Managing sarcopenia and its related-fractures to improve quality of life in geriatric populations

Exploring the causal link between circulating cytokines and sarcopenia traits: A Mendelian randomization analysis

BACKGROUND

Previous observational studies have linked circulating cytokines to sarcopenia, but their causal relationship remains unclear. This study employed Mendelian Randomization (MR) to investigate the causal links between circulating cytokines and sarcopenia-related traits using genetic data.

METHODS

A two-sample bidirectional MR analysis was conducted using data from individuals of European ancestry, utilizing genome-wide association studies (GWAS) statistics. The study selected instrumental single nucleotide polymorphisms (SNPs) significantly associated with circulating cytokines and applied multiple MR methods, including inverse variance weighted (IVW), Weighted Median, MR-Egger, Weighted Mode, Simple Mode, and MR-PRESSO. The traits analyzed were appendicular lean mass (ALM) and grip strength. Heterogeneity, robustness, and consistency of results were assessed using Cochran's Q statistic, MR-Egger regression, and "leave-one-out" sensitivity analyses.

RESULTS

The IVM-MR analysis showed a casual association between genetically predicted circulating levels of interleukin-16 and both ALM and grip strength (ALM: OR = 0.990, 95% CI: 0.980-1.000, p = .049; grip strength: OR = 0.971, 95% CI: 0.948-0.995, p = .020). Additionally, interferon-gamma-induced protein 10 (IP-10), interleukin-1-beta (IL-1β), and hepatocyte growth factor (HGF) were correlated with ALM and vascular endothelial growth factor (VEGF), interleukin-12 (IL-12), and interleukin-5 (IL-5) with grip strength. Comparable results were confirmed via the MR-Egger, Weighted Median, Weighted Mode, and Simple Mode methods. Sensitivity analysis showed no horizontal pleiotropy to bias the causal estimates.

CONCLUSION

The results suggest a significant causal effect of inflammatory cytokines on sarcopenia, offering new avenues for therapeutic target development. However, the study's focus on a European ancestry cohort limits its generalizability to other populations. Future research should aim to include diverse ethnic groups to validate and broaden these findings, thereby enhancing our understanding of sarcopenia's mechanisms in a global context.

Associations between blood manganese levels and sarcopenia in adults: insights from the National Health and Nutrition Examination Survey

Background

While increasing concerns arise about the health effects of environmental pollutants, the relationship between blood manganese (Mn) and sarcopenia has yet to be fully explored in the general population.

Objective

This study aims to investigate the association between blood manganese (Mn) levels and sarcopenia in adults.

Methods

In our study, we evaluated 8,135 individuals aged 18-59 years, utilizing data from the National Health and Nutrition Examination Survey (NHANES) spanning 2011 to 2018. We employed generalized additive model (GAM) to discern potential non-linear relationships and utilized the two-piecewise linear regression model to probe the association between blood Mn levels and sarcopenia.

Results

After adjusting for potential confounders, we identified non-linear association between blood Mn levels and sarcopenia, with an inflection point at 13.45 μg/L. The effect sizes and the confidence intervals on the left and right sides of the inflection point were 1.006 (0.996 to 1.048) and 1.082 (1.043 to 1.122), respectively. Subgroup analysis showed that the effect sizes of blood Mn on sarcopenia have significant differences in gender and different BMI groups.

Conclusion

Our results showed that a reverse U-shaped curve between blood Mn levels and sarcopenia, with an identified the inflection point at blood Mn level of 13.45 μg/L.

Genetic causality and site-specific relationship between sarcopenia and osteoarthritis: a bidirectional Mendelian randomization study

Background: Previous studies demonstrated a controversial relationship between sarcopenia (SP) and osteoarthritis (OA) and their genetic causality is unclear. Thus, we conducted a Mendelian randomization (MR) analysis to evaluate the possible causal association between sarcopenia-related traits (appendicular lean mass (ALM), grip strength, usual walking pace) and OA. Method: We used pooled genetic data from the UK Biobank for ALM(n = 450,243), left-hand grip strength (n = 461,026), right-hand grip strength (n = 461,089) and usual walking pace (n = 459,915). Moreover, summary statistics for OA were obtained from the latest study conducted by the Genetics of Osteoarthritis Consortium, including all OA (n = 826,690), hand OA (n = 303,7782), hip OA (n = 353,388) and knee OA (n = 396,054). The primary method for estimating causal effects was the inverse-variance weighted (IVW) method, with the utilizing of false discovery rate adjusted p values (P FDR). Additional MR methods such as MR-Egger regression, MR pleiotropy residual sum and outlier (MR-PRESSO), weighted median were employed as supplementary analyses. Results: We discovered ALM (odds ratio (OR) = 1.103, 95% confidence interval (CI) = 1.052-1.156, P FDR = 2.87E-04), hand grip strength (left, IVW OR = 0.823, 95% CI = 0.712 to 0.952, P FDR = 0.020; right, OR = 0.826, 95% CI = 0.718 to 0.950, P FDR = 0.020), and usual walking pace (OR = 0.339, 95% CI = 0.204 to 0.564, P FDR = 2.38E-04) were causally associated with OA risk. In the reverse MR analysis, we identified a causal effect of OA on ALM (β = -0.258, 95% CI = -0.369 to 0.146, P FDR = 0.6.07E-06), grip strength (left, β = -0.064, 95% CI = -0.104 to 0.024, P FDR = 0.002; right, β = -0.055, 95% CI = -0.095 to 0.014, P FDR = 0.008), and usual walking pace (β = -0.104, 95% CI = -0.147 to 0.061, P FDR = 1.61E-05). Conclusion: This present study suggests an obvious causality of SP on OA, with condition exhibiting site-specific effects, while evidence was also provided for the causal effect of OA on SP.

Association between sarcopenia-related traits and cardiovascular diseases: a bi-directional Mendelian randomization study

Background

The two geriatric diseases, sarcopenia and cardiovascular disease (CVD), often coexist, yet the causal relationship is unclear. However, few studies focus on the effect of muscle mass on CVD. This comprehensive study is dedicated to unearthing the potential connection between sarcopenia-related traits and CVD at the genetic level.

Method

A two-sample bi-directional Mendelian randomization (MR) study was conducted. In the first stage, we performed MR analysis regarding coronary heart disease (CHD), stroke, and myocardial infarction (MI) as exposure factors to reveal their effect on appendicular lean mass (ALM) and hand grip strength. In the second stage, we reverse the position of exposures and outcomes. The inverse variance weighted (IVW) method was used as the primary approach to reveal the potential causation between the exposure and outcome.

Results

The results of the IVW method revealed a negative causal effect of ALM on CHD (OR = 0.848, 95% CI = 0.804 to 0.894, p = 8.200E-10), stroke (OR = 0.931, 95% CI = 0.890 to 0.975, p = 2.220E-03), and MI (OR = 0.810, 95% CI = 0.694 to 0.901, p = 1.266E-13). Additionally, the left-hand grip strength is a significant protective factor for CHD (OR = 0.737, 95% CI = 0.601 to 0.904, p = 3.353E-03) and MI (OR = 0.631, 95% CI = 0.515 to 0.765, p = 2.575E-06), but is not causally linked to the stroke (OR = 0.971, 95% CI =0.829 to 1.139, p = 0.720). Meanwhile, the same conclusion about the effect of right-hand grip strength on CHD (OR = 0.681, 95% CI = 0.558 to 0.832, p = 1.702E-05), MI (OR = 0.634, 95% CI = 0.518 to 0.776, p = 9.069E-06), and stroke (OR = 1.041, 95% CI = 0.896 to 1.209, p = 0.604) was obtained. However, no significant causal effect of CVD (CHD, stroke, MI) on sarcopenia-related traits (ALM, handgrip strength) was found.

Conclusion

There is a unidirectional causal relationship between sarcopenia and CVD. The loss of muscle mass and strength has a significant causal role in promoting the occurrence and development of CVD, providing a reference for the prevention and treatment of comorbidities in older people.

Development of a finite element full spine model with active muscles for quantitatively analyzing sarcopenia effects on lumbar load

BACKGROUND AND OBJECTIVE

The musculoskeletal imbalance caused by disease is one of the most critical factors leading to spinal injuries, like sarcopenia. However, the effects of musculoskeletal imbalances on the spine are difficult to quantitatively investigate. Thus, a complete finite element spinal model was established to analyze the effects of musculoskeletal imbalance, especially concerning sarcopenia.

METHODS

A finite element spinal model with active muscles surrounding the vertebrae was established and validated from anatomic verification to the whole spine model in dynamic loading at multiple levels. It was then coupled with the previously developed neuromuscular model to quantitatively analyze the effects of erector spinae (ES) and multifidus (MF) sarcopenia on spinal tissues. The severity of the sarcopenia was classified into three levels by changing the physiological cross-sectional area (PCSA) of ES and MF, which were mild (60% PCSA of ES and MF), moderate (48% PCSA of ES and MF), and severe (36% PCSA of ES and MF).

RESULTS

The stress and strain levels of most lumbar tissues in the sarcopenia models were more significant than those of the normal model during spinal extension movement. The sarcopenia caused load concentration in several specific regions. The stress level of the L4-L5 intervertebral disc and L1 vertebra significantly increased with the severity of sarcopenia and showed relatively larger values than other segments. From the normal model to a severe sarcopenia model, the stress value of the L4-L5 intervertebral disc and L1 vertebra increased by 128% and 113%, respectively. The strain level of L5-S1 also inclined significantly with the severity of sarcopenia, and the relatively larger capsule strain values occurred at lower back segments from L3 to S1.

CONCLUSIONS

In summary, the validated spinal coupling model can be used for spinal injury risk analysis caused by musculoskeletal imbalance. The results suggested that sarcopenia can primarily lead to high injury risk of the L4-L5 intervertebral disc, L1 vertebrae, and L3-S1 joint capsule regarding significant stress or strain variance.

Reambulation following hindlimb unloading attenuates disuse-induced changes in murine fracture healing

Patients with bone and muscle loss from prolonged disuse have higher risk of falls and subsequent fragility fractures. In addition, fracture patients with continued disuse and/or delayed physical rehabilitation have worse clinical outcomes compared to individuals with immediate weight-bearing activity following diaphyseal fracture. However, the effects of prior disuse followed by physical reambulation on fracture healing cellular processes and adjacent bone and skeletal muscle recovery post-injury remains poorly defined. To bridge this knowledge gap and inform future treatment and rehabilitation strategies for fractures, a preclinical model of fracture healing with a history of prior unloading with and without reambulation was employed. First, skeletally mature male and female C57BL/6J mice (18 weeks) underwent hindlimb unloading by tail suspension (HLU) for 3 weeks to induce significant bone and muscle loss modeling enhanced bone fragility. Next, mice had their right femur fractured by open surgical dissection (stabilized with 24-gauge pin). The, mice were randomly assigned to continued HLU or allowed normal weight-bearing reambulation (HLU + R). Mice given normal cage activity throughout the experiment served as healthy age-matched controls. All mice were sacrificed 4-days (DPF4) or 14-days (DPF14) following fracture to assess healing and uninjured hindlimb musculoskeletal properties (6-10 mice per treatment/biological sex). We found that continued disuse following fracture lead to severely diminished uninjured hindlimb skeletal muscle mass (gastrocnemius and soleus) and femoral bone volume adjacent to the fracture site compared to healthy age-matched controls across mouse sexes. Furthermore, HLU led to significantly decreased periosteal expansion (DPF4) and osteochondral tissue formation by DPF14, and trends in increased osteoclastogenesis (DPF14) and decreased woven bone vascular area (DPF14). In contrast, immediate reambulation for 2 weeks after fracture, even following a period of prolonged disuse, was able to increase hindlimb skeletal tissue mass and increase osteochondral tissue formation, albeit not to healthy control levels, in both mouse sexes. Furthermore, reambulation attenuated osteoclast formation seen in woven bone tissue undergoing disuse. Our results suggest that weight-bearing skeletal loading in both sexes immediately following fracture may improve callus healing and prevent further fall risk by stimulating skeletal muscle anabolism and decreasing callus resorption compared to minimal or delayed rehabilitation regimens.

A Phytomolecule Icariin Protects from Sarcopenia Partially by Suppressing Myosin Heavy Chain Degradation in Orchiectomized Rats

Treatments are lacking for sarcopenia, which is an age-related disease characterized by loss of skeletal muscle mass, strength, and/or physical performance. Icariin is a phytomolecule from herbal Epimedium, a traditional Chinese medicine widely used to treat musculoskeletal disorders for thousands of years. Here the effects of icariin against sarcopenia are investigated and the underlying mechanism is elucidated. A classic rat model of bilaterally orchiectomized (ORX) is used to induce sarcopenia. After administration for 8 weeks, compared to the control group, the forelimb grip strength, the specific tetanic forces of the soleus (SOL) and extensor digitorum longus muscle (EDL) are higher, and the fiber cross-sectional areas (CSAs) of the gastrocnemius and tibialis anterior muscle are larger in the icariin group. In addition, icariin promotes mRNA and protein expressions of myosin heavy chain (MyHC) both in SOL and EDL. Mechanistically, icariin significantly suppresses the mRNA and protein expressions of FOXO3a, atrogin-1, and MuRF-1, which are related to the degradation of myosin heavy chain. Collectively, icariin protects from sarcopenia in ORX rats characterized by enhancing grip strength and skeletal muscle contraction, as well as increasing skeletal muscle CSA by inhibiting the ubiquitination degradation of the MyHC in skeletal muscle fibers.

[Research progress on the correlation between sarcopenia and osteoarthritis]

Objective

To review the research progress on the correlation between sarcopenia and osteoarthritis (OA).

Methods

The basic and clinical studies at home and abroad in recent years on sarcopenia and OA were extensively reviewed. The correlation between sarcopenia and OA was analyzed and summarized from five aspects: epidemiological status, risk factors, pathogenesis, clinical treatments, and the impact on joint arthroplasty.

Results

Sarcopenia and OA are common diseases in the elderly with high prevalence and can increase the ill risk of each other. They share a set of risk factors, and show negative interactive and influence on pathogenesis and clinical treatments, thus participating in each other's disease process and reducing the treatment benefits. Clinical studies show that sarcopenia can affect the rehabilitation effect and increase the risk of postoperative complications after total joint arthroplasty in many ways.

Conclusion

Current research results show that sarcopenia and OA are related and can be mutually affected in the above 5 aspects, but more studies are needed to further clarify the relationship between them, so as to provide more theoretical basis for the understanding, prevention, diagnosis, and treatments of the two diseases.

Gender difference in appendicular muscle strength: determinant of the quality of life in the older Taiwanese

Background: The loss of skeletal muscle mass by aging determines the health status and the quality of life (QoL).

Objective: To examine the relationships between appendicular muscle strength and the QoL of elderly adults in gender difference.

Methods: This was a cross-sectional study, in which 690 subjects who participated in older adults health examination in the health management center of Tri-Service General Hospital from 2018 to 2021. A structured questionnaire was used to collect basic demographic data. The 12-Item Short Form Survey (SF-12) was used to evaluate the QoL of subjects. Their grip strength and gait speed were measured, and Dual-energy X-ray absorptiometry was used to measure muscle mass and other body composition data. Multivariate regression analysis was used to examine the relationships between upper and lower limb muscle strength and the QoL of older adults.

Results: In men, legs muscle mass percentage (LegsMM%) (β = 3.67; 95% CI: 0.64–6.69; p = 0.018) and gait speed (β = 6.09; 95% CI: 3.88–8.30; p < 0.001) were positively associated with physical component summary (PCS) scores, and gait speed (β = 4.63; 95% CI: 2.66–6.60; p < 0.001) was also related to an improvement mental component summary (MCS) scores. In women, arms muscle mass percentage (ArmsMM%) (β = 6.50; 95% CI: 2.34–10.66; p = 0.002) and grip strength (β = 10.54; 95% CI: 6.27–14.81; p < 0.001) had the greatest effect on improving PCS scores, whereas grip strength (β = 7.58; 95% CI 4.00–11.17; p < 0.001) was also found to help improve MCS scores.

Conclusions: Men should focus on lower limb training, whereas females should focus on upper limb training to effectively improve their QoL. Appropriate exercise interventions should be designed for different genders for the promotion of the healthy aging policy.

Similarities Between Disuse and Age-Induced Bone Loss

Disuse and aging are known risk factors associated with low bone mass and quality deterioration, resulting in increased fracture risk. Indeed, current and emerging evidence implicate a large number of shared skeletal manifestations between disuse and aging scenarios. This review provides a detailed overview of current preclinical models of musculoskeletal disuse and the clinical scenarios they seek to recapitulate. We also explore and summarize the major similarities between bone loss after extreme disuse and advanced aging at multiple length scales, including at the organ/tissue, cellular, and molecular level. Specifically, shared structural and material alterations of bone loss are presented between disuse and aging, including preferential loss of bone at cancellous sites, cortical thinning, and loss of bone strength due to enhanced fragility. At the cellular level bone loss is accompanied, during disuse and aging, by increased bone resorption, decreased formation, and enhanced adipogenesis due to altered gap junction intercellular communication, WNT/β-catenin and RANKL/OPG signaling. Major differences between extreme short-term disuse and aging are discussed, including anatomical specificity, differences in bone turnover rates, periosteal modeling, and the influence of subject sex and genetic variability. The examination also identifies potential shared mechanisms underlying bone loss in aging and disuse that warrant further study such as collagen cross-linking, advanced glycation end products/receptor for advanced glycation end products (AGE-RAGE) signaling, reactive oxygen species (ROS) and nuclear factor κB (NF-κB) signaling, cellular senescence, and altered lacunar-canalicular connectivity (mechanosensation). Understanding the shared structural alterations, changes in bone cell function, and molecular mechanisms common to both extreme disuse and aging are paramount to discovering therapies to combat both age-related and disuse-induced osteoporosis. © 2022 American Society for Bone and Mineral Research (ASBMR).

The prevalence and impact of sarcopenia in females undergoing total hip arthroplasty: A prospective study

OBJECTIVES

Although both sarcopenia and hip disease decrease physical function, few studies have investigated the association. We investigated the prevalence of sarcopenia in patients awaiting total hip arthroplasty for osteoarthritis and examined the impact of sarcopenia on pre- and postoperative outcomes.

METHODS

This prospective study included 96 females. Participants were classified using two criteria. Cases defined as having sarcopenia by the Asian Working Group for Sarcopenia (AWGS) criteria were categorized as the AWGS-sarcopenia (A-S) group, and others were categorized as the AWGS-non-sarcopenia (A-NS) group. Those classified by hand grip strength (HGS) constituted the lower-HGS (L-H) and normal-HGS (N-H) groups. Patient demographics, physical function, and Japanese Orthopaedic Association (JOA) score were compared between each group.

RESULTS

The prevalence of the AWGS sarcopenia was 33.3%. In the pre- and postoperative analyses, the L-H group had significantly poorer physical function and JOA score than the N-H group. Postoperatively, the A-S group only demonstrated poorer HGS.

CONCLUSION

Preoperative physical function and JOA score was significantly poorer in the L-H group; physical function was significantly poorer even postoperatively. A HGS test is useful for detecting a decline in the pre- and postoperative physical function in females with hip osteoarthritis.

Factors Associated With Skeletal Muscle Mass Increase by Rehabilitation in Older Adults With Vertebral Compression Fractures

Age-related sarcopenia and osteoporosis-related fractures are critical health issues. Therefore, this study aimed to assess skeletal muscle mass changes in older patients with vertebral compression fractures undergoing rehabilitation and to evaluate factors associated with muscle increases. This study included 179 patients aged ≥80 years in rehabilitation wards with vertebral compression fractures. Appendicular skeletal muscle index was significantly higher at discharge (5.22 ± 1.04 kg/m2, p < .001) than on admission (5.03 ± 1.00 kg/m2). Multiple logistic regression analysis showed that length of hospital stay was significantly associated with increased skeletal muscle index (odds ratios, 1.020; 95% confidence intervals [1.000, 1.032]), whereas age, sex, body mass index, functional independence measure, protein intake, and exercise therapy duration were not. Participants with vertebral compression fractures aged ≥80 years achieved significantly increased skeletal muscle mass in rehabilitation wards. In addition, length of hospital stay was the factor independently associated with increased skeletal muscle index.

Orthostatic hypotension and age-related sarcopenia

Objectives

This study aims to determine the association of sarcopenia with orthostatic hypotension (OH) which is a significant precursor to falls and related injuries in elderly patients.

Patients and methods

A total of 91 outpatients (18 males, 73 females; mean age 79.3±4.0 years; range, 75 to 91 years) were prospectively enrolled and those who were eligible underwent comprehensive sarcopenia assessment including measurement of muscle mass, strength, physical performance, anthropometric measurements along with frailty tests. Patients classified as sarcopenic or non-sarcopenic based on these measurements underwent supine and standing blood pressure (BP) measurements. The frequency of OH was compared between the two groups.

Results

Of the 91 patients, 29 (31.9%) had sarcopenia. There was no statistical difference in measurements of functional tests which consisted of gait speed, timed up-and-go test and handgrip strength. However, timed sit-to-stand test values were higher in sarcopenic patients (18.2±7.9 vs. 15.0±5.1, p=0.04). Patients with sarcopenia developed OA and intolerance more often compared to the non-sarcopenic patients (n=15 [50.0%] vs. n=14 [23.0%], p<0.01 and n=13 [44.8%] vs. n=9 [15.3%], p<0.01, respectively). The adjusted odds ratio for sarcopenia was 7.80 (95% confidence interval 1.77-34.45), p=0.007.

Conclusion

Age-related sarcopenia increases the risk of OA in the elderly. This may in part explain the increased incidence of falls and also help identification of risky elderly patients for orthostatic BP drops.

Association of Monocyte Chemotactic Protein-1 and Dickkopf-1 with Body Composition and Physical Performance in Community-Dwelling Older Adults in Singapore

Objective

We aim to determine the association of monocyte chemotactic protein-1 (MCP-1) and dickkopft-1 (DKK-1) as potential biomarkers that may predict changes in body composition and physical performance in healthy older adults from Singapore.

Methods

Two-hundred community-dwelling older adults (mean age: 67.9 years; 68.5% females) were classified into elevated versus non-elevated groups based on quintile cut-offs of MCP-1 and DKK-1 levels (156.02 pg/mL and 606.31 pg/mL, respectively). Multiple linear regression was performed to examine the relationship between MCP-1 and DKK-1 with body composition and physical performance, adjusted for age, gender and ethnicity.

Results

MCP-1 was significantly associated with higher fat mass, fat mass index, percentage body fat, waist circumference and trunk-limb ratio for fat mass (all p<0.01), and repeated chair stand (p=0.004). DKK-1 was not associated with body composition and physical performance measures. Utilising the Asian Working Group for Sarcopenia (AWGS) 2019 criteria, there were 39 (19.5%) sarcopenia and 161 (80.5%) non-sarcopenia participants respectively, with MCP-1 levels significantly higher in sarcopenia compared with non-sarcopenia (p=0.046), but not for DKK-1 (p=0.525).

Conclusions

Elevated MCP-1 are associated with changes in fat composition, physical performance and sarcopenia, suggesting its usefulness in identifying at-risk group with sarcopenic obesity.

Engagement in Muscle-Strengthening Activities Lowers Sarcopenia Risk in Older Adults Already Adhering to the Aerobic Physical Activity Guidelines

Sarcopenia in older adults is associated with a higher risk of falls, disability, loss of independence, and mortality. Current physical activity (PA) guidelines recommend engagement in muscle-strengthening activities (MSA) in addition to aerobic moderate-to-vigorous physical activity (MVPA). However, little is known about the impact of MSA in addition to adherence to the MVPA recommendation in the guidelines. The aim of the present cross-sectional study was to determine whether or not engagement in MSA is linked to sarcopenia risk in older adults who meet the PA guidelines of 150 min of MVPA per week. A total of 193 community-dwelling older men and women (65–70 years) were included in the study. A continuous sex-specific clustered sarcopenia risk score (SRS) was created based on muscle mass assessed using bioelectrical impedance analysis, handgrip strength, and five times sit-to-stand (5STS) time, assessed using standardized procedures. Adherence to PA guidelines was assessed using the Actigraph GT3x accelerometer and the EPAQ2 questionnaire. Guideline adherence to MSA twice a week was related to a significantly (p < 0.05) lower SRS compared to those who did not. This finding was evident after adjustment for adherence to the protein intake guideline and abdominal obesity. Similar impacts were observed for muscle mass and 5-STS but not for handgrip strength. In conclusion, guideline adherence to MSA is related to lower sarcopenia risk in older adults who already accumulate 150 weekly minutes of MVPA, which reinforces the promotion of the MSA guideline, alongside the MVPA guideline, to fight against sarcopenia progression in ageing populations.

Association Between 10-Year Fracture Probability and Nonalcoholic Fatty Liver Disease With or Without Sarcopenia in Korean Men: A Nationwide Population-Based Cross-Sectional Study

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) and sarcopenia, which are common in elderly men, are known as risk factors of fracture. However, few studies have examined the association with fracture in these patients. Therefore, we aimed to investigate the association between NAFLD with or without sarcopenia and 10-year fracture probability in Korean men aged ≥50 years.

MATERIALS AND METHODS

Data of 2,525 individuals from the 2010-2011 Korea National Health and Nutrition Examination Survey were analyzed. NAFLD was defined using the fatty liver index (FLI) and comprehensive NAFLD score (CNS), and liver fibrosis using the fibrosis 4 calculator. Sarcopenia was defined as the lowest quintile for sex-specific sarcopenia index cutoff; values. The Fracture Risk Assessment (FRAX) tool was used to predict the 10-year probability of major osteoporotic and hip fractures.

RESULTS

Compared to the no NAFLD group, the 10-year major osteoporotic fracture probability was significantly associated with the FLI-defined (β = 0.16, P = 0.002) and CNS-defined (β = 0.20, P < 0.001) NAFLD groups with liver fibrosis. Similarly, the 10-year hip fracture probability was significantly associated with the FLI- and CNS-defined NAFLD with liver fibrosis groups compared to the group without NAFLD (FLI-defined group, β = 0.04, P = 0.046; CNS-defined group, β = 0.05, P = 0.048). Furthermore, in the group with sarcopenia, the 10-year major osteoporotic fracture probability was significantly associated with the FLI- and CNS-defined NAFLD with liver fibrosis groups compared to the group without NAFLD (FLI-defined group, β = 0.29, P = 0.003; CNS-defined group, β = 0.38, P < 0.001).

CONCLUSIONS

NAFLD with liver fibrosis is significantly associated with a higher 10-year major osteoporotic and hip fracture probability in Korean men aged ≥50 years, and this positive association was more profound in patients with sarcopenia. Therefore, screening middle-aged to elderly men who have NAFLD combined with liver fibrosis and sarcopenia may help prevent fractures.

Validation of the Thai version of SARC-F, MSRA-7, and MSRA-5 questionnaires compared to AWGS 2019 and sarcopenia risks in older patients at a medical outpatient clinic

Objectives

To validate the Thai Strength, Assistance with walking, Rise from a chair, Climb stairs and Falls (SARC-F), and 2 Mini Sarcopenia Risk Assessment (MSRA-5, and MSRA-7) questionnaires for sarcopenia screening in older patients in the medical outpatient setting, and to assess the improvements of the diagnostic accuracy by adapting the parameters in the SARC-F, MSRA-7, and MSRA-5 questionnaires. Risk factors for sarcopenia are also investigated.

Methods

Thai SARC-F, MSRA-7, and MSRA-5 questionnaires were translated backwards and forwards. Content validity and test–retest reliability were analyzed. Reliability analysis was used for SARC-F, MSRA-7, and MSRA-5 scores to increase the sensitivity and specificity. The sensitivity, specificity, likelihood ratio, and area under the receiver operating characteristic curves (AUCs) were analyzed.

Results

The prevalence of sarcopenia was 22.7% (65 of 286 patients). The sensitivity of the SARC-F, MSRA-7, and MSRA-5 questionnaires was 21.5%, 72.3%, and 61.5%, respectively. The specificity was 93.7%, 43%, and 67.4%, respectively. The AUCs were 0.58, 0.58, and 0.65, respectively. After weighting and adjusting the scores for the least responded-to items of the MSRA-5, the sensitivity increased to 82.6%, specificity to 43.4%, and AUC to 0.65. Multivariate analysis showed that the associated factors of sarcopenia were age [odds ratio (OR) = 5.92], body mass index < 18.5 [OR = 9.59], and currently working [OR = 0.11].

Conclusions

The modified MSRA-5 improved the sensitivity and diagnostic accuracy for screening for sarcopenia. It is potentially useful for screening for sarcopenia in settings with limited resources for bioelectrical impedance analysis, time, or health personnel.

Exercise Programs for Muscle Mass, Muscle Strength and Physical Performance in Older Adults with Sarcopenia: A Systematic Review and Meta-Analysis

Sarcopenia is an age-related condition that is characterized by progressive and generalized loss of muscle mass and function. Exercise treatment has been the most commonly used intervention among elderly populations. We performed a systematic review and meta-analysis to evaluate the available literature related to the effects of exercise interventions/programs on muscle mass, muscle strength and physical performance in older adults with sarcopenia. We searched PubMed, EMBASE, MEDLINE and the Web of Science for randomized controlled trials and controlled clinical trials exploring exercise in older adults with sarcopenia published through July 2019 without any language restrictions. Pooled analyses were conducted using Review Manager 5.3, with standardized mean differences (SMDs) and fixed-effect models. A total of 3898 titles and abstracts were initially identified, and 22 studies (1041 individuals, 80.75% females, mean age ranged from 60.51 to 85.90 years) were included in the meta-analysis. The exercise programs in the studies consisted of 30 to 80 min of training, with 1 to 5 training sessions weekly for 6 to 36 weeks. Muscle strength (grip strength [SMD 0.57, 95 % CI 0.42 to 0.73, P <0.00001] and timed five chair stands [SMD -0.56, 95 % CI -0.85 to -0.28, P < 0.0001]) and physical performance (gait speed [SMD 0.44, 95 % CI 0.26 to 0.61, P < 0.00001] and the timed up and go test [SMD -0.97, 95 % CI -1.22 to -0.72, P < 0.00001]) showed significant improvement following exercise treatment, while no differences in muscle mass (ASM [SMD 0.15, 95 % CI -0.05 to 0.36, P = 0.15] and ASM/height² [SMD 0.21, 95 % CI -0.05 to 0.48, P = 0.12]) were detected. Exercise programs showed overall significant positive effects on muscle strength and physical performance but not on muscle mass in sarcopenic older adults.

Impaired Fracture Healing in Sarco-Osteoporotic Mice Can Be Rescued by Vibration Treatment Through Myostatin Suppression

Sarcopenia is highly prevalent in fragility fracture patients and is associated with delayed healing. In this study, we investigated the effect of low-magnitude high-frequency vibration (LMHFV) on osteoporotic fracture with sarcopenia and the potential role of myostatin. Osteoporotic fractures created in sarcopenic SAMP8, non-sarcopenic SAMR1 were randomized to control or LMHFV (SAMP8, SAMR1, SAMP8-V, or SAMR1-V) groups. Healing and myostatin expression were evaluated at 2, 4, and 6 weeks post-fracture. In vitro, conditioned-media were collected from myofibers isolated from aged and young SAMP8 or C2C12 myoblasts with or without LMHFV. Osteoblastic MC3T3-E1 under osteogenic differentiation were treated with plain or conditioned-medium (±myostatin propeptide). LMHFV significantly enhanced callus formation was in non-sarcopenic SAMR1 mice; but the enhancement effect was not significant in SAMP8 mice at week 2. Myostatin expressions in callus and biceps femoris of SAMP8 group were significantly higher all groups with significant negative correlation with callus size (R²  = 0.7256; p = 0.0004). Mechanical properties (week 4) and callus remodeling (week 6) were inferior in SAMP8 versus SAMR1 and were significantly enhanced by LMHFV. Alkaline Phosphatase (ALP) and Runx2 expression of MC3T3-E1 was lower in aged myofiber compared with young, but upregulated by LMHFV or myostatin inhibition; also confirmed with C2C12. LMHFV enhanced early callus formation, microarchitecture, callus remodeling and mechanical properties of fracture healing in both SAMP8 and SAMR1; however, more effective in non-sarcopenic SAMR1 mice. Impaired fracture healing in sarcopenic SAMP8 mice is attributed by elevated myostatin expression in callus and muscle, which correlated negatively with callus formation. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:277-287, 2020.

[Atraumatic fractures of the spine : Current strategies for diagnosis and treatment]

Atraumatic fractures of the spine are a common orthopedic disease condition that can be asymptomatic or associated with complaints of varying intensity and quality. The risk factors for such fracture forms are often metabolic and genetic diseases, which have a direct or indirect effect on bone metabolism and therefore secondarily affect the stability of the spinal vertebrae. Furthermore, benign and malignant tumors as well as infectious diseases can also be causative for atraumatic spinal fractures; however, those factors that are attributable to lifestyle habits should also not be underestimated. The treatment of affected patients is complex and nearly always interdisciplinary. In addition to purely symptom-oriented treatment concepts, orthoses in particular and when indicated surgical treatment procedures can be implemented. This article summarizes the important clinical, diagnostic and therapeutic aspects of atraumatic spinal fractures.

Southampton Arm Fracture Frailty and Sarcopenia Study (SAFFSS): a study protocol for the feasibility of assessing frailty and sarcopenia among older patients with an upper limb fracture

INTRODUCTION

Falls are a major health problem for older people; 35% of people aged 65+ years fall every year, leading to fractures in 10%-15%. Upper limb fractures are often the first sign of osteoporosis and routine screening for osteoporosis is recommended by the National Institute for Health and Care Excellence to prevent subsequent hip fractures. However, both frailty and sarcopenia (muscle weakness) are associated with increased risk of falling and fracture but are not routinely identified in this group. The aim of this study is to evaluate the feasibility of assessing and managing frailty and sarcopenia among people aged 65+ years with an upper limb fracture.

METHODS AND ANALYSIS

This study will be conducted in three fracture clinics in one acute trust in England. 100 people aged 65+ years with an upper arm fracture will be recruited and assessed using six validated frailty measures and two sarcopenia tools. The prevalence of the two conditions and the best tools to use will be determined. Those with either condition will be referred to geriatric clinical teams for comprehensive geriatric assessment (CGA). We will document the proportion who are referred for CGA and those who receive CGA. Other outcome measures including falls, fractures and healthcare resource use over 6 months will be collected. In-depth interviews with a purposive sample of patients who undergo the frailty and sarcopenia assessments and healthcare professionals in fracture clinics and geriatric services will be carried out to their acceptability of assessing frailty and sarcopenia in a busy environment.

ETHICS AND DISSEMINATION

The study was given the relevant ethical approvals from NHS Research Ethics Committee (REC No: 18/NE/0377), the University Hospital Southampton NHS Foundation Trust, and the University of Southampton, Faculty of Medicine Ethics Committee and Research Governance Office. Findings will be published in scientific journals and presented to local, national and international conferences.

TRIAL REGISTRATION NUMBER

ISRCTN13848445.

The effect of acute oral phosphatidic acid ingestion on myofibrillar protein synthesis and intracellular signaling in older males

BACKGROUND

Age-related muscle loss (sarcopenia) may be driven by a diminished myofibrillar protein synthesis (MyoPS) response to anabolic stimuli (i.e. exercise and nutrition). Oral phosphatidic acid (PA) ingestion has been reported to stimulate resting muscle protein synthesis in rodents, and enhance resistance training-induced muscle remodelling in young humans.

PURPOSE

This study examined the effects of acute oral PA ingestion on resting and exercise-induced MyoPS rates in older individuals.

METHODS

Sixteen older males performed a bout of unilateral leg resistance exercise followed by oral ingestion of 750 mg of soy-derived PA or a rice-flour placebo (PL) over 60 min post-exercise. A primed-continuous infusion of l-[ring-¹³C₆]-phenylalanine with serial muscle biopsies was used to determine MyoPS at rest and between 0-150 and 150-300 min post-exercise.

RESULTS

Plasma [PA] concentrations were elevated above basal values from 180 to 300 min post-exercise in PA only (P = 0.02). Exercise increased MyoPS rates above basal values between 150 and 300 min post-exercise in PL (P = 0.001), but not PA (P = 0.83). Phosphorylation of p70S6K, rpS6, 4E-BP1 and Akt was elevated above basal levels in the exercised leg over 150-300 min post-exercise for PL only (P = 0.018, 0.007, 0.011 and 0.002, respectively), and were significantly greater than PA (P < 0.01 for all proteins). The effects of oral PA ingestion on proteolytic signaling markers were equivocal.

CONCLUSIONS

Acute oral phosphatidic acid ingestion appears to interfere with resistance exercise-induced intramuscular anabolic signaling and MyoPS in older males and, therefore, may not be a viable treatment to counteract sarcopenia. Clinicaltials.gov registration no: NCT03446924.

MicroRNA-672-5p Identified during Weaning Reverses Osteopenia and Sarcopenia in Ovariectomized Mice

Post-menopausal condition augments the biological aging process, characterized by multiple metabolic disorders in which bone loss is the most prevalent outcome and usually coupled with sarcopenia. Coexistence of such associated pathogenesis have much worse health outcomes, compared to individuals with osteoporosis only. Pre- and post-natal bone development demands calcium from mother to fetus during pregnancy and lactation leading to a significant maternal skeletal loss. It follows an anabolic phase around weaning during which there is a notable recovery of the maternal skeleton. Here, we have studied the therapeutic effect of microRNA-672-5p identified during weaning when it is predominantly expressed, in ovariectomized mice for both osteopenia and sarcopenia. miR-672-5p induced osteoblast differentiation and mineralization. These actions were mediated through inhibition of Smurf1 with enhanced Runx2 transcriptional activation. In vivo, miR-672-5p significantly increased osteoblastogenesis and mineralization, thus reversing bone loss caused by ovariectomy. It also improved bone-mineral density, load-bearing capacity, and bone quality. Sarcopenia was also alleviated by miR-672-5p, as we observed increased cross-sectional area and Feret's diameter of muscle fibers. We hypothesize that elevated miR-672-5p expression has therapeutic efficacy in estrogen-deficiency-induced osteopenia along with sarcopenia.

Osteoporosis and Sarcopenia Increase Frailty Syndrome in the Elderly

Musculoskeletal aging is a major public health interesting and strain due to the significant demographic modifications in the population, and it is linked to high risk of falls, loss of autonomy in elderly individuals and institutionalization with small health outcomes. Thus, this pathological status is related to high morbidity and health care rates. Bone mass and muscle mass and strength increase during late adolescence and early adulthood but start to reduce noticeably from the fifth decade of life and are closely linked. Bone and muscle tissues were increasingly recognized, as endocrine target organs and endocrine organs themselves, interacting through paracrine and endocrine signals. During growth, bone mineral content closely correlates with muscle mass, and several evidences suggest that osteoporosis and sarcopenia present common pathophysiological factors and show the correlation between low bone mineral density and sarcopenia in both men and women. Then, sarcopenia and osteoporosis, typical features of aging, are often associated with each other and with the frailty syndrome. In particular, sarcopenia and osteoporosis are major contributors to disability and frailty and the common denominators are age-related chronic inflammation, changes in body composition and hormonal imbalance. Frailty syndrome is characterized by a reduced response to stress, triggering the decline of the physiological functioning of the various systems. Frailty syndrome, typical of the older people, is frequently associated with a reduction in the quality of life and mobility. Falls often are the basis of reduced mobility and ability to perform the common functions of daily life and the increase in the number of institutionalizations. Moreover, the reduction of muscle mass, associated with altered muscle composition, fat and fibrous infiltration and alterations in innervations, and the increase in fat mass, have a synergistic effect on the increase in cardiovascular risk. The aim of this review is to analyze the pathophysiological mechanisms underlying the frailty syndrome and its association with sarcopenia and osteoporosis, and investigate possible intervention measures.

Correlation among sarcopenia, malnutrition and activities of daily living in patients with vertebral compression fractures: a comparison based on admission and discharge parameters evaluating these conditions

[Purpose] Sarcopenia may be associated with malnutrition in patients with vertebral compression fractures which may affect a patient’s functional prognosis. This study investigated the association between sarcopenia, malnutrition, and activities of daily living at the time of hospital discharge in patients with vertebral compression fractures. [Participants and Methods] The study included 36 patients who were hospitalized with vertebral compression fractures. Sarcopenia was assessed by measuring grip strength and calf circumference. The nutritional status was assessed at the time of hospital admission and at discharge using the Mini Nutritional Assessment Short Form screening tool. Activities of daily living were assessed using the Barthel Index. [Results] The prevalence of sarcopenia at the time of admission was 47.2%. The Barthel Index and Mini Nutritional Assessment Short Form scores in patients with sarcopenia at the time of admission were significantly lower at discharge than to those in patients without sarcopenia. Overall, at discharge, weight and calf circumference decreased significantly with a consequent increase in the prevalence of sarcopenia (55.6%). Multivariate analysis showed that the Mini Nutritional Assessment Short Form score, calf circumference loss, and age affected the Barthel Index at discharge. [Conclusion] Patients with vertebral compression fractures often show sarcopenia and malnutrition, which are conditions that may be exacerbated during hospitalization. These conditions can subsequently affect a patient’s activities of daily living; thus, nutritional rehabilitation is important in patients with vertebral compression fractures, as demonstrated in this study.

Globular adiponectin reverses osteo-sarcopenia and altered body composition in ovariectomized rats

Adiponectin regulates various metabolic processes including glucose flux, lipid breakdown and insulin response. We recently reported that adiponectin receptor1 (adipoR1) activation by a small molecule reverses osteopenia in leptin receptor deficient db/db (diabetic) mice. However, the role of adiponectin in bone metabolism under the setting of post-menopausal (estrogen-deficiency) osteopenia and associated metabolic derangements has not been studied. Here, we studied the therapeutic effect of the globular form of adiponectin (gAd), which is predominantly an adipoR1 agonist, in aged ovariectomized (OVX) rats and compared it with standard-of-care anti-osteoporosis drugs. In OVX rats with established osteopenia, gAd completely restored BMD and load bearing capacity and improved bone quality. Skeletal effects of gAd were comparable to PTH (osteoanabolic) but better than alendronate (anti-catabolic). Both osteoanabolic and anti-catabolic mechanisms led to the anti-osteoporosis effect of gAd. In cultured osteoblasts and bones, gAd increased a) adipoR1 and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) expression to promote mitochondrial respiration, which likely fueled osteoblast differentiation, b) suppressed sclerostin (a wnt antagonist) in a sirtuin1-dependent manner and c) decreased receptor-activator of nuclear factor κB ligand (RANKL) to achieve its anti-catabolic effect. The OVX-induced sarcopenia and insulin resistance were also improved by gAd. We conclude that gAd has therapeutic efficacy in estrogen deficiency-induced osteoporosis, sarcopenia and insulin resistance and hold metabolic disease modifying potential in postmenopausal women.

Age-Related Anabolic Resistance of Myofibrillar Protein Synthesis Is Exacerbated in Obese Inactive Individuals

CONTEXT

A diminished muscle anabolic response to protein nutrition may underpin age-associated muscle loss.

OBJECTIVE

To determine how chronological and biological aging influence myofibrillar protein synthesis (MyoPS).

DESIGN

Cross-sectional comparison.

SETTING

Clinical research facility.

PARTICIPANTS

Ten older lean [OL: 71.7 ± 6 years; body mass index (BMI) ≤25 kg ⋅ m-2], 7 older obese (OO: 69.1 ± 2 years; BMI ≥30 kg ⋅ m-2), and 18 young lean (YL) individuals (25.5 ± 4 years; BMI ≤25 kg ⋅ m-2).

INTERVENTION

Skeletal muscle biopsies obtained during a primed-continuous infusion of l-[ring-13C6]-phenylalanine.

MAIN OUTCOME MEASURES

Anthropometrics, insulin resistance, inflammatory markers, habitual diet, physical activity, MyoPS rates, and fiber-type characteristics.

RESULTS

Fat mass, insulin resistance, inflammation, and type II fiber intramyocellular lipid were greater, and daily step count lower, in OO compared with YL and OL. Postprandial MyoPS rates rose above postabsorptive values by ∼81% in YL (P < 0.001), ∼38% in OL (P = 0.002, not different from YL), and ∼9% in OO (P = 0.11). Delta change in postprandial MyoPS from postabsorptive values was greater in YL compared with OL (P = 0.032) and OO (P < 0.001). Absolute postprandial MyoPS rates and delta postprandial MyoPS change were associated with step count (r2 = 0.33; P = 0.015) and leg fat mass (r2 = 0.4; P = 0.006), respectively, in older individuals. Paradoxically, lean mass was similar between groups, and muscle fiber area was greater in OO vs OL (P = 0.002).

CONCLUSION

Age-related muscle anabolic resistance is exacerbated in obese inactive individuals, with no apparent detriment to muscle mass.

Agrin-LRP4-MuSK signaling as a therapeutic target for myasthenia gravis and other neuromuscular disorders

INTRODUCTION

Signal transduction at the neuromuscular junction (NMJ) is compromised in a diverse array of diseases including myasthenia gravis, Lambert-Eaton myasthenic syndrome, Isaacs' syndrome, congenital myasthenic syndromes, Fukuyama-type congenital muscular dystrophy, amyotrophic lateral sclerosis, and sarcopenia. Except for sarcopenia, all are orphan diseases. In addition, the NMJ signal transduction is impaired by tetanus, botulinum, curare, α-bungarotoxin, conotoxins, organophosphate, sarin, VX, and soman to name a few. Areas covered: This review covers the agrin-LRP4-MuSK signaling pathway, which drives clustering of acetylcholine receptors (AChRs) and ensures efficient signal transduction at the NMJ. We also address diseases caused by autoantibodies against the NMJ molecules and by germline mutations in genes encoding the NMJ molecules. Expert opinion: Representative small compounds to treat the defective NMJ signal transduction are cholinesterase inhibitors, which exert their effects by increasing the amount of acetylcholine at the synaptic space. Another possible therapeutic strategy to enhance the NMJ signal transduction is to increase the number of AChRs, but no currently available drug has this functionality.

An animal model of co-existing sarcopenia and osteoporotic fracture in senescence accelerated mouse prone 8 (SAMP8)

Sarcopenia and osteoporotic fracture are common aging-related musculoskeletal problems. Recent evidences report that osteoporotic fracture patients showed high prevalence of sarcopenia; however, current clinical practice basically does not consider sarcopenia in the treatment or rehabilitation of osteoporotic fracture. There is almost no report studying the relationship of the co-existing of sarcopenia and osteoporotic fracture healing. In this study, we validated aged senescence accelerated mouse prone 8 (SAMP8) and senescence accelerated mouse resistant 1 (SAMR1) as animal models of senile osteoporosis with/without sarcopenia. Bone mineral density (BMD) at the 5th lumbar and muscle testing of the two animal strains were measured to confirm the status of osteoporosis and sarcopenia, respectively. Closed fracture was created on the right femur of 8-month-old animals. Radiographs were taken weekly post-fracture. MicroCT and histology of the fractured femur were performed at week 2, 4 and 6 post-fracture, while mechanical test of both femora at week 4 and 6 post-fracture. Results showed that the callus of SAMR1 was significantly larger at week 2 but smaller at week 6 post-fracture than SAMP8. Mechanical properties were significantly better at week 4 post-fracture in SAMR1 than SAMP8, indicating osteoporotic fracture healing was delayed in sarcopenic SAMP8. This study validated an animal model of co-existing sarcopenia and osteoporotic fracture, where a delayed fracture healing might be resulted in the presence of sarcopenia.

Is Technology Present in Frailty? Technology a Back-up Tool for Dealing with Frailty in the Elderly: A Systematic Review

This study analyzes the technologies used in dealing with frailty within the following areas: prevention, care, diagnosis and treatment. The aim of this paper is, on the one hand, to analyze the extent to which technology is present in terms of its relationship with frailty and what technological resources are used to treat it. Its other purpose is to define new challenges and contributions made by physiotherapy using technology. Eighty documents related to research, validation and/or the ascertaining of different types of hardware, software or both were reviewed in prominent areas. The authors used the following scales: in the area of diagnosis, Fried's phenotype model of frailty and a model based on trials for the design of devices. The technologies developed that are based on these models accounted for 55% and 45% of cases respectively. In the area of prevention, the results proved similar regarding the use of wireless sensors with cameras (35.71%), and Kinect™ sensors (28.57%) to analyze movements and postures that indicate a risk of falling. In the area of care, results were found referring to the use of different motion, physiological and environmental wireless sensors (46,15%), i.e. so-called smart homes. In the area of treatment, the results show with a percentage of 37.5% that the Nintendo® Wii™ console is the most used tool for treating frailty in elderly persons. Further work needs to be carried out to reduce the gap existing between technology, frail elderly persons, healthcare professionals and carers to bring together the different views about technology. This need raises the challenge of developing and implementing technology in physiotherapy via serious games that may via play and connectivity help to improve the functional capacity, general health and quality of life of frail individuals.

Serum Leptin Concentration is Associated with Incident Frailty in Older Adults

Obesity has been associated with higher risk of frailty in older adults, but the pathophysiological mechanisms are unclear. No previous study has examined the association between leptin, an adipokine, and the risk of frailty in older adults, and whether this association could be explained by insulin resistance or chronic inflammation. Data were taken from 1,573 individuals without diabetes mellitus, aged ≥60 years, from the Seniors-ENRICA cohort. In 2008-2010, leptin, the homeostasis model assessment of insulin resistance (HOMA-IR) and C-reactive protein (CRP) were measured. Study participants were followed-up through 2012 to assess incident frailty, defined as at least two of the following Fried criteria: exhaustion, weakness, low physical activity, and slow walking speed. Analyses were performed with logistic regression and adjusted for the main confounders. Over a median follow-up of 3.5 years, 280 cases of incident frailty were identified. Compared to individuals in the lowest tertile of serum leptin, those in the highest tertile showed an increased risk of frailty (odds ratio [OR]: 2.12; 95% confidence interval [CI]: 1.47-3.06; p-trend <0.001). Further adjustment for the percentage of body fat led to an OR of 1.69 (95% CI: 1.11-2.61; p-trend=0.01). After additional adjustment for HOMA-IR and CRP, the OR for frailty was 1.59 (95% CI: 1.01-2.52; p-trend=0.04). Results did not vary according to sex, abdominal obesity or the percentage of body fat. Being in the highest versus lowest tertile of leptin was associated with increased risk of exhaustion (OR: 2.16; 95% CI: 1.32-3.55; p-trend=0.001) and muscle weakness (OR: 1.77; 95% CI: 1.25-2.51; p-trend=0.001), in the analyses adjusted for potential confounders and body fat. Higher leptin concentration was associated with greater risk of frailty in older adults. This association was only modestly explained by insulin resistance and chronic inflammation, as measured by CRP.

Soy-Dairy Protein Blend or Whey Protein Isolate Ingestion Induces Similar Postexercise Muscle Mechanistic Target of Rapamycin Complex 1 Signaling and Protein Synthesis Responses in Older Men

Background: Previous work demonstrated that a soy-dairy protein blend (PB) prolongs hyperaminoacidemia and muscle protein synthesis in young adults after resistance exercise.

Objective: We investigated the effect of PB in older adults. We hypothesized that PB would prolong hyperaminoacidemia, enhancing mechanistic target of rapamycin complex 1 (mTORC1) signaling and muscle protein anabolism compared with a whey protein isolate (WPI).

Methods: This double-blind, randomized controlled trial studied men 55–75 y of age. Subjects consumed 30 g protein from WPI or PB (25% soy, 25% whey, and 50% casein) 1 h after leg extension exercise (8 sets of 10 repetitions at 70% one-repetition maximum). Blood and muscle amino acid concentrations and basal and postexercise muscle protein turnover were measured by using stable isotopic methods. Muscle mTORC1 signaling was assessed by immunoblotting.

Results: Both groups increased amino acid concentrations (P < 0.05) and mTORC1 signaling after protein ingestion (P < 0.05). Postexercise fractional synthesis rate (FSR; P ≥ 0.05), fractional breakdown rate (FBR; P ≥ 0.05), and net balance (P = 0.08) did not differ between groups. WPI increased FSR by 67% (mean ± SEM: rest: 0.05% ± 0.01%; postexercise: 0.09% ± 0.01%; P < 0.05), decreased FBR by 46% (rest: 0.17% ± 0.01%; postexercise: 0.09% ± 0.03%; P < 0.05), and made net balance less negative (P < 0.05). PB ingestion did not increase FSR (rest: 0.07% ± 0.03%; postexercise: 0.09% ± 0.01%; P ≥ 0.05), tended to decrease FBR by 42% (rest: 0.25% ± 0.08%; postexercise: 0.15% ± 0.08%; P = 0.08), and made net balance less negative (P < 0.05). Within-group percentage of change differences were not different between groups for FSR, FBR, or net balance (P ≥ 0.05).

Conclusions: WPI and PB ingestion after exercise in older men induced similar responses in hyperaminoacidemia, mTORC1 signaling, muscle protein synthesis, and breakdown. These data add new evidence for the use of whey or soy-dairy PBs as targeted nutritional interventions to counteract sarcopenia. This trial was registered at clinicaltrials.gov as NCT01847261.

The prevalence of sarcopenia and related factors in a community-dwelling elders Thai population

Background

Sarcopenia is one of common problems among elderly worldwide.

Objectives

Sarcopenia is one of common problems among elderly worldwide. To determine the prevalence of sarcopenia and related factors in community-dwelling elders Thai population.

Methods

This cross-sectional study was performed in 243 subjects aged over 60 years. All participants were evaluated for handgrip strength by dynamometer and for gait speed by walking a 6-m distance. The muscle mass for subjects who had abnormal grip strength and/or gait speed was evaluated by bioimpedance analysis (BIA). The prevalence of sarcopenia was calculated and factors related to sarcopenia were also analyzed.

Results

The mean age was 69.7 ± 6.9 years with three-fourths female participants. Approximate 60% of subjects were overweight. There were 74 participants (30.5%, (95% CI: 25.0%–36.5%)) with abnormal grip strength; gait speed and muscle mass. Males had more prevalence than females (33.9% vs. 29.3% respectively). There is higher prevalence with increasing age among both genders (17.9%, 41.4% and 80.0% in young old, middle old, and the very old groups respectively in male; and 11.5%, 49.1%, and 65.0% in female). After using multivariate analysis, age, body mass index (BMI), and quadriceps strengths were significantly related to sarcopenia with the adjusted odds ratio of 15.47 (95% CI: 4.93, 48.54), 12.84 (95% CI: 3.85, 42.82) and 3.77 (95% CI: 1.70, 8.37) respectively.

Conclusions

Thirty percent of the community-based elderly experienced sarcopenia. As the prevalence is high, the screening for sarcopenia should be performed in community-dwelling elders especially older age, underweight subjects and lower quadriceps strength.

Effect of Angiotensin-Converting Enzyme Inhibitors on Physical Function in Elderly Subjects: A Systematic Review and Meta-Analysis

BACKGROUND

Sarcopenia has been accepted as a new geriatric syndrome, which will become a common and important public health challenge. And angiotensin-converting enzyme inhibitors (ACEIs) have been shown to improve exercise capacity in elderly without heart failure.

OBJECTIVES

To evaluate the effect of angiotensin-converting enzyme inhibitors (ACEIs) on physical function in elderly.

DATA SOURCES

The Cochrane Library, PubMed, EMBASE and Web of Science were searched.

ELIGIBILITY CRITERIA

All researches included were randomized controlled trials (RCTs) which compared any kind of ACEIs with placebo or other anti-hypertensives in elderly, and provided empirical data of grip strength and 6-min walk distance change from baseline.

STUDY APPRAISAL AND SYNTHESIS METHODS

Risk of bias was systematically assessed by using the Cochrane risk of bias tool. Data of grip strength and 6-min walk distance change from baseline were collected and mean differences (MDs) were calculated along with 95% CI (confidence interval) by using a random effects model.

RESULTS

In 3 RCTs including 337 elderly participants, ACEIs (n = 178) did not significantly improved 6-min walk distance (13.45, 95% CI: -16.71 to 43.61; P = 0.38) versus placebo or other antihypertensives (n = 159). In 3 RCTs including 499 elderly participants, grip strength was not significantly different (-0.67, 95% CI: -1.53 to 0.19; P = 0.12) between ACEIs (n = 260) and placebo or other antihypertensives (n = 239).

LIMITATIONS

There exists only 4 RCTs and the number of participants is limited. Pooling of data were from different trials including different participant characteristics. And intervention is not strictly consistent.

CONCLUSION

This study shows that ACEIs can not significantly improve walk distance or the age-related decline of muscle strength for older participants in clinical trials.

Circulating Lipocalin 2 Levels Predict Fracture-Related Hospitalizations in Elderly Women: A Prospective Cohort Study

Lipocalin 2 (LCN2) or neutrophil gelatinase-associated lipocalin (NGAL) is expressed in a wide range of cells and pathological states. Mounting evidence suggests lipocalin 2 may be an important regulator of bone homeostasis. Recently it has been suggested LCN2 is a novel mechanoresponsive gene central to the pathological response to low mechanical force. We undertook a prospective study of 1009 elderly women over 70 years of age to study the association between circulating LCN2 and potential associated variables, including estimated glomerular filtration rate, physical activity, and baseline measures of hip bone density and heel bone quality. Osteoporotic fractures requiring hospitalizations were identified from the Western Australian Data Linkage System. Over 14.5 years, 272 (27%) of women sustained an osteoporotic fracture-related hospitalization; of these, 101 were hip fractures. Circulating LCN2 levels were correlated with body mass index and estimated glomerular filtration rate (r = 0.249, p < 0.001 and r = -0.481, p < 0.001, respectively) that modified the association with hip and heel bone measures. Per standard deviation increase in LCN2, there was a 30% multivariable-adjusted increase in the risk of any osteoporotic fracture (hazard ratio [HR] = 1.30, 95% confidence interval [CI] 1.13-1.50, p < 0.001). In participants with elevated LCN2 levels above the median (76.6 ng/mL), there was an 80% to 81% increase in the risk of any osteoporotic or hip fracture (HR = 1.81, 95% CI 1.38-2.36, p < 0.001 and HR = 1.80, 95% CI 1.16-2.78, p = 0.008, respectively). These associations remained significant after adjustment for total hip bone mineral density (p < 0.05). In conclusion, we have demonstrated that circulating LCN2 levels predict future risk of osteoporotic fractures requiring hospitalization. Measurement of LCN2 levels may improve fracture prediction in addition to current fracture risk factors in the elderly, particularly in those with impaired renal function.

Pharmacological perspectives in sarcopenia: a potential role for renin-angiotensin system blockers?

Sarcopenia represents a major health problem highly prevalent in elderly and age-related chronic diseases. Current pharmacological strategies available to prevent and reverse sarcopenia are largely unsatisfactory thus raising the need to identify novel targets for pharmacological intervention and possibly more effective and safe drugs. This review highlights the current knowledge of the potential benefits of renin-angiotensin system blockade in sarcopenia and discuss the main mechanisms underlying the effects.

Does Rheumatoid Cachexia Predispose Patients with Rheumatoid Arthritis to Osteoporosis and Vertebral Fractures?

Objective.

To assess the prevalence and risk factors of rheumatoid cachexia (RC) and evaluate its relationship with osteoporosis and vertebral fractures (VF) in patients with rheumatoid arthritis (RA).

Methods.

We enrolled into a cross-sectional study 178 consecutive patients with RA (82.6% women) with a mean age of 54.1 ± 11.5 years (25–82) and who fulfilled the American College of Rheumatology criteria for the classification of RA. Body composition, lateral VF assessment images, and scans of the lumbar spine and proximal femur were obtained using dual-energy x-ray absorptiometry. RC was defined by a fat-free mass index below the 10th percentile and a fat mass index above the 25th percentile compared with a reference population. VF were defined using Genant semiquantitative approach.

Results.

RC was observed in 96 patients (53.9%) and osteoporosis in 52 patients (29.2%). Comparison between women with and without RC showed that women with RC had a longer disease duration, higher disease activity variables, higher steroid cumulative dose, and higher proportion of patients with erosive arthritis. Women with RC had lower total hip bone mineral density (BMD) and T score than women without RC, while comparison in men found only body mass index to be significantly lower in men with RC. Regression logistic analysis showed an independent and significant association between RC and age and disease activity in women.

Conclusion.

Our study showed that half of the patients with RA may have RC, a condition that was significantly associated with disease activity and low hip BMD, but not with VF.

Incidence and predictors of sarcopenia onset in community-dwelling elderly Japanese women: 4-year follow-up study

OBJECTIVES

Several studies have explored the prevalence and risk factors of sarcopenia, but they have been based on cross-sectional data. The objective of this study was to determine the incidence and predictors of the onset of sarcopenia over 4 years in community-dwelling elderly women.

DESIGN

Four-year longitudinal follow-up study.

SETTING

Urban community in Tokyo, Japan.

PARTICIPANTS

A total of 538 nonsarcopenic women older than 75 years.

MEASUREMENTS

Body composition was determined by bioelectrical impedance analysis. Functional fitness measurements, including grip strength, usual walking speed, timed up and go (TUG), and interview surveys were conducted at baseline and 4-year follow-up. Blood samples were obtained to analyze serum albumin and hemoglobin A1c, and kidney function was analyzed using serum creatinine and cystatin C. Sarcopenia was defined based on the criteria suggested by the European Working Group on Sarcopenia in Older People, and the development of all stages, that is, presarcopenia, sarcopenia, and severe sarcopenia as well as the components of sarcopenia skeletal muscle index (SMI), grip strength, and walking speed, were analyzed.

RESULTS

The incidence of total sarcopenia was 39.6% (presarcopenia 23.8%, sarcopenia 11.2%, severe sarcopenia 4.6%). Older age was significantly predictive of the development of presarcopenia and severe sarcopenia. Body mass index (BMI) lower than 21.0 kg/m(2) was significantly predictive of the development of all stages of sarcopenia, as well as declines in SMI, grip strength, and walking speed. Slow TUG was a predictor of the development of presarcopenia and severe sarcopenia. Increased calf circumference showed protective effects from the development of all stages of sarcopenia. Greater albumin levels also showed lower risk of declines in SMI, walking speed, and development of presarcopenia. Cystatin C was positively associated with the development of severe sarcopenia (odds ratio 1.83, 95% confidence interval 1.08-3.12). Heart disease and hyperlipidemia history were associated with presarcopenia and sarcopenia, respectively.

CONCLUSION

Age, BMI, calf circumference, and TUG were consistent predictors of the various stages and components of sarcopenia. The data also suggest that cystatin C was associated with higher odds of incident severe sarcopenia, and further study into kidney function and onset of sarcopenia in large populations is needed.