Adiposity to muscle ratio predicts incident physical limitation in a cohort of 3,153 older adults--an alternative measurement of sarcopenia and sarcopenic obesity

Correlation between fat-to-muscle mass ratio and cognitive impairment in elderly patients with type 2 diabetes mellitus: a cross-sectional study

BACKGROUND

Fat to muscle mass ratio (FMR), a novel index integrating fat and muscle composition, has garnered attention in age-related conditions such as type 2 diabetes mellitus (T2DM) and neurodegenerative diseases. Despite this research on the relationship between FMR and cognitive impairment (CI) in T2DM remains scarce. This study aimed to investigate the sex-specific association between FMR and CI in elderly T2DM patients.

METHODS

A total of 768 elderly (> 60 years) T2DM in-patients (356 men and 412 women) were recruited from the Department of Endocrinology at Tianjin Nankai University affiliated hospital. Bioelectrical Impedance Analysis (BIA) was used to assess body composition, and Montreal Cognitive Assessment (MoCA) was used to evaluate cognitive performance. T2DM patients were categorized into normal cognitive function (NC) and cognitive impairment (CI) groups based on MoCA scores and stratified by sex. Binary logistic regression was employed to examine the association between FMR and CI.

RESULTS

Among the participants, 42.7% of men and 56.3% of women experienced cognitive deterioration. Women with CI exhibited lower body mass index (BMI) and skeletal muscle mass index (SMI), while men with cognitive disorders showed lower SMI, FMR, and higher fat mass index (FMI). FMR was consistently unrelated to cognition in females, irrespective of adjustment made. However, in males, FMR was significantly associated with an increasing risk of cognitive dysfunction after adjusting for demographic and clinical variables (OR: 1.175, 95% CI: 1.045-1.320, p = 0.007). Furthermore, for each 0.1 increase in FMR, the incidence of CI rose by 31.1% after additional adjustment for BMI. In males, the prevalence of CI increased sequentially across FMR quartiles (p < 0.05).

CONCLUSION

Elderly T2DM men with high FMR had unfavorable cognitive function. FMR is independently associated with an increased risk of CI in male T2DM patients regardless of BMI.

Lean-to-fat tissue ratio as a risk factor for cognitive impairment in patients undergoing maintenance hemodialysis

OBJECTIVE

The relationship between body mass index (BMI) and cognitive impairment (CI) remains controversial, and no research has been done to explore the effect of lean-to-fat (L/F) tissue ratio on the risk of CI in patients undergoing maintenance hemodialysis (MHD) so far. This study aimed to explore the effect of L/F tissue ratio on the risk of incident CI in patients undergoing MHD.

METHODS

In this observational cohort study, 3356 patients were recruited and followed up for a median of 2 years. Global cognitive function was measured using Mini-Mental State Examination score. Lean tissue mass (LTM) and fat tissue mass (FTM) were analyzed using body composition monitor based on bioimpedance spectroscopy (BCM-BIS), and L/F tissue ratio was calculated by LTM divided by FTM. Hazard ratios (HRs) for incident CI were determined by Cox regression.

RESULTS

The median age of the cohort was 55 years, and 68.7% patients were less educated. During the follow-up period, 1249 patients (37.2%) experienced incident CI. Patients with lower L/F tissue ratios had significantly higher risks of CI (HR 1.51, 95% confidence interval 1.24-1.84; p < 0.001) than those with higher L/F tissue ratios. The association between L/F tissue ratio and incident CI persisted in all subgroups stratified by sex, age, education status, especially in older and less educated participants. Both in all our patients and subgroups, BMI and CI occurrence were not independently relevant.

CONCLUSION

The L/F tissue ratio rather than BMI was an independent risk factor of incident cognitive impairment in patients undergoing MHD.

Strong impact of sarcopenic state defined by skeletal muscle mass index on postoperative complication of Crohn's disease patients

Background

Malnutrition impacts the clinical course of Crohn's disease; however, there is little evidence of its influence on perioperative adverse events. We assessed whether nutritional indicators are associated with postoperative complications in surgical treatment of Crohn's disease.

Methods

137 patients with Crohn's disease who underwent surgical treatment between January 2011 and December 2020 were included. Skeletal muscle index was calculated by a single CT slice. We analyzed the risk factors for adverse events.

Results

37 % of patients had postoperative complications. Adverse events occurred more frequently in patients with high serum C-reactive protein, low serum albumin, prognostic nutritional index <38.3, skeletal muscle index <38.9 cm2/m2, abdominoperineal resection, long surgical duration, and mass hemorrhage. Among patients with skeletal muscle index <38.9 cm2/m2, patients who experienced adverse events had higher visceral fat index compared with those who did not (0.85 vs. 0.45, P = 0.04). Multivariate analysis revealed that skeletal muscle index <38.9 cm2/m2 and low serum albumin were the independent risk factors for postoperative complications (Odds ratio, 2.85; 95 % confidence interval, 1.13-7.16; P = 0.03, 2.62; 1.09-6.26; P = 0.03, respectively). Separated by sex, low serum albumin (<3.5 and <2.8 g/dL, male and female, respectively) and skeletal muscle index (<38.9 and <36.6 cm2/m2, male and female, respectively) were statistically related to postoperative complications.

Conclusions

Skeletal muscle index is the most useful nutritional predictor of postoperative complications in Crohn's disease patients among other nutritional indices. We believe that these patients are at high risk of postoperative complications and need appropriate nutritional support in the perioperative period.

A narrative review on the impact of sarcopenic obesity and its psychological consequence in quality of life

BACKGROUND AND AIM

Sarcopenia is a multifactorial metabolic-mediated complication that affects most of the geriatric population physically and mentally. In this study, we intended to study the association between sarcopenia and psychologically related symptoms. Primary objective of the study is to explore the interplay between sarcopenic obesity, psychological consequences and Quality of life in the affected population. The secondary objective is to discuss the diagnostic, treatment approaches and also the role of clinical pharmacist.

METHOD

The psychology-related complication and sarcopenia association was enumerated in this study based on previous clinical research findings.

RESULT

The clinical evidence shows a strong correlation between sarcopenia and Mental health and its health consequences and reflection on the quality of life.

CONCLUSION

Sarcopenia induced mental disturbance has been affirmed in many studies. We believe effective right pharmacological therapy and non-pharmacological therapies with respective lifestyle modification advice could be potential vital factors that can reduce further complications in geriatric populations.

Pathogenesis, Intervention, and Current Status of Drug Development for Sarcopenia: A Review

Sarcopenia refers to the loss of muscle strength and mass in older individuals and is a major determinant of fall risk and impaired ability to perform activities of daily living, often leading to disability, loss of independence, and death. Owing to its impact on morbidity, mortality, and healthcare expenditure, sarcopenia in the elderly has become a major focus of research and public policy debates worldwide. Despite its clinical importance, sarcopenia remains under-recognized and poorly managed in routine clinical practice, partly owing to the lack of available diagnostic testing and uniform diagnostic criteria. Since the World Health Organization and the United States assigned a disease code for sarcopenia in 2016, countries worldwide have assigned their own disease codes for sarcopenia. However, there are currently no approved pharmacological agents for the treatment of sarcopenia; therefore, interventions for sarcopenia primarily focus on physical therapy for muscle strengthening and gait training as well as adequate protein intake. In this review, we aimed to examine the latest information on the epidemiology, molecular mechanisms, interventions, and possible treatments with new drugs for sarcopenia.

Waist-to-calf circumstance ratio and cognitive function among Chinese older adults: Mediating roles of physical performance and social activity

Background

In light of the potentially detrimental effects of central fat and decreased muscle mass on cognitive function, it would be beneficial to learn more about the mediating mechanisms underpinning the association between the two. The purpose of this study is to determine the association between waist-to-calf circumstance ratio (WCR) and cognitive function, as well as to investigate whether physical performance and social activity mediate the relationship between WCR and cognitive function among older Chinese adults.

Methods

An analysis of 9,652 older Chinese adults was conducted during the 2018 wave of the Chinese Longitudinal Health Longevity Survey (CLHLS). The Mini-Mental State Examination (MMSE) and a self-reported scale were used to measure cognitive function, physical performance, and social activity, respectively. Multiple linear regression and mediation analyses were conducted.

Results

The findings suggest that a high WCR had a significant negative association with cognitive function (B = -0.535, 95% CI: -0.754, -0.317). Mediation analysis revealed that a high WCR influenced old adults' cognitive function in three ways: first, through the partial mediating effect of physical performance (B = -0.270; 95% CI: -0.340, -0.203); second, through the partial mediating effect of social activity (B = -0.035; 95% CI: -0.055, -0.017); and third, through the serial mediating effects of physical performance and social activity (B = -0.021, 95% CI: -0.029, -0.015).

Conclusion

The study results suggest the adverse impact of a high WCR on older adults' cognitive function, and the possible mechanisms of physical performance and social activity by which the association takes place. Multidimensional health and social interventions aimed at improving physical, social, and cognitive functioning among older adults with sarcopenic obesity are recommended.

A diagnostic proposal for sarcopenic obesity in adults based on body composition phenotypes

BACKGROUND & AIMS

Sarcopenic obesity (SO) associates a decrease in lean body mass (LBM) with an excessive increase in fat mass (FM). A number of diagnostic methods, definitions criteria, and thresholds have been proposed for SO resulting in markedly discordant prevalence estimates in populations with obesity. In this study, we first assessed several previously described SO diagnostic criteria and their limitations, and then we propose an innovative approach for identifying SO.

METHODS

Data were from a cross-sectional study of a cohort of overweight/obese patients who underwent clinical, laboratory, and body composition assessments by dual-energy X-ray absorptiometry (DXA). We performed unsupervised machine learning through clustering analysis to discriminate lean and fat compartments, and multivariate logistic regressions which provided prognostic variables applied on sex-specific models for SO diagnosis evaluation based on a training dataset (80% of total sample, n = 1165). The predicted models were validated by random forest (RF) machine learning algorithm in the validation dataset (20% of total sample, n = 262).

RESULTS

Data from 1427 subjects were analyzed, 79.8% women, mean (±s.d.) age 45.0 (±12.9) years, grade III obesity (BMI over 40 kg/m²) in 42.7%, diabetes in 20.7%, dyslipidemia in 86.3%, and arterial hypertension in 30.3%. Patients with grade III obesity had higher amounts of LBM, FM, and bone mass than subjects with overweight (BMI between 25.0 and 29.9 kg/m²) (p-values < 0.001). When published definitions of SO were applied to this cohort, the prevalence ranged from 0.6% to 96.6%. We built a model that identified 62 (4.3%) individuals as SO, 1125 (78.9%) as non-SO, and 240 (16.8%) as borderline-SO. SO patients showed higher body weight, FM, bone mass, leptin levels, and hepatic steatosis index, but lower LBM and all muscle indexes than non-SO subjects (p-values ≤ 0.001). Patients in the SO and borderline-SO categories were more often females than males (4.5% vs. 3.8% and 16.9% vs. 16.7% respectively, p-value < 0.001) and had significantly higher prevalence of metabolic syndrome and hypertension than non-SO subjects. Males with SO also had higher cardiovascular risk score, while females had higher prevalence of respiratory disorders (p-values < 0.05 for all).

CONCLUSIONS

Current diagnostic criteria for SO result in widely discrepant prevalence values leading to diagnosis uncertainty. We developed and validated diagnostic criteria based on body composition phenotypes, specifically for overweight/obese subjects, which identified patients at risk of cardio-metabolic complications. This approach may improve the identification of sarcopenia in subjects with obesity.

Nordic Walking Rather Than High Intensity Interval Training Reduced Myostatin Concentration More Effectively in Elderly Subjects and the Range of This Drop Was Modified by Metabolites of Vitamin D

The COVID-19 pandemic and subsequent self-isolation exacerbated the problem of insufficient amounts of physical activity and its consequences. At the same time, this revealed the advantage of vitamin D. Thus, there was a need to verify the effects of those forms of training that can be performed independently. In this study, we examined the effects of Nordic walking (NW) and high intensity interval training (HIIT) with regard to the impact of the metabolite vitamin D. We assigned 32 overweight adults (age = 61 ± 12 years) to one of two training groups: NW = 18 and HIIT = 14. Body composition assessment and blood sample collection were conducted before starting the training programs and a day after their completion. NW training induced a significant decrease in myostatin (p = 0.05) concentration; however, the range was dependent on the baseline concentrations of vitamin D metabolites. This drop was accompanied by a significant negative correlation with the decorin concentration. Unexpectedly, NW caused a decrement in both forms of osteocalcin: undercarboxylated (Glu-OC) and carboxylated-type (Gla-OC). The scope of Glu-OC changes was dependent on a baseline concentration of 25(OH)D₂ (r = −0.60, p = 0.01). In contrast, the HIIT protocol did not induce any changes. Overall results revealed that NW diminished the myostatin concentration and that this effect is more pronounced among adults with a sufficient concentration of vitamin D metabolites.

Review article: The aetiology of fatigue in inflammatory bowel disease and potential therapeutic management strategies

BACKGROUND

Fatigue is the inability to achieve or maintain an expected work output resulting from central or peripheral mechanisms. The prevalence of inflammatory bowel disease (IBD) fatigue can reach 86% in active disease, persisting in 50%-52% of patients with mild to inactive disease. Fatigue is the commonest reason for work absence in IBD, and patients often report fatigue burden to be greater than that of primary disease symptoms. Relatively few evidence-based treatment options exist, and the aetiology is poorly understood.

AIM

To review the available data and suggest a possible aetiology of IBD fatigue and to consider the efficacy of existing management strategies and highlight potential future interventions.

METHODS

We reviewed fatigue-related literature in IBD using PubMed database.

RESULTS

Disease related factors such as inflammation and pharmacological treatments negatively impact skeletal muscle and brain physiology, likely contributing to fatigue symptoms. Secondary factors such as malnutrition, anaemia, sleep disturbance and psychological comorbidity are potential determinants. Immune profile, faecal microbiota composition and physical fitness differ significantly between fatigued and non-fatigued patients, suggesting these may be aetiological factors. Solution-focused therapy, high-dosage thiamine supplementation and biological therapy may reduce fatigue perception in IBD. The effect of physical activity interventions is inconclusive.

CONCLUSIONS

A multimodal approach is likely required to treat IBD fatigue. Established reversible factors like anaemia, micronutrient deficiencies and active disease should initially be resolved. Psychosocial intervention shows potential efficacy in reducing fatigue perception in quiescent disease. Restoring physical deconditioning by exercise training intervention may further improve fatigue burden.

Irisin is a predictor of sarcopenic obesity in type 2 diabetes mellitus: A cross-sectional study

We aimed to evaluate sarcopenia and sarcopenic obesity (SO) in patients with type 2 diabetes mellitus (T2DM), possible relationships with serum irisin and myostatin levels, and the effect of glycemic control on SO.Ninety T2DM patients were included in this a cross-sectional study. Sarcopenia was determined by evaluating muscle mass (bioelectrical impedance analysis), muscle strength (HGS), and gait speed (GS). Patients with muscle mass loss with functionally reduced muscle strength and/or performance were considered sarcopenic. In addition, participants were divided into 3 groups according to the FM (fat mass)/FFM (fat-free mass) ratio [group 1:5th-50th percentiles; group 2:50th-95th percentiles and group 3: ≥95 percentiles (sarcopenic obese)]. Irisin, myostatin levels and metabolic parameters were measured in all patients.The prevalence of sarcopenia and SO was 25.6% and 35.6%, respectively. Irisin levels were lower in sarcopenic patients, while glycosylated hemoglobin (A1c), body mass index (BMI), FM, and FM index were higher (P < .05). From group 1 to group 3, BMI, FM, FM index, GS, myostatin, and A1c increased, and muscle mass percentage, HGS, and irisin decreased (P < .05). A positive correlation was found between FM/FFM and myostatin and a negative correlation between FM/FFM and irisin (r = 0.303, P = .004 vs. r = -0.491, P < .001). Irisin remained an important predictor of SO, even after adjusting for confounding variables (OR:1.105; 95% CI:0.965-1.338, P = .002). The optimal cut-off value for irisin to predict SO was 9.49 ng/mL (specificity = 78.1%, sensitivity = 75.8%). In addition, A1c was an independent risk factor for SO development (OR:1.358, P = .055).This study showed that low irisin levels (<9.49ng/mL) and poor glycemic control in T2DM patients were an independent risk factor, especially for SO.

Different body parts' fat mass and corrected QT interval on the electrocardiogram: The Fasa PERSIAN Cohort Study

Background

Previous studies suggested that obesity and fat mass are associated with QT interval prolongation, but the role of different body parts' fat mass is unclear. The associations between total and regional fat mass (FM) and corrected QT interval (QTc) were investigated for the first time in this study.

Methods

In this sub-analysis of Fasa PERSIAN cohort Study data, 3217 subjects aged 35–70 entered our study. Body fat mass was assessed by bioelectrical impedance analysis and QTc interval calculated by the QT interval measured by Cardiax^® software from ECGs and Bazett’s formula. Uni- and multi-variable linear and logistic regression was performed in IBM SPSS Statistics v23.

Results

In males, the fat mass to fat-free mass (FM/FFM) ratio in the trunk, arms, total body, and legs were significantly higher in the prolonged QTc group (QTc > 450 ms). Trunk (B = 0.148), total (B = 0.137), arms (B = 0.124), legs (B = 0.107) fat mass index (FMI) showed significant positive relationship with continuous QTc (P-value < 0.001). Also, just the fat-free mass index of legs had significant positive associations with QTc interval (P-value < 0.05). Surprisingly, in females, the mean of FM/FFM ratio in trunk and legs in the normal QTc group had higher values than the prolonged QTc group (QTc > 470 ms). Also, none of the body composition variables had a significant correlation with continuous QTc.

Conclusion

Our study suggested that FMI ratios in the trunk, total body, arms, and legs were positively associated with QTc interval in males, respectively, from a higher to a lower beta-coefficient. Such associations were not seen in females. Our study implies that body fat mass may be an independent risk factor for higher QTc interval and, consequently, more cardiovascular events that should be investigated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02095-2.

Understanding factors associated with sarcopenic obesity in older African women from a low-income setting: a cross-sectional analysis

BACKGROUND

High rates of food insecurity, obesity and obesity-related comorbidities in ageing South African (SA) women may amplify the risk of developing sarcopenic obesity. This study aimed to investigate the prevalence and correlates of sarcopenic obesity and its diagnostic components [grip strength, appendicular skeletal muscle mass (ASM) and body mass index (BMI)] in older SA women from a low-income setting.

METHODS

This cross-sectional study recruited black SA women between the ages of 60-85 years (n = 122) from a low-income community. Testing included a fasting blood sample (markers of cardiometabolic risk, HIV), whole body and regional muscle and fat mass (dual-energy absorptiometry x-ray), anthropometry, blood pressure, functional movement tests, current medication use, demographic and health questionnaires, physical activity (PA; accelerometery), household food insecurity access scale, and a one-week quantified food frequency questionnaire. Foundation for the National Institutes of Health (FNIH) criteria (grip strength and ASM, adjusted for BMI) were used to classify sarcopenia. Participants with sarcopenia alongside a BMI of > 30.0 kg/m² were classified as having sarcopenic obesity. Prevalence using other criteria (European Working Group on Sarcopenia in Older People, Asian Working Group for Sarcopenia and the International Working Group for Sarcopenia) were also explored.

RESULTS

The prevalence of sarcopenia was 27.9%, which comprised of sarcopenia without obesity (3.3%) and sarcopenic obesity (24.6%). Other classification criteria showed that sarcopenia ranged from 0.8-14.7%, including 0.8-9.8% without obesity and 0-4.9% with sarcopenic obesity. Using multivariate-discriminant analysis (OPLS-DA) those with sarcopenic obesity presented with a descriptive profile of higher C-reactive protein, waist circumference, food security and sedentary time than women without sarcopenic obesity (p = 0.046). A similar profile described women with low BMI-adjusted grip strength (p < 0.001).

CONCLUSIONS

The majority of women with sarcopenia were also obese (88%). We show a large discrepancy in the diagnostic criteria and the potential for significantly underestimating the prevalence of sarcopenia if BMI is not adjusted for. The main variables common to women with sarcopenic obesity were higher food security, lower PA and chronic inflammation. Our data highlights the importance of addressing obesity within these low-income communities to ensure the prevention of sarcopenic obesity and that quality of life is maintained with ageing.

Sarcopenia in heart failure: a systematic review and meta-analysis

AIMS

Sarcopenia has been found to be frequently associated with co-morbidity among patients with heart failure (HF). However, there remain insufficient data to accurately estimate the global prevalence of sarcopenia in HF. Therefore, the purpose of this research was to conduct a systematic review and meta-analysis to estimate the current overall prevalence of sarcopenia in patients with HF.

METHODS AND RESULTS

We searched relevant databases for studies published up to 13 July 2020, assessing sarcopenia in vpatients with HF. After careful screening, data of included articles were extracted with a predesigned Excel form. Then the pooled prevalence of sarcopenia in patients with HF was calculated using the random-effects model. The Q test was used to assess the heterogeneity, and I2 statistic was calculated to quantify and evaluate the heterogeneity. Subgroup analyses were conducted to determine potential sources of heterogeneity. A total of 2852 articles were initially identified, and after removing duplicate publications and applying the selection criteria, we reviewed 79 full-text articles. Finally, 11 articles (n = 1742 patients with HF) were included in this systematic review and meta-analysis. The pooled prevalence of sarcopenia in patients with HF was 34% [95% confidence interval (CI): 22-47%, I2  = 96.59%] and ranged from 10% to 69%. However, substantial heterogeneity between studies (I2  = 96.59%, P < 0.001) was observed. There was no significant heterogeneity between subgroups by sex (P = 0.803) or the method used to define sarcopenia (P = 0.307). While the heterogeneity between subgroups by population setting was statistically significant (P < 0.001), the pooled prevalence of sarcopenia was 55% (95% CI: 43-66%) for hospitalized patients with HF and 26% (95% CI: 16-37%) for ambulatory patients.

CONCLUSIONS

Sarcopenia was a common condition in patients with HF, and the prevalence of hospitalized patients was higher than for ambulatory patients. Early detection of sarcopenia was therefore important in patients with HF, and it was important to implement interventions so that physical therapists or managerial dieticians can easily be introduced into clinical practice.

Prevalence of sarcopenia and the association of sarcopenia, premorbid factors, early functional outcome and 1-year mortality in Hong Kong Chinese fragility hip fracture patients

Background/purpose:

Sarcopenia is a predictor of fall, which is a leading cause of fragility hip fractures (FHF). Dual energy X-ray absorptiometry (DXA) is a costly measurement method for sarcopenia. Rehabilitation and prognosis can be determined by early functional outcomes. Meanwhile, 1-year mortality of FHF patients is high.

Aims:

(i) To report the prevalence of sarcopenia. (ii) To investigate the relationships of sarcopenia, premorbid factors, early functional outcomes and 1-year mortality in Hong Kong Chinese FHF patients.

Methods:

FHF patients admitted to Queen Elizabeth Hospital in Hong Kong from April 2016 to March 2017 were reviewed, including outcomes of relative appendicular skeletal muscle mass index (RASM), handgrip strength (HGS), New Mobility Score (NMS), Modified Functional Ambulation Classification (MFAC), Modified Barthel Index (MBI), Cumulated Ambulation Score (CAS), Elderly Mobility Scale (EMS) and 1-year mortality.

Results:

One hundred sixty nine FHF patients, aged 82.68 ± 7.32 years, were reviewed. Prevalence of sarcopenia in male and female were 71.4% and 37.7%, respectively. RASM was correlated with HGS of both dominant ( r = 0.366, p < 0.001) and non-dominant side ( r = 0.383, p < 0.001), NMS ( rs = 0.239, p < 0.001), MFAC ( rs = 0.192, p = 0.013), MBI ( rs = 0.182, p = 0.018) and CAS ( rs = 0.183, p = 0.019). RASM was not significantly correlated with EMS-1 ( rs = 0.050, p = 0.525) and EMS-DC ( rs = 0.092, p = 0.249). There was significant correlation between Sarcopenia and EMS-DC ( rrb = −0.226, p = 0.004). Sarcopenia was marginally not associated with 1-year mortality ( χ 2 = 3.745, p = 0.053). One-year mortality of FHF patients with Sarcopenia and without Sarcopenia were 16.5% and 7.1%, respectively. FHF patients with Sarcopenia were not statistically significant to be more likely to face mortality within 1 year ( R 2 = 0.030, OR = 2.638, p = 0.060).

Conclusions:

Prevalence of sarcopenia was high in FHF patients and RASM was correlated with HGS and NMS, which can be easily administered as screening tools. Sarcopenia was correlated with early functional outcome but not with 1-year mortality. Early detection of Sarcopenia is crucial for early implementation of rehabilitation and treatment.

Resistance Training in Hypoxia as a New Therapeutic Modality for Sarcopenia-A Narrative Review

Hypoxic training is believed to be generally useful for improving exercise performance in various athletes. Nowadays, exercise intervention in hypoxia is recognized as a new therapeutic modality for health promotion and disease prevention or treatment based on the lower mortality and prevalence of people living in high-altitude environments than those living in low-altitude environments. Recently, resistance training in hypoxia (RTH), a new therapeutic modality combining hypoxia and resistance exercise, has been attempted to improve muscle hypertrophy and muscle function. RTH is known to induce greater muscle size, lean mass, increased muscle strength and endurance, bodily function, and angiogenesis of skeletal muscles than traditional resistance exercise. Therefore, we examined previous studies to understand the clinical and physiological aspects of sarcopenia and RTH for muscular function and hypertrophy. However, few investigations have examined the combined effects of hypoxic stress and resistance exercise, and as such, it is difficult to make recommendations for implementing universal RTH programs for sarcopenia based on current understanding. It should also be acknowledged that a number of mechanisms proposed to facilitate the augmented response to RTH remain poorly understood, particularly the role of metabolic, hormonal, and intracellular signaling pathways. Further RTH intervention studies considering various exercise parameters (e.g., load, recovery time between sets, hypoxic dose, and intervention period) are strongly recommended to reinforce knowledge about the adaptational processes and the effects of this type of resistance training for sarcopenia in older people.

End-stage knee osteoarthritis with and without sarcopenia and the effect of knee arthroplasty - a prospective cohort study

Background

Sarcopenia often accompanies osteoarthritis (OA), which is managed by total knee arthroplasty (TKA) in the late stage. Recent studies have suggested a higher risk of post-operative complications after TKA in sarcopenic OA subjects, but whether TKA can benefit them similar to non-sarcopenic subjects remains unexplored. This study aimed to examine the dynamic, mutual impact of sarcopenia and TKA in a one-year post-operative period.

Methods

This prospective cohort study was conducted between 2015 to 2018 at our hospital. Patients with end-stage OA of the knee waiting for TKA were recruited into the study. Primary outcome measures were change in muscle strength, mass and function. Secondary outcome measures were quality of life (QOL) measurements for pain, psychological and physical health.

Results

Fifty-eight patients were recruited, of which 79.3% were female and 32.8% already had sarcopenia at baseline. The average age of sarcopenic subjects and non-sarcopenic subjects was comparable (67.89 ± 7.07 vs. 67.92 ± 6.85; p = 0.99), but sarcopenic subjects had a lower body mass index (BMI) (25.64 ± 2.64 vs. 28.57 ± 4.04; p = 0.01). There was a statistically significant improvement in walking speed (10.24 ± 5.35 vs. 7.69 ± 2.68, p < 0.01) and muscle strength in both sarcopenic and non-sarcopenic patients after TKA. This was accompanied by an improvement trend in muscle mass in all subjects. There was no change in handgrip power before and after TKA and subsequent follow-up (19.31 ± 5.92 vs. 18.98 ± 6.37 vs. 19.36 ± 7.66; p = 0.97). QOL measured before, after and at follow-up with WOMAC (total: 42.27 ± 15.98 vs. 20.65 ± 15.24 vs. 16.65 ± 18.13) and SF12v2 (PCS: 33.06 ± 8.55 vs. 38.96 ± 8.01 vs. 40.67 ± 7.93) revealed progressive significant improvement (both comparisons p ≤ 0.01). Further analysis with the IPAQ also found increased engagement of high-intensity activities.

Conclusions

This study showed that sarcopenia among patients with end-stage OA of the knee is not uncommon, but both sarcopenic and non-sarcopenic OA patients achieved significant clinical and functional improvement after TKA. Further studies with a larger sample size and different ethnicities could help ascertain a beneficial role of TKA in sarcopenic OA subjects.

Trial registration

Registry: ClinicalTrials.gov, Registration number: NCT03579329. Date of registration: 6 July 2018. Retrospectively registered.

Validation of the Construct of Intrinsic Capacity in a Longitudinal Chinese Cohort

OBJECTIVES

We examined the structure and predictive ability of intrinsic capacity in a cohort of Chinese older adults.

METHODS

We used data from the MrOS and MsOS (Hong Kong) study, which was designed to examine the determinants of osteoporotic fractures and health in older Chinese adults. We analysed baseline and the 7-year follow-up data using exploratory factor analysis, confirmatory factor analysis (CFA), and mediation analysis.

RESULTS

The study consisted of 3736 participants at baseline (mean 72.2 years), with 1475 in the 7-year follow-up. Bi-factor CFA revealed five sub-factors labelled as 'cognitive', 'locomotor', 'vitality', 'sensory', and 'psychological' and one general factor labelled as 'intrinsic capacity'. The model fits the data well, with Root Mean Square Error of Approximation (RMSEA)=0.055 (90% CI=0.053-0.058) for the 5-factor model and RMSEA=0.031 (90% CI=0.028-0.035) for the bi-factor model. Significantly lower intrinsic capacity scores were found in older age groups, women, as well as those who had lower levels of education, lower subjective social status, reported more chronic diseases, or a higher number of IADL limitations (All p<0.0001). Intrinsic capacity had a direct effect in predicting incident IADL limitations at the 7-year follow-up (β=-0.21, p<0.001). The effect was larger than the direct effect of the number of chronic diseases on incident IADL limitations (β=0.05, not significant).

CONCLUSIONS

This study supports the construct and predictive validity of the proposed capacity domains of intrinsic capacity. The findings could inform the development of an intrinsic capacity score that would facilitate implementation of the concept of intrinsic capacity in clinical practice.

Safety of a Combined WB-EMS and High-Protein Diet Intervention in Sarcopenic Obese Elderly Men

Purpose

Whole-body electromyostimulation (WB-EMS) especially in combination with a high-protein supplementation has been established as an efficient treatment against sarcopenia. However, there are several case reports of rhabdomyolysis after WB-EMS application. Thus, we asked if this training could potentially lead to deteriorations of the cardiac as well as the renal function.

Materials and Methods

One hundred sarcopenic obese men aged 70 years and older were randomly balanced (1-1-1) and allocated to one of the three study arms. During 16 weeks of intervention, these groups either performed WB-EMS and took a protein supplement (WB-EMS&P), solely received the protein supplement (Protein) or served as control group (CG). WB-EMS consisted of 1.5×20 min (85 Hz, 350 μs, 4 s of strain to 4 s of rest) applied with moderate-to-high intensity while moving. We further generated a daily protein intake of 1.7-1.8 g/kg/body mass per day. At baseline and 8-10 days after completion of the intervention, blood was drawn and biomarkers of muscle, cardiac and renal health were assessed.

Results

Hereby, we found slight but significant elevations of creatine kinase (CK) levels in the WB-EMS group pointing to minor damages of the skeletal muscle (140 U/l [81-210], p < 0.001). This was accompanied by a significant, low-grade increase of creatine kinase-muscle brain (CK-MB, 0.43 ng/mL [-0.29-0.96], p < 0.01) and high-sensitivity troponin T (hsTnT, 0.001 ng/mL. [0.000-0.003], p < 0.001) but without a higher risk of developing heart failure according to N-terminal prohormone of brain natriuretic peptide (NT-proBNP, -5.7 pg/mL [-38.8-24.6], p = 0.17). Estimated glomerular filtration rate (eGFR) was impaired neither by the high-protein supplementation alone nor in combination with WB-EMS (CG 76.0 mL/min/1.73 m² [71.9-82.2] vs Protein 73.2 mL/min/1.73 m² [63.0-78.9] vs WB-EMS&P 74.6 mL/min/1.73 m² [62.8-84.1], p = 0.478).

Conclusion

In conclusion, even in the vulnerable group of sarcopenic obese seniors, the combination of WB-EMS with a high-protein intake revealed no short-term, negative impact on the eGFR, but potential consequences for the cardiovascular system need to be addressed in future studies.

Fat-to-muscle ratio as a predictor of insulin resistance and metabolic syndrome in Korean adults

BACKGROUND

The present study evaluated the associations of the fat-to-muscle ratio (FMR) with metabolic syndrome (MetS) and insulin resistance (IR) in Korean adults using nationally representative survey data.

METHODS

A two-stage stratified sampling method was reflected in a cross-sectional study involving a total of 13 032 participants aged ≥ 19 years who participated in the fourth and fifth Korea National Health and Nutrition Examination Surveys. The homeostasis model assessment for IR (HOMA-IR) was used to evaluate IR and was calculated as follows: [fasting plasma glucose level (mg/dL) × fasting plasma insulin level (uIU/mL)]/405. MetS was defined using the 2006 International Diabetes Federation criteria, and FMR was measured using whole-body dual-energy X-ray absorptiometry and calculated as follows: total fat mass (kg) divided by total lean mass (kg). In addition, the optimal FMR cut-off values for detecting MetS and the odds ratios (ORs) for MetS risk were determined according to the FMR quartile and sex.

RESULTS

Among all participants, the proportion of women was 58.4%, and the mean age was 44.22 ± 0.26 years. The FMR significantly differed between men and women (0.30 ± 0.002 vs. 0.53 ± 0.003, respectively, P < 0.001), and the prevalence of MetS and IR gradually increased as FMR increased (P for trend: <0.001). The optimal FMR cut-off value for detecting MetS was higher in women than in men (0.555 vs. 0.336, respectively). The negative predictive value was the highest in normal-weight participants (0.9992 in women and 0.9986 in men), while the positive predictive value was the highest in obese participants (0.5994 in women and 0.5428 in men). Based on the derived cut-off FMR, a high FMR was associated with poor outcomes in terms of cardiometabolic risk markers (P < 0.001). The multivariable-adjusted ORs for MetS, abdominal obesity, and IR (HOMA-IR ≥ 3) were 5.35 [95% confidence interval (CI): 4.39-6.52], 7.67 (95% CI: 6.33-9.30), and 3.25 (95% CI: 2.70-3.92), respectively, in men and 5.59 (95% CI: 4.66-6.72), 7.48 (95% CI: 6.35-8.82), and 2.55 (95% CI: 2.17-3.00), respectively, in women.

CONCLUSIONS

In the present study, a high FMR was significantly associated with the prevalence of MetS and IR. The present findings also showed that FMR can be a novel indicator for detecting the absence or presence of MetS, particularly in metabolically healthy normal-weight individuals and metabolically obese obese-weight individuals.

Effects of a lifestyle intervention on body composition in prostate cancer patients on androgen deprivation therapy

Background

Exercise and dietary (EX+D) interventions could represent an optimal treatment for attenuating or reversing adverse effects of androgen deprivation therapy (ADT) in prostate cancer (PCa) patients. The Individualized Diet and Exercise Adherence-Pilot (IDEA-P) trial compared the effects of an EX+D intervention relative to standard-of-care (SC) treatment among PCa patients undergoing ADT. The present study evaluated the effects of the EX+D intervention on body composition (BC) obtained via dual-energy X-ray absorptiometry (DXA) in a subsample of IDEA-P patients. A secondary objective was to explore the association of adiposity and lean mass with mobility performance and strength.

Methods

Complete DXA data were acquired from a subsample of 22 PCa patients (EX+D: n = 13; SC: n = 9) at baseline and 3 month follow-up. Intention-to-treat analysis included data from 30 participants (M age = 66.28; SD = 7.79) with baseline DXA assessments.

Results

Intention-to-treat analysis revealed EX+D resulted in significant improvements in fat mass (P = 0.022), per cent fat mass (P = 0.028), trunk fat mass (P = 0.017), fat mass/lean mass (P = 0.040), and per cent lean mass (P = 0.026) vs. SC. EX+D also resulted in more favourable changes in appendicular lean mass/body mass (d = 0.59). Select BC outcomes were also significantly correlated with mobility performance and strength (P < 0.05) at 3 month follow-up.

Conclusions

Findings suggest the EX+D intervention resulted in superior preservation of lean tissue and improvement in adiposity relative to SC treatment. Results underscore the utility of implementing EX+D interventions for preserving muscle mass and reducing adiposity in PCa patients undergoing ADT.

Prognostic networks for unraveling the biological mechanisms of Sarcopenia

Sarcopenia is an age-related multifactorial process that involved several biological mechanisms, whose specific contribution and interplay is still unknown. The present study proposes prognostic networks based on machine learning approaches to unravel the interplay among those biological mechanisms mainly involved in the development of Sarcopenia. After analyzing 114 biological and clinical variables in adults older than 70 years, and using all the biological prognostic networks detected by machine learning with accuracy higher than 82%, we designed a consensus classifier based on majority vote that improve the predictive accuracy of Sarcopenia up to 91%. Additionally, we applied logistic regression analysis to propose the interplay among the most discriminative biological variables of Sarcopenia: anthropometry, body composition, functional performance of lower limbs, systemic oxidative stress, presence of depression and medication for the digestive system based on proton-pump inhibitors. Our data also demonstrate that besides a loss of muscle mass, impairments on functional performance of lower limbs are more relevant for develop Sarcopenia than those affecting the muscle strength.

Sarcopenic obesity

Sarcopenic obesity, a chronic condition, is today a major public health problem with increasing prevalence worldwide, which is due to progressively aging populations, the increasing prevalence of obesity, and the changes in lifestyle during the last several decades. Patients usually present to healthcare facilities for obesity and related comorbidities (type 2 diabetes mellitus, non-alcoholic fatty liver disease, dyslipidemia, hypertension, and cardiovascular disease) or for non-specific symptoms related to sarcopenia per se (e.g., fatigue, weakness, and frailty). Because of the non-specificity of the symptoms, sarcopenic obesity remains largely unsuspected and undiagnosed. The pathogenesis of sarcopenic obesity is multifactorial. There is interplay between aging, sedentary lifestyle, and unhealthy dietary habits, and insulin resistance, inflammation, and oxidative stress, resulting in a quantitative and qualitative decline in muscle mass and an increase in fat mass. Myokines, including myostatin and irisin, and adipokines play a prominent role in the pathogenesis of sarcopenic obesity. It has been suggested that a number of disorders affecting metabolism, physical capacity, and quality of life may be attributed to sarcopenic obesity, although it is not as yet established whether sarcopenia and obesity act synergistically. There is to date no approved pharmacological treatment for sarcopenic obesity. The cornerstones of its management are weight loss and adequate protein intake combined with exercise, the latter in order to reduce the loss of muscle mass observed during weight loss following diet unpaired with exercise. A consensus on the definition of sarcopenic obesity is considered essential to facilitate the performance of mechanistic studies and clinical trials aimed at deepening our knowledge, thus enabling improved management of affected individuals in the near future.

The impact of DXA-derived fat-free adipose tissue on the prevalence of low muscle mass in older adults

BACKGROUND/OBJECTIVES

To investigate the impact of eliminating fat-free adipose tissue (aFFAT) on the prevalence of low muscle mass in older adults.

SUBJECTS/METHODS

Three hundred and forty-three (153 men and 190 women) well-functioning Japanese older adults (aged 65-79) had their appendicular lean mass (aLM) and appendicular fat mass (aFM) measured using dual-energy X-ray absorptiometry (DXA). aFFAT was then estimated from DXA-derived aFM (aFM = (FM/0.15)*0.85). Both traditional cutoffs and those corrected for aFFAT were used for diagnosing low muscle mass.

RESULTS

With traditional cutoff values, the prevalence of low muscle mass using the unadjusted aLM index was 20.1%. After adjusting the aLM index for aFFAT, the prevalence increased to 49.0% (p < 0.001). However, when the cutoff values were also adjusted for aFFAT, the prevalence of low muscle mass only increased to 23.0% (p < 0.001). Further, ~5% of the participants (7 men and 8 women) were newly classified as having low muscle mass after correction for aFFAT. However, several women (n = 5) were not classified as having low muscle mass using the corrected cutoff value, although they would have been when using the non-corrected cutoff.

CONCLUSIONS

Adjusting for the effect of aFFAT on DXA-derived aLM significantly increases the prevalence of low muscle mass in older adults. For clinical research and practice, the influence of aFFAT on DXA-derived aLM may need to be taken into consideration when diagnosing low muscle mass.

Clinical usefulness of psoas muscle thickness for the diagnosis of sarcopenia in patients with liver cirrhosis

Background/Aims

The most widely used method for diagnosing sarcopenia is the skeletal muscle index (SMI). Several studies have suggested that psoas muscle thickness per height (PMTH) is also effective for detecting sarcopenia and predicting prognosis in patients with cirrhosis. The aim of this study was to evaluate the optimal cutoff values of PMTH for detecting sarcopenia in cirrhotic patients.

Methods

All cirrhotic patients who underwent abdominal computed tomography (CT) scan including L3 and umbilical levels for measuring SMI and transverse psoas muscle thickness, respectively, were included. Two definitions of sarcopenia were used: (1) sex-specific cutoffs of SMI (≤52.4 cm² /m² in men and ≤38.5 cm² /m² in women) for SMI-sarcopenia and (2) cutoff of PMTH (<16.8 mm/m) for PMTH-sarcopenia.

Results

Six hundred fifty-three patients were included. The average age was 53.6 ± 10.2 years, and 499 patients (76.4%) were men. PMTH correlated well with SMI in both men and women (P<0.001). Two hundred forty-one (36.9%) patients met the criteria for SMI-sarcopenia. The best PMTH cutoff values for predicting SMI-sarcopenia were 17.3 mm/m in men and 10.4 mm/m in women, and these were defined as sex-specific cutoffs of PMTH (SsPMTH). The previously published cutoff of PMTH was defined as sex-nonspecific cutoff of PMTH (SnPMTH). Two hundred thirty (35.2%) patients were diagnosed with SsPMTH-sarcopenia, and 280 (44.4%) patients were diagnosed with SnPMTH-sarcopenia. On a multivariate Cox regression analysis, SsPMTH-sarcopenia (hazard ratio [HR], 1.944; 95% confidence interval [CI], 1.144–3.304; P=0.014) was significantly associated with mortality, while SnPMTH-sarcopenia was not (HR, 1.446; 95% CI, 0.861–2.431; P=0.164).

Conclusions

PMTH was well correlated with SMI in cirrhotic patients. SsPMTH-sarcopenia was an independent predictor of mortality in these patients and more accurately predicted mortality compared to SnPMTH-sarcopenia.

Sarcopenic obesity and health outcomes in patients seeking weight loss treatment

AIM

To investigate the prevalence of sarcopenic obesity (SO) and its association with health outcomes in patients seeking weight loss treatment from a bariatric center.

METHODS

In this retrospective study, patients [≥18 years old, body mass index (BMI) ≥30 kg/m²] from the Tallahassee Memorial Bariatric Center and with baseline body composition assessment by bioelectrical impedance analysis were included. Fat mass index (FMI = fat mass/height²) and fat-free mass index (FFMI = fat free mass/height²) were calculated. SO was defined by a FMI/FFMI ratio greater than the 95 percentile of sex, BMI and ethnicity specific population-representative references. Medical records were reviewed for biochemical and comorbidity measures.

RESULTS

One hundred and forty-four patients (∼69% females, mean age 55.6 years, mean BMI 46.6 kg/m²) were included. Patients' FMI/FFMI ratios ranged from 0.35 to 1.60 kg/m² across body weight spectrum, with 51% having SO. Blood pressure, fasting glucose, triglycerides, HDL or LDL were not different between patients with and without SO. However, the prevalence of high cholesterol, asthma, alcoholism and hernia were higher in patients with SO. SO was the strongest univariate predictor of high cholesterol (OR = 2.08, 95% CI 1.07-4.04) and asthma (OR = 2.77, 95% CI = 1.12-6.83).

CONCLUSION

SO was prevalent and associated with adverse health outcomes, beyond that captured by anthropometric measures in the present study.

Evaluation of sarcopenia in patients with distal radius fractures

Sarcopenia is more prevalent in patients with distal radius fracture (DRF) than in age- and sex-matched controls. Lower appendicular mass index in men and weaker grip strength in both men and women increase the likelihood of DRF.

INTRODUCTION

Sarcopenia is a core component of physical frailty that predisposes older people to falls and negatively impacts the activities of daily living. The objectives of this study were to compare the prevalence of sarcopenia in patients with DRF with that in age- and sex-matched controls without DRF; and evaluate the association between sarcopenia and the occurrence of DRF.

METHODS

We prospectively recruited 132 patients over 50 years of age who sustained DRF due to fall and 132 age- and sex-matched controls without DRF. A definition of sarcopenia was based on the consensus of the Asian Working Group for Sarcopenia. Sarcopenic components including appendicular lean body mass, grip strength, and gait speed were compared between the two groups. Other factors assessed for the occurrence of DRF were age, gender, body mass index (BMI), lumbar, and hip bone mineral density (BMD) values. A conditional logistic regression analysis was conducted to evaluate the associations between sarcopenia and the occurrence of DRF.

RESULTS

A total of 39 (30%) of 132 DRF patients were sarcopenic, whereas 23 (17%) of the 132 controls were within the sarcopenic criteria (p = 0.048). The patient group had significantly lower lean body mass and weaker grip strength than those of the control group. However, there was no significant difference in gait speed between the two groups. According to regression analysis, lower appendicular mass index in men was associated with an increased incidence of DRF (odds ratio [OR] = 0.84, 95% confidence interval [CI] = 0.72, 0.95) while weaker grip strength and lower total hip BMD values were associated with the occurrence of DRF in both men (OR = 0.77, 95% CI = 0.63, 0.92; and OR = 0.79, 95% CI = 0.64, 0.94, respectively) and women (OR = 0.78, 95% CI = 0.64, 0.93, and OR = 0.73, 95% CI = 0.52, 0.92, respectively).

CONCLUSIONS

Sarcopenia is more prevalent in patients with DRF than in age- and sex-matched controls. Lower appendicular mass in men, weaker grip strength, and lower hip BMD in both men and women increase the likelihood of DRF.

Fat mass to fat-free mass ratio reference values from NHANES III using bioelectrical impedance analysis

BACKGROUND & AIM

Low fat-free mass (FFM) or high fat mass (FM) are abnormal body composition phenotypes associated with morbidity. These conditions in combination lead to worse health outcomes, and can be identified by a high FM/FFM ratio. Here, we developed sex, age, and body mass index (BMI) stratified, population-based FM/FFM reference values using bioelectrical impedance analysis (BIA) measurements.

METHODS

White, non-Hispanic individuals aged 18-90 years old with data for weight, stature and BIA resistance measures from the third National Health and Nutrition Examination Survey (NHANES) III were included. Previously validated and sex-specific BIA prediction equations were used to calculate FM and FFM. FM/FFM values were generated at 5th, 50th and 95th percentiles for each sex, age (18-39.9, 40-59.9, 60-69.9 and 70-90 years), and BMI category (underweight, normal weight, overweight, class I/II and class III obesity).

RESULTS

A total of 6372 individuals who had estimated FM and FFM values were identified (3366 females, 3006 males). Median values of FM/FFM were 0.24 and 0.40 for young (≤39.9 years) males and females with normal BMI, and 0.34 for males and 0.59 for females who were overweight. For elderly individuals aged >70 years, median FM/FFM for males and females were respectively 0.28 and 0.45 for those with normal BMI, and 0.37 and 0.61 for those in the overweight category.

CONCLUSIONS

These FM/FFM reference values provide information on body composition characteristics that account for age, sex and BMI, which can be useful to identify individuals at risk for body composition abnormalities.

Sarcopenia

Sarcopenia refers to age-related muscle loss, defined using a combination of appendicular muscle mass, muscle strength, and physical performance measures. The pathogenesis depends on a balance between positive and negative regulators of muscle growth. Sarcopenia increases the risk for falls, fractures, dependency, use of hospital services, institutionalization, poor quality of life, and mortality. In clinical practice, brief screening tools, such as the 5-item SARC-F score, may be useful. Although pharmacologic treatments are actively being studied, the current mainstay consists of optimizing nutrition status, in particular protein and vitamin D status, and resistance exercises.

Body Composition Outcomes of a Qigong Intervention Among Community-Dwelling Aging Adults

Aging causes various changes in body composition, which are critical implications for health and physical functioning in aging adults. The aim of this study was to explore the body composition outcomes of a qigong intervention among community-dwelling aging adults. This was a quasi-experimental study in which 90 participants were recruited. Forty-eight participants (experimental group) attended a 30-min qigong program 3 times per week for 12 weeks, whereas 42 participants (control group) continued performing their usual daily activities. The experimental group achieved a greater reduction in the fat mass percentage at the posttest, and exhibited increased fat-free mass, lean body mass percentage, and lean body mass to fat mass ratio compared with the controls. No difference between the two groups in body mass index, fat mass, and lean body mass was observed. These results indicated that the qigong intervention showed beneficial outcomes of body composition among community-dwelling aging adults.

Therapeutic potential of eccentric exercises for age-related muscle atrophy

Recent studies have focused on evidence-based interventions to prevent mobility decline and enhance physical performance in older adults. Several modalities, in addition to traditional strengthening programs, have been designed to manage age-related functional decline more effectively. In this study, we reviewed the current relevant literatures to assess the therapeutic potential of eccentric exercises for age-related muscle atrophy (sarcopenia). Age-related changes in human skeletal muscle, and their relationship with physical performance, are discussed with reference to in vitro physiologic and human biomechanics studies. An overview of issues relevant to sarcopenia is provided in the context of the recent consensus on the diagnosis and management of the condition. A decline in mobility among the aging population is closely linked with changes in the muscle force-velocity relationship. Interventions based specifically on increasing velocity and eccentric strength can improve function more effectively compared with traditional strengthening programs. Eccentric strengthening programs are introduced as a specific method for improving both muscle force and velocity. To be more effective, exercise interventions for older adults should focus on enhancing the muscle force-velocity relationship. Exercises that can be performed easily, and that utilize eccentric strength (which is relatively spared during the aging process), are needed to improve both muscle force and velocity.

Qualitative muscle mass index as a predictor of skeletal muscle function deficit in Asian older adults

AIM

The present cross-sectional study was carried out among community-dwelling Koreans to determine the validity of various muscle mass indices and to propose more clinically relevant diagnostic criteria.

METHODS

This study measured the anthropometrics, body composition and physical capability of 415 older Koreans. Skeletal muscle indices were calculated by dividing appendicular lean mass by height or weight. Apart from this, we adjusted appendicular lean mass for body mass index, body surface area or waist-to-height ratio, which we then named the qualitative muscle mass index. Skeletal muscle function deficit was defined as a combination of weakness and slowness.

RESULTS

Qualitative muscle indices were closely associated with physical capabilities. Receiver operating characteristic and logistic analyses showed that qualitative muscle indices had significantly greater discriminatory powers regarding low muscle function than did the height-adjusted index in both men and women, and even showed higher discriminatory potentials than the weight-adjusted index in men (all P < 0.05). The cut-off values of qualitative muscle indices of body mass index-, body surface area-, and waist-to-height ratio-adjusted indices for identifying functional deficits were 0.760, 11.40 and 34.18 for men, and 0.530, 8.91 and 23.07 for women, respectively.

CONCLUSIONS

The present study suggests that qualitative muscle indices are more accurate in predicting low muscle function than are height- and weight-adjusted indices, because they consider anthropometric characteristics as part of the definition. The results might provide new avenues for conceptualizations of sarcopenia accompanied by obesity, and can be used as ethnic-specific reference values of muscle mass indices based on functional outcome in an elderly Korean/Asian population. Geriatr Gerontol Int 2017; 17: 99-107.

An Overview of Sarcopenic Obesity

Sarcopenic obesity (SO) refers to the copresence of sarcopenia and obesity. In this condition, a disproportion exists between the amount of lean mass relative to fat mass. Research on SO is important because the presence of both sarcopenia and obesity may have important health consequences. However, SO research has been hampered by the disparate number of definitions of SO. Various definitions of sarcopenia include ratios of appendicular mass to height(2) or body weight, measures of muscle strength, or physical function. More recent definitions incorporate all 3. Obesity is usually defined by high body mass index, but some studies have relied on percent body fat or visceral fat. Depending on the definition, the prevalence of SO ranges from 0% to 41% in older populations. The loss of lean mass and increase in fat mass with advancing age may share common etiologic pathways. Declines in physical activity can lead to poor muscle strength, lower muscle mass, and increased fat infiltration; all of which could lead to increases in fat mass. The increases in fat mass and accompanying increases in adipokines and inflammation may further adversely affect muscle quality. SO has been related to an increased risk of mobility disability, above and beyond sarcopenia, or obesity alone. Additional research is needed to further our understanding of the pathophysiology of SO and its consequences. Interventions aimed at reducing SO may improve physical function as well as reduce disability and death.

Comparisons of sarcopenia prevalence based on different diagnostic criteria in Chinese older adults

The study aimed to describe the prevalence of sarcopenia and discussed the applicability of different diagnostic criteria in Chinese older adults. 286 Chinese adults (136 men and 150 women) aged 60-88 were recruited. The prevalence of sarcopenia were calculated using different diagnostic criteria. Physical functioning was compared in sarcopenic and non-sarcopenic older adults. Compared with the standard of EWGSOP (European Working Group on Sarcopenia in Older People), the prevalence of sarcopenia was higher when the IWGS (International Working Group on Sarcopenia) standard was applied (Men: 7.4% vs. 0.8%; Women: 4.7% vs. 0%). If the AWGS (Aisa Working Group on Sarcopenia) standard was applied, the prevalence was 5.9% in men and 0.7% in women. In conclusion, the prevalence of sarcopenia in Chinese older adults ranged from 0% to around 10% when the diagnostic criteria of IGWS, EWGSOP and AGWS were applied. Further studies are still needed to investigate appropriate diagnostic criterion of sarcopenia for Chinese population.

Obesity in older persons

PURPOSE OF REVIEW

There is an increasing number of reports suggesting that indicators of obesity for the general adult population may need to be modified; that the magnitude of risk is attenuated or that adiposity may even be protective; and that additional adverse outcomes specific to older persons need to be considered. Finally, there are benefits and adverse effects of weight loss programmes for older persons. This article reviews publications addressing these issues from 2013 to March 2014.

RECENT FINDINGS

BMI was not considered to be as good an indicator of obesity because of loss of muscle mass with age. Higher body weight seems to be protective among older persons with chronic diseases or geriatric syndromes. Increased adiposity together with decreased muscle mass (sarcopenic obesity) is associated with adverse outcomes, although there is no consensus regarding the definition. Intentional weight loss has health benefits but is accompanied by muscle and bone loss, and therefore programmes should include components to counteract these changes.

SUMMARY

The magnitude of health risk associated with obesity is attenuated with age, and mild increase in adiposity may be beneficial for those who are frail and/or with chronic diseases. Weight loss programmes should include resistance exercises to counteract muscle loss.

Sarcopenia in Asia: consensus report of the Asian Working Group for Sarcopenia

Sarcopenia, a newly recognized geriatric syndrome, is characterized by age-related decline of skeletal muscle plus low muscle strength and/or physical performance. Previous studies have confirmed the association of sarcopenia and adverse health outcomes, such as falls, disability, hospital admission, long term care placement, poorer quality of life, and mortality, which denotes the importance of sarcopenia in the health care for older people. Despite the clinical significance of sarcopenia, the operational definition of sarcopenia and standardized intervention programs are still lacking. It is generally agreed by the different working groups for sarcopenia in the world that sarcopenia should be defined through a combined approach of muscle mass and muscle quality, however, selecting appropriate diagnostic cutoff values for all the measurements in Asian populations is challenging. Asia is a rapidly aging region with a huge population, so the impact of sarcopenia to this region is estimated to be huge as well. Asian Working Group for Sarcopenia (AWGS) aimed to promote sarcopenia research in Asia, and we collected the best available evidences of sarcopenia researches from Asian countries to establish the consensus for sarcopenia diagnosis. AWGS has agreed with the previous reports that sarcopenia should be described as low muscle mass plus low muscle strength and/or low physical performance, and we also recommend outcome indicators for further researches, as well as the conditions that sarcopenia should be assessed. In addition to sarcopenia screening for community-dwelling older people, AWGS recommends sarcopenia assessment in certain clinical conditions and healthcare settings to facilitate implementing sarcopenia in clinical practice. Moreover, we also recommend cutoff values for muscle mass measurements (7.0 kg/m(2) for men and 5.4 kg/m(2) for women by using dual X-ray absorptiometry, and 7.0 kg/m(2) for men and 5.7 kg/m(2) for women by using bioimpedance analysis), handgrip strength (<26 kg for men and <18 kg for women), and usual gait speed (<0.8 m/s). However, a number of challenges remained to be solved in the future. Asia is made up of a great number of ethnicities. The majority of currently available studies have been published from eastern Asia, therefore, more studies of sarcopenia in south, southeastern, and western Asia should be promoted. On the other hand, most Asian studies have been conducted in a cross-sectional design and few longitudinal studies have not necessarily collected the commonly used outcome indicators as other reports from Western countries. Nevertheless, the AWGS consensus report is believed to promote more Asian sarcopenia research, and most important of all, to focus on sarcopenia intervention studies and the implementation of sarcopenia in clinical practice to improve health care outcomes of older people in the communities and the healthcare settings in Asia.

Growing healthy muscles to optimise metabolic health into adult life

The importance of skeletal muscle for metabolic health and obesity prevention is gradually gaining recognition. As a result, interventions are being developed to increase or maintain muscle mass and metabolic function in adult and elderly populations. These interventions include exercise, hormonal and nutritional therapies. Nonetheless, growing evidence suggests that maternal malnutrition and obesity during pregnancy and lactation impede skeletal muscle development and growth in the offspring, with long-term functional consequences lasting into adult life. Here we review the role of skeletal muscle in health and obesity, providing an insight into how this tissue develops and discuss evidence that maternal obesity affects its development, growth and function into adult life. Such evidence warrants the need to develop early life interventions to optimise skeletal muscle development and growth in the offspring and thereby maximise metabolic health into adult life.

Body composition indices of a load-capacity model: gender- and BMI-specific reference curves

OBJECTIVE

Fat mass (FM) and fat-free mass (FFM) are frequently measured to define body composition phenotypes. The load-capacity model integrates the effects of both FM and FFM to improve disease-risk prediction. We aimed to derive age-, gender- and BMI-specific reference curves of load-capacity model indices in an adult population (≥18 years).

DESIGN

Cross-sectional study. Dual-energy X-ray absorptiometry was used to measure FM, FFM, appendicular skeletal muscle mass (ASM) and truncal fat mass (TrFM). Two metabolic load-capacity indices were calculated: ratio of FM (kg) to FFM (kg) and ratio of TrFM (kg) to ASM (kg). Age-standardised reference curves, stratified by gender and BMI (<25.0 kg/m2, 25.0-29.9 kg/m2, ≥30.0 kg/m2), were constructed using an LMS approach. Percentiles of the reference curves were 5th, 15th, 25th, 50th, 75th, 85th and 95th.

SETTING

Secondary analysis of data from the 1999-2004 National Health and Nutrition Examination Survey (NHANES).

SUBJECTS

The population included 6580 females and 6656 males.

RESULTS

The unweighted proportions of obesity in males and females were 25.5 % and 34.7 %, respectively. The average values of both FM:FFM and TrFM:ASM were greater in female and obese subjects. Gender and BMI influenced the shape of the association of age with FM:FFM and TrFM:ASM, as a curvilinear relationship was observed in female and obese subjects. Menopause appeared to modify the steepness of the reference curves of both indices.

CONCLUSIONS

This is a novel risk-stratification approach integrating the effects of high adiposity and low muscle mass which may be particularly useful to identify cases of sarcopenic obesity and improve disease-risk prediction.

A systematic review of the evidence that brain structure is related to muscle structure and their relationship to brain and muscle function in humans over the lifecourse

BACKGROUND

An association between cognition and physical function has been shown to exist but the roles of muscle and brain structure in this relationship are not fully understood. A greater understanding of these relationships may lead to identification of the underlying mechanisms in this important area of research. This systematic review examines the evidence for whether: a) brain structure is related to muscle structure; b) brain structure is related to muscle function; and c) brain function is related to muscle structure in healthy children and adults.

METHODS

Medline, Embase, CINAHL and PsycINFO were searched on March 6th 2014. A grey literature search was performed using Google and Google Scholar. Hand searching through citations and references of relevant articles was also undertaken.

RESULTS

53 articles were included in the review; mean age of the subjects ranged from 8.8 to 85.5 years old. There is evidence of a positive association between both whole brain volume and white matter (WM) volume and muscle size. Total grey matter (GM) volume was not associated with muscle size but some areas of regional GM volume were associated with muscle size (right temporal pole and bilateral ventromedial prefrontal cortex). No evidence was found of a relationship between grip strength and whole brain volume however there was some evidence of a positive association with WM volume. Conversely, there is evidence that gait speed is positively associated with whole brain volume; this relationship may be driven by total WM volume or regional GM volumes, specifically the hippocampus. Markers of brain ageing, that is brain atrophy and greater accumulation of white matter hyperintensities (WMH), were associated with grip strength and gait speed. The location of WMH is important for gait speed; periventricular hyperintensities and brainstem WMH are associated with gait speed but subcortical WMH play less of a role. Cognitive function does not appear to be associated with muscle size.

CONCLUSION

There is evidence that brain structure is associated with muscle structure and function. Future studies need to follow these interactions longitudinally to understand potential causal relationships.

Clinical characteristics of high plasma adiponectin and high plasma leptin as risk factors for arterial stiffness and related end-organ damage

OBJECTIVE

The relationship between plasma levels of adiponectin and cardiovascular events is inconclusive. We evaluated the clinical characteristics of people with high plasma adiponectin and high plasma leptin levels.

METHODS

Thousand seven hundred participants recruited from visitors to the Anti-Aging Doc were divided into four groups by combining the bipartiles of plasma adiponectin and leptin levels in men and women separately: AL, high adiponectin and high leptin; Al, high adiponectin and low leptin; al, low adiponectin and low leptin; aL, low adiponectin and high leptin. Body composition, including visceral fat area and thigh muscle cross-sectional area (CSA), brachial-ankle pulse wave velocity (baPWV), periventricular hyperintensity, and urinary albumin excretion, were determined.

RESULTS

Twenty percent of the studied population fell within the AL group. This group had a significantly higher visceral fat area than the Al group. Thigh muscle CSA was lowest in the AL group among groups. baPWV, brain white matter lesions, and albuminuria findings in the AL group were significantly higher than those of the Al group. Multiple and logistic regression analyses with confounding parameters further confirmed that plasma adiponectin was not an independent determinant for brain and renal small vessel-related disease.

CONCLUSION

These findings suggest that the plasma level of adiponectin alone is not enough for the risk stratification of cardiovascular disease. Leptin resistance associated with skeletal muscle loss in addition to obesity may need to be addressed to identify high risk people with high plasma adiponectin levels.

Sarcopenic obesity in aging population: current status and future directions for research

The combination of sarcopenia and obesity, an age-related change in body composition, is a concern in the aged society. Sarcopenic obesity is not the combination of two conditions, but is more related to cardio-metabolic and functional abnormalities. Sarcopenic obesity is associated with more physical functional decline than simple obesity. Sarcopenic obesity may be more insulin resistant, and have a higher risk for metabolic syndrome and atherosclerosis than simple obesity. However, the prevalence of sarcopenic obesity differs substantially among studies because of the lack of a standard definition. For further understanding of the pathophysiological role of sarcopenic obesity, a standardized definition for both sarcopenia and obesity is necessary.

Diagnostic criteria for sarcopenia and physical performance

Relative and absolute muscle mass and muscle strength are used as diagnostic criteria for sarcopenia. We aimed to assess which diagnostic criteria are most associated with physical performance in 180 young (18-30 years) and 281 healthy old participants (69-81 years) of the European study MYOAGE. Diagnostic criteria included relative muscle mass (total or appendicular lean mass (ALM) as percentage of body mass), absolute muscle mass (ALM/height squared and total lean mass), knee extension torque, and handgrip strength. Physical performance comprised walking speed, Timed Up and Go test (TUG), and in a subgroup physical fitness. Diagnostic criteria for sarcopenia and physical performance were standardized, and the associations were analyzed using linear regression models stratified by age category, with adjustments for age, gender, and country. In old participants, relative muscle mass was associated with faster walking speed, faster TUG, and higher physical fitness (all p < 0.001). Absolute muscle mass was not associated with physical performance. Knee extension torque and handgrip strength were associated with faster walking speed (both p ≤ 0.003). Knee extension torque was associated with TUG (p = 0.001). Knee extension torque and handgrip strength were not associated with physical fitness. In young participants, there were no significant associations between diagnostic criteria for sarcopenia and physical performance, except for a positive association between relative muscle mass and physical fitness (p < 0.001). Relative muscle mass, defined as lean mass or ALM percentage, was most associated with physical performance. Absolute muscle mass including ALM/height squared was not associated with physical performance. This should be accounted for when defining sarcopenia.

From simplicity towards complexity: the Italian multidimensional approach to obesity

Obesity is the result of a complex interplay among several factors leading to medical, functional and psychosocial consequences that markedly reduce life expectancy and impair quality of life. Is obesity itself a disease? Is obesity a brain disease? Who should treat obesity? This paper is a narrative review aimed to describe and to argue the prevalent position of some major Italian scientific and academic institutions dealing with obesity. According to the recent statements and recommendations published by the Italian Society for Obesity (SIO) and the Italian Society for the Study of Eating Disorders (SISDCA), the management of obese patients should include five main levels of care: (1) primary care, (2) outpatient treatment, (3) intensive outpatient treatment, (4) residential rehabilitative treatment, and (5) hospitalization. Ideally, patients suffering from obesity need a multidimensional evaluation intended to design an individualized treatment plan applying different procedures and therapeutic strategies (diet, physical activity and functional rehabilitation, educational therapy, cognitive-behavior therapy, drug therapy, and bariatric surgery). This thorough approach should address not only weight loss but also quality of weight loss, medical and psychiatric comorbidity, psychosocial problems, and physical disability. Such management of obesity requires an effective multiprofessional team, while health services have to overcome a number of administrative and organizational barriers that do not account for diseases requiring resources and professionals from different areas of medicine. Integrating several competences in a team-based approach demands specific education, skills and expertise. As for other diseases, the principles of complexity theory may offer a model useful to implement both teamwork and care delivery for patients with obesity.

The Official Positions of the International Society for Clinical Densitometry: Indications of Use and Reporting of DXA for Body Composition

The technique of body composition by dual-energy X-ray absorptiometry (DXA) has been used for several years in the research environment. Its ability to accurately and precisely measure lean, fat, and mineral composition in various body compartments has been well validated. Furthermore, the technique is widely available to clinical patients on existing DXA instruments throughout the world through the use of specific software packages and scanning algorithms. There have been few clear statements regarding the clinical indications for body composition measurement in patients outside the research setting. This is in part because of the lack of specific documented interventions that would be affected by body composition test results, beyond usual clinical advice. We have examined a few of the most common, specific scenarios (HIV therapy, sarcopenia, bariatric surgery, obesity) and proposed indications for body composition assessment. We have also discussed contraindications to body composition testing.