Inflammation and sarcopenia: A systematic review and meta-analysis

The Association of Circulating Amino Acids and Dietary Inflammatory Potential with Muscle Health in Chinese Community-Dwelling Older People

Amino acids (AAs) and dietary inflammatory potential play essential roles in muscle health. We examined the associations of dietary inflammatory index (DII) of habitual diet with serum AA profile, and ascertained if the associations between DII and muscle outcomes were mediated by serum AAs, in 2994 older Chinese community-dwelling men and women (mean age 72 years) in Hong Kong. Higher serum branched chain AAs (BCAAs), aromatic AAs and total glutathione (tGSH) were generally associated with better muscle status at baseline. A more pro-inflammatory diet, correlating with higher serum total homocysteine and cystathionine, was directly (90.2%) and indirectly (9.8%) through lower tGSH associated with 4-year decline in hand grip strength in men. Higher tGSH was associated with favorable 4-year changes in hand grip strength, gait speed and time needed for 5-time chair stands in men and 4-year change in muscle mass in women. Higher leucine and isoleucine were associated with decreased risk of sarcopenia in men; the associations were abolished after adjustment for BMI. In older men, perturbations in serum sulfur AAs metabolism may be biomarkers of DII related adverse muscle status, while the lower risk of sarcopenia with higher BCAAs may partly be due to preserved BMI.

The Associations of Dietary Inflammatory Potential With Musculoskeletal Health in Chinese Community-Dwelling Older People: The Mr. OS and Ms. OS (Hong Kong) Cohort Study

Inflammation, an important contributory factor of muscle and bone aging, is potentially modulated by diet. This study examined the associations of dietary inflammatory index (DII) score with musculoskeletal parameters and related disease outcomes in 3995 community-dwelling Chinese men and women aged ≥65 years in Hong Kong. DII score at baseline was estimated from a food frequency questionnaire. Bone mineral density (BMD) and muscle mass estimated by dual-energy X-ray absorptiometry (DXA), hand grip strength, gait speed, and chair stand test were measured at baseline, year 4, and year 14. The associations of DII score with the longitudinal changes of musculoskeletal parameters, and incidence of osteoporosis, sarcopenia, and fractures were examined by using general linear model, multinomial logistic regression model, and Cox proportional hazards regression model, respectively. After multiple adjustments, each tertile increase in DII score in men was associated with 0.37 (95% confidence interval [CI], 0.10-0.64) kg loss in grip strength and 0.02 (95% CI, 0.01-0.03) m/s loss in gait speed over 4 years. In men, the highest tertile of DII was associated with a higher risk of incident fractures, with adjusted and competing death adjusted hazard ratio (HR) (95% CI) of 1.56 (1.14-2.14) and 1.40 (1.02-1.91), respectively. In women, DII score was not significantly associated with any muscle-related outcomes or incidence of fracture, but a significant association between higher DII score and risk of osteoporosis at year 14 was observed, with the highest tertile of DII score having adjusted odds ratio (OR) (95% CI) of 1.90 (1.03-3.52). In conclusion, pro-inflammatory diet consumption promoted loss of muscle strength and physical function, and increased risk of fractures in older Chinese men. Pro-inflammatory diets had no significant association with muscle related outcomes but increased the long-term risk of osteoporosis in older Chinese women. © 2022 American Society for Bone and Mineral Research (ASBMR).

Malnutrition Is Highly Prevalent in Patients With Chronic Pancreatitis and Characterized by Loss of Skeletal Muscle Mass but Absence of Impaired Physical Function

Background/Aims

Patients with chronic pancreatitis (CP) have an increased risk of malnutrition, a condition linked to reduced muscle mass and physical performance. We have investigated the risk factors, phenotypic presentation, and health implications associated with malnutrition in CP.

Materials and Methods

In a multicenter cross-sectional study we recruited patients with confirmed CP and healthy volunteers as a control group. Malnutrition was diagnosed according to the criteria proposed by the Global Leadership Initiative on Malnutrition. We performed detailed examinations of body composition and physical function as well as testing of routine blood parameters and markers of inflammation.

Results

We included 66 patients [mean (±SD) age: 56.0 (±14.5) years; 51 males] and an equal number of age- and sex-matched controls. Moderate malnutrition was diagnosed in 21% (n = 14) and severe malnutrition in 42% (n = 28) of patients. Besides weight loss malnourished patients showed lower fat and skeletal muscle mass compared to both non-malnourished subjects and healthy controls. Only in severe malnutrition, blood parameters reflected elevated inflammation and reduced muscle reserves. Handgrip strength in patients did not differ by nutritional status but there was a significant correlation (rho = 0.705, p < 0.001) with skeletal muscle mass. Although 20 patients (30%) had pathologically reduced skeletal muscle mass, only two individuals (3%) had sarcopenia with concomitantly reduced handgrip strength.

Conclusion

Malnutrition is a frequent complication of CP characterized by loss of skeletal muscle mass. As this condition becomes evident only at an advanced stage, regular testing for altered body composition is recommended. Suitable biomarkers and the link between loss of muscle mass and physical function require further investigation.

Clinical Trial Registration

[https://clinicaltrials.gov/ct2/show/NCT04474743], identifier [NCT04474743].

The Association Between Cardiometabolic Risk Factors and Frailty in Older Adults: A Systematic Review

Background and Objectives

Enhanced management and prevention of frailty depend on our understanding of the association between potentially modifiable risk factors and frailty. However, the associations between potentially modifiable cardiometabolic risk factors and frailty are not clear. The purpose of this review was to appraise and synthesize the current evidence examining the associations between the cardiometabolic risk factors and frailty.

Research Design and Methods

Multiple databases, including MEDLINE (via PubMed), Embase (via Elsevier), and Web of Science (via Clarivate), were searched extensively. Studies that examined cardiometabolic risk factors and frailty as main predictors and outcome of interest, respectively, among older adults (≥60 years) were included. The Joanna Briggs Institute critical appraisal tools were used to evaluate the quality of studies. PRISMA (2020) guided this review, and findings were synthesized without meta-analysis. This systematic review was registered in PROSPERO (CRD42021252565).

Results

Twelve studies met the eligibility criteria and were included in the review. Abdominal obesity, hyperglycemia, and multiple co-occurring cardiometabolic risk factors were associated with the increased likelihood of frailty in older adults. There was inconsistency across the studies regarding the associations between dyslipidemia, elevated blood pressure, and frailty.

Discussion and Implications

Understanding the association between cardiometabolic risk factors and frailty can have translational benefits in developing tailored interventions for the prevention and management of frailty. More studies are needed to validate predictive and clinically significant associations between single and specific combinations of co-occurring cardiometabolic risk factors and frailty.

Sarcopenia Is an Independent Risk Factor for Severe Diabetic Nephropathy in Type 2 Diabetes: A Long-Term Follow-Up Propensity Score-Matched Diabetes Cohort Study

Background: Diabetic nephropathy is a common cause of chronic kidney disease (CKD) and end-stage kidney disease (ESKD) worldwide and results in tremendous wastage of medical resources. Determining the indicators of diabetic nephropathy, such as sarcopenia, and implementing early interventions to prevent disease progression is crucial. Purpose: The effect of sarcopenia on the risk of severe diabetic nephropathy in patients with type 2 diabetes (T2DM) remains unclear. Patients and Methods: We recruited patients with T2DM and categorized them into two groups, propensity score−matched at a ratio of 1:1, according to whether they had sarcopenia. We subsequently compared the groups’ risk of severe diabetic nephropathy. Results: The matching process yielded a final cohort of 105,166 patients with T2DM (52,583 and 52,583 in the sarcopenia and nonsarcopenia groups, respectively) who were eligible for inclusion in subsequent analyses. According to both the univariate and multivariate Cox regression analyses, the adjusted hazard ratio (aHR) (95% confidence interval) of severe diabetic nephropathy for the sarcopenia diabetes group compared with the control group was 1.10 (1.08−1.13; p < 0.001). Conclusion: The patients with T2DM and sarcopenia were at a higher risk of severe diabetic nephropathy than were those without sarcopenia. Our results may serve as a valuable reference for relevant government authorities in establishing health policies to promote early detection of sarcopenia and exercise to help patients with T2DM overcome sarcopenia.

Effects of age and gender on body composition indices as predictors of mortality in middle-aged and old people

To determine whether body composition indices interact with age and gender as a predictor of all-cause mortality, 1200 participants at least 40 years of age were recruited in 2009 and 2010. A multi-frequency bioelectrical impedance analysis device was used to measure each participant's body composition indices, including the fat mass index (FMI), fat free mass index (FFMI), skeletal muscle mass index (SMMI), and visceral fat area index (VFAI). A baseline questionnaire was used to collect demographic information about lifestyle habits, socioeconomic status, and medical conditions. All claimed records of death from 2009 to 2018 in the National Health Insurance Research Databank were identified. The all-cause mortality rate was 8.67% after a mean follow-up period of 5.86 ± 2.39 person-years. The Cox proportional hazard model analysis showed significantly negative associations between FFMI or SMMI with all-cause mortality in the total group and those aged ≥ 65 y/o. The FFMI and SMMI were negative predictors of mortality in both genders. The FMI and VFAI were positive predictors of mortality exclusively in females. In conclusion, the SMMI is a better predictor of mortality than the BMI, FMI, and FFMI, especially in older adults. A higher fat mass or visceral fat distribution may predict higher mortality in females.

Relationship between tooth loss and sarcopenia in suburban community-dwelling older adults in Shanghai and Tianjin of China

Both sarcopenia and loss of teeth are associated with aging. The purpose of this study was to investigate potential relationships between tooth loss and sarcopenia and its components in suburban community-dwelling older adults of Shanghai and Tianjin, China. The subjects were 1494 people over 60 years of age (40.7% men; aged 71.64 ± 5.97 years) from Chongming District of Shanghai and Hangu District of Tianjin. Asian Working Group for Sarcopenia(AWGS) criteria were used to define sarcopenia. Muscle mass, muscle strength, and physical performance were assessed using a bioelectrical impedance analyzer, a grip strength test, and a four-meter walk test, respectively. The subjects were divided into groups depending on self-reported loss of teeth. Our studies found no correlation between tooth loss and sarcopenia or muscle mass. However, the walking speed of female participants with at least 10 teeth lost was 0.059 m/s slower than that of participants with fewer than 10 teeth lost (p < 0.001), and grip strength was 1.577 kg lower among male participants with at least 10 teeth lost than among males with fewer than 10 teeth lost (p = 0.023). These results are consistent with the importance of good oral hygiene in preventing declines of physical performance in older adults.

Is there an association between inflammatory markers and lower physical performance in older adults?

Background

Maintenance of physical performance is essential for achievement of healthy aging. A few studies have explored the association between inflammatory markers and physical performance in older adults with inconclusive results. Our aim was to analyze the association of tumor necrosis factor-alpha (TNF-α), Interleukin-10 (IL-10), and C-reactive protein (CRP) with physical performance in a sample of older adults in rural settings of Mexico.

Methods

Our study comprised 307 community-dwelling older men and women who participated in the third wave of the Rural Frailty Study. We assessed the physical performance with the Short Physical Performance Battery (SPPB) and classified older adults as low performance if SPPB scored ≤8. Inflammatory markers were ascertained using serum by immunodetection methods. Logistic regression models were used to estimate the associations between inflammatory markers and physical performance.

Results

In comparison with the normal physical performance group, low physical performance individuals mainly were female (P <  0.01), older (P <  0.01), more illiterate (P = 0.02), more hypertensive (P < 0.01), fewer smokers (P = 0.02), and had higher CRP levels (P < 0.01). The logistic model results showed a significant association between the 3rd tertile of CRP and low physical performance (OR = 2.23; P = 0.03). IL-10 and TNF-α levels did not show a significant association.

Conclusions

The results of this study were mixed, with a significant association of physical performance with higher CRP levels but nonsignificant with IL-10 and TNF-α. Further studies with improved designs are needed by incorporating a broader set of inflammatory markers.

Sarcopenia as an Independent Risk Factor for Specific Cancers: A Propensity Score-Matched Asian Population-Based Cohort Study

Purpose: Whether preexisting sarcopenia is an independent risk factor for cancer incidence remains unclear. Therefore, we performed this propensity score (PS)-matched (PSM) population-based cohort study to compare the incidence rate ratios (IRRs) of specific cancers between patients with and without sarcopenia. Patients and Methods: The patients were categorized into two groups according to the presence or absence of sarcopenia, matched at a 4:1 ratio. Results: PS matching yielded a final cohort of 77,608 patients (15,527 in the sarcopenia and 62,081 nonsarcopenia groups) eligible for further analysis. In our multivariate Cox regression analysis, compared with the nonsarcopenia group, the adjusted hazard ratio (aHR; 95% confidence interval (CI)) for cancer risk in the sarcopenia group was 1.277 (1.10 to 1.36; p < 0.001). Furthermore, the adjusted IRRs (95% CIs) for sarcopenia patients were pancreatic cancer 3.77 (1.79 to 4.01), esophageal cancer 3.38 (1.87 to 4.11), lung cancer 2.66 (1.15 to 2.90), gastric cancer 2.25 (1.54 to 3.23), head and neck cancer 2.15 (1.44 to 2.53), colorectal cancer 2.04 (1.77 to 2.30), hepatocellular carcinoma 1.84 (1.30 to 2.36), breast cancer 1.56 (1.12 to 1.95), and ovarian cancer 1.43 (1.10 to 2.29), respectively. Conclusions: Sarcopenia might be a significant cancer risk factor for lung, colorectal, breast, head and neck, pancreas, gastric, esophageal, and ovarian cancer, as well as hepatocellular carcinoma.

Renal dysfunction independently predicts muscle mass loss in patients following liver transplantation

BACKGROUND: Liver transplantation (LT) is the only curative treatment for cirrhosis. However, the presence of complications can impact outcomes following LT. Sarcopenia, or muscle mass loss, is highly prevalent in patients with cirrhosis and is associated with longer hospitalization stays and a higher infection rate post-surgery. We aimed to identify patients at higher risk of early sarcopenia post-LT. METHODS: This retrospective study included 79 cirrhotic patients who underwent LT. Muscle mass was evaluated using the third lumbar spine vertebra skeletal muscle mass index (SMI) and sarcopenia was defined using established cut-off values. Computerized tomography (CT) scans performed within six-month peri-operative period (three months pre- and post-LT) were included in the study. Complications and comorbidities were collected and correlated to SMI post-LT and predictive models for SMI post-LT were constructed. RESULTS: The overall prevalence of sarcopenia was 46% and 62% before and after LT, respectively. Newly developed sarcopenia was found in 42% of patients. Post-LT sarcopenia was associated with longer hospital stays (54±37 vs 29±10 days, p = 0.002), higher number of infection (3±1 vs 1±2, p = 0.027), and greater number of complications (5±2 vs 3±2, p <0.001) compared to absence of sarcopenia. Multivariate analyses showed that the SMI post-LT was independently associated with pre-LT renal function markers, the glomerular filtration rate (GFR) and creatinine (Model 1, GFR: β = 0.33; 95% CI = 0.04–0.17; p = 0.003; Model 2, Creatinine: β = –0.29; 95% CI = –0.10 to –0.02; p = 0.009). CONCLUSIONS: The present study highlights the potential role of renal dysfunction in the development and persistence of sarcopenia after LT.

Farnesol-Loaded Nanoliposomes Inhibit Inflammatory Gene Expression in Primary Human Skeletal Myoblasts

There is a substantial unmet need for the treatment of skeletal muscle mass loss that is associated with aging and obesity-related increases in FFA. Unsaturated FFAs stimulate the inflammatory gene expression in human skeletal myoblasts (SkMs). Farnesol is a hydrophobic acyclic sesquiterpene alcohol with potential anti-inflammatory effects. Here, we created farnesol-loaded small unilamellar (SUVs) or multilamellar lipid-based vesicles (MLVs), and investigated their effects on inflammatory gene expression in primary human skeletal myoblasts. The attachment of SUVs or MLVs to SkMs was tracked using BODIPY, a fluorescent lipid dye. The data showed that farnesol-loaded SUVs reduced FFA-induced IL6 and LIF expression by 77% and 70% in SkMs, respectively. Farnesol-loaded MLVs were less potent in inhibiting FFA-induced IL6 and LIF expression. In all experiments, equal concentrations of free farnesol did not exert significant effects on SkMs. This report suggests that farnesol, if efficiently directed into myoblasts through liposomes, may curb FFA-induced inflammation in human skeletal muscle.

Associations between albumin, globulin, albumin to globulin ratio and muscle mass in adults: results from the national health and nutrition examination survey 2011-2014

Introduction

Chronic inflammation and malnutrition play important roles in muscle loss. Although albumin, globulin and albumin to globulin ratio (AGR) are considered to be useful inflammatory-nutritional biomarkers, their relationship with muscle mass remain unclear. This study aimed to investigate the relationship between them in adults.

Methods

We utilized data from the National Health and Nutrition Examination Survey (NHANES) 2011–2014 for analysis. Data on albumin, globulin, appendicular skeletal muscle mass, body mass index (BMI) and potential confounders (sociodemographic characteristics, medical conditions, laboratory parameters) were extracted and analyzed. We conducted multivariate linear regression models and smooth curve fittings to investigate the association between albumin, globulin, AGR and muscle mass. Subgroup analysis based on gender and muscle mass were performed.

Results

A total of 4110 participants were included, there were 294 participants with low muscle mass (LMM) and 3816 participants with normal muscle mass (NMM). LMM individuals were older, had greater prevalence of diabetes, higher BMI, globulin and triglycerides, lower albumin and AGR. Albumin was positively correlated to muscle mass in men, but negatively correlated with muscle mass in women. There were negative association between globulin and muscle mass, and positive association between AGR and muscle mass among men, but no significant associations were detected among women. Moreover, a linear relationship between albumin, globulin and muscle mass, as well as a non-linear relationship between AGR and muscle mass in men were identified.

Conclusions

The relationships between albumin, globulin, AGR and muscle mass were sex-specific. We speculate these indicators may be useful in assessing muscle mass in men.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03094-4.

Endothelin-1-mediated miR-let-7g-5p triggers interlukin-6 and TNF-α to cause myopathy and chronic adipose inflammation in elderly patients with diabetes mellitus

Background: Diabetes and sarcopenia are verified as mutual relationships, which seriously affect the quality of life of the elderly. Endothelin-1 is well investigated, is elevated in patients with diabetes, and is related to muscle cellular senescence and fibrosis. However, the mechanism of ET-1 between diabetes and myopathy is still unclear. The aim of this study was to evaluate the prevalence of sarcopenia in the elderly with diabetes and to clarify its relationship with ET-1 molecular biological mechanism, progress as well as changes in muscle and fat.

Methods: We recruited 157 type 2 diabetes patients over 55 years old and investigated the prevalence of sarcopenia in diabetes patients and examined the association of ET-1 alterations with HbA1c, creatinine, or AMS/ht2. Next, sought to determine how ET-1 regulates inflammation in muscle cells by western blot and qPCR assay. Using XF Seahorse Technology, we directly quantified mitochondrial bioenergetics in 3T3-L1 cells.

Results: ET-1 was positively correlated with HbA1c, creatinine levels, and duration of disease, and negatively correlated with AMS/ht2. We found that ET-1 dose-dependently induces tumor necrosis factor-α (TNF-α) and interleukin (IL)-6β expression through the PI3K/AKT, and NF-κB signaling pathways in C2C12 cells. Also identified that TNF-α, IL-6β, and visfatin releases were found in co-cultured with conditioned medium of ET-1/C2C12 in 3T3-L1 cells. ET-1 also reduces the energy metabolism of fat and induces micro-environment inflammation which causes myopathy. ET-1 also suppresses miR-let-7g-5p expression in myocytes and adipocytes.

Conclusion: We describe a new mechanism of ET-1 triggering chronic inflammation in patients with hyperglycemia.

Function Over Mass: A Meta-Analysis on the Importance of Skeletal Muscle Quality in COVID-19 Patients

COVID-19 caused by SARS-CoV-2 infection is a highly contagious disease affecting both the higher and lower portions of the respiratory tract. This disease reached over 265 million people and has been responsible for over 5.25 million deaths worldwide. Skeletal muscle quality and total mass seem to be predictive of COVID-19 outcome. This systematic review aimed at providing a critical analysis of the studies published so far reporting on skeletal muscle mass in patients with COVID-19, with the intent of examining the eventual association between muscle status and disease severity. A meta-analysis was performed to evaluate whether skeletal muscle quantity, quality and function were related to disease severity. Systematic reviews and meta-analyses were conducted according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions and reported according to the guidelines of the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guide. From a total of 1,056 references found, 480 were selected after removing duplicates. Finally, only 7 met the specified inclusion criteria. The results of this meta-analysis showed that skeletal muscle quality, rather than quantity, was associated with COVID-19 severity, as confirmed by lower skeletal muscle density and lower handgrip strength in patients with severe disease. Muscle function assessment can thus be a valuable tool with prognostic value in COVID-19.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Modified Glasgow prognostic score (mGPS) is correlated with sarcopenia and dominates the prognostic role of baseline body composition parameters in advanced gastric and esophagogastric junction cancer patients undergoing first-line treatment from the phase III EXPAND trial

PURPOSE

Sarcopenia represents an established adverse prognostic factor in cancer patients. Consequently, different means to counteract sarcopenia have been proposed to improve cancer treatment. Computed tomography (CT) based measurements, also labor intensive, are well validated for the analysis of sarcopenia. As inflammation plays a key role in the development of sarcopenia, we here studied the role of the modified Glasgow prognostic score (mGPS), consisting of inflammation parameters plasma C-reactive protein and albumin, to predicting sarcopenia and adipose tissue related body composition (BC) parameters at baseline and their changes during treatment and to analyze its prognostic role in conjunction with BC parameters.

PATIENTS AND METHODS

CT measurements of body composition parameters were performed at baseline and week 12 in patients with advanced gastric or esophago-gastric junction (EGJ) cancer from the phase III EXPAND trial, undergoing first-line platinum-fluoropyrimidine chemotherapy. mGPS was calculated from baseline CRP and albumin plasma levels. Pearson correlation and Cox regression analyses were performed.

RESULTS

mGPS is strongly prognostic for overall survival (OS). Baseline mGPS is significantly correlated with baseline mean muscle attenuation (MA), P<0.0001. Baseline mGPS did not predict a decline in muscle or adipose tissue parameters during 12 weeks of treatment and a decline in muscle or adipose tissue parameters was not prognostic for OS. MA lost its prognostic role for OS when mGPS or CRP was entered into the COX models. ECOG performance status together with CRP or mGPS remained as sole baseline prognostic factors for OS.

CONCLUSIONS

Our findings support a model where tumor-mediated inflammatory response represents a strong prognostic factor, which is causally related to sarcopenia, but with no direct causal path from sarcopenia to survival. Therefore, therapeutic targeting of systemic inflammation should be further explored as a promising strategy to improve both sarcopenia and the efficacy and tolerability of cancer treatment.

Multi-omics research in sarcopenia: Current progress and future prospects

Sarcopenia is a systemic disease with progressive and generalized skeletal muscle dysfunction defined by age-related low muscle mass, high content of muscle slow fibers, and low muscle function. Muscle phenotypes and sarcopenia risk are heritable; however, the genetic architecture and molecular mechanisms underlying sarcopenia remain largely unclear. In recent years, significant progress has been made in determining susceptibility loci using genome-wide association studies. In addition, recent advances in omics techniques, including genomics, epigenomics, transcriptomics, proteomics, and metabolomics, offer new opportunities to identify novel targets to help us understand the pathophysiology of sarcopenia. However, each individual technology cannot capture the entire view of the biological complexity of this disorder, while integrative multi-omics analyses may be able to reveal new insights. Here, we review the latest findings of multi-omics studies for sarcopenia and provide an in-depth summary of our current understanding of sarcopenia pathogenesis. Leveraging multi-omics data could give us a holistic understanding of sarcopenia etiology that may lead to new clinical applications. This review offers guidance and recommendations for fundamental research, innovative perspectives, and preventative and therapeutic interventions for sarcopenia.

Inflammatory cytokines and sarcopenia in Iranian adults-results from SARIR study

Some studies suggested the effects of inflammatory cytokines in reducing muscle mass and muscle strength and, performance. This study aimed to compare pro-inflammatory cytokines in sarcopenic and non-sarcopenic subjects. 120 men and women were selected out from the cross-sectional study ‘sarcopenia and its determinants among Iranian elders’ (SARIR). Sarcopenia was defined based on the first ‘European Working Group on sarcopenia in older people’ (EWGSOP₁) guidelines. A fasting blood sample was taken from each participant to measure serum high-sensitivity C-reactive protein (hs-CRP), Interleukin 6 (IL-6), and tumor necrosis factor α (TNFα). A total of 120 participants were included in this study. Mean age was 66.7 ± 7.7 years and mean body mass index (BMI) was 27.3 ± 4.2 kg/m². Forty participants had the criteria of EWGSOP₁ sarcopenia. A statistically significant difference was seen between normal and abnormal groups of muscle strength in hs-CRP (P-value = 0.04). Furthermore, we did not observe any remarkable association between inflammatory biomarkers including IL-6 (OR 1.15; 95% CI 0.31–4.28), TNF-α (OR 0.68; 95% CI 0.17–2.77), and hs-CRP (OR 2.39; 95% CI 0.87–6.55) and the presence of sarcopenia even after controlling for plausible confounders. We found that inflammatory biomarkers level was not associated with odds of sarcopenia. The lack of correlation between inflammatory cytokines and sarcopenia could be due to the participants’ age and genetics. Future studies are required to confirm these findings.

Association between prognosis and the use of angiotensin‐converting enzyme inhibitors and/or angiotensin II receptor blockers in frail patients with heart failure with preserved ejection fraction

Aims

The effectiveness of angiotensin‐converting enzyme inhibitors (ACE‐I) and angiotensin II receptor blockers (ARB) has not been demonstrated in patients with heart failure with preserved ejection fraction (HFpEF). We recently reported significant interaction between the use of ACE‐I and/or ARB (ACE‐I/ARB) and frailty on prognosis in patients with HFpEF. In the present study, we examined the association between ACE‐I/ARB and prognosis in patients with HFpEF stratified by the presence or absence of frailty.

Methods and results

We examined the association between the use of ACE‐I/ARB and prognosis according to the presence [Clinical Frailty Scale (CFS) ≥ 5] or absence (CFS ≤ 4) of frailty in patients with HFpEF in a post hoc analysis of registry data. Primary endpoint was the composite of all‐cause mortality and heart failure admission. Secondary endpoints were all‐cause mortality and heart failure admission. Of 1059 patients, median age was 83 years and 45% were male. Kaplan–Meier analysis showed that the risk of composite endpoint (log‐rank P = 0.001) and all‐cause death (log‐rank P = 0.005) in patients with ACE‐I/ARB was lower in those with CFS ≥ 5, but similar between patients with and without ACE‐I/ARB in patients with CFS ≤ 4 (composite endpoint: log‐rank P = 0.830; all‐cause death: log‐rank P = 0.192). In a multivariable Cox proportional hazards model, use of ACE‐I/ARB was significantly associated with lower risk of the composite endpoint [hazard ratio (HR) = 0.52, 95% confidence interval (CI) = 0.33–0.83, P = 0.005] and heart failure admission (HR = 0.45, 95% CI = 0.25–0.83, P = 0.010) in patients with CFS ≥ 5, but not in patients with CFS ≤ 4 (composite endpoint: HR = 1.41, 95% CI = 0.99–2.02, P = 0.059; heart failure admission: HR = 1.43, 95% CI = 0.94–2.18, P = 0.091). The association between ACE‐I or ARB and prognosis did not significantly differ by CFS (CFS ≤ 4: log‐rank P = 0.562; CFS ≥ 5: log‐rank P = 0.100, for with ACE‐I vs. ARB, respectively). Adjusted HRs for CFS 1–4 were higher than 1.0 but were <1.0 at CFS 5.

Conclusions

In patients with HFpEF, use of ACE‐I/ARB was associated with better prognosis in patients with frailty as assessed with the CFS, but not in those without frailty.

Prevalence of Sarcopenia in Pain Patients and Correlation Between the 2 Conditions: A Systematic Review and Meta-analysis

OBJECTIVES

Sarcopenia is a generalized and progressive skeletal muscle disorder and has been proven to be associated with many diseases; however, the correlation between sarcopenia and pain has not yet been systematically clarified. This review aimed to investigate the prevalence of sarcopenia in patients with pain and to ascertain whether pain is independently associated with sarcopenia.

DESIGN

Systematic review and meta-analysis.

SETTING AND PARTICIPANTS

A systematic literature search was performed from the Cochrane Central Register of Controlled Trials, Embase, MEDLINE and Epub Ahead of Print, In-Process, In-Data-Review, and Other Non-Indexed Citations, Daily and Versions for observational studies from inception until February 2021, and our search was updated on December 31, 2021.

METHODS

Sarcopenia prevalence was calculated according to the corresponding number of patients with sarcopenia and pain. We performed meta-analyses with random effects models to calculate the pooled prevalence of sarcopenia in pain and its correlations. Subgroup analyses were also performed based on pain classification, pain location, and diagnostic criteria for sarcopenia. Heterogeneity between the studies was described using the I² statistic.

RESULTS

Fourteen observational studies (13,953 participants, 44% women, and mean age from 40.1 to 76.6 years) were included. Study quality was rated moderate to high. The overall sarcopenia prevalence in patients with pain was 0.11 (95% CI 0.07-0.15, P < .001; I² = 92.3%). People with pain were independently associated with a higher risk of sarcopenia than those without pain (odds ratio [OR] 1.35; 95% CI 1.17-1.56; P = .025; I² = 51.1%). Subgroup analyses showed that the cumulative prevalence and effect measures of sarcopenia were increased when individuals suffered secondary musculoskeletal pain (Prevalence = 12%; OR 1.45; 95% CI 1.19-1.78) and low back pain (Prevalence = 21%; OR 1.95; 95% CI 1.22-3.12).

CONCLUSIONS AND IMPLICATIONS

The prevalence of sarcopenia in patients with pain is relatively high, and pain is significantly associated with sarcopenia in older adults. Attention is needed to screen sarcopenia among patients with pain and optimize its early detection and management in clinical practice.

Pyroptosis and Sarcopenia: Frontier Perspective of Disease Mechanism

With global ageing, sarcopenia, as an age-related disease, has brought a heavy burden to individuals and society. Increasing attention has been given to further exploring the morbidity mechanism and intervention measures for sarcopenia. Pyroptosis, also known as cellular inflammatory necrosis, is a kind of regulated cell death that plays a role in the ageing progress at the cellular level. It is closely related to age-related diseases such as cardiovascular diseases, Alzheimer’s disease, osteoarthritis, and sarcopenia. In the process of ageing, aggravated oxidative stress and poor skeletal muscle perfusion in ageing muscle tissues can activate the nod-like receptor (NLRP) family to trigger pyroptosis. Chronic inflammation is a representative characteristic of ageing. The levels of inflammatory factors such as TNF-α may activate the signaling pathways of pyroptosis by the NF-κB-GSDMD axis, which remains to be further studied. Autophagy is a protective mechanism in maintaining the integrity of intracellular organelles and the survival of cells in adverse conditions. The autophagy of skeletal muscle cells can inhibit the activation of the pyroptosis pathway to some extent. A profound understanding of the mechanism of pyroptosis in sarcopenia may help to identify new therapeutic targets in the future. This review article focuses on the role of pyroptosis in the development and progression of sarcopenia.

Association of Sarcopenia and Expression of Interleukin-16 in Gastric Cancer Survival

We designed the present work to explore the connection between sarcopenia and interleukin-16 (IL-16) expression and their integrated relation with gastric cancer (GC) survival. We deemed the sex-specific third lumbar vertebra skeletal muscle index cutoffs for sarcopenia to be ≤40.8 and ≤34.9 cm²/m² in male and female patients, respectively. Immunohistochemistry was carried out to detect IL-16 levels among GC tissues of the patients. We determined overall survival (OS) and relapse-free survival (RFS) by univariate and multivariate analyses. This study included 225 GC cases, with an average age of 62.7 years. There were 41 (18.2%) female patients, and 107 (47.5%) patients had sarcopenia. Sarcopenia and high IL-16 expression were identified as independent factors to predict OS (hazard ratios [HR] = 1.64 and 1.79, 95% confidence interval [CI] = 1.25–2.23 and 1.16–2.78, respectively) and RFS (HR = 1.43 and 1.60, 95% CI = 1.15–2.95 and 1.10–2.37, respectively). There were more cases showing high IL-16 expression detected in the sarcopenia group (55.7% vs. 37.3%, p = 0.003). Later, we grouped the patients with sarcopenia and IL-16 expression and discovered that the patients with sarcopenia and IL-16 upregulation displayed the poorest OS (HR = 3.02; 95% CI = 1.64–5.91) and RFS (HR = 2.34; 95% CI = 1.47–4.69). In conclusion, more IL-16 upregulation was noted in GC patients with sarcopenia. Sarcopenia accompanied by high IL-16 expression remarkably indicates a dismal prognosis in GC patients. This suggests that these biomarkers may be able to identify patients with GC with poor prognosis and enhance prognostication.

Application of Prognostic Models Based on Psoas Muscle Index, Stage, Pathological Grade, and Preoperative Carcinoembryonic Antigen Level in Stage II-III Colorectal Cancer Patients Undergoing Adjuvant Chemotherapy

Objective

To investigate the effect of sarcopenia on the prognosis of stage II-III colorectal cancer patients undergoing adjuvant chemotherapy.

Methods

A total of 196 stage II-III colorectal cancer patients who received 8 cycles of postoperative chemotherapy were retrospectively analyzed. An abdominal CT acquired at 3-4 weeks after surgery was used to calculate the psoas muscle index. Subsequently, once gender-specific receiver operating characteristic curves were plotted and cut-off values of psoas muscle index were defined, the clinicopathological characteristics and the prognosis of patients with high and low values were compared. Lastly, prognostic models were established based on the independent prognostic factors of relapse-free survival and overall survival identified by COX analysis.

Results

Based on the psoas muscle index, the prevalence of sarcopenia was 37.5% among 196 patients. This prevalence has significant correlation with patients' age and gender. However, it was not related to the AJCC stage, T stage, lymph node metastasis, pathological grade, grade III-IV myelosuppression, or preoperative carcinoembryonic antigen level. In addition, both the relapse-free and the overall survival of patients with low and high psoas muscle indexes were significantly different. COX analysis indicated that the psoas muscle index was an independent prognostic factor. Both the overall survival prognostic model based on patients' psoas muscle index, stage, pathological grade, and preoperative carcinoembryonic antigen level and the relapse-free survival prognostic model based on patients' psoas muscle index, pathological grade, and preoperative carcinoembryonic antigen level could accurately predict the prognosis of patients.

Conclusion

For stage II-III colorectal cancer patients, the presence of sarcopenia before adjuvant chemotherapy would adversely affect their recurrence-free and overall survival. Prognostic models based on psoas muscle index, stage, pathological grade, and preoperative carcinoembryonic antigen level could accurately predict the prognosis in these patients.

The association between low skeletal muscle mass and delirium: results from the nationwide multi-centre Italian Delirium Day 2017

Introduction

Delirium and sarcopenia are common, although underdiagnosed, geriatric syndromes. Several pathological mechanisms can link delirium and low skeletal muscle mass, but few studies have investigated their association. We aimed to investigate (1) the association between delirium and low skeletal muscle mass and (2) the possible role of calf circumference mass in finding cases with delirium.

Methods

The analyses were conducted employing the cross-sectional “Delirium Day” initiative, on patient 65 years and older admitted to acute hospital medical wards, emergency departments, rehabilitation wards, nursing homes and hospices in Italy in 2017. Delirium was diagnosed as a 4 + score at the 4-AT scale. Low skeletal muscle mass was operationally defined as calf circumference ≤ 34 cm in males and ≤ 33 cm in females. Logistic regression models were used to investigate the association between low skeletal muscle mass and delirium. The discriminative ability of calf circumference was evaluated using non-parametric ROC analyses.

Results

A sample of 1675 patients was analyzed. In total, 73.6% of participants had low skeletal muscle mass and 24.1% exhibited delirium. Low skeletal muscle mass and delirium showed an independent association (OR: 1.50; 95% CI 1.09–2.08). In the subsample of patients without a diagnosis of dementia, the inclusion of calf circumference in a model based on age and sex significantly improved its discriminative accuracy [area under the curve (AUC) 0.69 vs 0.57, p < 0.001].

Discussion and conclusion

Low muscle mass is independently associated with delirium. In patients without a previous diagnosis of dementia, calf circumference may help to better identify those who develop delirium.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40520-021-01950-8.

Red meat consumption and risk of frailty in older women

BACKGROUND

Red meat is a nutrient-dense source of protein fundamental for older adults; however, red meat is also high in detrimental components, including saturated fat. It is unclear whether habitual red meat consumption is associated with risk of frailty. This study aimed to examine the prospective association between the consumption of total, unprocessed, and processed red meat and the risk of frailty in older adults.

METHODS

We analysed data from 85 871 women aged ≥60 participating in the Nurses' Health Study. Consumption of total, unprocessed, and processed red meat was obtained from repeated food frequency questionnaires administered between 1980 and 2010. Frailty was defined as having at least three of the following five criteria from the FRAIL scale: fatigue, low strength, reduced aerobic capacity, having ≥5 chronic illnesses, and unintentional weight loss ≥5%. The occurrence of frailty was assessed every four years from 1992 to 2014.

RESULTS

During 22 years of follow-up (median follow-up 14 years), we identified 13 279 incident cases of frailty. Women with a higher intake of red meat showed an increased risk of frailty after adjustment for lifestyle factors, medication use, and dietary factors. The relative risk (95% confidence interval) for one serving/day increment in consumption was 1.13 (1.08, 1.18) for total red meat, 1.08 (1.02, 1.15) for unprocessed red meat, and 1.26 (1.15, 1.39) for processed red meat. When each component of the frailty syndrome was individually examined, each of them was positively associated with total red meat consumption, except for the weight loss criterion. Replacing one serving/day of unprocessed red meat with other protein sources was associated with significantly lower risk of frailty; the risk reduction estimates were 22% for fish and 14% for nuts, while for replacement of processed red meat, the percentages were 33% for fish, 26% for nuts, 13% for legumes, and 16% for low-fat dairy.

CONCLUSIONS

Habitual consumption of unprocessed and processed red meat was associated with a higher risk of frailty. Replacement of red meat by other protein sources might reduce the risk of frailty. These findings are in line with dietary guidelines promoting diets that emphasize plant-based sources of protein.

Muscle Mass and Inflammation in Older Adults: Impact of the Metabolic Syndrome

Background

Inflammatory processes are a cause of accelerated loss of muscle mass. Metabolic syndrome (MetS) is a highly prevalent age-related condition, which may promote and be promoted by inflammation. However, whether inflammation in MetS (metaflammation) is associated with lower muscle mass is still unclear.

Methods

Complete cross-sectional data on body composition, MetS, and the inflammatory markers interleukin (IL)-1β, IL-6, IL-10, tumor necrosis factor (TNF), and C-reactive protein (CRP) were available for 1,377 BASE-II participants (51.1% women; 68 ± 4 years old). Appendicular lean mass (ALM) was assessed by dual-energy X-ray absorptiometry. Low muscle mass (low ALM-to-BMI ratio [ALMBMI]) was defined according to the Foundation for the National Institutes of Health (FNIH) Sarcopenia Project. Regression models, adjusted for an increasing number of confounders (sex, age, physical activity, morbidities, diabetes mellitus type II, TSH, albumin, HbA1c, smoking habits, alcohol intake, education, and energy intake/day), were used to calculate the association between low ALMBMI and high inflammation (tertile 3) according to MetS.

Results

MetS was present in 36.2% of the study population, and 9% had low ALMBMI. In the whole study population, high CRP (odds ratio [OR]: 2.7 [95% CI: 1.6–4.7; p = 0.001]) and high IL-6 (OR: 2.1 [95% CI: 1.2–1.9; p = 0.005]) were associated with low ALMBMI. In contrast, no significant association was found between TNF, IL-10, or IL-1β with low ALMBMI. When participants were stratified by MetS, results for IL-6 remained significant only in participants with MetS.

Conclusions

Among BASE-II participants, low ALMBMI was associated with inflammation. Low-grade inflammation triggered by disease state, especially in the context of MetS, might favor loss of muscle mass, so a better control of MetS might help to prevent sarcopenia. Intervention studies to test whether strategies to prevent MetS might also prevent loss of muscle mass seem to be promising.

The Change in Muscle Mass Among Kidney Transplant Recipients: A Prospective Cohort Study

BACKGROUND

Recovery of renal function after transplantation leads to improved uremic conditions, increased physical activity, and liberation from severe dietary restrictions. Consequently, the muscle mass of kidney transplant recipients increases for several years after their transplant. However, the change in muscle mass and its associated factors among these patients remain largely unknown. Herein, we carried out a prospective cohort study with 1-year follow-up to investigate how muscle mass changes and to identify its risk factors among kidney transplant recipients.

PATIENTS AND METHODS

We performed a single-center, 1-year, prospective, observational cohort study from August 2017 to February 2019 at Osaka City University Hospital in Japan. The skeletal muscle mass index (SMI) was measured by bioelectrical impedance analysis. The risk factors related to the change in muscle mass were analyzed using multivariate linear regression models of age, sex, body mass index (BMI), dialysis vintage, transplant vintage, diabetes mellitus, hemoglobin, C-reactive protein, estimated glomerular filtration rate, and SMI at baseline.

RESULTS

A total of 180 kidney transplant recipients were enrolled in the present study. The median age was 55 years, and the median transplant vintage was 78 months. The median rate of change in SMI was +2.07%, and SMI increased in 118 (66%) patients during the 1-year follow-up. By multivariate analysis, the change in SMI at 1-year follow-up was independently associated with age (P = 0.017) and BMI (P = .023).

CONCLUSIONS

SMI increased in most of the kidney transplant recipients, and age and BMI might be the risk factors for this change in muscle mass among these patients.

Multifactorial Mechanism of Sarcopenia and Sarcopenic Obesity. Role of Physical Exercise, Microbiota and Myokines

Obesity and ageing place a tremendous strain on the global healthcare system. Age-related sarcopenia is characterized by decreased muscular strength, decreased muscle quantity, quality, and decreased functional performance. Sarcopenic obesity (SO) is a condition that combines sarcopenia and obesity and has a substantial influence on the older adults’ health. Because of the complicated pathophysiology, there are disagreements and challenges in identifying and diagnosing SO. Recently, it has become clear that dysbiosis may play a role in the onset and progression of sarcopenia and SO. Skeletal muscle secretes myokines during contraction, which play an important role in controlling muscle growth, function, and metabolic balance. Myokine dysfunction can cause and aggravate obesity, sarcopenia, and SO. The only ways to prevent and slow the progression of sarcopenia, particularly sarcopenic obesity, are physical activity and correct nutritional support. While exercise cannot completely prevent sarcopenia and age-related loss in muscular function, it can certainly delay development and slow down the rate of sarcopenia. The purpose of this review was to discuss potential pathways to muscle deterioration in obese individuals. We also want to present the current understanding of the role of various factors, including microbiota and myokines, in the process of sarcopenia and SO.

Dietary Patterns and Intrinsic Capacity in Community-Dwelling Older Adults: A Cross-Sectional Study

OBJECTIVES

Few studies have investigated the link between diet and intrinsic capacity (IC), and the potential sex difference in such association. This study examined the association between dietary patterns and IC and its sub-domains in Chinese community-dwelling older adults.

DESIGN

Cross-sectional analysis using baseline data from the MrOs and MsOs study.

SETTING

Community.

PARTICIPANTS

Chinese community-dwelling older adults aged ≥65 years in Hong Kong.

MEASUREMENTS

Dietary intake was assessed using a validated food frequency questionnaire and priori and posteriori dietary pattern scores were generated. IC including measures of cognitive, locomotor, vitality, sensory and psychological domains was assessed. Multiple logistic regression was performed to examine the associations between dietary pattern scores and the likelihood of greater IC and sub-domain scores with adjustment for sociodemographic and lifestyle factors.

RESULTS

Data of 3730 participants (aged 72.2±5.0 years, 50.4% men) was available. In men, higher Diet Quality Index-International (DQI-I) and Okinawan diet scores, and lower "meat-fish" pattern scores were associated with greater IC. A higher DQI-I score was associated with greater locomotion, whereas higher "snacks-drinks-milk products" pattern score was associated with a greater sensory function. In women, none of the dietary pattern scores was associated with IC. Higher DQI-I score, Mediterranean-DASH Intervention for Neurodegenerative Delay Diet (MIND) score and "vegetables-fruits" pattern score were associated with greater psychological function.

CONCLUSION

Various dietary patterns were associated with greater IC and its sub-domains in Chinese community-dwelling older adults, and more associations were observed in men than women. Strategies to improve diet and IC should take sex differences into account.

Association of urinary phthalate metabolites with sarcopenia in US adults: NHANES 1999-2006

Phthalates have been extensively detected in environmental and biological matrices. Exposure to phthalates is implicated in various human diseases. In this study, we conducted a cross-sectional study to determine whether urinary phthalate metabolite concentrations were correlated with prevalence of sarcopenia in US adult population. We included 3562 participants with detailed information on skeletal muscle mass and urinary phthalate metabolites based on National Health and Nutrition Examination Survey (NHANES) 1999-2006 data. A total of 7 main phthalate metabolites were analyzed in the urine sample of each participant. Appendicular skeletal muscle mass (ASM) was measured using dual-energy X-ray absorptiometry. Multivariable linear regression models were conducted following adjustment for multiple covariates. ASM adjusted by body mass index (ASM/BMI) was calculated, and sarcopenia was defined as the lowest quintile for ASM/BMI value. Compared with participants in quartile 1, those in quartile 2 of urinary mono-n-butyl phthalate (MnBP) and quartile 4 of urinary monobenzyl phthalate (MBzP) had decreased ASM/BMI. Urinary MnBP in quartile 4, as well as urinary MBzP in quartile 2, was shown to be significantly correlated with higher sarcopenia prevalence. In subgroup analysis, negative association of MBzP with ASM/BMI was observed in both males and females, while this negative association was only observed in males for MnBP. Females with higher urinary monoethyl phthalate (MEP) concentrations had higher sarcopenia risk. Taken together, the present study found several urinary phthalate metabolites were positively associated with sarcopenia prevalence in US adult population. These findings indicated phthalate exposure might be an important environmental risk factor contributing to sarcopenia development.

Association of Loss of Occlusal Pairs of Teeth with Sarcopenia in a Chinese Population of Community-Dwelling Elderly

OBJECTIVES

Tooth loss, which usually leads to malnutrition, is common in the elderly. However, limited information is available regarding its association with sarcopenia. This study aimed to investigate the relationship between loss of occlusal pairs of tooth and sarcopenia.

DESIGN

A cross-sectional retrospective study was performed.

SETTING

The elderly who participated in the National Basic Public Health Project in the Maigaoqiao Community Medical Center in Nanjing, Jiangsu Province, China.

PARTICIPANTS

A total of 2850 individuals aged ≥60 years were enrolled.

MEASUREMENTS

Sarcopenia was defined according to the criteria proposed by the Asian Working Group for Sarcopenia. A trained dentist assessed oral health status and counted the number of present teeth. Logistic regression analyses were performed to evaluate the association between the loss of occlusal pairs and sarcopenia.

RESULTS

The prevalence of sarcopenia was 7.1% (201/2850). Univariate logistic regression analysis showed that loss of occlusal pairs was associated with sarcopenia [anterior occlusal pairs (AOPs): odd ratio (OR) = 1.292, 95% confidence interval (CI) = 1.158-1.442; posterior occlusal pairs (POPs): OR = 1.147, 95% CI = 1.018-1.221]. Multivariate logistic regression analysis indicated that loss of POPs was still an independent risk for sarcopenia (OR = 1.108, 95% CI = 1.007-1.220) after adjustment for traditional confounders. Subgroup analysis showed that loss of POPs was more significantly linked to sarcopenia in those with advanced age (≥80years) (OR = 1.307, 95% CI = 1.116-1.532) and in females (OR = 1.165, 95%CI = 1.038-1.308). Compared to individuals with ≥5 occluding pairs of POPs, those with <5 occluding pairs of POPs had a higher incidence of sarcopenia.

CONCLUSIONS

Loss of POPs is associated with an increased risk of sarcopenia in the elderly in a Chinese population. Further research on the mechanism of the observed causal relationship is needed.

Association of Sarcopenia with Osteopenia and Osteoporosis in Community-Dwelling Older Korean Adults: A Cross-Sectional Study

Sarcopenia and bone disorders, such as osteopenia and osteoporosis, are common musculoskeletal disorders in older adults. Therefore, this study aimed to establish the association between sarcopenia and bone disorders such as osteoporosis and osteopenia according to sex. We analyzed 3077 participants from the 2008-2011 Korean National Health and Nutrition Examination Survey aged 65 years or older. After adjusting for all covariates, such as physical examinations, exercise, and nutrient intake (model 4), the odds ratios for the association between sarcopenia and bone disorders were 2.051 (95% confidence interval [CI]: 1.498-2.808) in osteopenia and 2.258 (95% CI: 1.584-3.218) in osteoporosis. However, when sex was analyzed separately, the odds ratio was significantly different in men (osteopenia-2.068, 95% CI: 1.462-2.924; osteoporosis-3.247, 95% CI: 1.953-5.399), but not in women. Therefore, the results of this study show an association between sarcopenia and bone disorders in older Korean adults. Sarcopenia is significantly related to osteopenia and osteoporosis, especially in men, when stratified by sex.

Lipoprotein subfractions in patients with sarcopenia and their relevance to skeletal muscle mass and function

OBJECTIVE

Loss of skeletal muscle mass is a characteristic of aging. Growing evidence suggests the role of fatty acids and their derived lipid intermediates in the regulation of skeletal muscle and function. However, the exact association between lipoprotein subfractions and sarcopenia in elderly individuals remains unclear. In this study, we aimed to investigate the levels of lipoprotein subfractions in sarcopenia patients and their relationship with skeletal muscle mass and function.

METHODS

A total of 84 elderly Chinese subjects aged ≥65 years who did not have diseases that obviously affected lipid metabolism were included. Concentrations of lipoprotein subfractions, including total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), HDL2, HDL3, low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), VLDL3, LDL-particle (LDL-P), lipoprotein(a) and remnant-like particle cholesterol (RLP-C), were determined by vertical auto profile. Triglyceride (TG) was measured by an enzymatic colorimetric assay. The skeletal muscle index (SMI) was assessed by bioelectrical impedance analysis. Handgrip strength was measured using a hand-held dynamometer.

RESULTS

The levels of TC, TG, LDL-C, LDL-P, IDL, VLDL, VLDL3, RLP-C and C-reactive protein were significantly higher in sarcopenia patients than in controls (p < 0.05). Pearson Product-Moment Correlation Coefficient analysis showed that the TC, TG, LDL-C, IDL, VLDL, VLDL3, and RLP-C levels were negatively associated with the SMI; The TG, IDL, VLDL, VLDL3, and RLP-C were negatively correlated with handgrip strength. In multivariate stepwise regression analysis, the VLDL and RLP-C levels were significantly correlated with the SMI. The sensitivity and specificity of the combined measurement of VLDL and RLP-C in predicting sarcopenia were 69.8% and 92.5% (AUC: 0.831; 95% CI:(0.739, 0.924); p < 0.05).

CONCLUSION

The occurrence of sarcopenia is associated with disorders of lipid metabolism, particularly VLDL and RLP-C.

A Multifactorial Approach for Sarcopenia Assessment: A Literature Review

Simple Summary

Sarcopenia is characterized by an accelerated decline in skeletal muscle mass and strength, which results in poor quality of life, disability, and death. In the literature, sarcopenia is defined as the progressive breakdown of muscle tissue. The prevalence ranges from 5% to 13% in people 60–70 years old and from 11% to 50% in people older than 80 years. The comparison of risk factors associated with sarcopenia based on the European Working Group on Sarcopenia (1 and 2) in Older People, the Asian Working Group for Sarcopenia (1 and 2), the International Working Group on Sarcopenia, and the Foundation for the National Institutes of Health revealed no consistent patterns. Accordingly, the identification of a single risk factor for sarcopenia is unpredictable. Due to its “multifactorial” pathogenesis related to the involvement of a multitude of factors. In this review, we summarize 13 relevant risk factors associated with this disease that are important to consider prior to embarking on any related sarcopenia research. We suggest that researchers should concentrate on the biology of sarcopenia to develop a uniform consensus for screening this condition. In this review, we identify 50 biochemical markers across six pathways that have previously been investigated in subjects with sarcopenia. We suggest that these summarized biomarkers can be considered in future diagnosis to determine the biology of this disorder, thereby contributing to further research findings. As a result, a uniform consensus may also need to be established for screening and defining the disease. Sarcopenia is associated with a number of adverse economic and social outcomes, including disability, hospitalization, and death. In relation to this, we propose that we need to develop strategies including exercise interventions in the COVID-19 era to delay the onset and effects of sarcopenia. This suggestion should impact on sarcopenia’s primary and secondary outcomes, including physical, medical, social, and financial interactions.

Abstract

Sarcopenia refers to a progressive and generalized weakness of skeletal muscle as individuals age. Sarcopenia usually occurs after the age of 60 years and is associated with a persistent decline in muscle strength, function, and quality. A comparison of the risk factors associated with sarcopenia based on the European Working Group on Sarcopenia (1 and 2) in Older People, the Asian Working Group for Sarcopenia (1 and 2), the International Working Group on Sarcopenia, and the Foundation for the National Institutes of Health revealed no consistent patterns. Accordingly, the identification of a single risk factor for sarcopenia is unpredictable due to its “multifactorial” pathogenesis, with the involvement of a multitude of factors. Therefore, the first aim of this review was to outline and propose that the multiple factors associated with sarcopenia need to be considered in combination in the design of new experimentation in this area. A secondary aim was to highlight the biochemical risk factors that are already identified in subjects with sarcopenia to assist scientists in understanding the biology of the pathophysiological mechanisms affecting the old people with sarcopenia. We also briefly discuss primary outcomes (physical) and secondary outcomes (social and financial) of sarcopenia. For future investigative purposes, this comprehensive review may be useful in considering important risk factors in the utilization of a panel of biomarkers emanating from all pathways involved in the pathogenesis of this disease. This may help to establish a uniform consensus for screening and defining this disease. Considering the COVID-19 pandemic, its impact may be exacerbated in older populations, which requires immediate attention. Here, we briefly suggest strategies for advancing the development of smart technologies to deliver exercise in the COVID-19 era in an attempt regress the onset of sarcopenia. These strategies may also have an impact on sarcopenia’s primary and secondary outcomes.

Impact of Sarcopenia and Inflammation on Patients with Advanced Non-Small Cell Lung Cancer (NCSCL) Treated with Immune Checkpoint Inhibitors (ICIs): A Prospective Study

BACKGROUND

Sarcopenia is a condition characterized by loss of skeletal muscle mass associated with worse clinical outcomes in cancer patients. Data on sarcopenia in patients undergoing immune checkpoint inhibitors (ICI) therapy are still limited. The aim of this prospective observational study was to investigate the relationship between sarcopenia, ICI treatment response and immunological profile, in patients with advanced non-small cell lung cancer (NSCLC).

METHODS

Forty-seven stage IV NSCLC patient candidates for starting ICI, were enrolled from the Policlinico Umberto I outpatient Oncology. Patients underwent baseline blood test, inflammatory markers, cytokine assessment and body composition with dual-energy X-ray absorptiometry (DXA). Sarcopenia was defined with appendicular skeletal muscle mass over height² (ASM/heigh²).

RESULTS

Overall, 19/47 patients (40.4%) results were sarcopenic. Sarcopenic patients showed significantly shorter PFS than non-sarcopenic ones (20.3 weeks, 95% CI 7.5-33.1 vs. 61 weeks, 95% CI 22.5-99.4, p = 0.047). Specifically, they had an 8.1 times higher risk of progression disease (PD) than non-sarcopenic patients (OR 8.1, 95%, p = 0.011).

CONCLUSIONS

Sarcopenic patients showed worse PFS and had a higher risk of PD compared to non-sarcopenic ones. Therefore, sarcopenia may reflect the increased metabolic activity of more aggressive tumors, which involves systemic inflammation and muscle wasting and could be considered a negative predictive factor for ICI response.

Prognostic Impact of Sarcopenia in Patients with Metastatic Hormone-Sensitive Prostate Cancer

The clinical value of sarcopenia has not been determined yet in metastatic hormone-sensitive prostate cancer (mHSPC). We retrospectively evaluated data of 70 consecutive patients with mHSPC receiving treatment with either early docetaxel (n = 42) or abiraterone acetate (n = 28) between July 2018 and April 2021. Skeletal muscle index was calculated from cross-sectional areas of skeletal muscle on baseline computed tomography (CT), defining sarcopenia as a skeletal muscle index of ≤52.4 cm²/m². Failure-free survival (FFS), radiographic progression-free survival, and time to prostate-specific antigen (PSA) progression were estimated using the Kaplan-Meier method, and differences in survival probability were compared using the log-rank test. Cox proportional hazards regression analysis was conducted to identify the predictors of clinical outcomes. Patients with sarcopenia (n = 47) had shorter FFS than those without sarcopenia (n = 23) (median, 20.1 months vs. not reached; log-rank p < 0.001). Sarcopenia was independently associated with shorter FFS (hazard ratio (HR), 6.69; 95% confidence interval (CI), 1.57-28.49; p = 0.010) and time to PSA progression (HR, 12.91; 95% CI, 1.08-153.85; p = 0.043). In conclusion, sarcopenia is an independent prognostic factor for poor FFS and time to PSA progression in patients with mHSPC who receive early docetaxel or abiraterone acetate treatment.

Metabolomics as an Important Tool for Determining the Mechanisms of Human Skeletal Muscle Deconditioning

Muscle deconditioning impairs both locomotor function and metabolic health, and is associated with reduced quality life and increased mortality rates. Despite an appreciation of the existence of phenomena such as muscle anabolic resistance, mitophagy, and insulin resistance with age and disease in humans, little is known about the mechanisms responsible for these negative traits. With the complexities surrounding these unknowns and the lack of progress to date in development of effective interventions, there is a need for alternative approaches. Metabolomics is the study of the full array of metabolites within cells or tissues, which collectively constitute the metabolome. As metabolomics allows for the assessment of the cellular metabolic state in response to physiological stimuli, any chronic change in the metabolome is likely to reflect adaptation in the physiological phenotype of an organism. This, therefore, provides a holistic and unbiased approach that could be applied to potentially uncover important novel facets in the pathophysiology of muscle decline in ageing and disease, as well as identifying prognostic markers of those at risk of decline. This review will aim to highlight the current knowledge and potential impact of metabolomics in the study of muscle mass loss and deconditioning in humans and will highlight key areas for future research.

Associations between homocysteine, inflammatory cytokines and sarcopenia in Chinese older adults with type 2 diabetes

Background

Sarcopenia, an age-related disease, has been implicated as both a cause and consequence of type 2 diabetes mellitus (T2DM) and a symbol of poor prognosis in older adults with T2DM. Therefore, early detection and effective treatment of sarcopenia are particularly important in older adults with T2DM. We aimed to investigate the prevalence of sarcopenia in Chinese older T2DM patients and explore whether homocysteine and inflammatory indexes could serve as biomarkers and participate in the development process of sarcopenia.

Methods

T2DM patients aged over 60 years were consecutively recruited from the ward of department of Endocrinology, Xuanwu Hospital between April 2017 and April 2019. Sarcopenia was defined based on the standard of the Asian Working Group of Sarcopenia, including muscle mass, grip strength and gait speed. Logistic regression was used to explore the association between biochemical indicators and sarcopenia. Receiver operating characteristic (ROC) curves were applied to determine the diagnostic effect of these clinical indicators.

Results

Totally 582 older adults with T2DM were characterized and analyzed in the study. Approximately 8.9% of the older T2DM patients had sarcopenia. After adjusting for age, sex, body mass index (BMI) and hemoglobin A1c (HbA1c), increased concentrations of homocysteine [odds ratio (OR): 2.829; 95% confidence interval (CI), 1.064–7.525] and high-sensitive C-reactive protein (hs-CRP) (OR: 1.021; 95% CI, 1.001–1.042) were independent predictors of sarcopenia; but not interleukin-6. The combination of age, sex, BMI and HbA1c provided a discriminatory effect of sarcopenia with an area under the curve (AUC) of 0.856, when homocysteine was added to the model, the value of the ROC curve was further improved, with an AUC of 0.861.

Conclusion

In the current study, we demonstrated a positive correlation of homocysteine, hs-CRP with sarcopenia in older adults with T2DM and the relationship remained significant even after adjustment for HbA1c. These biomarkers (homocysteine and hs-CRP) may play important roles in the pathological process of sarcopenia.

Free Fatty Acid Species Differentially Modulate the Inflammatory Gene Response in Primary Human Skeletal Myoblasts

Simple Summary

Epidemiological studies show that obesity increases the risk of muscle mass loss with age, a syndrome called sarcopenic obesity. Obesity leads to increased free fatty acids (FFAs) and excessive fat deposits, which impair the integrity of skeletal muscles by unknown mechanisms. This report indicates that FFAs directly affect human skeletal muscle cell replication and inflammatory gene expression. The structural characteristics of FFAs play a decisive role in triggering both processes. Thus, the characterization of abundant FFA species in the skeletal muscle of obese individuals may become a useful tool to predict the progression of sarcopenic obesity.

Abstract

Age-related loss of skeletal muscle is associated with obesity and inflammation. In animal models, intramuscular fat deposits compromise muscle integrity; however, the relevant fat components that mediate muscular inflammation are not known. Previously, we hypothesized that free fatty acids (FFAs) may directly induce inflammatory gene expression in skeletal muscle cells of obese rats. Here, we examined this hypothesis in primary human skeletal myoblasts (SkMs) using multiplex expression analysis of 39 inflammatory proteins in response to different FFA species. Multiplex mRNA quantification confirmed that the IL6, IL1RA, IL4, LIF, CXCL8, CXCL1, CXCL12 and CCL2 genes were differentially regulated by saturated and unsaturated C16 or C18 FFAs. Fluorescence staining revealed that only saturated C16 and C18 strongly interfere with myoblast replication independent of desmin expression, mitochondrial abundance and oxidative activity. Furthermore, we addressed the possible implications of 71 human receptor tyrosine kinases (RTKs) in FFA-mediated effects. Phosphorylated EphB6 and TNK2 were associated with impaired myoblast replication by saturated C16 and C18 FFAs. Our data suggest that abundant FFA species in human skeletal muscle tissue may play a decisive role in the progression of sarcopenic obesity by affecting inflammatory signals or myoblast replication.

Exercise as a Peripheral Circadian Clock Resynchronizer in Vascular and Skeletal Muscle Aging

Aging is characterized by several progressive physiological changes, including changes in the circadian rhythm. Circadian rhythms influence behavior, physiology, and metabolic processes in order to maintain homeostasis; they also influence the function of endothelial cells, smooth muscle cells, and immune cells in the vessel wall. A clock misalignment could favor vascular damage and indirectly also affect skeletal muscle function. In this review, we focus on the dysregulation of circadian rhythm due to aging and its relationship with skeletal muscle changes and vascular health as possible risk factors for the development of sarcopenia, as well as the role of physical exercise as a potential modulator of these processes.

Associations between inflammatory markers, body composition, and physical function: the Copenhagen Sarcopenia Study

BACKGROUND

Chronic low-grade inflammation has been suggested as one of the key elements in the development of sarcopenia, but in contrast to disease-related loss of muscle mass, the role of chronic low-grade inflammation in age-related (primary) sarcopenia is still not clear. The aim of this study was to investigate low-grade inflammation in relation to age and the potential association between inflammatory biomarkers and body composition, muscle strength and physical performance in a healthy Danish cohort.

METHODS

There were 1160 generally healthy men and women (range: 22-93 years) included. Appendicular lean mass (ALM) and visceral fat normalized to height (kg/m² ) was assessed by dual-energy X-ray absorptiometry (iDXA, GE Lunar). Muscle strength and physical performance were evaluated by handgrip strength (HGS), 30 s sit-to-stand performance, and maximal gait speed (GS). Systemic levels of TNF-α, IL-6, IL-1β, IL-4, IL-13, and IFN-γ were measured using multiplex bead-based immunoassays (Bio-Rad). hsCRP was assessed using latex particle-enhanced immunoturbidimetric assays (Roche Diagnostics).

RESULTS

With age, ALM/h² , HGS, sit-to-stand performance and GS decreased, whereas visceral fat/h² increased in both men and women (P < 0.05). Systemic levels of hsCRP, TNF-α, IL-4, and IFN-γ increased with age in men and women (P < 0.05), while IL-1β increased in women only (P < 0.01). Higher levels of hsCRP were associated with lower ALM/h² in elderly (≥65 years) men and women (P < 0.001). Higher levels of hsCRP were associated with lower handgrip strength in elderly women (P < 0.05) whereas higher levels of hsCRP was not associated with lower HGS in elderly men (P = 0.056). Higher levels of hsCRP were associated with lower GS (P < 0.05), whereas IFN-γ was positively associated with GS in elderly women (P < 0.05), but not elderly men. Visceral fat index was positively associated with hsCRP in elderly men and women (P < 0.001). Compared with elderly with normal HGS, elderly men and women with low HGS displayed higher levels of TNF-α and hsCRP (P < 0.05).

CONCLUSIONS

With age, systemic levels of hsCRP, TNF-α, IL-4, and IFN-γ increased, with hsCRP and TNF-α being especially elevated in more physically frail elderly supporting the association between low-grade systemic inflammation and poor physical function. In contrast, only high levels of hsCRP were weakly associated with low muscle mass and positively associated with visceral fat and low physical function, suggesting that chronic low-grade inflammation is not the main driver of age-related loss of muscle mass as previously suggested.

High-Intensity Interval Training Improves Physical Function, Prevents Muscle Loss, and Modulates Macrophage-Mediated Inflammation in Skeletal Muscle of Cerebral Ischemic Mice

Although skeletal muscle is the main effector organ largely accounting for disability after stroke, considerably less attention is paid to the secondary abnormalities of stroke-related skeletal muscle loss. It is necessary to explore the mechanism of muscle atrophy after stroke and further develop effective rehabilitation strategy. Here, we evaluated the effects of high-intensity interval (HIIT) versus moderate-intensity aerobic training (MOD) on physical function, muscle mass, and stroke-related gene expression profile of skeletal muscle. After the model of middle cerebral artery occlusion (MCAO) was successfully made, the blood lactate threshold corresponding speed (S_LT) and maximum speed (S_max) were measured. Different intensity training protocols (MOD < S_LT; S_LT < HIIT < S_max) were carried out for 3 weeks beginning at 7 days after MCAO in the MOD and HIIT groups, respectively. We found that both HIIT and MOD prevented stroke-related gastrocnemius muscle mass loss in MCAO mice. HIIT was more beneficial than MOD for improvements in muscle strength, motor coordination, walking competency, and cardiorespiratory fitness. Furthermore, HIIT was superior to MOD in terms of reducing lipid accumulation, levels of IL-1β and IL-6 in paretic gastrocnemius, and improving peripheral blood CD4+/CD8+ T cell ratio, level of IL-10. Additionally, RNA-seq analysis revealed that the differentially expressed genes among HIIT, MOD, and MCAO groups were highly associated with signaling pathways involved in inflammatory response, more specifically the I-kappaB kinase/NF-kappaB signaling. Following the outcome, we further investigated the infiltrating immune cells abundant in paretic muscles. The results showed that HIIT modulated macrophage activation by downregulating CD86+ (M1 type) macrophages and upregulating CD163+ (M2 type) macrophages via inhibiting the TLR4/MyD88/NFκB signaling pathway and exerting an anti-inflammatory effect in paretic skeletal muscle. It is expected that these data will provide novel insights into the mechanisms and potential targets underlying muscle wasting in stroke.

Cognitive Function, Sarcopenia, and Inflammation Are Strongly Associated with Frailty: A Framingham Cohort Study

BACKGROUND

Frailty is an important contributor to morbidity and mortality in chronic liver disease. Understanding the contributors to frailty has the potential to identify individuals at risk for frailty and may potentially provide targets for frailty-modifying interventions. We evaluated the relationship among cognitive function, inflammation, and sarcopenia and frailty.

METHODS

Using cohorts from the Framingham Heart Study (2011-2014), we evaluated for factors associated with frailty. Exposures included cognitive tests (combined Trails A/B test, Animal Naming Test, and combined Digit Span Forward/Backward test), inflammation (interleukin-6 and tumor necrosis factor receptor II), and sarcopenia (creatinine-to-cystatin C ratio). We performed linear and logistic regression to identify the relationship between these exposures and the Liver Frailty Index (LFI).

RESULTS

The study population (N = 1208) had a median age of 70 years, was 56% female, and 48.5% had evidence of liver disease. The combined Trails A/B test (β 0.05, P < .001), creatinine-to-cystatin C (β -0.17, P = .006), and both inflammatory markers, interleukin-6 levels (β 0.16, P = .002) and tumor necrosis factor receptor II (β 0.21, P = .04), were independently associated with the LFI. Using an LFI cutoff of ≥4.5 to define frailty, Trails A/B (odds ratio [OR] 1.21, 95% confidence interval [CI] 1.07-1.37), Animal Naming Test (OR 0.64, 95% CI 0.42-0.97), sarcopenia (OR 0.10, 95% CI 0.01-0.73), and interleukin-6 (OR 4.99, 95% CI 1.03-15.53) were all associated with frailty. Although liver disease did not modify the relationship between the LFI and the Trails A/B test, interleukin-6 was significantly associated with the LFI only in the presence of liver disease.

CONCLUSIONS

Cognitive performance, inflammation, and sarcopenia, each highly prevalent in cirrhosis, are associated with the LFI in this population-based study of persons without cirrhosis. Further research is warranted for interventions aiming to prevent frailty by tailoring their approach to the patient's underlying risk factors.

Inflammatory markers are associated with quality of life, physical activity, and gait speed but not sarcopenia in aged men (40-79 years)

BACKGROUND

Age-related chronic low-grade inflammation (inflammaging) is one of the proposed mechanisms behind sarcopenia. However, findings regarding inflammatory markers in sarcopenic older adults are conflicting. This study aimed to determine the association between inflammatory markers, prevalent as well as incident sarcopenia, sarcopenia-defining parameters, quality of life (QoL), and physical activity in middle-aged and older men.

METHODS

Men aged 40-79 years (mean 59.66 ± 11.00y) were recruited from population registers in eight European centres for participation in the European Male Aging study (EMAS). Subjects were assessed at baseline (2003-2005) and again after a median follow-up of 4.29 years. In 2577 participants, associations between baseline inflammatory markers [high-sensitive C-reactive protein (hs-CRP), white blood cell count (WBC), albumin] and baseline physical activity (PASE) and QoL (SF-36) were analysed. In the Leuven and Manchester cohort (n = 447), data were available on muscle mass (whole-body dual X-ray absorptiometry) and strength. In this subgroup, cross-sectional associations between baseline inflammatory markers and sarcopenia-defining parameters (handgrip strength, chair stand test, appendicular lean mass, and gait speed) and prevalent sarcopenia were examined. In a further subgroup (n = 277), associations with knee extensor strength were explored. Longitudinally, predictive value of baseline inflammation on functional decline, physical activity, QoL, and incident sarcopenia was examined. Subgroup analyses were performed in subgroups with chronic inflammation and stratified by age. Linear and logistic regressions were used, adjusted for age, body mass index, centre, and smoking.

RESULTS

At baseline, hs-CRP and WBC were negatively associated with PASE score (hs-CRP: β = -7.920, P < 0.001; and WBC: β = -4.552, P < 0.001) and the physical component score of SF-36 (hs-CRP: β = -1.025, P < 0.001; and WBC: β = -0.364, P < 0.001). Baseline WBC levels were negatively associated with gait speed (β = -0.013; P = 0.025), quadriceps isometric 90° (β = -5.983; P = 0.035) and isokinetic 60°/s peak torque/body weight (β = -5.532; P = 0.027). The prevalence of sarcopenia at baseline was 18.1% (n = 81). Of those without sarcopenia at baseline, 64 (18.6%) satisfied criteria for sarcopenia at follow-up. There were no significant associations between baseline inflammatory markers and either prevalent or incident sarcopenia, or change in level of sarcopenia-defining parameters between baseline and follow-up.

CONCLUSIONS

In middle-aged and older men, hs-CRP and WBC were negatively associated with QoL and PASE scores, while WBC was negatively associated with gait speed and knee strength. Associations with hs-CRP remained significant in all ages, whereas WBC levels were only associated with PASE, gait speed and knee strength in older adults (60-79 years). Baseline inflammatory markers (hs-CRP, WBC and albumin) did not predict functional decline, decline in physical activity, decreased QoL or incident sarcopenia.

Gintonin-enriched fraction improves sarcopenia by maintaining immune homeostasis in 20- to 24-month-old C57BL/6J mice

Background

Gintonin-enriched fraction (GEF) is a new non-saponin component glycolipoprotein isolated from ginseng root. This study examined the effect of GEF on age-related sarcopenia in old C57BL/6J mice.

Methods

Young (3–6 months) and old (20–24 months) C57BL/6J mice received oral GEF (50 mg/kg/day or 150 mg/kg/day) daily for 5 weeks. During the oral administration period, body weight and grip strength were measured weekly. After sacrifice, muscles from the hindlimb were excised and used for hematoxylin and eosin staining and western blotting to determine the effects of GEF on sarcopenia. The thymus was photographed to compare size, and flow cytometry was performed to examine the effect of GEF on immune homeostasis in the thymus and spleen. Blood samples were collected, and the concentrations of pro-inflammatory cytokines and IGF-1 were measured.

Results

GEF caused a significant increase in muscle strength, mass, and fiber size in old mice. GEF restored age-related disruption of immune homeostasis by maintaining T cell compartments and regulating inflammatory biomarkers. Thus, GEF reduced common low-grade chronic inflammatory parameters, which are the main cause of muscle loss.

Conclusion

GEF maintained immune homeostasis and inhibited markers of chronic inflammation, resulting in anti-sarcopenia effects in aged C57BL/6J mice. Thus, GEF is a potential therapeutic agent that slows sarcopenia in the elderly.