Association between Sarcopenia, Sarcopenic Obesity, and Chronic Disease in Korean Elderly

Machine-learning classifier models for predicting sarcopenia in the elderly based on physical factors

AIM

As the size of the elderly population gradually increases, musculoskeletal disorders, such as sarcopenia, are increasing. Diagnostic techniques such as X-rays, computed tomography, and magnetic resonance imaging are used to predict and diagnose sarcopenia, and methods using machine learning are gradually increasing. This study aimed to create a model that can predict sarcopenia using physical characteristics and activity-related variables without medical diagnostic equipment, such as imaging equipment, for the elderly aged 60 years or older.

METHODS

A sarcopenia prediction model was constructed using public data obtained from the Korea National Health and Nutrition Examination Survey. Models were built using Logistic Regression, Support Vector Machine (SVM), XGBoost, LightGBM, RandomForest, and Multi-layer Perceptron Neural Network (MLP) algorithms, and the feature importance of the models trained with the algorithms, except for SVM and MLP, was analyzed.

RESULTS

The sarcopenia prediction model built with the LightGBM algorithm achieved the highest test accuracy, of 0.848. In constructing the LightGBM model, physical characteristic variables such as body mass index, weight, and waist circumference showed high importance, and activity-related variables were also used in constructing the model.

CONCLUSIONS

The sarcopenia prediction model, which consisted of only physical characteristics and activity-related factors, showed excellent performance. This model has the potential to assist in the early detection of sarcopenia in the elderly, especially in communities with limited access to medical resources or facilities. Geriatr Gerontol Int 2024; 24: 595-602.

Prevalence of sarcopenic obesity in the older non-hospitalized population: a systematic review and meta-analysis

BACKGROUND

Sarcopenic obesity emerges as a risk factor for adverse clinical outcomes in non-hospitalized older adults, including physical disabilities, metabolic diseases, and even mortality. In this systematic review and meta-analysis, we investigated the overall SO prevalence in non-hospitalized adults aged ≥ 65 years and assessed the sociodemographic, clinicobiological, and lifestyle factors related to SO.

METHODS

We searched the PubMed, Embase, Cochrane Library, and Web of Science databases for studies reporting the prevalence of SO from database inception to October 2023. Two researchers independently screened the literature, evaluated the study quality, and extracted the data. Both fixed- and random-effects models were used in the meta-analysis to estimate the pooled SO prevalence and perform subgroup analyses. Publication and sensitivity bias analyses were performed to test the robustness of the associations.

RESULTS

Among 46 studies eligible for review and a total of 71,757 non-hospitalized older adults, the combined prevalence of SO was 14% (95% CI:11-17%, I2 = 99.5%, P < 0.01). Subgroup analysis according to lifestyle factors demonstrated that the SO prevalence was 17% (95% CI: 8-29%, I2 = 99.5%, P < 0.01) in older adults without exercise habits. Regarding clinicobiological factors, older adults with a history of falls (15% [95% CI: 10-22%, I2 = 82%, P < 0.01]), two or more chronic diseases (19% [95% CI: 10-29%, I2 = 97%, P < 0.01]), functional impairment (33% [95% CI: 29-37%, I2 = 0%, P = 0.95]), cognitive impairment (35% [95% CI: 9-65%, I2 = 83%, P = 0.02]), osteoporosis (20% [95% CI: 8-35%, I2 = 96%, P < 0.01]), high fasting glucose level (17% [95% CI: 1-49%, I2 = 98%, P < 0.01]), or the use of antipsychotics (13% [95% CI: 2-28%, I2 = 0%, P = 0.32]) exhibited a higher SO prevalence.

CONCLUSION

SO prevalence is high among non-hospitalized older adults, especially those with functional and cognitive impairments. Thus, SO is a potential problem for the aging population; implementation of planned interventions in the community is needed to reduce the prevalence and adverse outcomes of SO.

Sex-Specific Effects of Dietary Factors on Sarcopenic Obesity in Korean Elderly: A Nationwide Cross-Sectional Study

This study aimed to compare the dietary factors related to sarcopenia and obesity status in 5458 elderly individuals (2391 men and 3076 women) aged ≥65 years from the Korean National Health and Nutrition Examination Survey (2016-2019). Participants were categorized into normal, sarcopenia, obesity, and sarcopenic obesity groups. Sarcopenic obesity showed a higher prevalence of diabetes and lower HDL cholesterol levels compared to obesity. Sarcopenic obesity exhibited a lower total KHEI score and lower adequacy, including meat/fish/eggs/beans, than normal or obesity. In women, sarcopenic obesity scored lower than obesity on the total KHEI, adequacy for most foods, and balance of energy intake, and lower than sarcopenia on the adequacy of breakfast and milk/milk products. Sarcopenic obesity showed no significant difference in energy intake compared to sarcopenia, and less physical activity compared to sarcopenia and obesity, with a BMI/waist circumference comparable to that of obesity. Low total KHEI scores and scores for meat/fish/eggs/beans were most closely associated with sarcopenia in men and with sarcopenic obesity in women. In conclusion, low dietary quality and inadequate protein-rich foods are possibly associated with the prevalence of sarcopenic obesity in elderly Koreans, especially in women. Adequate energy intake and dietary diversity may be effective in managing sarcopenic obesity.

Effect of Sarcopenia on 10-Year Risk of Atherosclerotic Cardiovascular Disease in Patients with Type 2 Diabetes Mellitus

Objective

To investigate the impact of sarcopenia on the 10-year risk of atherosclerotic cardiovascular disease (ASCVD) among individuals with type 2 diabetes mellitus (T2DM).

Methods

This study included the clinical, laboratory, and body composition data of 1491 patients with T2DM who were admitted to the Department of Endocrinology and Metabolism at Tianjin Union Medical Center from July 2018 to July 2023. The China-PAR model was utilized to evaluate cardiovascular disease risk. Associations between ASCVD risk and various clinical parameters were analyzed, and the relationship between body composition parameters and ASCVD risk was assessed using logistic regression.

Results

The analysis revealed that T2DM patients with sarcopenia had a higher 10-year ASCVD risk compared to those without sarcopenia, with reduced muscle mass independently predicting an increased risk of cardiovascular disease. This association was significant among female T2DM patients, while male T2DM patients with sarcopenia showed a marginally higher median ASCVD risk compared to their non-sarcopenic counterparts. ASCVD risk inversely correlated with body muscle parameters and positively correlated with fat content parameters. Specifically, height- and weight-adjusted fat mass (FM, FM%, FMI) were identified as risk factors for ASCVD. Conversely, muscle parameters adjusted for weight and fat (ASM%, SMM%, FFM%, ASM/FM, SMM/FM, FMM/FM) were protective against ASCVD risk. These findings highlight the critical role of sarcopenia in influencing cardiovascular disease risk among Chinese patients with T2DM, as predicted by the China-PAR model.

Conclusion

This study highlights the importance of sarcopenia in T2DM patients, not only as an indicator of ASCVD risk, but possibly as an independent risk factor in this demographics.

Sarcopenia and risk factors among Japanese community-dwelling older adults during the COVID-19 pandemic: A cross-sectional study

The COVID-19 pandemic exposed older adults to high risk of sarcopenia. This study aimed to investigate the prevalence of sarcopenia and its risk factors among Japanese community-dwelling older adults during the COVID-19 pandemic. We collected data through questionnaires and physical measurements among 242 older adults. Sarcopenia was assessed using the Asian Working Group for Sarcopenia 2019 criteria. The results revealed that 14.5% had sarcopenia, which was significantly associated with age, nutritional status, number of prescription medications, body mass index, and self-rated health. On multivariate analysis, the risk of malnutrition was independently significantly associated with sarcopenia. Approximately 70% of participants reported decreased social interaction and going outside, but with no significant association with sarcopenia. In addition, approximately 65% of the participants had an exercise habit and went outside at least once a week, thus maintaining a good level of activity. These findings suggest that prevention of sarcopenia during the pandemic required provision of opportunities for older adults to remain active and positive assessment of nutritional status and well-being.

Dyslipidemia is associated with sarcopenia of the elderly: a meta-analysis

PURPOSE

Sarcopenia is a pathological change characterized by muscle loss in older people. According to the reports, there is controversy on the relationship between dyslipidemia and sarcopenia. Therefore, this meta-analysis aimed to explore the association between sarcopenia and dyslipidemia.

METHODS

We searched the Cochrane Library, Web of Science, PubMed, China National Knowledge Infrastructure (CNKI), Wan Fang, China Science and Technology Journal Database (VIP Database) for case‒control studies to extract data on the odds ratio (OR) between sarcopenia and dyslipidemia and the MD(mean difference) of TC, LDL-C, HDL-C, TG, and TG/HDL-C between sarcopenia and nonsarcopenia. The JBI(Joanna Briggs) guidelines were used to evaluate the quality. Excel 2021, Review Manager 5.3 and Stata 16.0 were used for the statistical analysis.

RESULTS

Twenty studies were included in the meta-analysis, 19 of which were evaluated as good quality. The overall OR of the relationship between sarcopenia and dyslipidemia was 1.47, and the MD values of TC, LDL-C, HDL-C, TG, and TG/HDL-C were 1.10, 1.95, 1.27, 30.13, and 0.16 respectively. In female, compared with the non-sarcopnia, the MD of TC, LDL-C, HDL-C, TG of sarcopenia were - 1.67,2.21,1.02,-3.18 respectively. In male, the MD of TC, LDL-C, HDL-C, TG between sarcopenia and non-sarcopenia were - 0.51, 1.41, 5.77, -0.67. The OR between sarcopenia and dyslipidemia of the non-China region was 4.38, and it was 0.9 in China. In the group(> 60), MD of TC between sarcopenia and non-sarcopenia was 2.63, while it was 1.54 in the group(20-60).

CONCLUSION

Dyslipidemia was associated with sarcopenia in the elderly, which was affected by sex, region and age.

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.

Sarcopenic Obesity as a Risk Factor for Cardiovascular Disease: An Underrecognized Clinical Entity

Sarcopenic obesity (SO) is a chronic condition and an emerging health challenge, in view of the growing elderly population and the obesity epidemic. Due to a lack of awareness among treating doctors and the non-specific nauture of the associated symptoms, SO remains grossly underdiagnosed. There is no consensus yet on a standard definition or diagnostic criteria for SO, which limits the estimation of the global prevalence of this condition. It has been linked to numerous metabolic derangements, cardiovascular disease (CVD) and mortality. The treatment of SO is multimodal and requires expertise across multiple specialties. While dietary modifications and exercise regimens have shown a potential therapeutic benefit, there is currently no proven pharmacological management for SO. However, numerous drugs and the role of bariatric surgery are still under trial, and have great scope for further research. This article covers the available literature regarding the definition, diagnostic criteria, and prevalence of SO, with available evidence linking it to CVD, metabolic disease and mortality, and an overview of current directives on management.

Machine Learning for Sarcopenia Prediction in the Elderly Using Socioeconomic, Infrastructure, and Quality-of-Life Data

Since the WHO's 2021 aging redefinition emphasizes "healthy aging" by focusing on the elderly's ability to perform daily activities, sarcopenia, which is defined as the loss of skeletal muscle mass, is now becoming a critical health concern, especially in South Korea with a rapidly aging population. Therefore, we develop a prediction model for sarcopenia by using machine learning (ML) techniques based on the Korea National Health and Nutrition Examination Survey (KNHANES) data 2008-2011, in which we focus on the role of socioeconomic status (SES), social infrastructure, and quality of life (QoL) in the prevalence of sarcopenia. We successfully identify sarcopenia with approximately 80% accuracy by using random forest (RF) and LightGBM (LGB), CatBoost (CAT), and a deep neural network (DNN). For prediction reliability, we achieve area under curve (AUC) values of 0.831, 0.868, and 0.773 for both genders, males, and females, respectively. Especially when using only male data, all the models consistently exhibit better performance overall. Furthermore, using the SHapley Additive exPlanations (SHAP) analysis, we find several common key features, which mainly contribute to model building. These include SES features, such as monthly household income, housing type, marriage status, and social infrastructure accessibility. Furthermore, the causal relationships of household income, per capita neighborhood sports facility area, and life satisfaction are analyzed to establish an effective prediction model for sarcopenia management in an aging population.

Associations between physical activity, physical fitness, and body composition in adults living in Germany: A cross-sectional study

BACKGROUND & AIMS

Body composition (BC) changes with age and is associated with morbidity and mortality. A physically active lifestyle influences BC and represents an important predictor of successful aging. To emphasize this, the World Health Organization established activity recommendations for all age groups. We describe BC during adulthood using a cross-sectional sample from a German community and investigate the associations between physical activity (PA), physical fitness (PF), and BC.

METHODS

Data from 329 men and women aged 35 to 86 years were analyzed. PA was measured by questionnaire and classified into sport activity and habitual activity. PF was measured through physical performance tests and BC by bioelectrical impedance analysis. Fat mass index (FMI) and fat-free mass index (FFMI) were calculated to represent height-adjusted BC. Associations between PA, PF, and BC were analyzed using linear regression models.

RESULTS

For both sexes, strength was positively associated with FFMI (♂: ß = 0.313; ♀: ß = 0.213) and phase angle (♂: ß = 0.357; ♀: ß = 0.409). For FMI, a significant negative association with strength was found only in women (ß = -0.189). Cardiorespiratory fitness showed a negative association with FMI (ß = -0.312) and FFMI (ß = -0.201) for men, while in women a positive association was found for FFMI (ß = 0.186). For coordination, a significant association with FMI was observed only in women (ß = -0.190). Regarding PA only one significant relationship between sport activity and FMI among women (ß = -0.170) was found.

CONCLUSIONS

In our sample, PF was closer related to BC than PA. Strength and cardiorespiratory fitness were the strongest predictors for BC. This supports the World Health Organization's activity recommendations to include both resistance and endurance training in the weekly sports program to maintain a healthy BC.

Association of socioeconomic factors and dietary intake with sarcopenic obesity in the Korean older population

BACKGROUND AND OBJECTIVES

This study investigated the relationship between socioeconomic factors, dietary intake, and sarcopenic obesity among older adults in Korea.

METHODS AND STUDY DESIGN

Data from the seventh Korean National Health and Nutrition Examination Survey (2016-2018) were analyzed. The study included 3,690 participants (1,645 men and 2,045 women) aged 65 years and older. Sarcopenic obesity was defined as the coexistence of low muscle strength (handgrip strength <28 kg in men and <18 kg in women) and abdominal obesity (waist circumference >90 cm in men and >85 cm in women). Socioeconomic factors assessed included age, living status, residential area, employment, education, and family income level. Dietary intake was evaluated using the nutrient adequacy ratio and mean adequacy ratio derived from 24-h dietary recall data. Multiple logistic regression was used to identify factors associated with sarcopenic obesity.

RESULTS

The prevalence rates of sarcopenic obesity were 6.5% in men and 17.4% in women. Low education levels were significantly associated with a higher prevalence of sarcopenic obesity in women, whereas lower family income levels were associated with an increased risk of sarcopenic obesity in men. In women, a lower mean adequacy ratio was significantly associated with a higher risk of sarcopenic obesity.

CONCLUSIONS

Lower family income and education level are associated with a higher prevalence of sarcopenic obesity. Ad-ditionally, overall nutritional adequacy is inversely related to the prevalence of sarcopenic obesity, particularly in women.

A scientometric analysis of sarcopenic obesity: Future trends and new perspectives

Sarcopenic obesity is a complex condition characterized by the combination of age-related loss of muscle mass and high levels of adiposity, or body fat. Up to 30% of older adults may be affected by this condition, and its prevalence varies by gender, race, and ethnicity. It can lead to postural instability and reduced physical activity, increasing the risk of falls, fractures, and functional limitations. The purpose of this study was to evaluate scientific articles on sarcopenic obesity using statistical methods and to assess the topic from a novel perspective. The Web of Science database publications on sarcopenic obesity published between 1980 and 2023 were analyzed using statistical and bibliometric methods. Spearman correlation coefficient was used in correlation analyses. A nonlinear cubic model regression analysis was performed to forecast the number of publications in the following years. Using keyword network visualization maps, recurrent topics, and relationships were identified. Between 1980 and 2023, the search criteria yielded 1013 publications on geriatric malnutrition. Nine hundred of these (articles, reviews, and meeting abstracts) were included in the analysis. Since 2005, the volume of published materials on the topic has increased dramatically and is continuing to rise. The USA and South Korea were the most active nations, Scott D and Prado CMM were the most active authors, and Osteoporosis International was the most active journal on the subject. This research has shown that countries with higher economic development tend to produce more research on the issue, and the number of publications on the topic will rise in the upcoming years. It is an important research topic in an aging society and needs to be further researched. We believe this article may aid clinicians and scientists in comprehending global efforts to combat sarcopenic obesity.

Sarcopenia Prediction for Elderly People Using Machine Learning: A Case Study on Physical Activity

Sarcopenia is a well-known age-related disease that can lead to musculoskeletal disorders and chronic metabolic syndromes, such as sarcopenic obesity. Numerous studies have researched the relationship between sarcopenia and various risk factors, leading to the development of predictive models based on these factors. In this study, we explored the impact of physical activity (PA) in daily life and obesity on sarcopenia prediction. PA is easier to measure using personal devices, such as smartphones and watches, or lifelogs, than using other factors that require medical equipment and examination. To demonstrate the feasibility of sarcopenia prediction using PA, we trained various machine learning models, including gradient boosting machine (GBM), xgboost (XGB), lightgbm (LGB), catboost (CAT), logistic regression, support vector classifier, k-nearest neighbors, random forest (RF), multi-layer perceptron, and deep neural network (DNN), using data samples from the Korea National Health and Nutrition Examination Survey. Among the models, the DNN achieved the most precise accuracy on average, 81%, with PA features across all data combinations, and the accuracy increased up to 90% with the addition of obesity information, such as total fat mass and fat percentage. Considering the difficulty of measuring the obesity feature, when adding waist circumference to the PA features, the DNN recorded the highest accuracy of 84%. This model accuracy could be improved by using separate training sets according to gender. As a result of measurement with various metrics for accurate evaluation of models, GBM, XGB, LGB, CAT, RF, and DNN demonstrated significant predictive performance using only PA features including waist circumference, with AUC values at least around 0.85 and often approaching or exceeding 0.9. We also found the key features for a highly performing model such as the quantified PA value and metabolic equivalent score in addition to a simple obesity measure such as body mass index (BMI) and waist circumference using SHAP analysis.

Sarcopenia and Cognitive Decline in Older Adults: Targeting the Muscle-Brain Axis

Declines in physical performance and cognition are commonly observed in older adults. The geroscience paradigm posits that a set of processes and pathways shared among age-associated conditions may also serve as a molecular explanation for the complex pathophysiology of physical frailty, sarcopenia, and cognitive decline. Mitochondrial dysfunction, inflammation, metabolic alterations, declines in cellular stemness, and altered intracellular signaling have been observed in muscle aging. Neurological factors have also been included among the determinants of sarcopenia. Neuromuscular junctions (NMJs) are synapses bridging nervous and skeletal muscle systems with a relevant role in age-related musculoskeletal derangement. Patterns of circulating metabolic and neurotrophic factors have been associated with physical frailty and sarcopenia. These factors are mostly related to disarrangements in protein-to-energy conversion as well as reduced calorie and protein intake to sustain muscle mass. A link between sarcopenia and cognitive decline in older adults has also been described with a possible role for muscle-derived mediators (i.e., myokines) in mediating muscle-brain crosstalk. Herein, we discuss the main molecular mechanisms and factors involved in the muscle-brain axis and their possible implication in cognitive decline in older adults. An overview of current behavioral strategies that allegedly act on the muscle-brain axis is also provided.

The effect of combining nutrient intake and physical activity levels on central obesity, sarcopenia, and sarcopenic obesity: a population-based cross-sectional study in South Korea

BACKGROUND

This study was conducted to investigate the effects of combining nutritional and physical activity (PA) factors on four different categories, according to the presence or absence of sarcopenia and central obesity.

METHODS

From the 2008-2011 Korea National Health and Nutrition Examination Survey, 2971 older adults aged ≥ 65 years were included and divided into four groups based on their sarcopenia and central obesity status: healthy control (39.3%), central obesity (28.9%), sarcopenia (27.4%), and sarcopenic obesity (4.4%). Central obesity was defined as a waist circumference of ≥ 90 cm in men and ≥ 85 cm in women. Sarcopenia was defined as an appendicular skeletal mass index of < 7.0 kg/m2 in men and < 5.4 kg/m2 in women, and sarcopenic obesity was defined as the coexistence of sarcopenia and central obesity.

RESULTS

Participants who consumed more energy and protein than the average requirement had a lower likelihood of having sarcopenia (odds ratio (OR): 0.601, 95% confidence interval (CI): 0.444-0.814) than those who did not consume enough nutrients. The likelihood of central obesity and sarcopenic obesity decreased in groups with recommended PA levels, regardless of whether energy intake met or did not meet the average requirement. Whether PA met or did not meet the recommended level, the likelihood of sarcopenia decreased in groups with energy intake that met the average requirement. However, when PA and energy requirements were met, there was a greater reduction in the likelihood of sarcopenia (OR: 0.436, 95% CI: 0.290-0.655).

CONCLUSION

These findings suggest that adequate energy intake that meets requirements is more likely to be effective as a major prevention and treatment goal for sarcopenia, whereas PA guidelines should be prioritized in the case of sarcopenic obesity.

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.

Association between Sarcopenic Obesity Status and Nonalcoholic Fatty Liver Disease and Fibrosis

Background/Aims

There are no data regarding the association between sarcopenic obesity status and nonalcoholic fatty liver disease (NAFLD) and NAFLD-associated liver fibrosis. Therefore, we aimed to investigate the relationship between sarcopenic obesity status (sarcopenia only, obesity only, and sarcopenic obesity) and NAFLD and liver fibrosis in Korean adults.

Methods

In total, 2,191 subjects completed a health checkup program, including abdominal ultrasonography and FibroScan. Subjects were classified into the following four categories: optimal body composition (nonobese and nonsarcopenic), sarcopenia only (nonobese), obesity only (nonsarcopenic), and sarcopenic obesity. Sarcopenic obesity was stratified by the skeletal muscle mass index and body fat using bioelectrical impedance analysis. NAFLD was diagnosed by ultrasonography, and liver fibrosis was assessed using transient elastography in subjects with NAFLD.

Results

The prevalence of NAFLD and liver fibrosis significantly increased according to the sarcopenic obesity status. In the logistic regression analysis, after adjusting for multiple risk factors, the odds ratio (OR) for the risk of NAFLD was largest in the sarcopenic obesity group (OR, 3.68; 95% confidence interval [CI], 2.94 to 4.60), followed by the obesity only (OR, 2.25; 95% CI, 1.67 to 3.03) and sarcopenia only (OR, 1.92; 95% CI, 1.30 to 2.84) groups, when compared with the optimal group. Additionally, liver fibrosis was independently associated with sarcopenic obesity status (OR 4.69, 95% CI 1.95 to 11.29; OR 4.17, 95% CI 1.56 to 11.17; OR 3.80, 95% CI 0.86 to 16.75, respectively).

Conclusions

These results demonstrated that sarcopenic obesity was independently associated with NAFLD and liver fibrosis and increased the risk of NAFLD and liver fibrosis more than obesity or sarcopenia alone.

Lower body muscle strength, dynapenic obesity and risk of type 2 diabetes -longitudinal results on the chair-stand test from the Survey of Health, Ageing and Retirement in Europe (SHARE)

BACKGROUND

The chair-stand test is a measure of lower body muscle strength. In a longitudinal study with older adults, we investigated whether results of the five-repetition chair-stand test (CST-5) are associated with incident type 2 diabetes, and whether diabetes risk in obese persons is modified by dynapenia (age-related loss of muscle strength) in the lower limbs.

METHODS

We used data of the Survey of Health, Ageing and Retirement in Europe (SHARE), a panel study with eight waves carried out between 2004 and 2020 in 28 European countries and Israel mainly in persons aged 50 years or older. Forty-six thousand one hundred nineteen persons (mean age 63.5 years, 44.1% men) with CST-5 data and follow-up data for diabetes were included from wave 2 and waves 4 to 7. The mean follow-up time was 5.3 years (standard deviation 2.9 years). Relative risks with 95% confidence intervals (CI) were estimated from log-linear models with a Poisson working likelihood and robust standard errors.

RESULTS

In the crude model, increased risks of diabetes were found for persons who considered the CST-5 as not safe, or whose times for the test were in the highest or second highest quartiles (relative risks 2.18 (95% CI: 1.95-2.43), 1.71 (1.54-1.91), 1.44 (95% CI: 1.29-1.61), reference: lowest quartile). These associations were attenuated in the fully adjusted regression model (relative risks 1.32 (95% CI: 1.17-1.48), 1.23 (1.10-1.37), 1.19 (1.06-1.33)). Furthermore, in fully adjusted models, the risk of diabetes in obese persons did not depend on whether they had low muscle strength or not. In obese persons with times for 5 sits and stands > 15 seconds, the adjusted risk of diabetes was 2.56 (95% CI: 2.22-2.95) times higher than in non-obese persons with times ≤15 seconds. The corresponding relative risk in obese persons with times ≤15 seconds was 2.45 (2.25-2.67).

CONCLUSIONS

Poor results in the CST-5 were associated with an increased risk of diabetes. Among obese persons, the risk of diabetes was not modified by results of the CST-5.

Prevalence of Sarcopenic Obesity in Various Comorbidities, Diagnostic Markers, and Therapeutic Approaches: A Review

The coexistence of sarcopenia and obesity characterizes sarcopenic obesity. In this condition, there is an imbalance between lean and fat mass amounts. It is a prevalent issue that is gaining prevalence among the elderly population. To evaluate the condition, allied health professionals may employ non-invasive diagnostic techniques, such as gait speed, skeletal muscle mass, and muscle strength. Nevertheless, early diagnosis and treatment of pathology are essential for preventing debilitating effects and providing the highest quality of care. This article reviews the prevalence of sarcopenic obesity in numerous medical conditions, such as cancer, arthritis, postoperative cases, diabetes mellitus, obesity, and metabolic syndrome. In addition, this paper aims to examine the available evidence regarding the prevalence of sarcopenic obesity in other conditions along with their diagnostic markers and therapeutic approaches.

Low skeletal muscle mass Accompanied by Abdominal Obesity Additively Increases the Risk of Incident Type 2 Diabetes

CONTEXT

Low skeletal muscle mass often accompanies abdominal obesity in the aging process.

OBJECTIVE

We aimed to investigate the effect of reduced skeletal muscle mass and its interaction with abdominal obesity on incident type 2 diabetes.

METHODS

This retrospective longitudinal study included a total of 36,304 diabetes-free Koreans who underwent two or more health check-ups annually or biennially. Appendicular skeletal muscle mass was measured by bioelectrical impedance analysis and was presented as a skeletal muscle mass index (SMI) adjusted for body weight. Pre-sarcopenia was defined as an SMI <1 standard deviation of the sex-specific mean for a healthy young reference group. Abdominal obesity was defined using waist circumference ≥ 90 cm for men and ≥ 85 cm for women. Participants were classified into four groups of normal, pre-sarcopenia alone, abdominal obesity alone, and pre-sarcopenic obesity according to initial body composition.

RESULTS

The cumulative incidence of diabetes was 9.1% during the 7-year follow-up. Compared with the highest tertile, the lowest sex-specific SMI tertile was significantly associated with a greater risk of incident type 2 diabetes (adjusted hazard ratio [HR] = 1.31, 95% confidence interval [CI] 1.18-1.45) in a fully adjusted model. Pre-sarcopenic obesity significantly increased incident diabetes risk (adjusted HR = 1.57, 95% CI 1.42-1.73) compared with normal body composition, pre-sarcopenia alone, or abdominal obesity alone.

CONCLUSIONS

Low skeletal muscle mass and its coexistence with abdominal obesity additively increased the risk of incident type 2 diabetes independent of the glycometabolic parameters.

Effects of three modes of physical activity on physical fitness and hematological parameters in older people with sarcopenic obesity: A systematic review and meta-analysis

Objective: This systematic review and meta-analysis assessed the effects of three modes of physical activity (PA) (aerobic training [AT], resistance training [RT], and aerobic combined with resistance training [MT]) on body composition (body weight [BW], body mass index [BMI] and percentage of body fat [BF%]), muscle mass (skeletal muscle mass [SM], appendicular skeletal muscle mass [ASM] and appendicular skeletal muscle mass index [ASMI]), muscle strength (handgrip strength [HG] and knee extension strength [KES]), physical performance (gait speed [GS]) and hematological parameters (inflammatory markers, insulin-like growth factor 1 [IGF-1] and lipid profiles) in older people with sarcopenic obesity (SO).

Methods: We searched all studies for PA effects in older people with SO from six databases published from January 2010 to November 2021. Two researchers independently screened studies, extracted data according to inclusion and exclusion criteria, and assessed the quality of included studies. Pooled analyses for pre-and post- outcome measures were performed by Review Manager 5.4. We calculated a meta-analysis with a 95% confidence interval (95% CI) and the standardized mean differences (SMD).

Results: 12 studies were analyzed. There were 614 older people (84.9% female) with SO, aged 58.4 to 88.4 years. Compared with a no-PA control group, AT decreased BW (SMD = −0.64, 95% CI: −1.13 to −0.16, p = 0.009, I² = 0%) and BMI (SMD = −0.69, 95% CI: −1.18 to −0.21, p = 0.005, I² = 0%); RT improved BF% (SMD = −0.43, 95% CI: −0.63 to −0.22, p < 0.0001, I² = 38%), ASMI (SMD = 0.72, 95% CI: 0.24 to 1.21, p = 0.004, I² = 0%), ASM (SMD = −0.94, 95% CI: −1.46 to −0.42, p = 0.0004), HG (SMD = 1.06, 95% CI: 0.22 to 1.91, p = 0.01, I² = 90%) and KES (SMD = 1.06, 95% CI: 0.73 to 1.39, p < 0.00001, I² = 14%); MT improved BMI (SMD = −0.77, 95% CI: −1.26 to −0.28, p = 0.002, I² = 0%), BF% (SMD = −0.54, 95% CI: −0.83 to −0.25, p = 0.0003, I² = 0%), ASMI (SMD = 0.70, 95% CI: 0.22 to 1.19, p = 0.005, I² = 0%) and GS (SMD = 0.71, 95% CI: 0.23 to 1.18, p = 0.004, I² = 37%). PA increased IGF-1 (SMD = 0.38, 95% CI: 0.11 to 0.66, p = 0.006, I² = 0%), but had no effect on inflammatory markers and lipid profiles.

Conclusion: PA is an effective treatment to improve body composition, muscle mass, muscle strength, physical performance, and IGF-1 in older people with SO.

Molecular Mechanisms of Inflammation in Sarcopenia: Diagnosis and Therapeutic Update

Sarcopenia is generally an age-related condition that directly impacts the quality of life. It is also related to chronic diseases such as metabolic dysfunction associated with diabetes and obesity. This means that everyone will be vulnerable to sarcopenia at some point in their life. Research to find the precise molecular mechanisms implicated in this condition can increase knowledge for the better prevention, diagnosis, and treatment of sarcopenia. Our work gathered the most recent research regarding inflammation in sarcopenia and new therapeutic agents proposed to target its consequences in pyroptosis and cellular senescence. Finally, we compared dual X-ray absorptiometry (DXA), magnetic resonance imaging (MRI), and ultrasound (US) as imaging techniques to diagnose and follow up on sarcopenia, indicating their respective advantages and disadvantages. Our goal is for the scientific evidence presented here to help guide future research to understand the molecular mechanisms involved in sarcopenia, new treatment strategies, and their translation into clinical practice.

Hypoglycaemic therapy in frail older people with type 2 diabetes mellitus-a choice determined by metabolic phenotype

Frailty is a newly emerging complication of diabetes in older people and increasingly recognised in national and international clinical guidelines. However, frailty remains less clearly defined and frail older people with diabetes are rarely characterised. The general recommendation of clinical guidelines is to aim for a relaxed glycaemic control, mainly to avoid hypoglycaemia, in this often-vulnerable group of patients. With increasing age and development of frailty, body composition changes are characterised by an increase in visceral adipose tissue and a decrease in body muscle mass. Depending on the overall body weight, differential loss of muscle fibre types and body adipose/muscle tissue ratio, the presence of any associated frailty can be seen as a spectrum of metabolic phenotypes that vary in insulin resistance of which we have defined two specific phenotypes. The sarcopenic obese (SO) frail phenotype with increased visceral fat and increased insulin resistance on one side of spectrum and the anorexic malnourished (AM) frail phenotype with significant muscle loss and reduced insulin resistance on the other. In view of these varying metabolic phenotypes, the choice of hypoglycaemic therapy, glycaemic targets and overall goals of therapy are likely to be different. In the SO phenotype, weight-limiting hypoglycaemic agents, especially the new agents of GLP-1RA and SGLT-2 inhibitors, should be considered early on in therapy due to their benefits on weight reduction and ability to achieve tight glycaemic control where the focus will be on the reduction of cardiovascular risk. In the AM phenotype, weight-neutral agents or insulin therapy should be considered early on due to their benefits of limiting further weight loss and the possible anabolic effects of insulin. Here, the goals of therapy will be a combination of relaxed glycaemic control and avoidance of hypoglycaemia; and the focus will be on maintenance of a good quality of life. Future research is still required to develop novel hypoglycaemic agents with a positive effect on body composition in frailty and improvements in clinical outcomes.

Association between platelet, white blood cell count, platelet to white blood cell ratio and sarcopenia in community-dwelling older adults: focus on Bushehr Elderly Health (BEH) program

BACKGROUND

Sarcopenia is a progressive age-related skeletal muscle disorder associated with harmful impacts on health. The present study aimed to investigate the relation between sarcopenia, platelet (PLT), white blood cell (WBC), and PLT to WBC ratio (PWR) due to the importance of early sarcopenia diagnosis.

METHODS

This cross-sectional study was conducted based on the second stage of the Bushehr Elderly Health (BEH) Program. Sarcopenia was defined based on the revised edition of the European Working Group on Sarcopenia in Older People (EWGSOP2) in accordance with the Iranian cut-off point. Univariate and adjusted multivariate logistic regression and linear regression were used to evaluate the associations.

RESULTS

The prevalence of sarcopenia among participants was 35.73%. PLT count and PWR were statistically higher in severe sarcopenic participants, while no differences were seen in WBC. In crude analysis, sarcopenia was not associated with quartiles of PLT, WBC, and PWR, while after adjusting for age, marital status, and sex, the association was seen in the fourth quartile of PLT and PWR [OR (95%CI) = 1.40 (1.08 to 1.81), p-value = 0.009 for PLT; OR (95%CI) =1.55 (1.20 to 2.00), p-value =0.001 for PWR]. This association remained significant in the fully adjusted model [OR (95%CI) =1.82 (1.20 to 2.78), p-value =0.005 for PLT; OR (95%CI) =1.57 (1.03 to 2.40), p-value =0.035 for PWR]. Among sarcopenia parameters, PLT count was more likely to be associated with handgrip strength and muscle mass. After stratifying the participants by gender, sarcopenia parameters were no longer statistically significant in men.

CONCLUSION

This study showed that PLT and PWR were associated with sarcopenia after considering confounding factors, while this association was not seen in WBC. Moreover, results showed that gender had an important impact on sarcopenia parameters.

Impact of Sarcopenia on the Severity of the Liver Damage in Patients With Non-alcoholic Fatty Liver Disease

An extensive body of the literature shows a strong interrelationship between the pathogenic pathways of non-alcoholic fatty liver disease (NAFLD) and sarcopenia through the muscle-liver-adipose tissue axis. NAFLD is one of the leading causes of chronic liver diseases (CLD) affecting more than one-quarter of the general population worldwide. The disease severity spectrum ranges from simple steatosis to non-alcoholic steatohepatitis (NASH), cirrhosis, and its complications: end-stage chronic liver disease and hepatocellular carcinoma. Sarcopenia, defined as a progressive loss of the skeletal muscle mass, reduces physical performances, is associated with metabolic dysfunction and, possibly, has a causative role in NAFLD pathogenesis. Muscle mass is a key determinant of the whole-body insulin-mediated glucose metabolism and impacts fatty liver oxidation and energy homeostasis. These mechanisms drive the accumulation of ectopic fat both in the liver (steatosis, fatty liver) and in the muscle (myosteatosis). Myosteatosis rather than the muscle mass per se, seems to be closely associated with the severity of the liver injury. Sarcopenic obesity is a recently described entity which associates both sarcopenia and obesity and may trigger worse clinical outcomes including hepatic fibrosis progression and musculoskeletal disabilities. Furthermore, the muscle-liver-adipose tissue axis has a pivotal role in changes of the body composition, resulting in a distinct clinical phenotype that enables the identification of the "sarcopenic NAFLD phenotype." This review aims to bring some light into the complex relationship between sarcopenia and NAFLD and critically discuss the key mechanisms linking NAFLD to sarcopenia, as well as some of the clinical consequences associated with the coexistence of these two entities: the impact of body composition phenotypes on muscle morphology, the concept of sarcopenic obesity, the relationship between sarcopenia and the severity of the liver damage and finally, the future directions and the existing gaps in the knowledge.

Equivalent servings of free-range reindeer promote greater net protein balance compared to commercial beef

Wild game consumption has been associated with health benefits but the acute influence on human protein metabolism remains unknown. We compared feeding-induced responses of equivalent amounts of free-range reindeer (FR) and commercial beef (CB) on protein kinetics using stable isotope methodology. Seven participants (age: 40 ± 14 years; body mass index: 24 ± 3 kg/m2) completed two randomised studies, ingesting 2 oz of FR or CB. L-[ring 2H5]phenylalanine & L-[ring 2H2]tyrosine were delivered via primed, continuous intravenous infusion. Blood samples were collected during the basal period and following consumption of FR or CB. Feeding-induced changes in whole-body protein synthesis (PS), protein breakdown (PB), and net protein balance (NB) were determined via plasma sample isotope enrichment analysis by gas chromatography-mass spectrometry; plasma essential amino acid (EAA) concentrations were determined by liquid chromatography-electrospray ionisation-mass spectrometry. Plasma post-prandial EAA concentrations were higher with FR compared to CB (P < 0.05). The acute feeding-induced PS response was not different, but PB was reduced and contributed to a superior level of NB (P < 0.00001) in FR compared to CB. Our results demonstrate that FR may influence more favourable protein metabolism than CB. These data support potential health benefits of wild game onf whole-body protein.Abbreviations: BMI: body mass index; DIAAS: digestible indispensable amino acid score; CB: commercial beef; EAA: essential amino acids; FR: free-range reindeer; Ra: rate of appearance; UAF: University of Alaska Fairbanks; USDA: USA Department of Agriculture.

Associated Factors of Sarcopenia in Community-Dwelling Older Adults: A Systematic Review and Meta-Analysis

(1) Background: To review the associated factors of sarcopenia in community-dwelling older adults. (2) Methods: PubMed, Embase, Web of Science, and four Chinese electronic databases were searched for observational studies that reported the associated factors of sarcopenia from inception to August 2021. Two researchers independently selected the literature, evaluated their quality, and extracted relevant data. The pooled odds ratio (OR) and its 95% confidence interval (CI) were calculated for each associated factors of sarcopenia using random-effects/fixed-effects models. Publication bias was assessed using funnel plot and the Eggers test. We performed statistical analysis using Stata 15.0 software. (3) Results: A total of 68 studies comprising 98,502 cases were included. Sociodemographic associated factors of sarcopenia among community-dwelling older adults included age (OR = 1.12, 95% CI: 1.10-1.13), marital status (singled, divorced, or widowed) (OR = 1.57, 95% CI: 1.08-2.28), disability for activities of daily living (ADL) (OR = 1.49, 95% CI: 1.15-1.92), and underweight (OR = 3.78, 95% CI: 2.55-5.60). Behavioral associated factors included smoking (OR = 1.20, 95% CI: 1.10-1.21), physical inactivity (OR = 1.73, 95% CI: 1.48-2.01), malnutrition/malnutrition risk (OR = 2.99, 95% CI: 2.40-3.72), long (OR = 2.30, 95% CI: 1.37-3.86) and short (OR = 3.32, 95% CI: 1.86-5.93) sleeping time, and living alone (OR = 1.55, 95% CI: 1.00-2.40). Disease-related associated factors included diabetes (OR = 1.40, 95% CI: 1.18-1.66), cognitive impairment (OR = 1.62, 95% CI: 1.05-2.51), heart diseases (OR = 1.14, 95% CI: 1.00-1.30), respiratory diseases (OR = 1.22, 95% CI: 1.09-1.36), osteopenia/osteoporosis (OR = 2.73, 95% CI: 1.63-4.57), osteoarthritis (OR = 1.33, 95% CI: 1.23-1.44), depression (OR = 1.46, 95% CI: 1.17-1.83), falls (OR = 1.28, 95% CI: 1.14-1.44), anorexia (OR = 1.50, 95% CI: 1.14-1.96), and anemia (OR = 1.39, 95% CI: 1.06-1.82). However, it remained unknown whether gender (female: OR = 1.10, 95% CI: 0.80-1.51; male: OR = 1.50, 95% CI: 0.96-2.34), overweight/obesity (OR = 0.27, 95% CI: 0.17-0.44), drinking (OR = 0.92, 95% CI: 0.84-1.01), hypertension (OR = 0.98, 95% CI: 0.84-1.14), hyperlipidemia (OR = 1.14, 95% CI: 0.89-1.47), stroke (OR = 1.70, 95% CI: 0.69-4.17), cancer (OR = 0.88, 95% CI: 0.85-0.92), pain (OR = 1.08, 95% CI: 0.98-1.20), liver disease (OR = 0.88, 95% CI: 0.85-0.91), and kidney disease (OR = 2.52, 95% CI: 0.19-33.30) were associated with sarcopenia. (4) Conclusions: There are many sociodemographic, behavioral, and disease-related associated factors of sarcopenia in community-dwelling older adults. Our view provides evidence for the early identification of high-risk individuals and the development of relevant interventions to prevent sarcopenia in community-dwelling older adults.

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.

Association of Body Composition and Sarcopenia with NASH in Obese Patients

Obese patients often suffer from sarcopenia or sarcopenic obesity (SO) that can trigger inflammatory diseases including non-alcoholic steatohepatitis (NASH). Sarcopenia and SO can be diagnosed through measuring parameters of body composition such as skeletal muscle mass (SMM), skeletal muscle index (SMI) and fat mass (FM) obtained by bioelectrical impedance analysis (BIA). The aim of this study was to assess the relationship of body composition and NASH in patients with obesity. A total of 138 patients with obesity that underwent bariatric surgery were included in this study. BIA was used to estimate body composition. A liver biopsy was taken intraoperatively and histological assessment of NASH was performed. A total of 23 patients (17%) were classified as NASH and 65 patients (47%) met the criteria for borderline NASH. Body mass index (BMI) was significantly higher in patients with NASH compared to borderline NASH and no NASH (56.3 kg/m² vs. 51.6 kg/m² vs. 48.6 kg/m², p = 0.004). Concerning body composition, FM, but also SMM and SMI were significantly higher in patients with NASH (p-values 0.011, 0.005 and 0.006, resp.). Fat mass index (FMI) and weight-adjusted skeletal muscle index (SMI_weight) failed to reach statistical significance (p-values 0.067 and 0.661). In patients with obesity, higher FM were associated with NASH. Contrary to expectations, SMM and SMI were also higher in patients with NASH. Therefore, higher body fat, rather than sarcopenia and SO, might be decisive for development of NASH in patients with obesity.

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.

Effect of CCL11 on In Vitro Myogenesis and Its Clinical Relevance for Sarcopenia in Older Adults

BACKGROUND

The C-C motif chemokine ligand 11 (CCL11) has been receiving attention as a potential pro-aging factor. Accordingly, it may be involved in muscle metabolism and sarcopenia, a key component of aging phenotypes. To clarify this potential, we investigated the effects of CCL11 on in vitro muscle biology and its clinical relevance for sarcopenia parameters in older adults.

METHODS

Myogenesis was induced in mouse C2C12 myoblasts with 2% horse serum. Human blood samples were collected from 79 participants who underwent a functional assessment. Thereafter, CCL11 level was measured using a quantikine ELISA kit. Sarcopenia was defined using the Asian-specific guideline.

RESULTS

Recombinant CCL11 treatment significantly stimulated myogenesis in a dose-dependent manner, and consistently increased the expression of myogenic differentiation markers. Among the C-C chemokine receptors (CCRs), CCR5, not CCR2 and CCR3, was predominantly expressed in muscle cells. Further, the CCR5 inhibitor blocked recombinant CCL11-stimulated myogenesis. In a clinical study, serum CCL11 level was not significantly different according to the status of sarcopenia, low muscle mass, weak muscle strength, and poor physical performance, and was not associated with skeletal muscle index, grip strength, short physical performance battery score, gait speed, and time to complete 5 chair stands, after adjusting for sex, age, and body mass index.

CONCLUSION

Contrary to expectations, CCL11 exerted beneficial effects on muscle metabolism at least in vitro system. However, its impact on human muscle health was not evident, suggesting that circulating CCL11 may not be a useful biomarker for sarcopenia risk assessment in older adults.

Relationship between low skeletal muscle mass, sarcopenic obesity and left ventricular diastolic dysfunction in Korean adults

BACKGROUND

Heart failure with preserved ejection fraction is an emerging global health issue attributed to an ageing population. However, the association between low skeletal muscle mass, sarcopenic obesity, and left ventricular diastolic dysfunction remains unclear. In the current study, we aimed to investigate the relationship between low skeletal muscle mass, sarcopenic obesity, and diastolic dysfunction in a large cohort of Korean adults.

METHODS

We conducted a cross-sectional study of 31 258 subjects who underwent health examinations at Samsung Medical Centre's Health Promotion Centre in Seoul, Republic of Korea. Relative skeletal muscle mass was calculated using the skeletal muscle mass index [SMI (%) = appendicular skeletal muscle mass (kg)/body weight (kg) × 100], which was estimated by bioelectrical impedance analysis. Cardiac structure and function were evaluated by echocardiography.

RESULTS

Amongst the 31 258 subjects, 3058 (9.78%) were determined to have diastolic dysfunction. The odds ratio (OR) of diastolic dysfunction was 1.56 [95% confidence interval (CI): 1.31-1.85; p for trend <0.001] for the lowest SMI tertile relative to the highest SMI tertile following multivariable adjustment. Furthermore, the risk of diastolic dysfunction was much higher in the sarcopenic obesity (OR: 1.70, 95% CI: 1.44-1.99), followed by in the obesity-only (OR: 1.40, 95% CI: 1.21-1.62), and sarcopenia-only (OR: 1.32, 95% CI: 1.08-1.61) when compared with the nonobese, nonsarcopenic group. These results remained consistent amongst the elderly (age ≥ 65 years).

CONCLUSIONS

Our findings demonstrate that lower skeletal muscle mass and sarcopenic obesity are strongly associated with diastolic dysfunction in middle-aged and older adults.

The Association Between Diabetes Mellitus and Risk of Sarcopenia: Accumulated Evidences From Observational Studies

AIM

We performed a meta-analysis of observational studies to evaluate the association between the presence of sarcopenia and HbA1c, prediabetes, diabetes and diabetic complications.

METHOD

The PubMed, Embase, Cochrane and Web of Science databases were searched from inception to May 2021. We included full-text English language articles that reported the prevalence of sarcopenia in patients with and without diabetes. Quality assessment was performed according to the Newcastle- Ottawa scale for observational studies.

RESULTS

Sixteen studies were included in the meta-analysis. Three studies showed that high HbA1c levels lead to loss of muscle mass, and one study involving prediabetes showed that people with prediabetes had lower muscle mass, strength, and performance than non-diabetic population. Seven studies showed that people with diabetes had a higher risk of sarcopenia than those without diabetes (combined OR: 2.09, 95% CI:1.62-2.70). The remaining five studies suggested that diabetic complications increased the risk of sarcopenia (combined OR: 2.09,95% CI:1.62-2.70).

CONCLUSION

High HbA1c levels, prediabetes, diabetes and diabetes complications were associated with an increased risk of sarcopenia. Therapeutic strategies addressed to avoid the conversion of IGT to diabetes and to optimize glycemic control are warranted to prevent or arrest sarcopenia in the diabetic population.

Implications of Race and Ethnicity in Sarcopenia US National Prevalence of Sarcopenia by Muscle Mass, Strength, and Function Indices

Sarcopenia prevalence varies widely by definitions and populations, which led to the creation of new criteria by the Sarcopenia Definitions and Outcomes Consortium. Yet, the degree to which sarcopenia prevalence varies according to these criteria across race and ethnic groups in the U.S. population needs further investigation. We estimated the US national prevalence of sarcopenia using different indices among adults aged 50-80 years across race and ethnicity groups utilizing data from the National Health and Nutrition Examination Surveys (NHANES: 1999-2002 and 2011-2014). Sarcopenia was defined by appendicular lean mass divided by body mass index (ALM/BMI), grip strength, and gait speed. For each index the following samples were constructed: grip strength (NHANES 2011-2014: N=4,615), gait speed (NHANES 1999-2002: N=3,448) and ALM/BMI (NHANES 1999-2002: N=3,448) among adults aged 50-80 years. Sarcopenia prevalence varied by race/ethnicity: NH-Whites (11.2-24.3%), Hispanics (21.9-36.0%), NH-Blacks (4.4-27.7%), and Asians/others (18.5-35.7%). Based on the multivariable models, compared to NH-Whites, NH-Blacks were less likely to have sarcopenia by ALM/BMI (OR=0.26, 95%CI: 0.18-0.39), and more likely by gait speed (OR=3.90, 95% CI: 3.00-5.06) with no difference by grip strength (OR=0.96, 95%CI: 0.75-1.24). While, Hispanics and Asians/others were more likely to have sarcopenia by grip strength, gait speed, and ALM/BMI (ORs=2.15-3.21) compared to NH-Whites. This study suggests the need for inclusion of race/ethnicity related criteria in sarcopenia definitions. Future investigations could determine whether this discrepancy between race/ethnicity across sarcopenia indices, particularly in NH-Blacks, is partly due to either muscle mass or functional changes with aging.

Type 2 Diabetes Mellitus is Associated with Increased Risk of Sarcopenia: A Systematic Review and Meta-analysis

Diabetes mellitus (DM) is associated with an increased risk of fractures, mainly due to impaired bone architecture and microvascular complications. Whether DM is also associated with increased risk of sarcopenia is not yet known, with studies yielding inconclusive results. The aim of this study was to systematically review and synthesize the best available evidence regarding the association between DM and sarcopenia risk. A comprehensive search was conducted in PubMed, CENTRAL and Scopus databases. Data are expressed as odds ratio (OR) with 95% confidence intervals (CI). The I² index was employed for heterogeneity. Only studies which had implemented at least two of the three criteria for sarcopenia diagnosis (low muscle mass, muscle strength and/or muscle performance), as defined by the international studying groups, were included. Fifteen studies fulfilled eligibility criteria, yielding a total of 1832 patients with type 2 DM (T2DM) and 1159 cases of sarcopenia. Patients with T2DM demonstrated a higher risk of sarcopenia compared with euglycemic subjects (OR 1.55, 95% CI 1.25-1.91, p < 0.001; I² 34.6%). This risk remained significant when analysis was restricted to studies matched for age and sex. Sarcopenia risk was independent of disease definition or study design. Notably, T2DM patients presented lower muscle performance and strength compared with euglycemic subjects, whereas no difference in muscle mass was observed between groups. Patients with T2DM have an increased risk of sarcopenia compared with euglycemic subjects.

New hypoglycaemic therapy in frail older people with diabetes mellitus-phenotypic status likely to be more important than functional status

Frail older people are largely excluded from clinical trials and therefore glycaemic targets and optimum hypoglycaemic therapy in this group has not been fully investigated. Guidelines generally recommend tight glycaemic control in functionally fit individuals and relaxed targets in frail ones mainly due to the fear of hypoglycaemia. The newly introduced sodium glucose cotransporter-2 inhibitors and the glucagon like peptide-1 receptor agonists have shown benefit that is independent of glycaemic control and a minimal risk of hypoglycaemia. However, guidelines still express caution about its use in frail older people due to fear of other side effects such as weight loss, hypotension and falls. Some frail older people will miss out on the benefits of this new therapy if frailty is considered as a one entity with a blanket application of guidelines. We propose that frailty should be viewed as two distinct metabolically different phenotypes, the sarcopenic-obese, in which new therapy will improve their metabolic profile and should be liberally used if no contraindications, and the anorexic-malnourished phenotype in which the new therapy should be cautiously considered. In other words, glycaemic targets should be driven by individual's overall function but the use of new therapy should be driven by frailty phenotype.

Health Consequences of Sarcopenic Obesity: A Narrative Review

Sarcopenia is defined as the age-related loss of muscle mass and strength or physical performance. Increased amounts of adipose tissue often accompany sarcopenia, a condition referred to as sarcopenic obesity. The prevalence of sarcopenic obesity among adults is rapidly increasing worldwide. However, the lack of a universal definition of sarcopenia limits comparisons between studies. Sarcopenia and obesity have similar pathophysiologic factors, including lifestyle behaviors, hormones, and immunological factors, all of which may synergistically affect the risk of developing a series of adverse health issues. Increasing evidence has shown that sarcopenic obesity is associated with accelerated functional decline and increased risks of cardiometabolic diseases and mortality. Therefore, the identification of sarcopenic obesity may be critical for clinicians in aging societies. In this review, we discuss the effect of sarcopenic obesity on multiple health outcomes and its role as a predictor of these outcomes based on the components of sarcopenia, including muscle mass, muscle strength, and physical performance.

Relationship between sarcopenia and pain catastrophizing in patients with lumbar spinal stenosis: A cross-sectional study

Objectives

The purpose of this study is to clarify the psychological factors related to sarcopenia in patients with lumbar spinal stenosis (LSS).

Methods

This cross-sectional study included 72 patients with LSS (38 males and 34 females; mean age, 70.4 ± 6.9 years). Demographic data, lower extremity pain, back pain, Japanese Orthopaedic Association score, Pain Catastrophizing Scale (PCS) score, Hospital Anxiety and Depression Scale (HADS) score, Fear-Avoidance Beliefs Questionnaire score, walking velocity, grip strength, walking distance, and appendicular muscle mass were assessed. Muscle mass was measured using bioelectrical impedance analysis. Patients were grouped based on sarcopenia status according to skeletal muscle mass index.

Results

The prevalence of sarcopenia was 13.9% (10 of 72 patients). Sarcopenia was significantly more common in females. The incidence of dyslipidemia and cardiovascular disease were significantly higher in the sarcopenia group. The sarcopenia group had lower body weight, body mass index, grip strength, and walking distance than the control group. The sarcopenia group had higher PCS scores and HADS-anxiety scores. Multivariate analysis identified body weight, dyslipidemia, walking distance, and PCS score as significantly related to sarcopenia.

Conclusions

Pain catastrophizing might be the most relevant psychological factor in sarcopenia. Evaluation of both physical function and pain catastrophizing is needed when investigating sarcopenia in LSS.

Application of body composition zones in boys with nonalcoholic fatty liver disease

PURPOSE

Screening nonalcoholic fatty liver disease (NAFLD) by body mass index (BMI) as a single surrogate measure for obesity has limitations. We suggest considering body composition zones by drawing a body composition chart composed of body composition indices, including BMI and percent body fat (PBF), to visualize the risk of NAFLD in obese children and adolescents.

METHODS

Thirty-eight boys diagnosed with NAFLD were selected retrospectively from patients who visited Konkuk University Medical Center from 2006 to 2015. They had gone through body composition analysis by bioelectrical impedance analysis (BIA), and biochemical analyses, including a liver function test (LFT) and lipid panel, were performed. Fat-free mass index (FFMI) and fat mass index (FMI) were calculated from body composition analysis and height. We plotted FFMI and FMI of patients on a body composition chart and classified the patients into zones A to D. In addition, we analyzed the correlations between LFT, lipid panel, and body composition indices.

RESULTS

Thirty-three of 38 boys (86.8%) were located in zone C, corresponding to high BMI and PBF. Four boys (10.5%) were located in zone D, which correlates with sarcopenic obesity. One boy located in zone B was a muscular adolescent. Alanine aminotransferase level was positively correlated with PBF, FMI, and BMI z-score.

CONCLUSION

Body composition zones on a body composition chart might be useful in risk assessment in obesity-related diseases such as NAFLD. Zones on a body composition chart could have practical applications, especially in sarcopenic obese children and adolescents.

Body Composition and Biochemical Markers of Nutrition in Non-dialysis-Dependent Chronic Kidney Disease Patients

The aim of this study was to examine the body composition in stages 3b to 5 of chronic kidney disease. There were 149 patients included in the study, with the mean age of 65.5 ± 16.5 years, body mass index (BMI) of 29.4 ± 5.6 kg/m², and estimated glomerular filtration rate (eGFR) of 23.2 ± 9.3/min/1.73m². They remained with dialysis. Body composition was measured using bioimpedance spectroscopy, and handgrip strength was measured with a hydraulic dynamometer. The main biochemical markers assessed consisted of serum protein, albumin, prealbumin, high-sensitivity C-reactive protein (hsCRP), and interleukin (IL)-6 content. We found that 39% of patients were overweight and 41% were obese. Obesity was more prevalent in stage 3b of chronic kidney disease than in stages 4-5 in women and in patients older than 60 years of age. Thirty-eight percent of the study population were sarcopenic, of whom 20% presented a sarcopenic obesity phenotype. There were significant associations between lean tissue index (LTI) and serum prealbumin content and handgrip strength. Fat tissue index (FTI) was associated and hsCRP, serum protein, body mass index (BMI), waist-hip ratio, and waist-to-height ratio. There were inverse associations between FTI-LTI and LTI-age. We conclude that the prevalence of obesity in non-dialysis-dependent patients with chronic kidney disease is higher than that in the general population. Earlier stages of chronic kidney disease are associated with a higher prevalence of obesity.

Sex differences in the prevalence and adverse outcomes of sarcopenia and sarcopenic obesity in community dwelling elderly in East China using the AWGS criteria

BACKGROUND

Sarcopenia and sarcopenic obesity (SO) have a greater impact on the elderly. This study aimed to explore whether there were sex differences in the prevalence and adverse outcomes of sarcopenia and SO in community-dwelling elderly individuals in East China.

METHODS

This was a cross-sectional study that enrolled 213 males and 418 females aged > 65 years. Demographic characteristics, body composition, hand grip, gait speed, and indices of glucose and lipid metabolism were collected. Sarcopenia and SO were diagnosed using the Asian Working Group for Sarcopenia criteria.

RESULTS

(1) The prevalence of sarcopenia was 19.2% in males and 8.6% in females. The prevalence of SO was 7.0% in males and 2.4% in females. (2) In males, the odds ratios (ORs) of osteoporosis and dyslipidemia in the SO group were 4.21-fold and 4.15-fold higher than those in the normal group, respectively. In females, the ORs of osteoporosis and hyperglycemia in the SO group were 1.12-fold and 4.21-fold higher than those in the normal group.

CONCLUSIONS

Males were more likely to be sarcopenic and to have SO than females using the AWGS criteria. Females with SO were more likely to have higher blood glucose, whereas males with SO were more likely to have osteoporosis and dyslipidemia.

Association of lifestyle factors and inflammation with sarcopenic obesity: data from the PREDIMED-Plus trial

BACKGROUND

Sarcopenia is a progressive age-related skeletal muscle disorder associated with increased likelihood of adverse outcomes. Muscle wasting is often accompanied by an increase in body fat, leading to 'sarcopenic obesity'. The aim of the present study was to analyse the association of lifestyle variables such as diet, dietary components, physical activity (PA), body composition, and inflammatory markers, with the risk of sarcopenic obesity.

METHODS

A cross-sectional analysis based on baseline data from the PREDIMED-Plus study was performed. A total of 1535 participants (48% women) with overweight/obesity (body mass index: 32.5 ± 3.3 kg/m² ; age: 65.2 ± 4.9 years old) and metabolic syndrome were categorized according to sex-specific tertiles (T) of the sarcopenic index (SI) as assessed by dual-energy X-ray absorptiometry scanning. Anthropometrical measurements, biochemical markers, dietary intake, and PA information were collected. Linear regression analyses were carried out to evaluate the association between variables.

RESULTS

Subjects in the first SI tertile were older, less physically active, showed higher frequency of abdominal obesity and diabetes, and consumed higher saturated fat and less vitamin C than subjects from the other two tertiles (all P < 0.05). Multiple adjusted linear regression models evidenced significant positive associations across tertiles of SI with adherence to the Mediterranean dietary score (P-trend < 0.05), PA (P-trend < 0.0001), and the 30 s chair stand test (P-trend < 0.0001), whereas significant negative associations were found with an inadequate vitamin C consumption (P-trend < 0.05), visceral fat and leucocyte count (all P-trend < 0.0001), and some white cell subtypes (neutrophils and monocytes), neutrophil-to-lymphocyte ratio, and platelet count (all P-trend < 0.05). When models were additionally adjusted by potential mediators (inflammatory markers, diabetes, and waist circumference), no relevant changes were observed, only dietary variables lost significance.

CONCLUSIONS

Diet and PA are important regulatory mediators of systemic inflammation, which is directly involved in the sarcopenic process. A healthy dietary pattern combined with exercise is a promising strategy to limit age-related sarcopenia.