Body composition and its association with cardiometabolic risk factors in the elderly: a focus on sarcopenic obesity

Sarcopenic obesity and the risk of atrial fibrillation in non-diabetic older adults: A prospective cohort study

BACKGROUND

Evidence of an association between sarcopenic obesity (SO) and the risk of long-term atrial fibrillation (AF) is lacking, and the underlying involvement of insulin resistance (IR) and inflammation is not clear.

METHODS

This community-based prospective cohort study evaluated sarcopenia, obesity, and baseline clinical characteristics in 4321 non-diabetic older adults between 2007 and 2011. Sarcopenia was identified using skeletal muscle mass/body weight (SMM/BW), appendicular lean mass (ALM)/BW, and handgrip strength (HGS), and obesity was identified by fat mass (FM)/BW. The association of sarcopenia and obesity with AF risk was determined by Kaplan-Meier analysis and a Cox proportional hazards model. Interaction analysis, a restricted cubic splines model, mediation analysis, and a Fine-Gray competing-risk model were also used.

RESULTS

Over an average of 10.9 years of follow-up, 546 (11.98 per 1000 person-years) participants developed AF. Low SMM/BW, low ALM/BW, low HGS, high FM/BW, sarcopenia and obesity, were significantly associated with an increased AF risk. There was a significant synergistic relationship between sarcopenia and obesity in the increased AF risk [hazard ratio (HR): 2.029, 95 % confidence interval (CI): 1.639-2.512]. Compared with participants without sarcopenia and obesity, AF risk was the highest in those with SO (HR: 2.669, 95 % CI: 2.110-3.377], followed by sarcopenia alone (HR: 1.980, 95%CI: 1.453-2.699) and obesity (HR: 1.839, 95%CI: 1.475-2.292). Mediation analysis found that estimated glucose disposal rate (a surrogate marker of IR), high-sensitivity C-reactive protein, and galectin-3 were mediating factors in the increased AF risk caused by SO, accounting for 34.87 %, 27.56 %, and 21.05 % of the total effect, respectively.

CONCLUSIONS

SO significantly increased AF risk in these non-diabetic older individuals. Sarcopenia and obesity not only acted alone but also exhibit had a synergistic relationship to increase AF risk. IR and inflammation mediated the increased AF risk associated with SO.

Association of possible Sarcopenia, Sarcopenia and sarcopenic obesity with multimorbidity among middle-aged and older adults: findings from the China health and retirement longitudinal study

BACKGROUND AND OBJECTIVES

The association between possible sarcopenia, sarcopenia and sarcopenic obesity on multimorbidity risk remains poorly investigating. We aimed to evaluate the associations between possible sarcopenia, sarcopenia and sarcopenic obesity on multimorbidity prevalence and incidence among middle-aged and older Chinese population.

METHODS

A total of 13,036 participants from the China Health and Retirement Longitudinal Study 2011 were included in cross-sectional analyses. 5771 participants were including in longitudinal analyses and were followed up in 2018. Sarcopenia status was defined according to the Asian Working Group for Sarcopenia 2019 (AWGS 2019) criteria. Obesity was defined according to body mass index.

RESULTS

In cross-sectional analyses, possible sarcopenia, sarcopenia and sarcopenic obesity were significantly associated with higher multimorbidity prevalence. During the 7 years of follow-up, 2295(39.77%) participants with new-onset multimorbidity were identified. Compared with participants without sarcopenia or obesity, a greater increase in the risk of multimorbidity incidence was found among participants with obesity only (OR = 1.39, 1.21-1.59), sarcopenia only (OR = 1.45, 1.35-1.58) and sarcopenic obesity (OR = 2.42, 2.03-2.89). Both pre-sarcopenia, sarcopenia and sarcopenic obesity were positively related to an increased number of morbidities.

CONCLUSION

Pre-sarcopenia, sarcopenia and sarcopenic obesity were associated with higher multimorbidity prevalence and incidence. Our findings provide important implications for screening and preventing possible sarcopenia, sarcopenia and obesity, which may be beneficial in reducing chronic disease burden.

Effects of changes in body composition on cardiometabolic diseases by sex and presence of sarcopenia

BACKGROUND

Muscle mass loss and fat mass increase are risk factors for cardiometabolic disease. We evaluated the effect of changes in body composition on the incidence of cardiometabolic diseases in older adults with or without sarcopenia, over two-year follow-up.

MATERIALS AND METHODS

Changes in body composition and the development of cardiometabolic diseases over 2 years were measured in community-dwelling older adults recruited from the Korean Frailty Aging Cohort Study. Individuals with sarcopenia were 1:1 matched to those without sarcopenia via propensity score matching.

RESULTS

Among a total of 1634 eligible subjects, 353 were identified with sarcopenia. In men without sarcopenia, an increase in waist circumference by 1 cm was associated with a 32 % higher risk of the development of hypertension. Conversely, an increase in appendicular lean mass by 1 kg was associated with lower risks of the development of cardiovascular disease (41 % lower) and hyperlipidemia (28 % lower). However, there were no significant associations between changes in body composition and any incident cardiometabolic diseases in men with sarcopenia. Women without sarcopenia who experienced an increase in weight of 1 kg were 21 % less likely to develop hyperlipidemia. In women with sarcopenia, the risk of diabetes mellitus was reduced by 30 % with an incremental increase in weight by 1 kg, while the risk of hyperlipidemia increased almost threefold with an increase in appendicular lean mass by 1 kg.

CONCLUSIONS

In older adults without sarcopenia, a decrease in obesity-related indices and a gain in muscle gain are beneficial for men, but inverse relationships between weight and cardiometabolic diseases were reported in women. We found no cardiometabolic benefit of increasing lean mass in older adults with sarcopenia regardless of sex.

The Use of SGLT-2 Inhibitors and GLP-1RA in Frail Older People with Diabetes: A Personalised Approach Is Required

Background: Frailty is an increasingly recognised complication of diabetes in older people and should be taken into consideration in management plans, including the use of the new therapies of sodium glucose cotransporter-2 (SGLT-2) inhibitors and glucagon like peptide-1 receptor agonists (GLP-1RA). The frailty syndrome appears to span across a spectrum, from a sarcopenic obese phenotype at one end, characterised by obesity, insulin resistance, and prevalent cardiovascular risk factors, to an anorexic malnourished phenotype at the other end, characterised by significant weight loss, reduced insulin resistance, and less prevalent cardiovascular risk factors. Therefore, the use of the new therapies may not be suitable for every frail older individual with diabetes. Objectives: To review the characteristics and phenotype of frail older people with diabetes who should benefit from the use of SGLT-2 inhibitors or GLP-1RA. Methods: A narrative review of the studies investigating the benefits of SGLT-2 inhibitors and GLP-1RA in frail older people with diabetes. Results: The current evidence is indirect, and the literature suggests that the new therapies are effective in frail older people with diabetes and the benefit appears to be proportional with the severity of frailty. However, frail patients described in the literature who benefited from such therapy appeared to be either overweight or obese, and to have a higher prevalence of unfavourable metabolism and cardiovascular risk factors such as dyslipidaemia, gout, and hypertension compared to non-frail subjects. They also have a higher prevalence of established cardiovascular disease compared with non-frail individuals. In absolute terms, their higher cardiovascular baseline risk meant that they benefited the most from such therapy. The characteristics of this group of frail patients fulfil the criteria of the sarcopenic obese frailty phenotype, which is likely to benefit most from the new therapies due to the unfavourable metabolic profile of this phenotype. There is no current evidence to suggest the benefit of the new therapies in the anorexic malnourished phenotype, which is underrepresented or totally excluded from these studies, such as in patients living in care homes. This phenotype is likely to be intolerant to such therapy due to its associated risk of inducing further weight loss, dehydration, and hypotension. Conclusions: Clinicians should consider the early use of the new therapies in frail older people with diabetes who are either of normal weight, overweight, or obese with prevalent cardiovascular risk factors, and avoid their use in those frail subjects who ae underweight, anorexic, and malnourished.

Sarcopenic Obesity: A Comprehensive Approach for Postmenopausal Women

Sarcopenic obesity, characterized by the concurrent presence of muscle loss and obesity, poses significant health challenges, especially in the elderly. This review explores the impact of sarcopenic obesity on disability, metabolic health, comorbidities, and potential management strategies. With the aging global population, the prevalence of sarcopenic obesity is expected to increase, necessitating a comprehensive management approach. Early screening, prevention, and ongoing research on its underlying mechanisms and therapeutic options are crucial for promoting healthy aging.

Non-pharmacological treatment strategies for anthropometric, physical capacity and physiological indicators among sarcopenic obesity patients: a systematic review of rigorous randomized controlled trials

OBJECTIVES

To investigate the effects of non-pharmacological treatments on sarcopenic obesity (SO).

METHODS

A search for randomized controlled trials (RCTs) on SO was conducted in PubMed, Web of Science, CINAHL, CENTRAL, SPORTDiscus, CNKI, Wanfang and VIP. A meta-analysis was conducted using random-effects models for MDs.

RESULTS

The meta-analysis on 21 RCTs showed that exercise improved PBF (MD: -1.67%, p < .01, I2 = 35%), grip strength (MD: 2.2 kg, p = .03, I2 = 61%), GS (MD: 0.08 m/s, p = .02, I2 = 0%), TCR (MD: 2.22 repetitions, p < .01, I2 = 0%), TUG (MD: -1.48 s, p < .01, I2 = 61%), UE strength (MD: 1.88 kg/kg, p < .01, I2 = 0%) and LE strength (MD: 2.19 kg/kg, p < .01, I2 = 0%). Nutritional interventions improved grip strength (MD: 1.52 kg, p < .01, I2 = 0%). Combine interventions improved PBF (MD: -1.97%, p < .01, I2 = 38%), ASMM (MD: 0.4 kg, p < .01, I2 = 6%), grip strength (MD: 1.83 kg, p < .01, I2 = 38%) and GS (MD: 0.04 m/s, p < .01, I2 = 0%). Combined interventions were more effective than nutrition alone for reducing PBF (MD: -0.8%, p = .05, I2 = 0%).

CONCLUSION

The effects of exercise and nutrition interventions on SO are limited individually, especially regarding muscle mass, but their combination can yield optimal results. Additionally, physical therapy also demonstrated some potential.

Steatosarcopenia: A New Terminology for Clinical Conditions Related to Body Composition Classification

Body composition analysis focuses on measuring skeletal muscle mass and total body fat. The loss of muscle function and mass is related to clinical conditions such as frailty, increased risk of falls, and prolonged hospitalizations. Despite the relevance of the definition of sarcopenic obesity, there is still a gap in the monitoring of patients who have the combination of sarcopenia and myosteatosis, regardless of the presence of obesity. Therefore, we propose a new nomenclature, steatosarcopenia, a condition characterized by the loss of mass or skeletal muscle strength and performance associated with the excessive deposition of ectopic reserve fat in muscle tissue, in the same individual, not necessarily related to excess fat total body mass. A greater understanding of this condition may assist in developing strategies for preventing and treating metabolic diseases.

Sarcopenic obesity is associated with cardiometabolic multimorbidity in Chinese middle-aged and older adults: a cross-sectional and longitudinal study

OBJECTIVES

Sarcopenic obesity (SO) has been found to increase the risk of metabolic disorders, however, its relationship with cardiometabolic multimorbidity (CMM) remains unexplored. This study aims to investigate the potential association between SO and CMM in the middle-aged and older population.

METHODS

Our study subjects were from CHARLS. SO was defined as the combination of impaired grip strength (grip strength <28 kg for men and <18 kg for women) and increased body mass index (BMI ≥25 kg/m2). CMM was defined as having two or more cardiometabolic diseases, including diabetes mellitus, stroke, and heart disease. The participants were divided into four groups according to their sarcopenia and obesity status, and logistic regression analysis was used to examine the association between SO and CMM.

RESULTS

A total of 15,252 study subjects were included in the cross-sectional study, with an average age of 60.6 years and a male proportion of 47.4%. In the cross-sectional analysis conducted in 2015, the prevalence of CMM was highest in the SO group (9.1%), followed by the obesity (3.7%) and sarcopenia (3.5%) group. After adjustment for confounding factors, SO [OR (95%CI): 2.453 (1.742-3.455)], sarcopenia [OR (95% CI): 1.601 (1.157-2.217)], obesity [OR (95% CI): 1.446 (1.107-1.888)] were all observed to be associated with CMM, with the strongest association in the SO group. Furthermore, in the longitudinal analysis, only the SO group demonstrated a significant risk for developing CMM [OR (95% CI): 2.302 (1.239-4.228)].

CONCLUSIONS

SO was independently and positively associated with CMM in middle-aged and older population.

Sex-specific associations between total and regional Fat-to-muscle Mass ratio and cardiometabolic risk: findings from the China National Health Survey

BACKGROUND

The fat-to-muscle mass ratio (FMR), integrating the antagonistic effects of fat and muscle mass, has been suggested as a valuable indicator to assess cardiometabolic health independent of overall adiposity. However, the specific associations of total and regional FMR with cardiometabolic risk are poorly understood. We aimed to examine sex-specific associations of total and regional FMR with single and clustered cardiometabolic risk factors (CRFs).

METHODS

13,505 participants aged 20 years and above were included in the cross-sectional study. Fat mass and muscle mass were assessed using a bioelectrical impedance analysis device. FMR was estimated as fat mass divided by muscle mass in corresponding body parts (whole body, arm, leg, and trunk). Clustered CRFs was defined as the presence of two or more risk factors, including hypertension, elevated blood glucose, dyslipidemia, insulin resistance (IR), and hyperuricemia. IR was assessed by the triglyceride glucose (TyG) index. Multivariable logistic regression models were applied to explore the associations of FMR in the whole body and body parts with single and clustered CRFs.

RESULTS

The odds ratios (ORs) increased significantly for all single and clustered CRFs with the per quartile increase of total and regional FMR in both sexes (P for trend < 0.001), following adjustment for confounders. Among the regional parts, FMRs of the legs presented the strongest associations for clustered CRFs in both men and women, with adjusted OR of 8.54 (95% confidence interval (CI): 7.12-10.24) and 4.92 (95% CI: 4.24-5.71), respectively. Significant interactions (P for interaction < 0.05) were identified between age and FMRs across different body parts, as well as between BMI status and FMRs in different regions for clustered CRFs. Restricted cubic splines revealed significant non-linear relationships between FMRs of different body parts and clustered CRFs in both sexes (P for nonlinear < 0.05).

CONCLUSIONS

FMRs in the whole body and different regions were significantly associated with single and clustered CRFs in the general Chinese population. The association between FMR and clustered CRFs was more pronounced in youngers than in the elderly.

Efficacy of high-intensity interval training versus continuous training on serum myonectin and lipid outcomes in adults with metabolic syndrome: A post-hoc analysis of a clinical trial

BACKGROUND

Myonectin is a myokine with potential effects on the lipid metabolism; however, its regulation by exercise in humans remains unclear. We aimed to compare the efficacy of high-intensity interval training low-volume (HIIT) versus moderate-intensity continuous training (MICT) on serum myonectin, serum lipids, appendicular fat and lean mass, and intramuscular lipids in humans.

METHODS

Secondary analysis of a controlled, randomized, clinical trial in adults of both sexes with metabolic syndrome, who underwent a supervised, three-times/week, 12-week treadmill program. HIIT (n = 29) consisted of six intervals with one-minute, high-intensity phases at 90% of peak oxygen consumption (VO2peak) for a total of 22 min. MICT (n = 31) trained at 60% of VO2peak for 36 min. Serum myonectin was measured using a human enzyme-linked immunosorbent assay. Lipid profile was determined by enzymatic methods and free fatty acids (FFA) were measured by gas chromatography. Fat and lean mass were assessed by dual-energy X-ray absorptiometry. Intramuscular lipids were measured through proton magnetic resonance spectroscopy.

RESULTS

Subjects had a mean age of 50.8±6.0 years and body mass index of 30.6±4.0 kg/m2. Compared to MICT, HIIT was not superior at increasing serum myonectin (p = 0.661) or linoleic acid (p = 0.263), reducing palmitic (p = 0.286) or stearic acid (p = 0.350), or improving lipid profile (all p>0.05), appendicular fat mass index -AFMI- (p = 0.713) or appendicular lean mass percentage -ALM- (p = 0.810). Compared to baseline, only HIIT significantly increased myonectin (p = 0.042), with a large effect size, although both interventions reduced AFMI and increased ALM with a large effect size. Lipid profile, FFA and intramuscular lipids did not change in any intervention group (p>0.05).

CONCLUSIONS

Compared to MICT, HIIT low volume did not demonstrate superiority in improving serum lipids. The fact that both training types reduced AFMI without paralleled significant changes in serum myonectin suggests that this myokine may have a minor effect on short-middle-term exercise-induced fat mobilization.

Mapping Knowledge Landscapes and Emerging Trends of Sarcopenic Obesity in Older Adults: A Bibliometric Analysis From 2004 to 2023

Background The prevalence of obesity in combination with sarcopenia, the age-related loss of muscle mass and strength or physical function, is on the rise among adults aged 65 years and older. A significant portion of this demographic now falls under the classification of sarcopenic obesity, a high-risk geriatric syndrome predominantly seen in an aging population vulnerable to compounded complications from both sarcopenia and obesity. It is essential to promptly evaluate the impact of academic research in this field, taking into account factors such as geographical regions, authors, journals, and institutions. Furthermore, exploring current topics and identifying potential areas that could inspire future researchers to conduct additional studies is crucial for advancing overall health in this population. Methodology A search was conducted in the Web of Science Core Collection database to identify English language articles and reviews focusing on sarcopenic obesity in older adults, published between January 1, 2004, and December 31, 2023. Bibliometric analysis was performed using VOSviewer (v.1.6.18) and CiteSpace (v.6.1.R2). Results A total of 985 original English-language articles were collected, consisting of 783 articles and 202 reviews. The volume of research publications in this field has shown significant growth since 2012. The United States leads in contributions, with 239 articles (24.3% of the total) and the highest number of citations at 18,403, along with the highest total link strength. The University of Melbourne in Australia stands out with 25 published articles (2.5% of the total). University of Verona in Italy has the most citations at 9,405, and Monash University in Australia has the highest total link strength at 53. Among prolific authors, John A. Batsis from Duke University is the most productive with 24 articles (2.4% of the total). The journal "Nutrients" has the most articles on sarcopenic obesity in older adults, publishing 54 articles (5.5% of the total). Key topics in this area include sarcopenia, obesity, sarcopenic obesity, and elderly. Recent interventions focus on "nutrition" and "exercise" for sarcopenic obesity in older adults. Conclusions Research on sarcopenic obesity in older adults has seen significant growth on a global scale from 2004 to 2023, indicating a promising area for further study with potential benefits from current advancements. Although academic inquiries have shed light on various aspects of sarcopenic obesity in older adults, there remains a noticeable dearth of clinical research and evidence-based medicine on the effective management of this condition in elderly individuals. Future studies could focus on developing tailored interventions for older adults with sarcopenic obesity.

Correlation between low handgrip strength and metabolic syndrome in older adults: a systematic review

Muscle weakness has been associated to insulin resistance and metabolic syndrome in the general population. However, it is still unclear whether this association is maintained in older adults. This study investigated correlations between low handgrip strength (HGS) and metabolic syndrome, or some of its components, in older adults through a systematic review of the literature. Searches were conducted in the Virtual Health Library Regional Portal, Scopus, Cochrane, Embase, MEDLINE/ PubMed, SciELO, and Web of Science databases for relevant studiesinvestigating muscle weakness (measured by hand dynamometer) and metabolic syndrome or its components in older adult populations, published up to September 2023. From the 2050 references initially identified, 20 studies, comprising a total of 31,264 older adults of both genders, completely met the inclusion/exclusion criteria. Eighteen studies showed that lower HGS was associated with metabolic syndrome or some of its risk factors, such as abdominal obesity, hyperglycemia, insulin resistance, dyslipidemia, or high blood pressure. Two studies found that older men with high blood pressure had increased HGS. Most studies included in this systematic review revealed a significant correlation between reduced HGS and metabolic syndrome or some of its components, especially abdominal obesity and insulin resistance. We conclude that below-average HGS can be associated with metabolic syndrome in older adults.

Cardiovascular risk reduction in older people with type 2 diabetes mellitus-a comprehensive narrative review

Metabolic targets are controversial in older people with type 2 diabetes due to functional heterogeneity and morbidity burden. Tight blood pressure and metabolic control appears beneficial in fit individuals who are newly diagnosed with type 2 diabetes and have fewer comorbidities. The benefits of low blood pressure and tight metabolic control is attenuated with the development of comorbidities, especially frailty. Guidelines consider frail older people as one category and recommend relaxed targets. However, sarcopenic obese frail individuals may benefit from tight targets and intensification of therapy due to their unfavourable metabolic profile, accelerated diabetes trajectory and high cardiovascular risk. In addition, the early use of sodium glucose transporter-2 inhibitors and glucagon like peptide-1 receptor agonists may be beneficial in this frailty phenotype due to their cardio-renal protection, which is independent of glycaemic control, provided they are able to engage in resistance exercise training to avoid loss of muscle mass. In the anorexic malnourished frail individual, early use of insulin, due to its weight gain and anabolic properties, is appropriate. In this phenotype, targets should be relaxed with deintensification of therapy due to significant weight loss, decelerated diabetes trajectory and increased risk of medication side effects.

Abdominal computed tomography measurements of body composition and waitlist mortality in kidney transplant candidates

Body mass index is often used to determine kidney transplant (KT) candidacy. However, this measure of body composition (BC) has several limitations, including the inability to accurately capture dry weight. Objective computed tomography (CT)-based measures may improve pre-KT risk stratification and capture physiological aging more accurately. We quantified the association between CT-based BC measurements and waitlist mortality in a retrospective study of 828 KT candidates (2010-2022) with clinically obtained CT scans using adjusted competing risk regression. In total, 42.5% of candidates had myopenia, 11.4% had myopenic obesity (MO), 68.8% had myosteatosis, 24.8% had sarcopenia (probable = 11.2%, confirmed = 10.5%, and severe = 3.1%), and 8.6% had sarcopenic obesity. Myopenia, MO, and sarcopenic obesity were not associated with mortality. Patients with myosteatosis (adjusted subhazard ratio [aSHR] = 1.62, 95% confidence interval [CI]: 1.07-2.45; after confounder adjustment) or sarcopenia (probable: aSHR = 1.78, 95% CI: 1.10-2.88; confirmed: aSHR = 1.68, 95% CI: 1.01-2.82; and severe: aSHR = 2.51, 95% CI: 1.12-5.66; after full adjustment) were at increased risk of mortality. When stratified by age, MO (aSHR = 2.21, 95% CI: 1.28-3.83; P interaction = .005) and myosteatosis (aSHR = 1.95, 95% CI: 1.18-3.21; P interaction = .038) were associated with elevated risk only among candidates <65 years. MO was only associated with waitlist mortality among frail candidates (adjusted hazard ratio = 2.54, 95% CI: 1.28-5.05; P interaction = .021). Transplant centers should consider using BC metrics in addition to body mass index when a CT scan is available to improve pre-KT risk stratification at KT evaluation.

Comparing the efficacy of low-load resistance exercise combined with blood flow restriction versus conventional-load resistance exercise in Chinese community-dwelling older people with sarcopenic obesity: a study protocol for a randomised controlled trial

INTRODUCTION

Sarcopenic obesity (SO) is characterised by decreased muscle mass, diminished muscle strength and/or reduced physical performance and a high percentage of body fat (PBF). Conventional-load resistance exercise (CRE) may be difficult for older people with SO owing to their declining physical functions. Low-load resistance exercise (LRE) combined with blood flow restriction (BFR; LRE-BFR) is a viable alternative to CRE for improving muscle mass and strength and potential exercise mode for managing SO. This study has two objectives: (1) to comprehensively evaluate the efficacy of CRE and LRE-BFR in improving body composition, muscle strength, physical performance, haematological parameters, cardiovascular disease (CVD) risk factors and quality of life and (2) to compare the efficacy of CRE and LRE-BFR and explore their potential mechanisms.

METHODS AND ANALYSIS

This work is a 12-week assessor-blinded randomised clinical trial that will be conducted thrice a week. Sarcopenia will be defined using the Asian Working Group for Sarcopenia 2019, and obesity will be determined using the criteria developed by the World Health Organization. Community-dwelling older people aged ≥ 65 years will be screened as the participants using inclusion and exclusion criteria. A total of 33 participants will be randomised into a CRE group (n = 11), an LRE-BFR group (n = 11) and a control group that will be given only health education (n = 11). The primary outcomes will be knee extensor strength and PBF, and the secondary outcomes will be body composition, anthropometric measurements, muscle strength of upper limbs, physical performance, haematological parameters, CVD risk factors and quality of life. The outcomes will be measured at the baseline (week 0), end of the intervention (week 12) and follow up (week 24). All the collected data will be analysed following the intention-to-treat principle.

ETHICS AND DISSEMINATION

The Ethics Research Committee has approved this study (approval No. CMEC-2022-KT-51). Changes or developments in this study will be reported at www.chictr.org.cn .

TRIAL REGISTRATION

ChiCTR2300067296 (3 January 2023).

Evidence of whole-body vibration exercises on body composition changes in older individuals: a systematic review and meta-analysis

Introduction: The aging process is associated with changes in body composition, including fat gain and skeletal muscle loss from middle age onward. Moreover, increased risk of functional decline and the development of chronic diseases are also related to aging. Objective: This systematic review and meta-analysis aimed to evaluate the effects of whole-body vibration exercise (WBVE), as a physical exercise, on body composition in people over 60 years of age. Methods: Searches were performed on PubMed, Scopus, Web of Science, and Embase. Only randomized clinical trials evaluating the effects of WBVE on body composition in older individuals were considered. The methodological quality of the studies involved was assessed using the Physiotherapy Evidence Database (PEDro) scale, recommendations from the Cochrane Collaboration were used to assess risk of bias, and quality of evidence was assessed using the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology. RevMan 5.4 was used to calculate standardized mean differences and confidence intervals of 95% (CIs). Results: Eight studies were included in this review with a mean methodological quality score of 7.5, which is considered high quality on the PEDro scale. The included studies suggest that more robust research with protocols and well-designed comparison groups is required to better assess changes in the body composition of older individuals through WBVE. Quantitative results were calculated, with differences in weighted means, differences in standardized means, and 95% confidence intervals (CIs). Conclusion: WBVE evaluated by the studies included in this review did not demonstrate improvements in body composition, and no significant effect of WBVE was found on fat mass with standardized differences (SD = -1.92; 95% CI: -4.81 to -0.98; p = 0.19), lean mass with standardized mean differences (SMD = 0.06 CI 95% [-0.21; -0.33]; p = 0.67), or skeletal muscle mass with standardized differences (SD = 0.10; CI 95% [-1.62; 1.83]; p = 0.91). Therefore, to date, there is lack of adequate evidence to state that WBVE can benefit the body composition of men and women over 60 years of age. However, further studies are required to better understand the physiological impacts of WBVE on body composition. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/#myprosperoCRD42021248871, identifier CRD42021248871.

Association of fat-to-muscle ratio with non-alcoholic fatty liver disease: a single-centre retrospective study

OBJECTIVES

Sarcopenia is a known risk factor for non-alcoholic fatty liver disease (NAFLD). Studies evaluating the association between the fat-to-muscle ratio (FMR) and NAFLD are limited. Therefore, the aim of our study was to investigate the association between FMR and NAFLD.

DESIGN

A retrospective study was conducted on individuals who underwent health examination at Wuhan Union Hospital between January 2020 and November 2021. Clinical data were collected from electronic medical records.

SETTING

Wuhan Union Hospital, Wuhan, China.

PARTICIPANTS

1592 participants aged ≥40 years who underwent body composition analysis and liver ultrasonography were retrospectively reviewed.

OUTCOME MEASURES

Liver ultrasonography was used to assess liver steatosis, and the fibrosis-4 index was used to calculate the risk scores for liver fibrosis. The 10-year atherosclerotic cardiovascular disease (ASCVD) risk prediction model was used to calculate ASCVD risk scores.

RESULTS

The FMR was significantly higher in individuals with NAFLD than in those without NAFLD (p<0.001). The prevalence of NAFLD gradually increased from FMR tertile 1 (reference) to tertile 2 (OR=1.49, 95% CI 1.13 to 1.97) and tertile 3 (OR=2.85, 95% CI 2.08 to 3.90). In addition, patients with NAFLD in FMR tertile 3 had a significantly higher risk of liver fibrosis (OR=4.48, 95% CI 2.12 to 9.50) and ASCVD (OR=4.63, 95% CI 2.62 to 8.19) than those in FMR tertile 1 after adjustment for multiple confounders.

CONCLUSION

In this study, we found a significant association between FMR and NAFLD. A higher FMR indicates a higher risk of NAFLD in the study population and a higher risk of liver fibrosis and ASCVD in NAFLD patients.

U-shaped association between plasma C-peptide and sarcopenia: A cross-sectional study of elderly Chinese patients with diabetes mellitus

Limited research exists regarding the relationship between fasting plasma C-peptide levels and sarcopenia. As a result, our study aimed to examine this association in elderly Chinese diabetic patients. This cross-sectional study included 288 elderly patients with diabetes mellitus from the Fourth People's Hospital in Guiyang who were enrolled prospectively between March 2020 and February 2023. The independent variable of interest was fasting plasma C-peptide, while the dependent variable was sarcopenia. Data on several covariates, including demographic factors, lifestyle habits, co-morbidities, anthropometric indicators, and laboratory indicators, were also collected. Of the 288 participants, 27.43% (79/288) had sarcopenia. After adjusting for potential confounding variables, we found a U-shaped association between fasting plasma C-peptide levels and sarcopenia, with inflection points identified at approximately 774 pmol/L and 939 mmol/L. Within the range of 50-744 pmol/L, each 100 pmol/L increase in CysC was associated with a 37% decrease in the odds of sarcopenia (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.49 to 0.83; P < 0.001). Additionally, within the range of 939-1694 pmol/L, each 100 pmol/L increase in fasting plasma C-peptide was associated with a 76% increase in the odds of sarcopenia (odds ratio [OR], 1.76; 95% confidence interval [CI], 1.11 to 2.81; P = 0.017). Our study revealed a U-shaped association between fasting plasma C-peptide levels and the likelihood of sarcopenia, with lower risk in the range of 774-939 pmol/L. These findings may assist in the development of more effective prevention and treatment strategies for sarcopenia in elderly diabetic patients.

A Novel Frailty Score Based on Laboratory Parameters (FIMS Score) for the Management of Older Patients with Severe Aortic Stenosis

This study aimed to develop a novel score based on common laboratory parameters able to identify frail and sarcopenic patients as well as predict mortality in elderly patients with severe aortic stenosis (AS) for tailored clinical decision-making. A total of 109 patients (83 ± 5 years; females, 68%) with AS underwent a multidisciplinary pre-operative assessment and finalized a "frailty-based management" for the AS interventional treatment. Laboratory parameters of statistically significant differences between sarcopenic and non-sarcopenic individuals were tested in the structural equation model (SEM) to build a Frailty Inflammation Malnutrition and Sarcopenia score (FIMS score). Mortality at 20 months of follow-up was considered an outcome. FIMS score, in particular, the cut-off value ≥ 1.28 was able to identify "frail" and "early frail" patients and predict mortality with a sensitivity of 83.3% and 82.6%, respectively (p = 0.001) and was an independent determinant associated with a higher risk of mortality (HR 5.382; p-value = 0.002). The FIMS score, easily achievable and usable in clinical practice, was able to identify frail and sarcopenic patients as well as predict their adverse clinical outcomes. This score could provide appropriate guidance during decision-making regarding elderly patients with severe AS.

Effects of Yijinjing combined with resistance training on body fat distribution and hepatic lipids in middle-aged and older people with prediabetes mellitus: A randomized controlled trial

PURPOSE

This randomized controlled trial aimed to study the effects of Yijinjing plus Elastic Band Resistance exercise on intrahepatic lipid (IHL), body fat distribution, glucolipid metabolism and biomarkers of inflammation in middle-aged and older people with pre-diabetes mellitus (PDM).

PARTICIPANTS AGESND METHODS

34 PDM participants (mean age, 62.62 ± 4.71 years; body mass index [BMI], 25.98 ± 2.44 kg/m2) were randomly assigned to the exercise group (n = 17) or control group (n = 17). The exercise group performed moderate-intensity Yijinjing and Elastic Band Resistance training 5 times per week for 6 months. The control group maintained their previous lifestyle. We measured body composition (body weight and body fat distribution), IHL, plasma glucose, lipid and the homeostatic model assessment of insulin resistance (HOMA-IR), inflammatory cytokines at baseline and 6 months.

RESULTS

Compared with baseline, exercise significantly reduced IHL (reduction of 1.91 % ± 2.61 % vs an increase of 0.38 % ± 1.85 % for controls; P = 0.007), BMI (reduction of 1.38 ± 0.88 kg/m2 vs an increase of 0.24 ± 1.02 kg/m2 for controls; P = 0.001), upper limb fat mass, thigh fat mass and whole body fat mass. Fasting glucose, HOMA-IR, plasma total cholesterol (TC), and triglyceride (TG) were decreased in the exercise group (P < 0.05). There were no effects of exercise on liver enzyme levels and inflammatory cytokines. The decrease in IHL was positively correlated with the decreases in BMI, body fat mass and HOMA-IR.

CONCLUSION

Six months of Yijinjing and resistance exercise significantly reduced hepatic lipids and body fat mass in middle-aged and older people with PDM. These effects were accompanied by weight loss, improved glycolipid metabolism and insulin resistance.

Effect of cadmium exposure on body composition deterioration: A propensity score-matched cohort study

This propensity score-matched cohort study investigated the effects of blood cadmium (Cd) levels on body composition. Body composition was assessed by multifrequency bioelectrical impedance analysis and categorized into three groups: metabolically healthy obesity (MHO), adiposity obesity (AO), and sarcopenic obesity (SO). At baseline, 85 and 101 participants had MHO and AO, respectively (mean age, 51 ± 7 years; male-to-female ratio, 1.0:1.3). During the 14-year follow-up, the body composition of 40 MHO and 6 AO participants deteriorated to AO and SO, respectively. The incidence of AO and SO differed according to age, sex, and blood Cd level. High blood Cd level increased the risk of body composition deterioration, particularly among those aged 60-69 years (hazard ratio [HR] = 2.14), women (HR = 1.46), and those with AO at baseline (HR = 1.63; all p < 0.05). Cd exposure deteriorates body composition in older and female individuals, particularly from AO to SO.

Sarcopenic obesity research perspectives outlined by the sarcopenic obesity global leadership initiative (SOGLI) - Proceedings from the SOGLI consortium meeting in rome November 2022

The European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity (EASO) launched the Sarcopenic Obesity Global Leadership Initiative (SOGLI) to reach expert consensus on a definition and diagnostic criteria for Sarcopenic Obesity (SO). The present paper describes the proceeding of the Sarcopenic Obesity Global Leadership Initiative (SOGLI) meeting that was held on November 25th and 26th, 2022 in Rome, Italy. This consortium involved the participation of 50 researchers from different geographic regions and countries. The document outlines an agenda advocated by the SOGLI expert panel regarding the pathophysiology, screening, diagnosis, staging and treatment of SO that needs to be prioritized for future research in the field.

Association between Skeletal Muscle Mass-to-Visceral Fat Ratio and Dietary and Cardiometabolic Health Risk Factors among Korean Women with Obesity

Sarcopenic obesity (SO) is more associated with cardiovascular diseases than sarcopenia or obesity alone. This study aimed to assess the association between the skeletal muscle mass-to-visceral fat area ratio (SVR) and dietary and cardiometabolic health risk factors in obese women. Fifty-nine women aged 19-65 years with BMI values of ≥25 kg/m² and <32 kg/m² were included. The SVR was inversely correlated with blood lipids (total cholesterol, β = -0.369, p = 0.022; low-density lipoprotein cholesterol, β = -0.326, p = 0.049) and hs-CRP (β = -0.305, p = 0.043). Among the dietary factors, fatty acid intake (saturated fatty acids (SFA), β = -0.287, p = 0.044; monounsaturated fatty acids (MUFA), β = -0.282, p = 0.048; polyunsaturated fatty acids (PUFA), β = -0.301, p = 0.035) was inversely correlated with the SVR. Conversely, vitamin B₆ and B₁₂ intake (vitamin B₆, β = 0.338, p = 0.012; vitamin B₁₂, β = 0.281, p = 0.024) showed positive associations with the SVR. Individuals with a lower SVR were more likely to have SO and higher blood lipids and inflammatory marker levels. Regarding dietary factors, the SVR increased with vitamin B₆ and B₁₂ intake, which was less likely to occur in individuals with SO.

The association between muscle-to-fat ratio and cardiometabolic risks: The China National Health Survey

BACKGROUND

The relationship between muscle mass and fat mass might be an indicator to assess the cardiometabolic risk independently from overweight/obesity, but evidence from a representative general Chinese population is lacking.

OBJECTIVE

To understand the age- and sex-specific associations between muscle-to-fat ratio (MFR) and cardiometabolic risks in Chinese population.

METHODS

31,178 (12,526 men and 18,652 women) subjects from the China National Health Survey were included. Muscle mass and fat mass were assessed by a bioelectrical impedance device. MFR was calculated as muscle mass divided by fat mass. Systolic blood pressure (SBP) and diastolic blood pressure (DBP), serum lipids, fasting plasma glucose and serum uric acid were measured. General linear regressions, quantile regressions and restricted cubic-spline (RCS) regressions were applied to assess the effect of MFR on cardiometabolic profiles.

RESULTS

Per unit increase of MFR was associated with a 0.631 (0.759-0.502) mmHg SBP decrease in men, 2.648 (3.073-2.223) in women; 0.480 (0.568-0.392) mmHg DBP decrease in men, 2.049 (2.325-1.774) in women; a 0.054 (0.062-0.046) mmol/L total cholesterol decrease in men, 0.147 (0.172-0.122) in women; 0.084 (0.098-0.070) mmol/L triglycerides decrease in men, 0.225 (0.256-0.194) in women; a 0.045 (0.054-0.037) mmol/L low-density lipoprotein decrease in men, 0.183 (0.209-0.157) in women; a 2.870 (2.235-3.506) μmol/L serum uric acid decrease in men, 13.352 (14.967-11.737) in women; and a 0.027 (0.020-0.033) mmol/L high-density lipoprotein increase in men, 0.112 (0.098-0.126) mmol/L in women. The effect in overweight/obese people was much significant than in under/normal weight counterparts. The RCS curves revealed both linear and non-linear relationships between increased MFR and lower cardiometabolic risk.

CONCLUSIONS

Muscle-to-fat ratio is independently associated with multiple cardiometabolic parameters among Chinese adults. Higher MFR is related with better cardiometabolic health, and the effect is much significant in overweight/obese people and women.

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.

Does an Association among Sarcopenia and Metabolic Risk Factors Exist in People Older Than 65 Years? A Systematic Review and Meta-Analysis of Observational Studies

Sarcopenia is defined as the generalized and progressive loss of skeletal muscle strength and mass that may be affected by metabolic factors, although this relationship has been poorly studied. The aim of this review and meta-analysis was to analyze the relationship among the different metabolic risk factors and sarcopenia in people older than 65 years. Following the PRISMA 2020 guide, we searched for articles that studied the relationship among sarcopenia and metabolic risk factors in adults over 65 years of age, published between 2012 and 2022 in four databases: PubMed, Web of Science, Cochrane Plus, and CINAHL. A total of 370 articles were identified in the initial search, of which 13 articles were selected for inclusion in this review. It was observed that metabolic risk factors such as Body Mass Index, systolic and diastolic blood pressure, glucose, cholesterol, or triglycerides had a significant association with sarcopenia. There is evidence of the association of different metabolic risk factors with sarcopenia in adults over 65 years of age, so it is necessary to carry out studies that investigate different strategies that reduce the appearance of sarcopenia, and with it, the incidence of metabolic diseases.

Metabolic Impact of Frailty Changes Diabetes Trajectory

Diabetes mellitus prevalence increases with increasing age. In older people with diabetes, frailty is a newly emerging and significant complication. Frailty induces body composition changes that influence the metabolic state and affect diabetes trajectory. Frailty appears to have a wide metabolic spectrum, which can present with an anorexic malnourished phenotype and a sarcopenic obese phenotype. The sarcopenic obese phenotype individuals have significant loss of muscle mass and increased visceral fat. This phenotype is characterised by increased insulin resistance and a synergistic increase in the cardiovascular risk more than that induced by obesity or sarcopenia alone. Therefore, in this phenotype, the trajectory of diabetes is accelerated, which needs further intensification of hypoglycaemic therapy and a focus on cardiovascular risk reduction. Anorexic malnourished individuals have significant weight loss and reduced insulin resistance. In this phenotype, the trajectory of diabetes is decelerated, which needs deintensification of hypoglycaemic therapy and a focus on symptom control and quality of life. In the sarcopenic obese phenotype, the early use of sodium-glucose transporter-2 inhibitors and glucagon-like peptide-1 receptor agonists is reasonable due to their weight loss and cardio-renal protection properties. In the malnourished anorexic phenotype, the early use of long-acting insulin analogues is reasonable due to their weight gain and anabolic properties, regimen simplicity and the convenience of once-daily administration.

Are Women with Normal-Weight Obesity at Higher Risk for Cardiometabolic Disorders?

OBJECTIVES

This study aimed to evaluate the cardiometabolic abnormalities in women with normal-weight obesity (NWO) in comparison with lean, overweight, and obese women.

METHODS

This cross-sectional study evaluated the assessment of cardiometabolic abnormalities of women with NWO compared to lean, overweight, and obese women. NWO was defined as a BMI < 25 kg.m^-2 and a BFP higher than 30%. Anthropometric variables, cardiometabolic abnormality markers (fasting blood glucose (FBG), blood pressure (BP), lipid profile, insulin resistance, and high-sensitivity C-reactive protein (hs-CRP)), and liver enzymes were also examined.

RESULTS

Significant differences were observed in HDL concentrations between NWO, lean, and obese participants (p < 0.05). There were no significant differences in FBG, insulin resistance, liver enzymes, or cholesterol between groups (p > 0.05). The prevalence of the abnormal metabolic phenotype was higher in NWO compared to the lean group (4.0% and 24.1%, respectively; p < 0.05). Women with type 2 and 3 obesity had abnormal metabolic profiles (60.9% and 73.9%, respectively) compared to NWO participants (p < 0.01). The NWO group had a significantly higher incidence of cardiometabolic abnormalities compared to the lean participants (p < 0.05), while the type 2 and 3 obese individuals had significantly higher incidences compared to the NWO group (p < 0.001 and p < 0.001, respectively).

CONCLUSIONS

Individuals with NWO had a significantly higher incidence of cardiometabolic abnormalities when compared to lean participants. These abnormalities strongly relate to BFP and waist circumferences.

The Effect of Childhood Obesity or Sarcopenic Obesity on Metabolic Syndrome Risk in Adolescence: The Ewha Birth and Growth Study

The prevalence of obesity and metabolic syndrome (MetS) in the pediatric population has increased globally. We evaluated the impact of childhood obesity and sarcopenic obesity on the risk of MetS in adolescence using the Ewha Birth and Growth Cohort study data. In this study, we analyzed data from 227 participants who were followed up at the ages of 7-9 and 13-15 years. Overweight and obesity were defined as a body mass index of the 85th percentile or higher based on national growth charts, and sarcopenic obesity was defined using body composition data. Metabolic diseases in adolescence were identified by calculating the pediatric simple metabolic syndrome score (PsiMS), continuous metabolic syndrome score (cMetS), and single-point insulin sensitivity estimator (SPISE) as MetS indices. The prevalence of overweight was approximately 15% at both 7-9 and 13-15 years old, and that of sarcopenic obesity (7-9 years old) was 19.5%. Boys aged 13-15 years had a significantly larger waist circumference (WC) and higher systolic blood pressure (SBP) than girls. The MetS indices (PsiMS, cMetS, and SPISE) showed no significant differences by gender. Overweight and sarcopenic obese people have a higher overall risk of MetS components than normal people. The overweight group had a significantly higher prevalence of PsiMS and cMetS than the normal group, while the SPISE was significantly lower and the MetS indicator was worse in the overweight group than in the normal group. Similar results were obtained in the group with sarcopenic obesity. Both overweight and sarcopenic obesity remained significantly associated with MetS indicators, even after adjusting for covariates. Furthermore, metabolic health assessed by the cMetS in adolescence was affected not only by childhood overweight but also by adolescence, which showed an interaction effect. The results of this study emphasize the importance and need for early detection of childhood obesity and effective public health interventions.

Combining Fat-to-Muscle Ratio and Alanine Aminotransferase/Aspartate Aminotransferase Ratio in the Prediction of Cardiometabolic Risk: A Cross-Sectional Study

PURPOSE

Altered body composition and liver enzymes are known to be related to cardiometabolic risk. Our study aimed to evaluate the association between fat-to-muscle ratio (FMR), alanine aminotransferase/aspartate aminotransferase (ALT/AST) ratio and cardiometabolic risk.

METHODS

In total, 1557 participants aged ≥40 years were included. A bioelectrical impedance analyzer (BIA) was used to measure fat mass and muscle mass. We created a cardiometabolic risk score with one point for each cardiometabolic risk factor, including elevated triglycerides (TGs), decreased high-density lipoprotein cholesterol (HDL-C), elevated blood pressure (BP), and abnormal blood glucose, yielding a score of 0-4 for each participant (≥2 for high-risk and <2 for low-risk). Logistic regression analyses were used to analyze the relationship between FMR, ALT/AST ratio and cardiometabolic risk.

RESULTS

FMR and ALT/AST ratio were significantly higher in the high-risk group than in the low-risk group (P<0.001). FMR and ALT/AST ratio were both positively correlated with a higher cardiometabolic risk score and the presence of each cardiometabolic risk factor. In subgroup analyses categorized according to FMR and ALT/AST ratio cutoffs, the high-FMR/high-ALT/AST group had the highest cardiometabolic risk (OR=8.51; 95% CI 4.46-16.25 in women and OR=5.09; 95% CI 3.39-7.65 in men) after adjusting for confounders.

CONCLUSION

FMR and ALT/AST ratio were positively associated with cardiometabolic risk. Combining these two indicators improved the prediction of cardiometabolic risk.

Mitochondrial Iron Metabolism: The Crucial Actors in Diseases

Iron is a trace element necessary for cell growth, development, and cellular homeostasis, but insufficient or excessive level of iron is toxic. Intracellularly, sufficient amounts of iron are required for mitochondria (the center of iron utilization) to maintain their normal physiologic function. Iron deficiency impairs mitochondrial metabolism and respiratory activity, while mitochondrial iron overload promotes ROS production during mitochondrial electron transport, thus promoting potential disease development. This review provides an overview of iron homeostasis, mitochondrial iron metabolism, and how mitochondrial iron imbalances-induced mitochondrial dysfunction contribute to diseases.

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.

Effect of low skeletal muscle mass and sarcopenic obesity on chronic kidney disease in patients with type 2 diabetes

OBJECTIVE

This study aimed to investigate the association between low muscle mass or sarcopenic obesity and the risk of incident chronic kidney disease (CKD) in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 3123 patients with T2DM with preserved renal function were followed up for incident CKD. Skeletal muscle mass was estimated from bioelectrical impedance analysis. CKD was defined as estimated glomerular filtration rate < 60 mL/min/1.73 m² . Sarcopenic obesity was defined as the coexistence of sarcopenia and abdominal obesity.

RESULTS

During 8.9 years of follow-up, 530 (17.0%) patients developed incident CKD. When patients were divided into three groups based on sex-specific tertiles, lower muscle mass was not associated with an increased risk of incident CKD after adjustment for risk factors. However, when patients were divided into four groups according to the presence of sarcopenia and obesity, sarcopenic obesity was associated with an increased risk of incident CKD (adjusted hazard ratio 1.77; 95% CI: 1.24-2.51; p = 0.001) compared with the other groups.

CONCLUSIONS

Sarcopenic obesity, but not low muscle mass alone, may increase the risk of CKD in patients with T2DM.

The "Iron Tale"- iron indices and handgrip strength in community-dwelling adults

Sarcopenia is a precursor for physical frailty and is associated with adverse outcomes. Low handgrip strength (HGS) is one of the diagnostic criteria for sarcopenia. Multiple factors can influence muscle quality, including muscle composition, architecture, fat infiltration, fibrosis, excessive iron deposition, and neural activation. There is limited evidence on the association of iron and HGS in community-dwelling older adults. We aim to examine the association of HGS with iron indices and inflammation. The Healthy Older People Everyday study is a subset of the Singapore Population Health Studies cohort. Complete cross-sectional data and iron indices were available for 477 participants. Sociodemographics, comorbidities, and final scores of the FRAIL scale, Barthel Index, Lawton Scale, HGS, and timed-up-and-go were collected and analyzed. Laboratory parameters including hemoglobin, hsCRP and iron indices were measured. The mean age of the participants was 70.9 ± 5.0 years, 258(54.1%) were females, and most were of Chinese(85.3%) ethnicity. Amongst the participants, 6.9% were frail, 39.4% were pre-frailt, and 53.7% were robust. Mean HGS was 22.2 ± 7.0 kg. Low HGS was prevalent in 47.8%, the highest amongst Indians. Prevalence of diabetes, chronic kidney disease, and ischaemic heart disease were significantly higher in those with low HGS. In multivariate regression adjusting for age, sex, comorbidities and Hb, ferritin (β = 0.004 95%CI 0.0002-0.007, p = 0.04), transferrin saturation (β = 0.06 95%CI 0.01-0.10, p = 0.02) and hsCRP (β = - 0.15 95%CI - 0.26 to - 0.04, p < 0.01) were significantly associated with HGS. CRP was negatively associated with HGS, whereas ferritin and transferrin saturation were positively associated with HGS. Older people with iron deficiency should be assessed for sarcopenia, and vice versa, as both can occur in multisystemic disorder, and need to be managed concurrently. Prospective longitudinal studies and clinical trials may be required to establish the causal effect of iron deficiency on muscle strength and sarcopenia and the benefits of iron therapy to improve function and quality of life.

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.

Sex Differences in Adiposity and Cardiovascular Diseases

Body fat distribution is a well-established predictor of adverse medical outcomes, independent of overall adiposity. Studying body fat distribution sheds insights into the causes of obesity and provides valuable information about the development of various comorbidities. Compared to total adiposity, body fat distribution is more closely associated with risks of cardiovascular diseases. The present review specifically focuses on the sexual dimorphism in body fat distribution, the biological clues, as well as the genetic traits that are distinct from overall obesity. Understanding the sex determinations on body fat distribution and adiposity will aid in the improvement of the prevention and treatment of cardiovascular diseases (CVD).

Effect of Sarcopenia on Mortality in Type 2 Diabetes: A Long-Term Follow-Up Propensity Score-Matched Diabetes Cohort Study

Purpose: The effect of sarcopenia on the survival of patients with type 2 diabetes remains unclear. Therefore, we designed a propensity score-matched population-based cohort study to compare the patients with diabetes with or without sarcopenia. Patients and Methods: We included patients with type 2 diabetes and categorized them into two groups according to whether they had sarcopenia and compared their survival; patients in the groups were matched at a ratio of 1:2. Results: The matching process yielded a final cohort of 201,698 patients (132,805 and 68,893 in the sarcopenia and nonsarcopenia diabetes groups, respectively) who were eligible for further analysis. According to both univariate and multivariate Cox regression analyses, the adjusted hazard ratios (aHRs; 95% confidence interval [CI]) of all-cause death for the sarcopenia diabetes group compared with the control group: 1.35 (1.33−1.38; p < 0.001). The aHRs (95% CIs) of all-cause death for those aged 41−50, 51−60, and >60 years (compared with those aged ≤40 years) were 1.53 (1.48−1.60), 2.61 (2.52−2.72), and 6.21 (5.99−6.45), respectively. The aHR (95% CI) of all-cause death for the male patients compared with the female patients was 1.56 (1.54−1.60). The aHRs (95% CIs) of all-cause death for those with adapted Diabetes Complications Severity Index (aDCSI) scores of 1, 2, 3, 4, and ≥5 (compared with an aDCSI score of 0) were 1.01 (1.00−1.14), 1.38 (1.35−1.42), 1.58 (1.54−1.63), and 2.23 (2.14−2.33), respectively. Conclusion: Patients with type 2 diabetes and sarcopenia had higher mortality than did those without sarcopenia.

Associations of Dynapenic Obesity and Sarcopenic Obesity with the Risk of Complications in COVID-19

Ageing is associated with changes in body composition, such as low muscle mass (sarcopenia), decreased grip strength or physical function (dynapenia), and accumulation of fat mass. When the accumulation of fat mass synergistically accompanies low muscle mass or reduced grip strength, it results in sarcopenic obesity and dynapenic obesity, respectively. These types of obesity contribute to the increased risk of cardiovascular disease and mortality in the elderly, which could increase the damage caused by COVID-19. In this review, we associated factors that could generate a higher risk of COVID-19 complications in dynapenic obesity and sarcopenic obesity. For example, skeletal muscle regulates the expression of inflammatory cytokines and supports metabolic stress in pulmonary disease; hence, the presence of dynapenic obesity or sarcopenic obesity could be related to a poor prognosis in COVID-19 patients.

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.

Sarcopenic Obesity in Children and Adolescents: A Systematic Review

Sarcopenic obesity (SO) is defined as co-occurrence of increased fat mass and sarcopenia and may predict adverse health outcomes in the pediatric population. However, the prevalence of SO and its association with adverse health outcomes have not been well defined in children and adolescents. We systematically reviewed data on the SO definition, prevalence, and adverse outcomes in the pediatric population. A total of 18 articles retrieved from PubMed or Web of Science databases were included. Overall, there was a wide heterogeneity in the methods and thresholds used to define SO. The prevalence of SO ranged from 5.66% to 69.7% in girls, with a range between 7.2% and 81.3% in boys. Of the 8 studies that evaluated outcomes related to SO, all showed a significant association of SO with cardiometabolic outcomes, non-alcoholic fatty liver disease (NAFLD) severity, inflammation, and mental health. In conclusion, this review found that SO is highly prevalent in children and adolescents and is associated with various adverse health outcomes. Findings of this review highlight the need for the development of a consensus regarding definition, standardized evaluation methods, and age and gender thresholds for SO for different ethnicities in the pediatric population. Further studies are needed to understand the relationship between obesity and sarcopenia and SO impact on adverse health outcomes in children and adolescents.

Hormonal and metabolic responses of older adults to resistance training in normobaric hypoxia

PURPOSE

In young adults, the hormonal responses to resistance exercise are amplified by normobaric hypoxia. Hormone concentrations and metabolism are typically dysregulated with age, yet the impact of hypoxia on these responses to resistance exercise are uncharacterised. Therefore, this study aimed to characterise the acute and chronic hormonal and metabolic responses of older adults to resistance training in normobaric hypoxia.

METHODS

Adults aged 60-75 years completed 8 weeks of resistance training in either normoxia (20.9% O₂; n = 10) or normobaric hypoxia (14.4% O₂, n = 10) twice weekly at 70% of their predicted 1-repetition maximum. Growth hormone, glucose, lactate, insulin, homeostatic model assessment of insulin resistance (HOMA-IR), cortisol, total testosterone, adrenaline, noradrenaline and dopamine were quantified at pre- and post-training, and in the 60 min following the first training session (untrained state) and the last training session (trained state).

RESULTS

Eight weeks of training in hypoxia did not affect the resting levels of the hormones or physiological factors measured. However, hypoxia significantly blunted the acute growth hormone response in the 15 min following the last training session at week eight (43.87% lower in the hypoxic group; p = 0.017). This novel and unexpected finding requires further investigation. All other hormones were unaffected acutely by hypoxia in the 60 min following the first and the last training session.

CONCLUSION

Chronic resistance training in normobaric hypoxia supresses the growth hormone response to exercise in older adults. All other hormones and metabolic markers were unaffected both acutely and chronically by hypoxia.

Definition and Diagnostic Criteria for Sarcopenic Obesity: ESPEN and EASO Consensus Statement

INTRODUCTION

Loss of skeletal muscle mass and function (sarcopenia) is common in individuals with obesity due to metabolic changes associated with a sedentary lifestyle, adipose tissue derangements, comorbidities (acute and chronic diseases) and during the ageing process. Co-existence of excess adiposity and low muscle mass/function is referred to as sarcopenic obesity (SO), a condition increasingly recognized for its clinical and functional features that negatively influence important patient-centred outcomes. Effective prevention and treatment strategies for SO are urgently needed, but efforts are hampered by the lack of a universally established SO definition and diagnostic criteria. Resulting inconsistencies in the literature also negatively affect the ability to define prevalence as well as clinical relevance of SO for negative health outcomes.

AIMS AND METHODS

The European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity (EASO) launched an initiative to reach expert consensus on a definition and diagnostic criteria for SO. The jointly appointed international expert panel proposes that SO is defined as the co-existence of excess adiposity and low muscle mass/function. The diagnosis of SO should be considered in at-risk individuals who screen positive for a co-occurring elevated body mass index or waist circumference, and markers of low skeletal muscle mass and function (risk factors, clinical symptoms, or validated questionnaires). Diagnostic procedures should initially include assessment of skeletal muscle function, followed by assessment of body composition where presence of excess adiposity and low skeletal muscle mass or related body compartments confirm the diagnosis of SO. Individuals with SO should be further stratified into stage I in the absence of clinical complications or stage II if cases are associated with complications linked to altered body composition or skeletal muscle dysfunction.

CONCLUSIONS

ESPEN and EASO, as well as the expert international panel, advocate that the proposed SO definition and diagnostic criteria be implemented into routine clinical practice. The panel also encourages prospective studies in addition to secondary analysis of existing data sets, to study the predictive value, treatment efficacy and clinical impact of this SO definition.

Sarcopenic Obesity with Normal Body Size May Have Higher Insulin Resistance in Elderly Patients with Type 2 Diabetes Mellitus

OBJECTIVE

Data are limited regarding how body composition is linked to insulin resistance in elderly patients with type 2 diabetes mellitus (T2DM). We examined the association between body composition and insulin resistance in elderly T2DM patients.

METHODS

The cross-sectional study included 488 Chinese elderly patients wth T2DM. Subjects were classified into four groups based on body composition: normal body composition (NBC), low muscle mass alone (LMM), high body fat alone (HBF), both low muscle mass and high body fat (LMMHBF).

RESULTS

The percentage of subjects with LMMHBF was 14.5% (11.9% in men and 17.7% in women). Homeostasis model assessment of insulin resistance (HOMA2-IR) was higher in the LMMHBF group than in the HBF group (p = 0.045), and was also significantly higher in the LMMHBF or HBF group than in the NBC or LMM group. The HBF group showed the highest body mass index (BMI) of the four groups of different body compositions, and the LMMHBF group showed lower BMI than the HBF group; however, there was no significant difference in BMI or waist to hip ratio (WHR) between the LMMHBF group and the NBC group. The LMMHBF and HBF groups were significantly associated with increased risk of insulin resistance compared to the NBC group, with odds ratios (ORs) of 4.47 [95% confidence interval (CI) 2.06-9.68, p < 0.001] and 1.76 (95% CI 1.02-3.02, p = 0.041) respectively, even after the adjustment for covariates.

CONCLUSION

In China, though elderly T2DM patients with the body composition of sarcopenic obesity (as defined by coexistence of low muscle mass and high body fat) seemed to have normal body size, they exhibited the most severe degree and the highest risk of insulin resistance.

Effect of Exercise on Secondary Sarcopenia: A Comprehensive Literature Review

Simple Summary

Sarcopenia is an inevitable component of aging. It is officially recognized as a muscle disease with an ICD-10-MC diagnosis code that can be used to bill for care in some countries. Sarcopenia can be classified into primary or age-related sarcopenia and secondary sarcopenia. The condition is referred to as secondary sarcopenia when any other comorbidities are present in conjunction with aging. Secondary sarcopenia is more prevalent than primary sarcopenia and requires special attention. Exercise interventions may help in our understanding and prevention of sarcopenia with a specific morbidity Glomerular filtration rate that exercise improves muscle mass, quality or physical function in elderly subjects with cancer, type 2 diabetes, kidney diseases and lung diseases. In this review, we summarize recent research that has studied the impact of exercise on patients with secondary sarcopenia, specifically those with one comorbid condition. We did not discover any exercise intervention specifically for subjects with secondary sarcopenia (with one comorbidity). Even though there is a strong argument for using exercise to improve muscle mass, quality or physical function in subjects with cancer, type 2 diabetes, kidney diseases, lung diseases and many more, very few studies have reported baseline sarcopenia assessments. Based on the trials summarized in this review, we may propose but not conclude that resistance, aerobic, balance training or even walking can be useful in subjects with secondary sarcopenia with only one comorbidity due to the limited number of trials. This review is significant because it reveals the need for broad-ranging research initiatives involving secondary sarcopenic patients and highlights a large secondary sarcopenia research gap.

Abstract

Background: Sarcopenia has been recognized as an inevitable part of aging. However, its severity and the age at which it begins cannot be predicted by age alone. The condition can be categorized into primary or age-related sarcopenia and secondary sarcopenia. Sarcopenia is diagnosed as primary when there are no other specific causes. However, secondary sarcopenia occurs if other factors, including malignancy or organ failure, are evident in addition to aging. The prevalence of secondary sarcopenia is far greater than that of primary sarcopenia and requires special attention. To date, nutrition and exercise have proven to be the best methods to combat this disease. The impact of exercise on subjects suffering from sarcopenia with a specific morbidity is worthy of examination for understanding and prevention. The purpose of this review, therefore, is to summarize recent research that has investigated the impact of exercise in patients with secondary sarcopenia, specifically with one comorbidity. Methods: Pubmed, Web of Science, Embase and Medline databases were searched comprehensively with no date limit for randomized controlled trials. The literature was specifically searched for clinical trials in which subjects were sarcopenic with only one comorbidity participating in an exercise intervention. The most visible comorbidities identified and used in the search were lung disease, kidney disease, heart disease, type 2 diabetes, cancer, neurological diseases, osteoporosis and arthritis. Results: A total of 1752 studies were identified that matched the keywords. After removing duplicates, there were 1317 articles remaining. We extracted 98 articles for full screening. Finally, we included 21 relevant papers that were used in this review. Conclusion: Despite a strong rationale for using exercise to improve muscle mass, quality or physical function in subjects with cancer, type 2 diabetes, kidney disease, lung disease and many more, baseline sarcopenia evaluation has been reported in very few trials. The limited number of studies does not allow us to conclude that exercise can improve sarcopenia in patients with other comorbidities. This review highlights the necessity for wide-ranging research initiatives involving secondary sarcopenic patients.

Obesity, Body Composition, and Sex Hormones: Implications for Cardiovascular Risk

Cardiovascular disease (CVD) continues to be the leading cause of death in adults, highlighting the need to develop novel strategies to mitigate cardiovascular risk. The advancing obesity epidemic is now threatening the gains in CVD risk reduction brought about by contemporary pharmaceutical and surgical interventions. There are sex differences in the development and outcomes of CVD; premenopausal women have significantly lower CVD risk than men of the same age, but women lose this advantage as they transition to menopause, an observation suggesting potential role of sex hormones in determining CVD risk. Clear differences in obesity and regional fat distribution among men and women also exist. While men have relatively high fat in the abdominal area, women tend to distribute a larger proportion of their fat in the lower body. Considering that regional body fat distribution is an important CVD risk factor, differences in how men and women store their body fat may partly contribute to sex-based alterations in CVD risk as well. This article presents findings related to the role of obesity and sex hormones in determining CVD risk. Evidence for the role of sex hormones in determining body composition in men and women is also presented. Lastly, the clinical potential for using sex hormones to alter body composition and reduce CVD risk is outlined. © 2022 American Physiological Society. Compr Physiol 12:1-45, 2022.

Effects of different exercise training modes on muscle strength and physical performance in older people with sarcopenia: a systematic review and meta-analysis

OBJECTIVE

We conducted a systematic review and meta-analysis to clarify the effects of different exercise modes (resistance training [RT], whole body vibration training [WBVT], and mixed training [MT, resistance training combined with other exercises such as balance, endurance and aerobic training]) on muscle strength (knee extension strength [KES]) and physical performance (Timed Up and Go [TUG], gait speed [GS] and the Chair Stand [CS]) in older people with sarcopenia.

METHOD

All studies published from January 2010 to March 2021 on the effects of exercise training in older people with sarcopenia were retrieved from 6 electronic databases: Pubmed, Cochrane Library, Embase, Web of Science, the China National Knowledge Infrastructure (CNKI), and Wanfang Database. Two researchers independently extracted and evaluated studies that met inclusion and exclusion criteria. Pooled analyses for pre- and post- outcome measurements were performed using Review Manager 5.4 with standardized mean differences (SMDs) and fixed-effect models.

RESULT

Twenty-six studies (25 randomized controlled trails [RCTs] and one non-randomized controlled trail) were included in this study with 1191 older people with sarcopenia (mean age 60.6 ± 2.3 to 89.5 ± 4.4). Compared with a control group, RT and MT significantly improved KES (RT, SMD = 1.36, 95% confidence intervals [95% CI]: 0.71 to 2.02, p < 0.0001, I2 = 72%; MT, SMD = 0.62, 95% CI: 0.29 to 0.95, p = 0.0002, I2 = 56%) and GS (RT, SMD = 2.01, 95% CI: 1.04 to 2.97, p < 0.0001, I2 = 84%; MT, SMD = 0.69, 95% CI: 0.29 to 1.09, p = 0.008, I2 = 81%). WBVT showed no changes in KES (SMD = 0.65, 95% CI: - 0.02 to 1.31, p = 0.06, I2 = 80%) or GS (SMD = 0.12, 95% CI: - 0.15 to 0.39, p = 0.38, I2 = 0%). TUG times were significantly improved with all exercise training modes (SMD = -0.66, 95% CI: - 0.94 to - 0.38, p < 0.00001, I2 = 60%). There were no changes in CS times with any of the exercise training modes (SMD = 0.11, 95% CI: - 0.36 to 0.57, p = 0.65, I2 = 87%).

CONCLUSIONS

In older people with sarcopenia, KES and GS can be improved by RT and MT, but not by WBVT. All three training modes improved TUG times, but not improved CS times.

Effects of resistance training in healthy older people with sarcopenia: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

We conducted a meta-analysis to analyze the effects of resistance training on measures of body composition, muscle strength, and muscle performance in older people with sarcopenia.

METHODS

All randomized controlled trials on the effects of resistance training on outcome variables in older people with sarcopenia were searched on Pubmed, Embase, Cochrane Library, the China National Knowledge Infrastructure (CNKI), and Wanfang. Data from January 2010 to October 2020 were reviewed. Two researchers extracted data and evaluated the quality of the studies that met the inclusion criteria independently. Meta-analysis for pre-post changes were calculated as standardized mean difference (SMD) with 95% confidence intervals (CI).

RESULTS

Fourteen studies meeting inclusion criteria included 561 healthy older adults (age 65.8 to 82.8) with sarcopenia. Compared with the control group, resistance training had positive effects on body fat mass (SMD = -0.53, 95% CI - 0.81 to - 0.25, p = 0.0002, I² = 0%), handgrip strength (SMD = 0.81, 95%CI 0.35 to 1.27, p = 0.0005, I² = 81%), knee extension strength (SMD = 1.26, 95% CI 0.72 to 1.80, p < 0.0001, I² = 67%), gait speed (SMD = 1.28, 95%CI 0.36 to 2.19, p = 0.006, I² = 89%), and the timed up and go test (SMD = -0.93, 95% CI - 1.30 to - 0.56, p < 0.0001, I² = 23%). Resistance training had no effects on appendicular skeletal muscle mass (SMD = 0.25, 95% CI - 0.27 to 0.78, p = 0.35, I² = 68%), skeletal muscle mass (SMD = 0.27, 95% CI - 0.02 to 0.56, p = 0.07, I² = 0%) and leg lean mass (SMD = 0.12, 95% CI - 0.25 to 0.50, p = 0.52, I² = 0%). Old people with sarcopenia of different ages, genders or diagnostic criteria and weights have different gains in muscle mass, handgrip strength, knee extension strength and muscle performance after different intervention duration, frequencies, mode and intensity resistance training.

CONCLUSION

Resistance training is an effective treatment to improve body fat mass, muscle strength, and muscle performance in healthy older people with sarcopenia.