Association of serum iron metabolism with muscle mass and frailty in older adults: A cross-sectional study of community-dwelling older adults.

This study aimed to explore the correlation between serum ferritin and additional biomarkers associated with iron metabolism, as well as their connection to muscle atrophy and frailty in the community-dwelling middle-aged and elderly population. The study included 110 middle-aged and elderly participants. Participants were categorized into an iron accumulation group (31 cases) and a normal iron group (79 cases) based on the standard ferritin values for men and women. Based on the criteria of the Asian Working Group on Muscular Dystrophy, participants were classified into a sarcopenia group (31 cases) and a non-sarcopenia group (79 cases). Using the Fried frailty syndrome criteria, participants were categorized into non-frailty (7 cases), pre-frailty (50 cases), and frailty (53 cases) groups. We employed multiple linear regression, binary logistic regression, partial correlation analysis, and ordinal logistic regression to assess the associations between iron metabolism indices and the presence of muscle atrophy and frailty. Compared with the normal iron group, the iron overload group had significantly higher ferritin, weight loss, fatigue, slow gait, and frailty scores (P < .05). Among the 3 models we set, ferritin was not significantly correlated with muscle mass in models 1 and 3 (P > .05), ferritin was positively correlated with muscle mass in model 2 (Pmodel2 = .048), but Transferrin saturation was positively correlated with muscle mass in all 3 models (Pmodel1 = .047, Pmodel2 = .026, Pmodel3 = .024). Ferritin, body mass index and iron overload were the influencing factors of sarcopenia (Pferritin = .027, PBMI < .001, Piron overload = .028). Ferritin was positively correlated with weight loss, fatigue, slow gait, frailty score, and frailty grade (P < .05). Age, gender and ferritin were the influencing factors of frailty classification (P < .05). Disrupted iron metabolism can lead to decreased muscle mass and function among the middle-aged and elderly, increasing frailty risk. It's crucial to prioritize community-based frailty screening and prevention, focusing on iron utilization as well as storage, since accelerating the body's iron metabolism cycle might influence muscle health more significantly than iron reserves.

Adipokines and Myokines as Markers of Malnutrition and Sarcopenia in Patients Receiving Kidney Replacement Therapy: An Observational, Cross-Sectional Study.

Chronic kidney disease (CKD) is linked to an elevated risk of malnutrition and sarcopenia, contributing to the intricate network of CKD-related metabolic disorders. Adipokines and myokines are markers and effectors of sarcopenia and nutritional status. The aim of this study was to assess whether the adipokine-myokine signature in patients on kidney replacement therapy could help identify malnutrition and sarcopenia. The study involved three groups: 84 hemodialysis (HD) patients, 44 peritoneal dialysis (PD) patients, and 52 kidney transplant recipients (KTR). Mean age was 56.1 ± 16.3 years. Malnutrition was defined using the 7-Point Subjective Global Assessment (SGA) and the Malnutrition-Inflammation Score (MIS). Sarcopenia was diagnosed based on reduced handgrip strength (HGS) and diminished muscle mass. Concentrations of adipokines and myokines were determined using the enzyme-linked immunosorbent assay (ELISA). 32.8% of all study participants were identified as malnourished and 20.6% had sarcopenia. For malnutrition, assessed using the 7-Point SGA, in ROC analysis albumin (area under the curve (AUC) 0.67 was the best single biomarker identified. In dialysis patients, myostatin (AUC 0.79) and IL-6 (AUC 0.67) had a high discrimination value for sarcopenia, and we were able to develop a prediction model for sarcopenia, including age, albumin, adiponectin, and myostatin levels, with an AUC of 0.806 (95% CI: 0.721-0.891). Adipokines and myokines appear to be useful laboratory markers for assessing malnutrition and sarcopenia. The formula we propose could contribute to a better understanding of sarcopenia and potentially lead to more effective interventions and management strategies for dialysis patients.

Association between non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio and sarcopenia in individuals with cancer: a cross-sectional study.

BACKGROUND: Cancer and sarcopenia are both closely related to lipid metabolism, but the relationship between lipid metabolism and patients with cancer and sarcopenia has not been thoroughly studied. The non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) is a reliable measure of lipid metabolism. The purpose of this study was to determine the possible relationship between the NHHR and sarcopenia in individuals with cancer. METHODS: Data from the National Health and Nutrition Examination Survey (NHANES) database for individuals with cancer, with and without sarcopenia was analyzed using weighted multiple regression equations, weighted regression cubic spline (RCS) analysis, and weighted subgroup analysis. RESULTS: In total, 1,602 individuals with cancer were included, of whom 17.1% had sarcopenia. In Adjusted Model 2, the occurrence of sarcopenia was found to be significantly associated with a higher NHHR in cancer (95% confidence interval [CI]:1.01-1.39, P = 0.036). Individuals with high a NHHR had a 2.09-fold higher risk of developing sarcopenia in comparison to those with a low NHHR (95% CI:1.12-3.92, P = 0.022). RCS analysis further identified a U-shaped non-linear relationship between females with cancer and the muscle index. Subgroup analysis indicated that sex was a significant stratifying factor, whereas age, race, marital status, smoking and drinking habits, and history of cardiovascular disease, arthritis, hypertension, and diabetes had no significant impact. CONCLUSION: From the perspective of lipid metabolism, the NHHR may serve as an indicator for monitoring and preventing the occurrence of sarcopenia in individuals with cancer, particularly for females with cancer who appear to have greater sensitivity.

Metabolic signatures and risk of sarcopenia in suburb-dwelling older individuals by LC-MS-based untargeted metabonomics.

Background: Untargeted metabonomics has provided new insight into the pathogenesis of sarcopenia. In this study, we explored plasma metabolic signatures linked to a heightened risk of sarcopenia in a cohort study by LC-MS-based untargeted metabonomics. Methods: In this nested case-control study from the Adult Physical Fitness and Health Cohort Study (APFHCS), we collected blood plasma samples from 30 new-onset sarcopenia subjects (mean age 73.2 ± 5.6 years) and 30 healthy controls (mean age 74.2 ± 4.6 years) matched by age, sex, BMI, lifestyle, and comorbidities. An untargeted metabolomics methodology was employed to discern the metabolomic profile alterations present in individuals exhibiting newly diagnosed sarcopenia. Results: In comparing individuals with new-onset sarcopenia to normal controls, a comprehensive analysis using liquid chromatography-mass spectrometry (LC-MS) identified a total of 62 metabolites, predominantly comprising lipids, lipid-like molecules, organic acids, and derivatives. Receiver operating characteristic (ROC) curve analysis indicated that the three metabolites hypoxanthine (AUC=0.819, 95% CI=0.711-0.927), L-2-amino-3-oxobutanoic acid (AUC=0.733, 95% CI=0.598-0.868) and PC(14:0/20:2(11Z,14Z)) (AUC= 0.717, 95% CI=0.587-0.846) had the highest areas under the curve. Then, these significant metabolites were observed to be notably enriched in four distinct metabolic pathways, namely, "purine metabolism"; "parathyroid hormone synthesis, secretion and action"; "choline metabolism in cancer"; and "tuberculosis". Conclusion: The current investigation elucidates the metabolic perturbations observed in individuals diagnosed with sarcopenia. The identified metabolites hold promise as potential biomarkers, offering avenues for exploring the underlying pathological mechanisms associated with sarcopenia.

Cystatin C and sarcopenia index are associated with cardiovascular and all-cause death among adults in the United States.

OBJECTIVES: This study aimed to investigate the association of cystatin C, serum creatinine and sarcopenia index with cardiovascular and all-cause death in general population. METHODS: Data of participants from the National Health and Nutrition Examination Surveys (NHANES) from 1999 to 2004 were used and all participants were followed up regularly until December 31, 2019. Multivariable Cox analysis was used to investigate the association of cystatin C, serum creatinine and sarcopenia index with cardiovascular and all-cause death. Restricted cubic spline was conducted to evaluate the nonlinear association. RESULTS: A total of 9894 participants with a mean age of 45.64 years were enrolled and followed up for a mean duration of 15.62 ± 4.68 years. Approximately 50.3% were male and there were a total of 2681 all-cause deaths and 691 cardiovascular deaths recorded during the follow-up period. In final adjusted model, compared with the first quartile of cystatin C (< 0.659 mg/L), the risk of cardiovascular and all-cause death increased 2.36-fold and 1.71-fold for participants in the fourth quartile (≥ 0.877 mg/L) (HR: 3.36, 95% CI: 2.06-5.46, P < 0.001; HR: 2.71, 95% CI: 2.17-3.38, P < 0.001; respectively). Furthermore, a higher sarcopenia index (< 88.41 vs. ≥125.52) was associated with the reduced risk of cardiovascular death (HR: 0.41, 95% CI: 0.31-0.53, P < 0.001) as well as all-cause death (HR: 0.41, 95% CI: 0.35-0.49, P < 0.001). Additionally, restricted cubic splines showed that there was a nonlinear relationship between sarcopenia index levels and all-cause death while there was a linear relationship between sarcopenia index levels and cardiovascular death. CONCLUSIONS: Higher sarcopenia index was associated with the decreased risk of cardiovascular and all-cause death in general population in the United States. Elevated cystatin C was positively associated with cardiovascular and all-cause death.

Association between systemic immune-inflammation index and sarcopenic obesity in middle-aged and elderly Chinese adults: a cross-sectional study and mediation analysis.

BACKGROUND: Despite the known association between chronic inflammation and reduced muscle mass, there is a gap in research regarding the association between the systemic immune-inflammation index (SII) and sarcopenic obesity (SO). This study aims to assess the relationship between SII and SO in middle-aged and elderly adults and the mediating role of triglyceride-glucose index (TyG). METHODS: This cross-sectional study involved 2,719 participants aged 45-90 years who underwent health check-ups. SO was evaluated by combining sarcopenia [assessed by handgrip strength and appendicular skeletal muscle index (ASMI)] with obesity (determined by body fat percentage). Association between SII and SO, sarcopenia, and obesity in middle-aged and elderly individuals was examined using multivariable logistic regression, restricted cubic spline analysis, and subgroup analysis. Bidirectional mediation analysis was conducted to determine the direct and indirect effects through SII and TyG. RESULTS: The study included 2,719 participants, of which 228 had SO (8.4%). SO prevalence increased as the SII quartiles rose (Pfor trend <0.001). SII (per SD increase) had a significantly positive association with SO in both middle-aged individuals (OR = 1.69, 95% CI: 1.43 ~ 1.99) and older adults (OR = 2.52, 95% CI: 1.68 ~ 3.77). The relationship between SII and SO was found to be non-linear (Pnonlinear<0.05). In addition, SII showed a strong negative relationship with both handgrip strength and ASMI across all participants. In subgroup analysis, SII was still shown to significantly increase the risk of SO in all subgroups by gender, body mass index, waist circumference, smoking, drinking, hypertension, diabetes, dyslipidemia. TyG was found to mediate 21.36%, 11.78%, and 9.94% of the associations between SII and SO, sarcopenia, and obesity, respectively. SII had no mediation effect on the association between TyG and SO, sarcopenia, and obesity (P>0.05). CONCLUSIONS: Elevated levels of SII were associated with an increased risk of SO in middle-aged and elderly adults, especially in the elderly population, and elevated TyG levels played a role in this relationship.

Lower serum creatinine to cystatin C ratio associated with increased incidence of frailty in community-dwelling elderly men but not in elderly women.

BACKGROUND: Sarcopenia has been reported to play an important role in frailty syndrome. The serum creatinine/serum cystatin C ratio (Scr/Cys C ratio) has recently been recognized as a valuable indicator for assessing sarcopenia. However, few studies have examined the association between serum creatinine/serum cystatin C ratio and frailty. The objective of this study is to investigate the relationship between the serum creatinine/serum cystatin C ratio and frailty among older adults residing in the community. METHODS AND MATERIALS: A Total of 1926 community-dwelling older adults aged ≥ 60 years in the 2011 waves of the China Health and Retirement Longitudinal Study (CHARLS) were included. The participants' frailty status was determined using a 39 item frailty index (FI), which classified individuals as "robust" (FI ≤ 0.1), "pre-frailty" (0.1 < FI < 0.25), or "frailty" (FI ≥ 0.25). The Scr/Cys C ratio was determined by dividing the serum creatinine level (mg/dL) by the cystatin C level (mg/L). The one-way analysis of variance(ANOVA) and Chi-squared test (χ2)were applied to compare the differences between the 3 groups. Both linear regression and logistic regression models were used to further investigate the relationship between Scr/Cys C ratio and frailty. RESULTS: After adjusting for potential confounding factors, the study revealed that participants in the Q1 quartile of Scr/Cys C ratio had increased odds of frailty (Q1vs.Q4: OR = 1.880, 95% CI 1.126-3.139, p = 0.016) compared with those in the Q4 quartile group. In fully adjusted logistic regression models, male participants in the Q2 quartile of Scr/Cys C ratio were significantly correlated with higher odds of pre-frailty (Q2 vs.Q4: OR = 1.693, 95%CI 1.040-2.758, p = 0.034). However, this correlation was not observed in females (OR = 0.984, 95% CI 0.589-1.642, p = 0.950,). Additionally, the study observed an increase in both the frailty index and the incidence of frailty as age increased in both males and females. CONCLUSION: Among community-dwelling older adults, lower Serum creatinine to cystatin C ratio were found to be associated with increased odds of frailty prevalence in males.

Clinical significance and normal reference value of serum creatinine to cystatin C ratio in children.

BACKGROUND & AIMS: Sarcopenia is a serious problem in adults and children. However, limited modalities are available for diagnosing pediatric sarcopenia. The serum creatinine to cystatin C ratio (Cre/CysC ratio) is a promising method for muscle quantification, although its clinical significance in the pediatric population is unknown. This study aimed to evaluate the relationship between the Cre/CysC ratio and physical performance. METHODS: This was a single-center retrospective study. Patients aged <15 years who had visited the University of Tokyo Hospital for measurements of serum creatinine and cystatin C levels, body height, and body weight were included. The patients were assigned according to their age (<2 or ≥2 years), and the relationship between the Cre/CysC ratio and physical performance at the time of measurement was analyzed. RESULTS: We included 266 patients, revealing a significant relationship between Cre/CysC ratio and physical performance in children aged ≥2 years (p < 0.001) but not in children aged <2 years (p = 0.42). The repeater-operator curve analysis of Cre/CysC to predict bedridden status showed good performance (the area under the curve was 0.82 (95% CI, 0.75-0.89)) and the cut-off value 0.44 had good accuracy (sensitivity 0.87, specificity 0.61). CONCLUSIONS: The Cre/CysC ratio was a significant marker of impaired physical performance, and a Cre/CysC ratio <0.44 accurately predicted bedridden status in children aged >2 years.

GDF-15 is associated with sarcopenia and frailty in acutely admitted older medical patients.

BACKGROUND: Growth differentiation factor-15 (GDF-15) has been associated with senescence, lower muscle strength, and physical performance in healthy older people. Still, it is not clear whether GDF-15 can be utilized as a biomarker of sarcopenia and frailty in the early stages of hospitalization. We investigated the association of plasma GDF-15 with sarcopenia and frailty in older, acutely admitted medical patients. METHODS: The present study is based on secondary analyses of cross-sectional data from the Copenhagen PROTECT study, a prospective cohort study including 1071 patients ≥65 years of age admitted to the acute medical ward at Copenhagen University Hospital, Bispebjerg, Denmark. Muscle strength was assessed using handgrip strength, and lean mass was assessed using direct segmental multifrequency bioelectrical impedance analyses and used to clarify the potential presence of sarcopenia defined according to guidelines from the European Working Group on Sarcopenia in Older People. Frailty was evaluated using the Clinical Frailty Scale. Plasma GDF-15 was measured using electrochemiluminescence assays from Meso Scale Discovery (MSD, Rockville, MD, USA). RESULTS: We included 1036 patients with completed blood samples (mean age 78.9 ± 7.8 years, 53% female). The median concentration of GDF-15 was 2669.3 pg/mL. Systemic GDF-15 was significantly higher in patients with either sarcopenia (P < 0.01) or frailty (P < 0.001) compared with patients without the conditions. Optimum cut-off points of GDF-15 relating to sarcopenia and frailty were 1541 and 2166 pg/mL, respectively. CONCLUSIONS: Systemic GDF-15 was higher in acutely admitted older medical patients with sarcopenia and frailty compared with patients without. The present study defined the optimum cut-off for GDF-15, related to the presence of sarcopenia and frailty, respectively. When elevated above the derived cutoffs, GDF-15 was strongly associated with frailty and sarcopenia in both crude and fully adjusted models.

Plasma C-terminal agrin fragment concentrations across adulthood: Reference values and associations with skeletal muscle health.

BACKGROUND: Increasing interest surrounds the utility of blood-based biomarkers for diagnosing sarcopenia. C-terminal agrin fragment (CAF), a marker of neuromuscular junction stability, is amongst the most promising candidates; however, a dearth of reference data impedes the incorporation of its use in public health settings. This study aimed to establish reference values for plasma CAF concentrations across adulthood in a large, well-characterized cohort of healthy adults; and comprehensively examine the association between plasma CAF levels and skeletal muscle health. METHODS: One thousand people aged between 18 and 87 years took part in this study (mean age = 50.4 years; 51% females). Body composition and muscle strength were examined using DXA and hand dynamometry. Plasma CAF concentrations were measured, in duplicate, using commercially available ELISA kits. Sarcopenia and individual sarcopenia signatures [low skeletal muscle index (SMI) only/low grip strength only] were classified using the EWGSOP2 algorithm. RESULTS: Detailed reference CAF values, according to sex and age, are presented. A significant but modest age-related increase in plasma CAF concentration was observed (P = 0.018). Across adulthood, CAF concentrations were negatively associated with grip strength and SMI (both P < 0.001). In people ≥50 years old, CAF concentrations were 22.6% higher in those with sarcopenia (P < 0.001), 11.3% higher in those with low SMI (P = 0.006) and 9.6% higher in those with low grip strength (P = 0.0034), compared with controls. People in the highest CAF concentration quartile, had 3.25 greater odds for sarcopenia (95% CI = 1.41-7.49, P = 0.005), 2.76 greater odds for low SMI (95% CI = 1.24-5.22, P = 0.012), and 2.56 greater odds for low grip strength (95% CI = 1.07-5.57, P = 0.037), compared with those in the lowest quartile. People with a CAF Z-score ≥2 had 9.52 greater odds for sarcopenia (95% CI = 3.01-30.05, P < 0.001) compared with a Z-score <1. Plasma CAF concentration had an acceptable level of diagnostic accuracy for sarcopenia (AUC = 0.772, 95% CI = 0.733-0.807, P < 0.001). CONCLUSIONS: The reference values presented herein may guide the clinical interpretation of circulating CAF and help identify people at risk of poor skeletal muscle outcomes for inclusion in therapeutic interventions. Our findings add clarity to existing data, demonstrating a robust relationship between circulating CAF and skeletal muscle integrity in the largest adult cohort to date, and support the use of CAF as an accessible, cost-effective screening tool for sarcopenia. However, further research into the prognostic utility of plasma CAF, and the establishment of normative data from other populations, are urgently needed if routine CAF screening is to be embedded into public healthcare settings.

Exploring the impact of interleukins on sarcopenia development: A systematic review and meta-analysis.

BACKGROUND: The role of interleukins in sarcopenia development has been acknowledged, yet the specifics of their involvement remain to be fully understood. This study aimed to explore alterations in interleukin levels among sarcopenia patients. METHODS: Searches were conducted in Embase, Medline, and the Cochrane Library for literature published up to May 2023. Eligible observational studies with a diagnosis of sarcopenia were included. The Newcastle-Ottawa Scale was utilized for quality assessment. For data synthesis, a random-effects model was used, and the Mantel-Haenszel method was used for pooled estimates. RESULTS: Of the 7685 articles screened, 37 met the inclusion criteria. Statistically significant differences in the levels of IL-1ß, IL-6 and IL-10 were detected in sarcopenia patients. Specifically, IL-1ß (95 % CI: 0.33 [0.12, 0.54], P < 0.05), IL-6 (95 % CI: 0.91 [0.59, 1.24], P < 0.05), and IL-10 (95 % CI: 0.11 [0.07,0.15], P < 0.05) were detected. However, no significant associations were found between serum IL-4 (95 % CI: 0.36 [-0.18, 0.42], P = 0.44), IL-8 (95 % CI: -1.05 [-3.06, 0.95], P = 0.3), IL-12 (95 % CI: -3.92 [-8.32,0.48], P = 0.08) or IL-17 (95 % CI: 0.22 [-2.43, 2.88], P = 0.87) and sarcopenia. Subgroup analysis showed no significant difference in IL-6 (95 % CI: -0.03 [-0.72, 0.66], P = 0.93) and IL-10 (95 % CI: 0.1 [-0.44, 0.64], P = 0.72) among patients with European standard sarcopenia. CONCLUSIONS: Inflammation plays a role in sarcopenia, and the serum levels of IL-1ß, IL-6, and IL-10 are associated with sarcopenia. Further research is needed to clarify these associations. CLINICAL TRIALS REGISTRATION NUMBER: CRD42024506656.

Effectiveness of resistance training in modulating inflammatory biomarkers among Asian patients with sarcopenia: a systematic review and meta-analysis of randomized controlled trials.

Objective: Given the high incidence of sarcopenia among Asians, it is imperative to identify appropriate intervention methods. The International Clinical Practice Guidelines for Sarcopenia, developed by the International Conference on Sarcopenia and Frailty Research (ICFSR) task force, recommends resistance training (RT) as a primary treatment for managing sarcopenia. Inflammatory biomarkers serve as indicators of sarcopenia. However, there is currently insufficient conclusive evidence regarding the effectiveness of RT in modulating inflammatory biomarker levels among Asian participants with sarcopenia. Data sources: Four databases were utilized for this study until October 9, 2023. This study focused on randomized controlled trials (RCTs) that examined the effects of RT on interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), and interleukin-10 (IL-10) about sarcopenia. This study has been registered in the PROSPERO database (CRD42024501855). Results: The meta-analysis included six studies from Asians involving 278 participants. The results showed a significant decrease in RT for IL-6 (weighted mean difference (WMD) = -0.73, 95% confidence interval (CI) = -1.02 to -0.44; n=5). However, no significant differences were found for TNF-α (WMD = -1.00, 95% CI = -2.47 to 0.46; n=5), CRP (WMD = -0.45, 95% CI = -1.14 to 0.23; n=3), and IL-10 (WMD = 0.13, 95% CI = -3.99 to 4.25; n=2). Subgroup analysis revealed that factors including gender selection, intervention methods, frequency, period, and duration could have a particular effect on the part of inflammatory biomarkers. Conclusion: RT has been shown to reduce part of the level of inflammatory markers, specifically IL-6, in Asian sarcopenia participants. However, other inflammatory factors, such as TNF-α, CRP, and IL-10, did not show significant changes. Further research should confirm the impact of RT on these indicators and explore the potential effects of various factors on different inflammatory markers, such as diet, body composition, and medications. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=501855, identifier CRD42024501855.

Combination of sarcopenia and systemic inflammation-based markers for predicting the prognosis of patients undergoing pancreaticoduodenectomy for pancreatic cancer.

BACKGROUND: This study aimed to evaluate the effects of sarcopenia and inflammation on the prognosis of patients with pancreatic cancer after pancreaticoduodenectomy. METHODS: Eighty patients who had undergone pancreaticoduodenectomy for pancreatic cancer between July 2010 and December 2023 were included in this study. The psoas muscle index was used to assess sarcopenia. The C-reactive protein-to-albumin ratio, prognostic nutritional index, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio were used to calculate the preoperative inflammatory marker levels. The prognostic factors for overall survival were determined using Cox regression analysis. RESULTS: Twenty-four patients were diagnosed with sarcopenia. Sarcopenia showed a significant association with advanced tumor stage. Univariate analysis revealed a significant reduction in overall survival in patients with a prognostic nutritional index of <45, C-reactive protein-to-albumin ratio of ≥0.047, cancer antigen 19-9 levels of ≥130 U/mL, sarcopenia, lymph node metastasis, and vascular invasion. Multivariate analysis revealed that a C-reactive protein-to-albumin ratio of ≥0.047 (hazards ratio, 3.383; 95% confidence interval: 1.384-8.689; p< 0.001), cancer antigen 19-9 levels of ≥130 U/mL (hazards ratio, 2.720; 95% confidence interval: 1.291-6.060; p = 0.008), sarcopenia (hazards ratio, 3.256; 95% confidence interval: 1.535-7.072; p = 0.002) and vascular invasion (hazards ratio, 2.092; 95% confidence interval: 1.057-4.170; p = 0.034) were independent predictors of overall survival. Overall survival in the sarcopenia and high C-reactive protein-to-albumin ratio groups was significantly poorer than that in the non-sarcopenia and low C-reactive protein-to-albumin ratio and sarcopenia or high C-reactive protein-to-albumin ratio groups. CONCLUSION: Sarcopenia and a high C-reactive protein-to-albumin ratio are independent prognostic factors in patients with pancreatic cancer after pancreaticoduodenectomy. Thus, sarcopenia may have a better prognostic value when combined with the C-reactive protein-to-albumin ratio.

Circulating myostatin as a biomarker of muscle mass and strength in individuals with cancer or obesity.

BACKGROUND & AIMS: Our study aims to determine whether myostatin (MSTN) is associated with muscle mass and strength in individuals with cancer or obesity, as well as with cancer cachexia (CC) or sarcopenic obesity (SO). METHODS: The ACTICA study included individuals with CC (n = 70) or without CC (NC, n = 73). The MYDIASECRET study included individuals with obesity evaluated before (T0) and 3 months (T3) after bariatric surgery (n = 62). Body composition was assessed using bioelectrical impedance analysis (BIA). Skeletal muscle mass (SMM) and appendicular SMM (ASMM) were calculated from Janssen's and Sergi's equations, respectively, and expressed as indexes (SMMI and ASMMI). Handgrip strength (HGS) was assessed using a Jamar hand-held dynamometer. MSTN plasma levels were measured using ELISA. Spearman's coefficient was used to correlate MSTN with muscle mass and strength. Receiver operating characteristic (ROC) curve analysis was performed to identify an optimal MSTN cutoff level for the prediction of CC or SO. RESULTS: In the ACTICA study, muscle mass and strength were lower in CC individuals than in NC individuals (SMMI: 8.0 kg/m2vs 9.0 kg/m2, p = 0.004; ASMMI: 6.2 kg/m2vs 7.2 kg/m2, p < 0.001; HGS: 28 kg vs 38 kg, p < 0.001). MSTN was also lower in CC individuals than in NC individuals (1434 pg/mL vs 2149 pg/mL, p < 0.001). Muscle mass and strength were positively correlated with MSTN (SMMI: R = 0.500, p < 0.001; ASMMI: R = 0.479, p < 0.001; HGS: R = 0.495, p < 0.001). ROC curve analysis showed a MSTN cutoff level of 1548 pg/mL (AUC 0.684, sensitivity 57%, specificity 75%, p < 0.001) for the prediction of CC. In the MYDIASECRET study, muscle mass and strength were reduced at T3 (SMMI: -8%, p < 0.001; ASMMI: -12%, p < 0.001; HGS: -6%, p = 0.005). MSTN was also reduced at T3 (1773 pg/mL vs 2582 pg/mL, p < 0.001). Muscle mass and strength were positively correlated with MSTN at T0 and T3 (SMMI-T0: R = 0.388, p = 0.002; SMMI-T3: R = 0.435, p < 0.001; HGS-T0: R = 0.337, p = 0.007; HGS-T3: R = 0.313, p = 0.013). ROC curve analysis showed a MSTN cutoff level of 4225 pg/mL (AUC 0.835, sensitivity 98%, specificity 100%, p = 0.014) for the prediction of SO at T3. CONCLUSIONS: MSTN is positively correlated with muscle mass and strength in individuals with cancer or obesity, suggesting its potential use as a biomarker of muscle mass and strength. The ROC curve analysis suggests the potential use of MSTN as a screening tool for CC and SO.

Serum iron level is independently associated with sarcopenia: a retrospective study.

Sarcopenia greatly reduces the quality of life of the elderly, and iron metabolism plays an important role in muscle loss. This study aimed to investigate the association between iron status and sarcopenia. A total of 286 adult patients hospitalized between 2019 and 2021 were included in this study, of which 117 were diagnosed with sarcopenia. Serum iron, total iron binding capacity (TIBC), transferrin, and transferrin saturation levels were compared between groups with and without sarcopenia and were included in the logistic analyses, with significant variables further included in the logistic regression model for the prediction of sarcopenia. Serum iron, TIBC, and transferrin levels decreased significantly in the sarcopenia group (p < 0.05), and were negatively associated with handgrip strength, relative skeletal muscle index, and multiple test performances (p < 0.05). Multivariate logistic analysis showed that sex, age, body mass index (BMI), and serum iron level were independent risk factors for sarcopenia. In the final logistic regression model, male sex (odds ratio [OR] 3.65, 95% confidence interval [CI] 1.67-7.98), age > 65 years (OR 5.40, 95% CI 2.25-12.95), BMI < 24 kg/m2 (OR 0.17, 95% CI 0.08-0.36), and serum iron < 10.95 µmol/L (OR 0.39, 95% CI 0.16-0.93) were included. Our study supported the impact of iron metabolism on muscle strength and performance.

Impact of the serum creatinine and cystatin C ratio for prediction of sarcopenia and prognosis in biliary tract cancer.

BACKGROUND: Sarcopenia is a poor prognostic factor in cancer patients. In recent years, there have been reports that serum creatinine and cystatin C (Cr/CysC) ratio is associated with sarcopenia. However, the prognostic value of the Cr/CysC ratio in biliary tract cancer is unclear. We evaluated the impact of the Cr/CysC ratio on sarcopenia and prognosis in biliary tract cancer. METHODS: We retrospectively reviewed the records of 190 patients with biliary tract cancer who had undergone surgical resection from January 2017 to March 2023. Frozen serum samples collected at the time of surgery were used to measure CysC. We calculated the Cr/CysC ratio and investigated the relationship with sarcopenia and the prognostic significance. RESULTS: We calculated the cutoff value of the Cr/CysC ratio for low skeletal muscle index (SMI) (< 42 cm2/m2 for males and < 38 cm2/m2 for females). The optimal cutoff value of the Cr/CysC ratio was 0.848. The low Cr/CysC ratio group was significantly associated with higher preoperative CRP and lower albumin, lower SMI, lower handgrip strength, and higher intramuscular adipose tissue content. In multivariate analysis, patients with a low Cr/CysC ratio showed poorer overall survival (hazard ratio 2.60, 95% confidence interval 1.07-6.29, p = 0.033), which was significantly worse than in those with a high Cr/CysC ratio. CONCLUSIONS: In patients with biliary tract cancer, the Cr/CysC ratio showed weak correlation with sarcopenic indicators. However, the Cr/CysC ratio could be strong prognostic factor in biliary tract cancer.

Iron status and sarcopenia-related traits: a bi-directional Mendelian randomization study.

Although serum iron status and sarcopenia are closely linked, the presence of comprehensive evidence to establish a causal relationship between them remains insufficient. The objective of this study is to employ Mendelian randomization techniques to clarify the association between serum iron status and sarcopenia. We conducted a bi-directional Mendelian randomization (MR) analysis to investigate the potential causal relationship between iron status and sarcopenia. MR analyses were performed using inverse variance weighted (IVW), MR-Egger, and weighted median methods. Additionally, sensitivity analyses were conducted to verify the reliability of the causal association results. Then, we harvested a combination of SNPs as an integrated proxy for iron status to perform a MVMR analysis based on IVW MVMR model. UVMR analyses based on IVW method identified causal effect of ferritin on appendicular lean mass (ALM, ß = - 0.051, 95% CI - 0.072, - 0.031, p = 7.325 × 10-07). Sensitivity analyses did not detect pleiotropic effects or result fluctuation by outlying SNPs in the effect estimates of four iron status on sarcopenia-related traits. After adjusting for PA, the analysis still revealed that each standard deviation higher genetically predicted ferritin was associated with lower ALM (ß = - 0.054, 95% CI - 0.092, - 0.015, p = 0.006). Further, MVMR analyses determined a predominant role of ferritin (ß = - 0.068, 95% CI - 0.12, - 0.017, p = 9.658 × 10-03) in the associations of iron status with ALM. Our study revealed a causal association between serum iron status and sarcopenia, with ferritin playing a key role in this relationship. These findings contribute to our understanding of the complex interplay between iron metabolism and muscle health.

Effect of whole-body vibration stimulation on plasma soluble TNF receptors in elderly with sarcopenia: a randomized controlled trial.

Sarcopenia is a pathology resulting from a progressive and severe loss of muscle mass, strength, and function in the course of aging, which has deleterious consequences on quality of life. Among the most widespread studies on the issue are those focused on the effect of different types of physical exercise on patients with sarcopenia. This randomized controlled study aimed to compare the effects of a whole-body vibration exercise (WBV) session on the inflammatory parameters of non-sarcopenic (NSG, n=22) and sarcopenic elderly (SG, n=22). NSG and SG participants were randomly divided into two protocols: intervention (squat with WBV) and control (squat without WBV). After a one-week washout period, participants switched protocols, so that everyone performed both protocols. Body composition was assessed by dual-energy radiological absorptiometry (DXA) and function through the six-minute walk test (6MWD) and Short Physical Performance Battery (SPPB). Plasma soluble tumor necrosis factor receptors (sTNFR) were determined by enzyme-linked immunosorbent assay (ELISA) and measured before and immediately after each protocol. After exercise with WBV, there was an increase in sTNFR2 levels in the NSG (P<0.01; d=-0.69 (-1.30; -0.08) and SG (P<0.01, d=-0.95 (-1.57; -0.32) groups. In conclusion, an acute session of WBV influenced sTNFr2 levels, with sarcopenic individuals showing a greater effect. This suggested that WBV had a more pronounced impact on sTNFr2 in those with loss of muscle strength and/or physical performance. Additionally, WBV is gaining recognition as an efficient strategy for those with persistent health issues.

Usefulness of the serum creatinine/cystatin C ratio as a blood biomarker for sarcopenia components among age groups in community-dwelling older people: The SONIC study.

AIM: The serum creatinine/cystatin C ratio (CCR) or sarcopenia index is considered a useful marker of muscle mass. However, its usefulness in late-stage older adults remains unclear. We aimed to determine the usefulness of CCR as an indicator of sarcopenia in community-dwelling Japanese adults aged >75 years. METHODS: Our study recruited participants aged 70, 80, and 90 ± 1 years during the baseline years, and included a 3-year follow-up in the Septuagenarians, Octogenarians, Nonagenarians, Investigation with Centenarians study. From 2015 to 2018, 955 participants were eligible: 367 in their 70s, 304 in their 80s, and 284 in their 90s. The diagnostic components of sarcopenia, including "low muscle mass, plus low muscle strength, and/or low physical performance," were evaluated using the bioelectrical impedance analysis-measured skeletal muscle mass index (SMI), handgrip strength, and short physical performance battery (SPPB) score, respectively, in accordance with the Asia Working Group for Sarcopenia 2019 criteria. Separate analyses were performed between each component and CCR, adjusting for sex, body mass index, and other blood biomarkers in each group. RESULTS: The relationship between CCR and sarcopenia components was significant for handgrip strength (ß = 0.21, 0.13, 0.19, and P < 0.0001, =0.0088, <0.0001, for the 70s, 80s, and 90s age groups, respectively); however, it was limited for SMI (ß = 0.14; P = 0.0022, only for the 90s) and not significant for the SPPB score. CONCLUSION: CCR is a limited indicator of sarcopenia in late-stage older adults. Although its association with muscle strength was significant, its relationship with muscle mass and physical performance was less pronounced. Geriatr Gerontol Int 2024; 24: 529-536.

Value of Cystatin C-Based Sarcopenia Index in Patients Undergoing Surgery for Renal Tumors.

INTRODUCTION: Sarcopenia is a condition of low muscle strength and quantity, severe if low physical performances. The sarcopenia index (SI), calculated by blood levels of creatinine and cystatin C, had been reported to be correlated with skeletal muscle mass and is a potential simple screening tool for sarcopenia. We hypothesized that patients with a low SI, meaning low muscle mass, would have an inflated estimated glomerular filtration rate (eGFR) value based on serum creatinine levels. We also tested the prognostic value of the SI in a cohort of patients who had surgery for renal malignancies. PATIENTS AND METHODS: We conducted a retrospective, observational study of 322 patients that had surgery for renal tumors in National Cancer Center Hospital East (Kashiwa, Chiba) between April 2017 and June 2023. We assessed sarcopenia measuring psoas muscle index (PMI), psoas muscle density (PMD), and skeletal muscle area (SMA) by computed tomography. We assessed the association between SI and eGFR before and after surgery. We also assessed the association between SI and postoperative outcome, including overall survival. RESULTS: Of the 322 patients, 211 (66%) were males, with a median age of 69 years. SI had a weak correlation with both PMI and PMD in males (PMI: ρ = 0.25; PMD: ρ = 0.21). In females, SI and PMD exhibited a low correlation (ρ = 0.26), while SI and PMI displayed an insignificant correlation (ρ = 0.19). The correlation between SMA and SI was moderate for both males and females (males: ρ = 0.51; females: ρ = 0.46). After radical nephrectomy, eGFR decreased in 98% of patients with high SI, compared to 69% of patients with low SI. We also demonstrated that low SI predicted poor prognosis. CONCLUSIONS: Clinicians can recognize the possibility of overestimated eGFR in the low SI group by measuring SI around the surgery. Low SI may also help predict poor prognosis.