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.

Malnutrition: muscle wasting, inflammation, RDW, and their relation with adverse outcomes.

OBJECTIVE: The objective of the study was to explore red cell distribution width (RDW) as a surrogate marker of inflammation, alone and in conjunction with muscle wasting to predict malnutrition-related adverse outcomes. METHODS: This was a single-center observational study including adult hospitalized patients. Demographic variables, malnutrition criteria, and RDW were captured within 24 hours of hospital admission. Correlation tests and regression models were performed between these variables (RDW and muscle wasting) and adverse outcomes (in-hospital mortality and unplanned transfer to critical care areas (CCA). RESULTS: Five hundred and forty-five patients were included in the final analysis. Muscle wasting showed an independent association with adverse outcomes in every regression model tested. RDW alone showed fair predictive performance for both outcomes' significance and the adjusted model with muscle wasting showed association only for unplanned transfer to CCA. CONCLUSION: RDW did not improve the prediction of adverse outcomes compared to muscle wasting assessed by physical examination and simple indexes for acute and chronic inflammation. Malnourished patients presented higher RDW values showing a possible metabolic profile (higher inflammation and lower muscle). It is still unknown whether nutrition support can influence RDW value over time as a response marker or if RDW can predict who may benefit the most from nutritional support.

OBJETIVO: Explorar el ancho de distribución eritrocitaria (ADE) como un marcador subrogado de inflamación, individualmente y en conjunto con el desgaste muscular, para predecir resultados adversos asociados a la desnutrición. MÉTODO: Estudio unicéntrico, observacional, incluyendo pacientes adultos hospitalizados. Se capturaron variables demográficas, criterios de desnutrición y el ADE en las primeras 24 horas de ingreso. Se realizaron pruebas de correlación y modelos de regresión entre dichas variables (ADE y desgaste) y resultados adversos (mortalidad hospitalaria y traslado no planeado a áreas críticas). RESULTADOS: Se incluyeron 545 pacientes. El desgaste muscular mostró asociación independiente con los resultados adversos en cada modelo. El ADE individualmente mostró un desempeño aceptable para la predicción de ambos resultados, y en modelos ajustados con desgaste muscular mostró asociación únicamente con traslado no planeado a áreas críticas. CONCLUSIONES: El ADE no mejoró la predicción de resultados adversos comparado con el desgaste muscular por exploración física e índices simples de inflamación. Los pacientes con desnutrición presentaron mayores valores de ADE, mostrando un posible perfil metabólico (mayor inflamación y menos músculo). Aún se desconoce si el soporte nutricional puede influenciar el ADE como un marcador de respuesta o si puede predecir una respuesta favorable al soporte nutricional.

Elevated serum Activin A in chronic obstructive pulmonary disease with skeletal muscle wasting

OBJECTIVE: Muscle wasting contributes to the reduced quality of life and increased mortality in chronic obstructive pulmonary disease (COPD). Muscle atrophy in mice with cachexia was caused by Activin A binding to ActRIIB. The role of circulating Activin A leading to muscle atrophy in COPD remains elusive. METHODS: In the present study, we evaluated the relationship between serum levels of Activin A and skeletal muscle wasting in COPD patients. The expression levels of serum Activin A were measured in 78 stable COPD patients and in 60 healthy controls via ELISA, which was also used to determine the expression of circulating TNF-α levels. Total skeletal muscle mass (SMM) was calculated according to a validated formula by age and anthropometric measurements. The fat-free mass index (FFMI) was determined as the fat-free mass (FFM) corrected for body surface area. RESULTS: Compared to the healthy controls, COPD patients had upregulated Activin A expression. The elevated levels of Activin A were correlated with TNF-α expression, while total SMM and FFMI were significantly decreased in COPD patients. Furthermore, serum Activin A expression in COPD patients was negatively associated with both FFMI and BMI. CONCLUSION: The above results showed an association between increased circulating Activin A in COPD patients and the presence of muscle atrophy. Given our previous knowledge, we speculate that Activin A contributes to skeletal muscle wasting in COPD.

Electroestimulación neuromuscular intradiálisis, fuerza muscular, capacidad funcional y composición corporal / Intradialysis neuromuscular electro stimulation muscle strength, functional capacity and body composition

Introducción: La capacidad funcional disminuida y la importante atrofia muscular caracterizan a los pacientes en hemodiálisis (HD). El ejercicio físico intradiálisis y recientemente la electroestimulación neuromuscular (EMS), representan dos serias opciones terapéuticas para mejorar esta deteriorada condición física. Actualmente, no existen estudios publicados sobre el papel de la EMS y la composición corporal en los pacientes en HD. Objetivo: Analizar que efecto produce un programa de EMS sobre la fuerza muscular, capacidad funcional, parámetros nutricionales y composición corporal en nuestros pacientes en HD. Material y Métodos: Estudio unicéntrico, prospectivo de 12 semanas de duración. Los pacientes incluidos realizaron un programa adaptativo de EMS en ambos cuádriceps intradiálisis mediante el dispositivo Compex R Theta 500i. Analizamos: 1.- Parámetros nutricionales (Albumina, pre albúmina, triglicéridos, colesterol total y fracciones, ferritina y Proteína C reactiva). 2.- Datos musculares: Composición muscular cuadriceps, Fuerza extensión máxima cuádriceps (FEMQ) y handgrip (HG) brazo dominante. 3.- Test funcionales: “Sit to stand to sit” (STS10) y “six- minutes walking test” (6MWT). 4.- Composición corporal mediante biompedancia electrica (BIA). Resultados: 13 pacientes incluidos: (69.2% hombres). Edad media: 65.7 años y 33.9 meses en HD. I.Charlson medio 9.1. La principal etiología de la ERC fue la DM ( 38.5%). Al final del estudio se observó una mejoría en (*p<0.05): FEMQ* ( 11.7±7.1 vs 13.4±7.4 Kg), STS10 (39.3±15.5 vs 35.8±13.7 seg), 6MWT* (9.9%, 293.2 vs 325.2 m). En relación a la composición corporal, se observó únicamente un aumento significativo del área muscular (AMQ*: 128.6 ± 30.2 vs 144.6 ± 22.4 cm2) y una disminución del área grasa (AGQ*: 76.5 ± 26.9 vs 62.1 ± 20.1 cm2) a nivel quadricipital, sin cambios en el resto de datos analizados (% grasa abdominal, peso graso, peso magro, agua corporal total). No se objetivaron cambios relevantes en los parámetros nutricionales y de adecuación dialítica. Conclusiones: 1.- La electroestimulación neuromuscular intradialísis mejoró la fuerza muscular, la capacidad funcional y la composición muscular del cuadriceps de nuestros pacientes en HD. 2.- Nuestros resultados remarcan el carácter local de la electroes-timulación neuromuscular, dada la ausencia de cambios relevantes en el resto de los parámetros nutricionales y datos corporales analizados. 3.- No obstante, son necesarios futuros estudios mejor diseñados, de cara a discernir si la electroestimulación neuromuscular podría ser una nueva alternativa terapéutica para evitar la atrofia muscular y el deterioro progresivo de la condición física de éstos pacientes (AU)

Background: The reduced functional capacity and significant muscle atrophy characterized patients on hemodialysis. Intradialytic exercise and recently neuromuscular electrostimulation (EMS) represent two serious therapeutical options to improve the deteriorated physical condition. Until date, there are no published studies about the role of EMS and body composition in HD patients. Objectives: Analyze the effect a program of EMS on muscle strength, functional capacity, nutritional parameters and body composition in our HD patients. Methods: A 12 weeks single-center, prospective study. Patients included in the study performed an intradialysis EMS adaptive program in both quadriceps using the Compex R Theta 500i device. We analyzed: 1.- Nutritional parameters (albumin, pre-albumin, triglycerides, total cholesterol and fractions, ferritin and C-reactive protein). 2.- Muscular data: Muscular composition, Maximum length quadriceps strength (MLQS) and “hand-grip” (HG) dominant arm. 3.- Functional capacity test: “Sit to stand to sit” (STS10) and “six- minutes walking test” (6MWT). 4.- Body composition. Results: 13 HD patients included: 69.2 % men. Mean age 65.7 years and 33.9 months on HD. A significant (* p < 0,05) improvement was observed in MLQS* (11.7±7.1 vs 13.4±7.4 Kg), STS10* (39.3±15.5 vs 35.8±13.7 seg), 6MWT* (9.9%, 293.2 vs 325.2 m). There was a signi-ficant increase in the quadriceps muscular area (QMA*: 128.6 ± 30.2 vs 144.6 ± 22.4 cm2) and decrease of fat quadricipital area (FQA*: 76.5 ± 26.9 vs 62.1 ± 20.1 cm2). No significant changes were observed in nutritional parameters, body composition (body fat percentage, lean and fat mass, total body water) or dialysis adecuacy data. Conclusions: 1.- Intradialysis quadriceps EMS improved muscle strength, functional capacity and the quadriceps muscle composition in our HD patients. 2.- Our results underline the local aspects on EMS, given the absence of relevant changes on nutritional parameters and body composition. 3.- Future studies are manadatory in order to establish if EMS could be a new alternative to prevent muscle atrophy and the progressive deterioration of the physical condition of these patients (AU)