarcopenia exacts a heavy toll of functional impairment, metabolic disorders, morbidity, mortality, and healthcare costs. Thus, the consequences of sarcopenia include disability, quality of life impairments, falls, osteoporosis, dyslipidemia, an increased cardiovascular risk, metabolic syndrome, and immunosuppression. The adverse effects of sarcopenia are particularly great in patients with a high fat mass, a condition known as sarcopenic obesity. The diagnosis of sarcopenia rests on muscle mass measurements and on functional tests that evaluate either muscle strength or physical performance (walking, balance). No specific biomarkers have been identified to date. The management of sarcopenia requires a multimodal approach combining a sufficient intake of high-quality protein and fatty acids, physical exercise, and antiinflammatory medications. Selective androgen receptor modulators and anti-myostatin antibodies are being evaluated as potential stimulators of muscle anabolism.

The impact of exercise and nutrition on the regulation of skeletal muscle mass

The maintenance of skeletal muscle mass and strength throughout life is a key determinant of human health and well-being. There is a gradual loss of both skeletal muscle mass and strength with ageing (a process termed sarcopenia) that increases the risk of functional dependence, morbidity and mortality. Understanding the factors that regulate the size of human muscle mass, particularly during the later years of life, has therefore become an area of intense scientific inquiry. The amount of muscle mass is determined by coordinated changes in muscle protein synthesis (MPS) and muscle protein breakdown (MPB). In this review, we assess both classical and contemporary work that has examined how resistance exercise and nutrition impact on MPS and MPB. Special consideration is given to the role of different sources of dietary protein (food vs. supplements) and non-protein nutrients such as omega-3 fatty acids in regulating MPS. We also critically evaluate recent studies that have employed novel 'omic' technologies such as dynamic protein profiling to probe for changes in rates of MPS and MPB at the individual protein level following exercise. Finally, we provide suggestions for future research that we hope will yield important information for the development of exercise and nutritional strategies to counteract muscle loss in a variety of clinical settings.

Current Status of Sarcopenia in Korea: A Focus on Korean Geripausal Women

Sarcopenia is defined as an age-associated decline in muscle mass and function caused by several etiologies and mechanisms. Muscle mass and function do not decrease concurrently, and a loss of muscle function may be more highly associated with adverse health outcomes. Despite the clinical significance of sarcopenia, no universally operational definition of sarcopenia or standardized intervention programs are currently available. Sarcopenia, osteoporosis, and obesity share several pathophysiological mechanisms, and a combination of these entities may lead to an increased risk of musculoskeletal, cardio-metabolic, and psychological morbidities especially in geripause populations. Treatment for sarcopenia is mainly nonpharmacological, however, various drugs are currently being developed. It is conceivable that sarcopenia is the next immediate clinical target in musculoskeletal science.

Prediction of sarcopenia using a combination of multiple serum biomarkers

Sarcopenia is a gradual loss of skeletal muscle mass and function with aging. Given that sarcopenia has been recognized as a disease entity, effective molecular biomarkers for early diagnosis are required. We recruited 46 normal subjects and 50 patients with moderate sarcopenia aged 60 years and older. Sarcopenia was clinically identified on the basis of the appendicular skeletal muscle index by applying cutoff values derived from the Asian Working Group for Sarcopenia. The serum levels of 21 potential biomarkers were analyzed and statistically examined. Interleukin 6, secreted protein acidic and rich in cysteine, macrophage migration inhibitory factor, and insulin-like growth factor 1 levels differed significantly between the normal and sarcopenia groups. However, in each case, the area under the receiver operating characteristics curve (AUC) was <0.7. Subsequent combination of the measurements of these biomarkers into a single risk score based on logistic regression coefficients enhanced the accuracy of diagnosis, yielding an AUC value of 0.763. The best cutoff value of 1.529 had 70.0% sensitivity and 78.3% specificity (95% CI = 2.80–21.69, p < 0.0001). Combined use of the selected biomarkers provides higher diagnostic accuracy than individual biomarkers, and may be effectively utilized for early diagnosis and prognosis of sarcopenia.

Association of sarcopenia and fractures in community-dwelling older adults: a systematic review and meta-analysis of cohort studies

To our knowledge, no comprehensive meta-analysis has examined the association between sarcopenia and the risk of fractures. This systematic review and meta-analysis of prospective cohort studies aims to summarize whether sarcopenia is a risk factor for fractures among community-dwelling older adults. We searched four electronic literature databases (Ovid MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, PubMed) for relevant publications from inception to December 2017, using relevant keywords. We conducted a pooled analysis of the association between sarcopenia and the risk of fractures by employing a random-effects model. Subgroup analyses were conducted based on definitions of sarcopenia and gender. In total, nine studies were included in our systematic review and meta-analysis. The prevalence of sarcopenia ranged from 4.3 to 33.1%. The pooled RR of fractures for the sarcopenic versus the nonsarcopenic was 1.34 (95% CI = 1.13-1.58, P = 0.001, I² = 5.5%, P-heterogeneity = 0.391). Subgroup analyses showed that associations between sarcopenia and fractures were significant when using the AWGS definition (combined effect size = 1.78, 95% CI = 1.25-2.54, P = 0.001), and studies in males (combined effect size = 1.39, 95% CI = 1.13-1.71, P = 0.002). In conclusion, we found that compared to nonsarcopenic, the association between sarcopenia and fractures among community-dwelling older people was significant when using the AWGS definition, and only for males. Future studies are needed to establish a possible association between sarcopenia definitions and risk of fractures of different sites.

Determinants of muscle preservation in individuals with cerebral palsy across the lifespan: a narrative review of the literature

In individuals with cerebral palsy (CP), smaller muscle and atrophy are present at young age. Many people with CP also experience a decline in gross motor function as they age, which might be explained by the loss of muscle mass. The clinical observation of muscle wasting has prompted a comparison with sarcopenia in older adults, and the term accelerated musculoskeletal ageing is often used to describe the hallmark phenotype of CP through the lifespan. However, there has been very little research emphasis on the natural history of ageing with CP and even less with respect to the determinants or prevention of muscle loss with CP. Considering the burgeoning interest in the science of muscle preservation, this paper aims to (i) describe the characteristics of accelerated musculoskeletal ageing in people with CP, (ii) describe the pathophysiology of sarcopenia and parallels with CP, and (iii) discuss possible therapeutic approaches, based on established approaches for sarcopenia.