The relationship between all-cause mortality sarcopenia and sarcopenic obesity among hospitalized older people

Adipose tissue in older individuals: a contributing factor to sarcopenia

Sarcopenia is a geriatric syndrome characterized by a functional decline in muscle. The prevalence of sarcopenia increases with natural aging, becoming a serious health problem among elderly individuals. Therefore, understanding the pathology of sarcopenia is critical for inhibiting age-related alterations and promoting health and longevity in elderly individuals. The development of sarcopenia may be influenced by interactions between visceral and subcutaneous adipose tissue and skeletal muscle, particularly under conditions of chronic low-grade inflammation and metabolic dysfunction. This hypothesis is supported by the following observations: (i) accumulation of senescent cells in both adipose tissue and skeletal muscle with age; (ii) gut dysbiosis, characterized by an imbalance in gut microbial communities as the main trigger for inflammation, sarcopenia, and aged adipose tissue; and (iii) microbial dysbiosis, which could impact the onset or progression of a senescent state. Moreover, adipose tissue acts as an endocrine organ, releasing molecules that participate in intricate communication networks between organs. Our discussion focuses on novel adipokines and their role in regulating adipose tissue and muscle, particularly those influenced by aging and obesity, emphasizing their contributions to disease development. On the basis of these findings, we propose that age-related adipose tissue and sarcopenia are disorders characterized by chronic inflammation and metabolic dysregulation. Finally, we explore new potential therapeutic strategies involving specialized proresolving mediator (SPM) G protein-coupled receptor (GPCR) agonists, non-SPM GPCR agonists, transient receptor potential (TRP) channels, antidiabetic drugs in conjunction with probiotics and prebiotics, and compounds designed to target senescent cells and mitigate their pro-inflammatory activity.

Sarcopenia, sarcopenic obesity and the clinical outcome of the older inpatients with COVID-19 infection: a prospective observational study

OBJECTIVE

We aimed to investigate the impact of sarcopenia and sarcopenic obesity (SO) on the clinical outcome in older patients with COVID-19 infection and chronic disease.

METHODS

We prospectively collected data from patients admitted to Huadong Hospital for COVID-19 infection between November 1, 2022, and January 31, 2023. These patients were included from a previously established comprehensive geriatric assessment (CGA) cohort. We collected information on their pre-admission condition regarding sarcopenia, SO, and malnutrition, as well as their medical treatment. The primary endpoint was the incidence of intubation, while secondary endpoints included in-hospital mortality rates. We then utilized Kaplan-Meier (K-M) survival curves and the log-rank tests to compare the clinical outcomes related to intubation or death, assessing the impact of sarcopenia and SO on patient clinical outcomes.

RESULTS

A total of 113 patients (age 89.6 ± 7.0 years) were included in the study. Among them, 51 patients had sarcopenia and 39 had SO prior to hospitalization. Intubation was required for 6 patients without sarcopenia (9.7%) and for 18 sarcopenia patients (35.3%), with 16 of these being SO patients (41%). Mortality occurred in 2 patients without sarcopenia (3.3%) and in 13 sarcopenia patients (25.5%), of which 11 were SO patients (28%). Upon further analysis, patients with SO exhibited significantly elevated risks for both intubation (Hazard Ratio [HR] 7.43, 95% Confidence Interval [CI] 1.26-43.90, P < 0.001) and mortality (HR 6.54, 95% CI 1.09-39.38, P < 0.001) after adjusting for confounding factors.

CONCLUSIONS

The prevalence of sarcopenia or SO was high among senior inpatients, and both conditions were found to have a significant negative impact on the clinical outcomes of COVID-19 infection. Therefore, it is essential to regularly assess and intervene in these conditions at the earliest stage possible.

Sarcopenic obesity in older adults: a clinical overview

Sarcopenic obesity is characterized by a concurrent decline in muscle mass and function, along with increased adipose tissue. Sarcopenic obesity is a growing concern in older adults owing to significant health consequences, including implications for mortality, comorbidities and risk of developing geriatric syndromes. A 2022 consensus statement established a new definition and diagnostic criteria for sarcopenic obesity. The pathophysiology of this condition involves a complex interplay between muscle, adipose tissue, hormonal changes, inflammation, oxidative stress and lifestyle factors, among others. Sarcopenic obesity is treated with a range of management approaches, such as lifestyle interventions, exercise, nutrition and medical therapies. Emerging therapies that were developed for treating other conditions may be relevant to sarcopenic obesity, including novel pharmacological agents and personalized approaches such as precision medicine. In this Review, we synthesize the current knowledge of the clinical importance of sarcopenic obesity, its assessment and diagnosis, along with current and emerging management strategies.

Body composition assessment for sarcopenic obesity and 3-year mortality in older adults: A comparison study

BACKGROUND

There is no universally accepted definition of sarcopenic obesity (SO), and its prevalence is ambiguous. This study aimed to investigate the prevalence of SO in older adults based on different definitions and determine which predicts all-cause mortality.

METHODS

This prospective longitudinal follow-up study included outpatients aged ≥60 years. SO was defined by sarcopenia definition based on the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) criteria plus obesity. Three different methods were used to define obesity. Body mass index (BMI) ≥ 30 kg/m2, waist circumference (WC) ≥ 102 cm for men and ≥88.0 cm for women, and body fat percentage (BF%) ≥ 37.3% for men and ≥51.1% for women. Different definitions of SO and their mortality predictions were compared.

RESULTS

The median age of the 584 patients in the study was 70.0 (interquartile range, 66.0-76.0) years. The prevalence of sarcopenia was 38.5% (47.5% in men and 35.7% in women). The prevalence of SO based on BMI, WC, and BF% was 15.3%, 16.4%, and 10.5%, respectively. The mortality rate was 6.7%. SO based on BMI (odds ratio [OR], 2.73; 95% CI, 1.12-17.9; P = 0.024) and BF% (OR, 1.43; 95% CI, 1.19-3.02; P = 0.007) were significantly associated with 3-year mortality after adjusting for the confounding variables of age, sex, and number of comorbidities. SO based on WC was not associated with mortality (OR, 0.78; 95% CI, 0.07-1.27; P = 0.104).

CONCLUSION

The use of BF% and BMI for defining SO is appropriate in outpatient older adults.

Obesity paradox in older sarcopenic adults - a delay in aging: A systematic review and meta-analysis

The prognostic significance of obesity in sarcopenic adults is controversial. This systematic review and meta-analysis aimed to investigate the effect of additional obesity on health outcomes in sarcopenia. MEDLINE, EMBASE, Scopus and CENTRAL were systematically searched for studies to compare health outcomes of adults with sarcopenic obesity (SO) to those of sarcopenic non-obese (SNO) adults. We also considered the methods of assessing obesity. Of 15060 records screened, 65 papers were included (100612 participants). Older community-dwelling SO adults had 15% lower mortality risk than the SNO group (hazard ratio, HR: 0.85, 95% confidence interval 0.76, 0.94) even when obesity was assessed by measurement of body composition. Additionally, meta-regression analysis revealed a significant negative linear correlation between the age and the HR of all-cause mortality in SO vs. SNO community-dwelling adults, but not in severely ill patients. Compared with SNO, SO patients presented lower physical performance, higher risk for metabolic syndrome, but similar cognitive function, risk of falls and cardiovascular diseases. Age-related obesity, SO and later fat loss leading to SNO represent consecutive phases of biological aging. Additional obesity could worsen the health state in sarcopenia, but above 65 years SO represents a biologically earlier phase with longer life expectancy than SNO.

Low lean mass with obesity in older adults with hypertension: prevalence and association with mortality rate

BACKGROUND

The influence of sarcopenic obesity (SO) on overall survival in older adults with hypertension has not been addressed. The aim of this study was to investigate the prevalence and mortality predictive value of various body composition phenotypes, focusing mainly on SO, in older adults with hypertension.

METHODS

We included 1105 hypertensive patients aged ≥ 60 years from the National Health and Nutrition Examination Survey 1999-2004. Sarcopenia was broadly defined based on low lean mass (LLM; as measured by dual-energy X-ray absorptiometry), and was defined using appendicular lean mass (ALM) divided by height squared (ALM/height2), weight (ALM/weight), and body mass index (BMI; ALM/BMI), respectively. Obesity was defined as BMI ≥ 30 kg/m2, body fat percentage ≥ 30/42%, or waist circumference ≥ 102/88 cm. The prevalence of LLM with obesity was estimated according to each ALM index (ALMI). Multivariable Cox regression analysis and sensitivity analysis were used to examine the association between various body composition phenotypes and all-cause mortality.

RESULTS

In older adults with hypertension, the prevalence of LLM with obesity by the ALM/height2 index (9.8%) was lower relative to the ALM/weight (11.7%) and ALM/BMI indexes (19.6%). After a median follow-up of 15.4 years, 642 deaths occurred. In the fully adjusted models, LLM with obesity was significantly associated with a higher risk of all-cause mortality (hazard ratio [HR] 1.69, 95% confidence interval [CI] 1.14-2.49, P = 0.008; HR 1.48, 95% CI 1.04-2.10, P = 0.028; HR 1.30, 95% CI 1.02-1.66, P = 0.037; respectively) compared with the normal body phenotype, with no statistical differences found in individuals with LLM or obesity alone. Sensitivity analysis confirmed the robustness of the results.

CONCLUSIONS

The prevalence of LLM with obesity markedly differed in older adults with hypertension according to the 3 different ALMIs, varying from 9.8%, 11.7%, to 19.6%. Patients with both LLM and obesity had a higher risk of all-cause mortality. Further large, prospective, cohort studies are warranted to validate these findings and uncover underlying mechanisms.

The impact of sarcopenia and obesity on mortality of older adults: five years results

AIM

Sarcopenia and obesity can cause severe physical and metabolic complications. We aimed to investigate the risk of mortality associated with sarcopenia and obesity in older adults.

METHOD

We designed a retrospective, observational cohort study showing the 5-year mortality of older patients in a tertiary geriatric outpatient clinic. Sociodemographic characteristics, medical history, anthropometric measurements, medications, and comorbidities were recorded. Sarcopenia was evaluated with skeletal muscle mass, handgrip strength, and gait speed. We defined sarcopenic obesity as sarcopenia plus obesity (as a body mass index ≥ 30 kg/m2). We classified the participants into four groups according to whether they were sarcopenic and/or obese: non-sarcopenic non-obese, non-sarcopenic obese, sarcopenic non-obese, and sarcopenic obese. The final overall survival of the patients was obtained from the hospital data system.

RESULTS

Of the 175 patients, the mean age was 76.1 ± 6.4, and the majority were female (n = 120). Sixty-eight had sarcopenia (39%). The prevalence of obesity was 27%. Thirty-eight patients had died within five years (22%). The mortality rate was significantly higher in the oldest (age 85 and above) and sarcopenic groups (p < 0.001, 0.004, respectively). The mortality rate was highest in the sarcopenic obese group (40.9%). Age (HR: 1.13, 95% CI: 1.07-1.19, p: < 0.001), sarcopenic obesity (HR: 4.85, 95% CI: 1.91-12.31, p: 0.001), sarcopenia (HR: 2.26, 95% CI: 1.15-4.43, p: 0.018) and obesity (HR: 2.15, 95% CI: 1.11-4.17, p: 0.023) were independently associated with mortality at 5 years. The Kaplan-Meier analysis and Log-Rank test showed that sarcopenic obese patients had the highest cumulative mortality incidence rates.

CONCLUSION

Sarcopenic-obese participants had the highest mortality incidence compared to those without obesity or sarcopenia. In addition, the presence of sarcopenia or obesity alone also had a significant role in mortality risk. So, we should especially focus on maintaining or increasing muscle mass and preventing obesity.

Obesity phenotypes and cardiovascular risk: From pathophysiology to clinical management

Obesity epidemic reached the dimensions of a real global health crisis with more than one billion people worldwide living with obesity. Multiple obesity-related mechanisms cause structural, functional, humoral, and hemodynamic alterations with cardiovascular (CV) deleterious effects. A correct assessment of the cardiovascular risk in people with obesity is critical for reducing mortality and preserving quality of life. The correct identification of the obesity status remains difficult as recent evidence suggest that different phenotypes of obesity exist, each one associated with different degrees of CV risk. Diagnosis of obesity cannot depend only on anthropometric parameters but should include a precise assessment of the metabolic status. Recently, the World Heart Federation and World Obesity Federation provided an action plan for management of obesity-related CV risk and mortality, stressing for the instauration of comprehensive structured programs encompassing multidisciplinary teams. In this review we aim at providing an updated summary regarding the different obesity phenotypes, their specific effects on CV risk and differences in clinical management.

Deciphering the "obesity paradox" in the elderly: A systematic review and meta-analysis of sarcopenic obesity

Aging and obesity are two global concerns in public health. Sarcopenic obesity (SO), defined as the combination of age-related sarcopenia and obesity, has become a pressing issue. This systematic review and meta-analysis summarize the current clinical evidence relevant to SO. PubMed, Embase, and Web of Science were searched, and 106 clinical studies with 167,151 elderlies were included. The estimated prevalence of SO was 9% in both men and women. Obesity was associated with 34% reduced risk of sarcopenia (odds ratio [OR] 0.66, 95% CI 0.48-0.91; p < 0.001). The pooled hazard ratio (HR) of all-cause mortality was 1.51 (95% CI 1.14-2.02; p < 0.001) for people with SO compared with healthy individuals. SO was associated with increased risk of cardiovascular disease and related mortality, metabolic disorders, cognitive impairment, arthritis, functional limitation, and lung diseases (all ORs > 1.0, p < 0.05). The attenuated risk of sarcopenia in elderlies with obesity ("obesity paradox") was dependent on higher muscle mass and strength. Apart from unifying the diagnosis of SO, more research is needed to subphenotype people with obesity and sarcopenia for individualized treatment. Meanwhile, the maintenance of proper body composition of muscle and fat may delay or attenuate the adverse outcomes of aging.

Sarcopenic obesity is associated with impaired physical function and mortality in older patients with heart failure: insight from FRAGILE-HF

Background

The purpose of this study was to clarify the prevalence, association with frailty and exercise capacity, and prognostic implication of sarcopenic obesity in patients with heart failure.

Methods

The present study included 779 older adults hospitalized with heart failure (median age: 81 years; 57.4% men). Sarcopenia was diagnosed based on the guidelines by the Asian Working Group for Sarcopenia. Obesity was defined as the percentage of body fat mass (FM) obtained by bioelectrical impedance analysis. The FM cut-off points for obesity were 38% for women and 27% for men. The primary endpoint was 1-year all-cause death. We assessed the associations of sarcopenic obesity occurrence with the short physical performance battery (SPPB) score and 6-minute walk distance (6MWD).

Results

The rates of sarcopenia and obesity were 19.3 and 26.2%, respectively. The patients were classified into the following groups: non-sarcopenia/non-obesity (58.5%), non-sarcopenia/obesity (22.2%), sarcopenia/non-obesity (15.3%), and sarcopenia/obesity (4.0%). The sarcopenia/obesity group had a lower SPPB score and shorter 6MWD, which was independent of age and sex (coefficient, − 0.120; t-value, − 3.74; P < 0.001 and coefficient, − 77.42; t-value, − 3.61; P < 0.001; respectively). Ninety-six patients died during the 1-year follow-up period. In a Cox proportional hazard analysis, sarcopenia and obesity together were an independent prognostic factor even after adjusting for a coexisting prognostic factor (non-sarcopenia/non-obesity vs. sarcopenia/obesity: hazard ratio, 2.48; 95% confidence interval, 1.22–5.04; P = 0.012).

Conclusion

Sarcopenic obesity is a risk factor for all-cause death and low physical function in older adults with heart failure.

Trial registration

University Hospital Information Network (UMIN-CTR: UMIN000023929).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03168-3.

Pathogenesis of sarcopenia and the relationship with fat mass: descriptive review

Age-associated obesity and muscle atrophy (sarcopenia) are intimately connected and are reciprocally regulated by adipose tissue and skeletal muscle dysfunction. During ageing, adipose inflammation leads to the redistribution of fat to the intra-abdominal area (visceral fat) and fatty infiltrations in skeletal muscles, resulting in decreased overall strength and functionality. Lipids and their derivatives accumulate both within and between muscle cells, inducing mitochondrial dysfunction, disturbing β-oxidation of fatty acids, and enhancing reactive oxygen species (ROS) production, leading to lipotoxicity and insulin resistance, as well as enhanced secretion of some pro-inflammatory cytokines. In turn, these muscle-secreted cytokines may exacerbate adipose tissue atrophy, support chronic low-grade inflammation, and establish a vicious cycle of local hyperlipidaemia, insulin resistance, and inflammation that spreads systemically, thus promoting the development of sarcopenic obesity (SO). We call this the metabaging cycle. Patients with SO show an increased risk of systemic insulin resistance, systemic inflammation, associated chronic diseases, and the subsequent progression to full-blown sarcopenia and even cachexia. Meanwhile in many cardiometabolic diseases, the ostensibly protective effect of obesity in extremely elderly subjects, also known as the 'obesity paradox', could possibly be explained by our theory that many elderly subjects with normal body mass index might actually harbour SO to various degrees, before it progresses to full-blown severe sarcopenia. Our review outlines current knowledge concerning the possible chain of causation between sarcopenia and obesity, proposes a solution to the obesity paradox, and the role of fat mass in ageing.

Sarcopenia, Obesity, and Sarcopenic Obesity: Relationship with Skeletal Muscle Phenotypes and Single Nucleotide Polymorphisms

Obesity may aggravate the effects of sarcopenia on skeletal muscle structure and function in the elderly, but no study has attempted to identify the gene variants associated with sarcopenia in obese women. Therefore, the aims of the present study were to: (1) describe neuromuscular function in sarcopenic and non-sarcopenic women with or without obesity; (2) identify gene variants associated with sarcopenia in older obese women. In 307 Caucasian women (71 ± 6 years, 66.3 ± 11.3 kg), skeletal muscle mass was estimated using bioelectric impedance, and function was tested with a 30 s one-leg standing-balance test. Biceps brachii thickness and vastus lateralis cross-sectional area (VL_ACSA) were measured with B-mode ultrasonography. Handgrip strength, maximum voluntary contraction elbow flexion (MVC_EF), and knee extension torque (MVC_KE) were measured by dynamometry, and MVC_KE/VL_ACSA was calculated. Genotyping was performed for 24 single-nucleotide polymorphisms (SNPs), selected based on their previous associations with muscle-related phenotypes. Based on sarcopenia and obesity thresholds, groups were classified as sarcopenic obese, non-sarcopenic obese, sarcopenic non-obese, or non-sarcopenic non-obese. A two-way analysis of covariance was used to assess the main effects of sarcopenia and obesity on muscle-related phenotypes and binary logistic regression was performed for each SNP to investigate associations with sarcopenia in obesity. There were no significant obesity * sarcopenic status interactions for any of the investigated muscle-related phenotypic parameters. Neither sarcopenia nor obesity had a significant effect on biceps brachii thickness, but sarcopenia was associated with lower VL_ACSA (p = 0.003). Obesity was associated with lower MVC_EF (p = 0.032), MVC_KE (p = 0.047), and MVC_KE/VL_ACSA (p = 0.012) with no significant effect of sarcopenia. Adjusted for age and height, three SNPs (ACTN3 rs1815739, MTHFR rs1801131, and MTHFR rs1537516) were associated with sarcopenia in obese participants. Sarcopenia was associated with a smaller muscle size, while obesity resulted in a lower muscle quality irrespective of sarcopenia. Three gene variants (ACTN3 rs1815739, MTHFR rs1801131, and MTHFR rs1537516) suspected to affect muscle function, homocysteine metabolism, or DNA methylation, respectively, were associated with sarcopenia in obese elderly women. Understanding the skeletal muscle features affected by sarcopenia and obesity, and identification of genes related to sarcopenia in obese women, may facilitate early detection of individuals at particular risk of sarcopenic obesity.

Malnutrition-sarcopenia syndrome and all-cause mortality in hospitalized older people

PURPOSE

Malnutrition-sarcopenia syndrome (MSS) describes the presence of sarcopenia and malnutrition together. This study aims to evaluate the relationship between MSS and all-cause mortality at two years in hospitalised older Turkish people.

METHODS

This is a bi-centered prospective cohort study conducted in older individuals in hospital settings (University hospital and research, research and training hospital). Sarcopenia was diagnosed according to the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) criteria. Muscle mass was measured by bioelectrical impedance analysis. Malnutrition (MN) was assessed by the Mini Nutritional Assessment. Six study groups were formed according to sarcopenia and MN status; MSS, sarcopenia with malnutrition risk (MNR), sarcopenia, MN, MNR, and normal nutrition. The relationship between MSS and other study groups with mortality was assessed by Cox regression model. Survival curves were estimated using the Kaplan-Meier method.

RESULTS

350 hospitalised older people participated (mean age: 77.2 ± 7.6, 56% female). During the 2-year follow-up, 98 (28%) of the participants died. MSS, sarcopenia, sarcopenia with MNR and MN groups were independently associated with all-cause mortality at two years. MSS group had the highest hazard ratio (HR:19.8). Survival curves of MSS sarcopenia, sarcopenia with MNR, and MN groups were significantly different from MNR and normal nutrition groups. MSS had the worst survival curve.

CONCLUSIONS

Hospitalised older people should be evaluated for the presence of both sarcopenia and MN because of increased mortality. Preventive measures are needed for both conditions to decrease adverse health outcomes such as mortality.

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.

Global prevalence of sarcopenic obesity in older adults: A systematic review and meta-analysis

BACKGROUND & AIMS

Sarcopenic obesity (SO), which refers to the coexistence of sarcopenia and obesity. It can lead to physical disability, morbidity, and even mortality. This systematic review and meta-analysis aimed to estimate the global prevalence of SO in older adults.

METHODS

We searched PubMed, Embase, and Web of Science for studies reporting the prevalence of SO from inception to December 2020. Two researchers independently screened the literature, evaluated study quality, and extracted data. A random-effects model was used to pool the estimates for the prevalence of SO. Subgroup analysis, sensitivity analysis, and meta-regression analysis were conducted. Publication bias was assessed using a funnel plot and the Egger test. All statistical analyses were performed using Stata 15.0 software.

RESULTS

This review included 50 studies, we found that the global prevalence of SO in older adults was 11%. Subgroup analyses showed that the prevalence of SO was higher among studies using diagnostic criteria of muscle mass alone (15%) to diagnose sarcopenia, using dual-energy X-ray absorptiometry (15%) to assess muscle mass, and those focused on age ≥ 75 years old (23%), hospitalized (16%), South Americans (21%) and North Americans (19%). There were no significant differences in the prevalence of SO among studies using body fat percentage (10%), body mass index (13%), waist circumference (16%) to diagnose obesity and in female (14%), male (10%) patients. Sensitivity analysis showed that none of the studies affected the overall pooled results. Meta-regression analysis found that publication year, geographical region, study setting, and the diagnostic criteria of sarcopenia were sources of heterogeneity.

CONCLUSION

This meta-analysis indicated SO affects more than one in ten older adults globally. Therefore, we should attach importance to the screening and early diagnosis of SO in older adults, then selecting appropriate interventions to reduce the occurrence of it and various adverse outcomes in this demographic.

Relationship between smoking and the incidence of sarcopenia: The SarcoPhAge cohort

INTRODUCTION

The association of tobacco use and incidence of muscle impairments has not been extensively explored in research. In this study, the relationship between smoking and the incidence of sarcopenia is investigated.

METHODS

The present longitudinal study used data from the Sarcopenia and Physical Impairment with advancing Age (SarcoPhAge) cohort, which includes older adults aged ≥65 years. All individuals with follow-up data on muscle health were included in this post hoc analysis. A diagnosis of sarcopenia was established, at each year of follow-up, according to the European Working Group on Sarcopenia in older People 2 (EWGSOP2) criteria. A sensitivity analysis was performed using other diagnostic criteria for sarcopenia. The smoking status and the number of cigarettes smoked per day were self-reported. The relationship between smoking status or the number of cigarettes smoked per day and the incidence of sarcopenia/severe sarcopenia throughout the 5 years of follow-up was evaluated using the Cox proportional hazards model.

RESULTS

In total, the study population included 420 participants, with a median age of 71.7 years (P25-P75 = 67.7-76.9 years) and 59.8% were female. Over the 5 years of follow-up, 78 participants (18.6%) became sarcopenic as per the EWGSOP2 criteria and 41 individuals (9.8%) developed severe sarcopenia. There were significantly more smokers than non-smokers who developed sarcopenia (35.9% vs 16.8%, P-value = 0.003). A fully adjusted Cox model confirmed this observation, yielding a hazard ratio of 2.36 (95% confidence interval [CI]: 1.31-4.26), meaning that smokers have a 2.36-fold higher risk of developing sarcopenia. Furthermore, individuals who smoked had a 2.68 times increased risk of developing severe sarcopenia (95% CI: 1.21-5.93) than those who did not smoke. Sensitivity analyses globally confirmed these findings when applying other diagnostic criteria for sarcopenia.

DISCUSSION

Smoking seems to be an important predictor for the onset of sarcopenia, highlighting, once again, that tobacco use is a major public health problem.

Effects of whole-body electromyostimulation on function, muscle mass, strength, social participation, and falls-efficacy in older people: A randomized trial protocol

Background

Resistance training has a positive impact on functional capacity and muscle mass in the elderly. However, due to physical limitations or a simple aversion against regular exercise, a majority of the elderly do not reach the recommended exercise doses. This led us to evaluate the effect of whole-body electromyostimulation (WB-EMS), a novel, time-efficient, and smooth training technology on physical function, fat-free mass, strength, falls-efficacy, and social participation of the elderly.

Methods

The present study is a randomized, parallel group clinical trial approved by the Ethics Committee of our Institution. Sixty-six volunteers (age ≥ 60 years) will be recruited from the geriatric outpatient department in a tertiary hospital and primary care units and randomized into two groups: WB-EMS group or active control group (aCG). The WB-EMS or aCG protocol will consist of 16 sessions for 8 consecutive weeks, twice per week. The primary outcomes will be maximal isometric knee extension (IKE), functional lower extremity strength, fat-free mass, gait speed, and risk of falls measured before and after intervention. The secondary outcomes will be social participation and falls-efficacy assessed before and after the intervention and at three and six months of follow-up. Participant’s satisfaction with and awareness of electrical stimulation therapy will also be assessed immediately after the 8-week intervention.

Discussion

Patients receiving WB-EMS exercises are believed to have better outcomes than those receiving conventional, more time-consuming resistance exercises. Hence, innovative, time-efficient, joint-friendly, and highly individualized exercise technologies (such as WB-EMS) may be a good choice for the elderly with time constraints, physical limitations, or little enthusiasm, who are exercising less than the recommended amounts for impact on muscle mass, strength, and function.

Sarcopenia, Low Handgrip Strength, and Low Absolute Muscle Mass Predict Long-Term Mortality in Older Hospitalized Patients: An Observational Inception Cohort Study

OBJECTIVE

Sarcopenia is highly prevalent in hospitalized older patients and associated with short-term mortality. This study aimed to investigate whether sarcopenia and its measures handgrip strength (HGS) and muscle mass at hospital admission were associated with long-term mortality in a cohort of hospitalized older patients.

DESIGN

Observational, prospective, longitudinal inception cohort study.

SETTING AND PARTICIPANTS

Academic teaching hospital; patients age ≥70 years admitted to the internal medicine, acute admission, trauma, or orthopedic wards.

METHODS

HGS and muscle mass were measured at admission using a hand dynamometer and bioelectrical impedance analysis. Sarcopenia was determined based on the European Working Group on Sarcopenia in Older People definition. HGS and muscle mass (skeletal muscle mass index, appendicular lean mass, relative skeletal muscle mass) were expressed as sex-specific tertiles. The associations of sarcopenia, HGS, and muscle mass with mortality (during a follow-up of 3.4-4.1 years) were analyzed using Cox regression, adjusted for age, sex, comorbidity, and weight or height. Associations of HGS and muscle mass were stratified by sex.

RESULTS

Out of 363 patients [mean age: 79.6 years (standard deviation: 6.4), 49.9% female] 49% died. Probable sarcopenia (prevalence of 53.7%) and sarcopenia (prevalence of 20.8%) were significantly associated with long-term mortality [hazard ratio (HR) 1.53, 95% confidence interval (CI) 1.08‒2.17 and 1.71 95% CI 1.12‒2.61, respectively]. Low HGS, skeletal muscle mass index, and appendicular lean mass were associated with a higher mortality risk (lowest tertile vs highest tertile: HR 2.660, 95% CI 1.40‒5.05; HR 1.95, 95% CI 1.06‒3.58 and HR 1.99 (95% CI 1.12‒3.53) in male patients. No statistically significant associations of relative muscle mass with mortality were found.

CONCLUSIONS AND IMPLICATIONS

Sarcopenia and its measures (low HGS and low absolute muscle mass at admission) predict long-term mortality in older hospitalized patients.

Growth differentiation factor-15 as a biomarker for sarcopenia in aging humans and mice

Sarcopenia is a pathologic status characterized by impaired muscle strength or function accompanying decreased muscle mass. It results in increased vulnerability to chronic diseases. Despite growing clinical concerns about sarcopenia in an aging society, there are few validated biomarkers for age-related sarcopenia. We tested the potential of growth differentiation factor-15 (GDF-15) as a biomarker for sarcopenia in mice and humans across wide age ranges. We used four groups of mice (6, 10, 14, and 18 months old) to explore the association between GDF-15 levels and age, muscle mass, and endurance capacity. Among those four groups, 6- and 18-month-old mice were exposed to 8 weeks of treadmill exercise. The GDF-15 levels were measured in serum and muscle at baseline and after exercise intervention. The body composition was assessed using animal dual-energy X-ray absorptiometry (DXA). GDF-15 levels in tissue and serum increased with age in these mice. The serum levels of GDF-15 had a strong negative correlation with both muscle weight and exercise endurance capacity. Expression of GDF-15 in muscle also had a negative trend with muscle weight and endurance capacity. The muscle expression of GDF-15 was significantly attenuated after 8 weeks of exercise compared with the group without exercise, particularly in older mice. GDF-15 levels were also related to functional capacity and showed responses to therapeutic exercise intervention in this model. We also measured serum GDF-15 levels and muscle mass using DXA in healthy human adults (19 men and 18 women). As in mice, serum levels of GDF-15 were correlated positively with age, but negatively with muscle mass in these subjects. These findings support the potential of GDF-15 as a biomarker for age-related sarcopenia.

The Predictive Value of Sarcopenia and Its Individual Criteria for Cardiovascular and All-Cause Mortality in Suburb-dwelling Older Chinese

OBJECTIVES

The aim of the present study is to investigate the associations between the Asian Working Group for Sarcopenia (AWGS) sarcopenic definition, and its individual criteria, and risk of cardiovascular disease (CVD) and all-cause mortality in the Chinese elderly.

METHODS

Longitudinal analysis of 1,264 participants aged 60 years or older at baseline (2013-2014) living in suburban areas, China. Sarcopenia was defined according to the recommended algorithm of AWGS. Muscle mass was measured by a direct segmental multifrequency bioelectrical impedance analysis. Muscle strength was assessed by handgrip strength, and physical performance measured via usual walking speed.

RESULTS

Cox proportional hazard models were used to assess the risk of CVD and all-cause mortality. After 40 months of follow-up, forty-eight deaths (4.2%) died in this cohort. The mortality rate with sarcopenia was 4.7% in men and 3.8% in women. After adjusting for potential confounders, the risk of all-cause death was 4.15 times higher in subjects with sarcopenia. Furthermore, low muscle mass (HR: 2.62, 95% CI 1.34-5.13) and low grip strength (HR: 5.79; 95% CI 2.28-14.71), but not walking speed, were found to be significantly associated with all-cause mortality. Risk of CVD mortality was significantly greater in sarcopenia. Low grip strength and low walking speed were associated with 11 times (HR: 11.03, 95% CI 1.58-77.02) and 13 times (HR: 13.02; 95% CI 1.18-143.78) higher risk of CVD mortality.

CONCLUSIONS

Sarcopenia and components of sarcopenia were associated with greater CVD and all-cause mortality. Pertinent prevention or rehabilitation programs projects should look to promote healthy aging in different types of sarcopenia group.