Skeletal Muscle Mass Regulation in Critical Illness

2014 ◽  
Author(s):  
Zudin Puthucheary ◽  
Hugh Montgomery ◽  
Nicholas Hart ◽  
Stephen Harridge
Keyword(s):  
Skeletal Muscle ◽  
Critical Illness ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Bed Rest ◽  
Protein Homeostasis ◽  
Highly Sensitive ◽  
And Function ◽  
Inadequate Nutrition

Muscle is a dynamic, plastic, and malleable tissue that is highly sensitive to mechanical and metabolic signals. Muscle mass is regulated by protein homeostasis, with protein being continually turned over, reflecting a balance between synthesis and breakdown. This chapter discusses the effect of critical illness on skeletal muscle mass, protein homeostasis, and the intracellular signalling driving anabolism and catabolism. The focus will be on the unique challenges to which the skeletal muscle are exposed, such as inflammation, sepsis, sedation, and inadequate nutrition, which, in combination with the disuse signals of immobilization and bed rest, engender dramatic changes in muscle structure and function. The mechanisms regulating muscle loss during critical illness are being unravelled, but many questions remain unanswered. Detailed understanding of these mechanisms will help drive strategies to minimize or prevent intensive care-acquired muscle weakness and the long-term consequences experienced by ICU survivors.

scholarly journals Clinical impact of sarcopenia assessment in patients with hepatocellular carcinoma undergoing treatments

2020 ◽  
Vol 55 (10) ◽  
pp. 927-943 ◽  
Author(s):  
Giovanni Marasco ◽  
Matteo Serenari ◽  
Matteo Renzulli ◽  
Luigina Vanessa Alemanni ◽  
Benedetta Rossini ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Skeletal Muscle ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Appropriate Treatment ◽  
Risk Of Mortality ◽  
Short And Long Term ◽  
Poor Outcomes ◽  
And Function

Abstract Changes in body composition are associated with poor outcomes in cancer patients including hepatocellular carcinoma (HCC). Sarcopenia, defined as the loss of skeletal muscle mass, quality and function, has been associated with a higher rate of complications and recurrences in patients with cirrhosis and HCC. The assessment of patient general status before HCC treatment, including the presence of sarcopenia, is a key-point for achieving therapy tolerability and to avoid short- and long-term complications leading to poor patients’ survival. Thus, we aimed to review the current literature evaluating the role of sarcopenia assessment related to HCC treatments and to critically provide the clinicians with the most recent and valuable evidence. As a result, sarcopenia can be predictive of poor outcomes in patients undergoing liver resection, transplantation and systemic therapies, offering the chance to clinicians to improve the muscular status of these patients, especially those with high-grade sarcopenia at high risk of mortality. Further studies are needed to clarify the predictive value of sarcopenia in other HCC treatment settings and to evaluate its role as an additional staging tool for identifying the most appropriate treatment. Besides, interventional studies aiming at increasing the skeletal muscle mass for reducing complications and increasing the survival in patients with HCC are needed.

Effects of lower limb unloading on skeletal muscle mass and function in humans

1991 ◽  
Vol 70 (4) ◽  
pp. 1882-1885 ◽  
Author(s):  
H. E. Berg ◽  
G. A. Dudley ◽  
T. Haggmark ◽  
H. Ohlsen ◽  
P. A. Tesch
Keyword(s):  
Skeletal Muscle ◽  
Muscle Mass ◽  
Lower Limb ◽  
Skeletal Muscle Mass ◽  
Bed Rest ◽  
Experimental Period ◽  
Peak Torque ◽  
Human Model ◽  
Cross Sectional ◽  
And Function

A model to simulate effects of microgravity on skeletal muscle mass and function in humans has been developed. Unilateral lower limb unloading that allowed ankle, knee, and hip joint mobility was conducted in six healthy men by suspending one lower limb and having the subjects walk on crutches. They performed maximal unilateral concentric or eccentric quadriceps actions at different angular velocities before and after 4 wk of suspension and after 4 days and after 7 wk of uncontrolled recovery. Peak torque (PT) and angle-specific torque (AST) were measured. Muscle cross-sectional area (CSA) and radiological density (RD) of the thigh were assessed by means of computerized tomography. Concentric and eccentric PT and AST across speeds decreased (P less than 0.05) by 22 and 16%, respectively, in response to unloading. At 4 days of recovery PT (-11%) and AST (-7%) were still lower (P less than 0.05) than before. Muscle CSA and RD decreased (P less than 0.05) by 7 and 6%, respectively. After 7 wk of recovery PT, AST, CSA, and RD had returned to normal. The control limb showed no changes over the experimental period except for a 6% decrease (P less than 0.05) in RD. It is suggested that this human model of unloading could serve to simulate effects of microgravity on skeletal muscle mass and function because reductions in muscle mass and strength were of similar magnitude to those produced by bed rest.

scholarly journals Assessment of Sarcopenia in the Intensive Care Unit and 1-Year Mortality in Survivors of Critical Illness

Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2726
Author(s):  
Naoya Yanagi ◽  
Tomotaka Koike ◽  
Kentaro Kamiya ◽  
Nobuaki Hamazaki ◽  
Kohei Nozaki ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Intensive Care Unit ◽  
Intensive Care ◽  
Critical Illness ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Cox Regression ◽  
Study Endpoint ◽  
Icu Discharge ◽  
And Function

Skeletal muscle wasting in the intensive care unit (ICU) has been associated with mortality, but it is unclear whether sarcopenia, defined by skeletal muscle mass and function, is useful for detailed risk stratification after ICU discharge. In this cohort study, 72 critically ill patients with an ICU stay of ≥48 h were identified. Skeletal muscle mass was assessed from the muscle thickness (MT) of the patients’ quadriceps using ultrasound images before ICU discharge. Skeletal muscle function was assessed from the patients’ muscle strength (MS) before ICU discharge according to the Medical Research Council sum score. A diagnosis of sarcopenia in the ICU was made in patients with low MT and low MS. The study endpoint was 1-year mortality. Sarcopenia in the ICU was diagnosed in 26/72 patients (36%). After adjusting for covariates in the Cox regression, sarcopenia in the ICU was significantly associated with 1-year mortality (hazard ratio 3.82; 95% confidence interval, 1.40–10.42). Sarcopenia in the ICU, defined by low skeletal muscle mass and function, was associated with 1-year mortality in survivors of critical illness. Skeletal muscle mass and function assessed at the bedside could be used to identify higher-risk patients in the ICU.

630 IMPACT OF LOW SKELETAL MUSCLE MASS AND DENSITY ON OUTCOMES OF LOCALLY ADVANCED ESOPHAGEAL CANCER PATIENTS TREATED WITH RADICAL RADIOTHERAPY

2021 ◽  
Vol 34 (Supplement_1) ◽  
Author(s):  
Yuan Wang ◽  
Ningjing Yang ◽  
Hongyuan Jia ◽  
Long Liang ◽  
Lei Wu ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Esophageal Cancer ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Mass Density ◽  
Locally Advanced ◽  
Radical Radiotherapy ◽  
Term Survival ◽  
Locally Advanced Esophageal Cancer

Abstract   Low skeletal muscle mass and density are independent predictors of clinical outcomes in multiple gastrointestinal cancers. However, its effect on the long-term survival of locally advanced esophageal cancer patients undergoing radical radiotherapy is still unclear. Methods Patients with stage II-III esophageal cancer undergoing radical radiotherapy, enrolled in a observational cohort study, were included. Skeletal muscle mass and density were measured on CT. Patients with high and low skeletal muscle mass and density were compared regarding overall survival (OS). Results 165 patients (75.8% males, median age 63) were included, from March-2012 to September-2017. Before radiotherapy, 26.7% patients had low skeletal-muscle-mass and 23.0% patients had low skeletal-muscle-density. After radiotherapy, 40.6% patients had low skeletal-muscle-mass and 30.3% patients had low skeletal-muscle-density.The median OS of high skeletal-muscle-mass/density group was significantly higher than that of low skeletal-muscle-mass/density group before radiotherapy (28.7 vs 28.2 months, p = 0.041; 29.6 vs 16.9 months, p = 0.025). The median OS of high skeletal-muscle-mass/density group was also significantly higher than that of low skeletal-muscle-mass/density group after radiotherapy (30.3 vs 20.3 months, P = 0.012; 29.6 vs 17.2 months, p = 0.018). Conclusion Low skeletal muscle mass and density are associated with long-term outcome in patients undergoing radical radiotherapy. It is suggested that oncologists should pay more attention to the management of muscle mass and density of patients with esophageal cancer undergoing radiotherapy in order to improve their nutritional status and long-term survival.

scholarly journals NEUROMUSCULAR CHANGES WITH AGING AND SARCOPENIA

2018 ◽  
pp. 1-3
Author(s):  
B.C. Clark
Keyword(s):  
Skeletal Muscle ◽  
Muscle Mass ◽  
Muscle Function ◽  
Skeletal Muscle Mass ◽  
The Past ◽  
Conceptual Definition ◽  
Age Related ◽  
Per Se ◽  
Definition Of ◽  
And Function

Sarcopenia was originally conceptualized as the age-related loss of skeletal muscle mass. Over the ensuing decades, the conceptual definition of sarcopenia has changed to represent a condition in older adults that is characterized by declining muscle mass and function, with “function” most commonly conceived as muscle weakness and/or impaired physical performance (e.g., slow gait speed). Findings over the past 15-years, however, have demonstrated that changes in grip and leg extensor strength are not primarily due to muscle atrophy per se, and that to a large extent, are reflective of declines in the integrity of the nervous system. This article briefly summarizes findings relating to the complex neuromuscular mechanisms that contribute to reductions in muscle function associated with advancing age, and the implications of these findings on the development of effective therapies.

scholarly journals Sarcopenia in women with hip fracture: A comparison of hormonal biomarkers and their relationship to skeletal muscle mass and function

2020 ◽  
Vol 6 (3) ◽  
pp. 139-145
Author(s):  
Ming Li Yee ◽  
Raphael Hau ◽  
Alison Taylor ◽  
Mark Guerra ◽  
Peter Guerra ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Hip Fracture ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
And Function
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