Insulin sensitivity and metabolic flexibility decrease in response to bed rest, but the temporal and causal adaptations in human skeletal muscle metabolism are not fully defined. Here, we use an integrative approach to assess human skeletal muscle metabolism during bed rest and provide a multi-system analysis of how skeletal muscle and the circulatory system adapt to short- and long-term bed rest (German Clinical Trials: DRKS00015677). We uncover that intracellular glycogen accumulation after short-term bed rest accompanies a rapid reduction in systemic insulin sensitivity and less GLUT4 localization at the muscle cell membrane, preventing further intracellular glycogen deposition after long-term bed rest. We provide evidence of a temporal link between the accumulation of intracellular triglycerides, lipotoxic ceramides, and sphingomyelins and an altered skeletal muscle mitochondrial structure and function after long-term bed rest. An intracellular nutrient overload therefore represents a crucial determinant for rapid skeletal muscle insulin insensitivity and mitochondrial alterations after prolonged bed rest.
The world population is ageing rapidly. As society ages, the incidence of physical limitations is dramatically increasing, which reduces the quality of life and increases healthcare expenditures. In western society, ~30% of the population over 55 years is confronted with moderate or severe physical limitations. These physical limitations increase the risk of falls, institutionalization, co-morbidity, and premature death. An important cause of physical limitations is the age-related loss of skeletal muscle mass, also referred to as sarcopenia. Emerging evidence, however, clearly shows that the decline in skeletal muscle mass is not the sole contributor to the decline in physical performance. For instance, the loss of muscle strength is also a strong contributor to reduced physical performance in the elderly. In addition, there is ample data to suggest that motor coordination, excitation-contraction coupling, skeletal integrity, and other factors related to the nervous, muscular, and skeletal systems are critically important for physical performance in the elderly. To better understand the loss of skeletal muscle performance with ageing, we aim to provide a broad overview on the underlying mechanisms associated with elderly skeletal muscle performance. We start with a system level discussion and continue with a discussion on the influence of lifestyle, biological, and psychosocial factors on elderly skeletal muscle performance. Developing a broad understanding of the many factors affecting elderly skeletal muscle performance has major implications for scientists, clinicians, and health professionals who are developing therapeutic interventions aiming to enhance muscle function and/or prevent mobility and physical limitations and, as such, support healthy ageing.
Skeletal muscle-related symptoms are common in both acute coronavirus disease (Covid)-19 and post-acute sequelae of Covid-19 (PASC). In this narrative review, we discuss cellular and molecular pathways that are affected and consider these in regard to skeletal muscle involvement in other conditions, such as acute respiratory distress syndrome, critical illness myopathy, and post-viral fatigue syndrome. Patients with severe Covid-19 and PASC suffer from skeletal muscle weakness and exercise intolerance. Histological sections present muscle fibre atrophy, metabolic alterations, and immune cell infiltration. Contributing factors to weakness and fatigue in patients with severe Covid-19 include systemic inflammation, disuse, hypoxaemia, and malnutrition. These factors also contribute to post-intensive care unit (ICU) syndrome and ICU-acquired weakness and likely explain a substantial part of Covid-19-acquired weakness. The skeletal muscle weakness and exercise intolerance associated with PASC are more obscure. Direct severe acute respiratory syndrome coronavirus (SARS-CoV)-2 viral infiltration into skeletal muscle or an aberrant immune system likely contribute. Similarities between skeletal muscle alterations in PASC and chronic fatigue syndrome deserve further study. Both SARS-CoV-2-specific factors and generic consequences of acute disease likely underlie the observed skeletal muscle alterations in both acute Covid-19 and PASC.
Onderzoek toont aan dat explosief spiervermogen ('muscle power') de bepalende factor is voor fysiek functioneren van ouderen. Er zijn steeds meer aanwijzingen dat het specifiek trainen van power het fysiek functioneren en zelfredzaamheid van ouderen positief beïnvloedt.Doel Dit onderzoek heeft als doel om de effectiviteit van powertraining op het fysieke functioneren en de zelfredzaamheid van ouderen vast te stellen. Resultaten Dit onderzoek loopt nog. Na afloop vind je hier de resultaten. Looptijd 17 september 2017 - 01 augustus 2024 Aanpak We ontwikkelden een interventie waarin ouderen enkele weken lang specifieke spieren trainen. We volgen ouderen die de training volgen tot twee jaar om de effecten van de training te meten ten opzichte van ouderen die geen training volgden. Zie ook http://www.powerful-ageing.nl
The admission of patients to intensive care units (ICU) is sometimes planned after a large operation. However, most admissions are acute, because of life-threatening infections or trauma as a result of accidents. Their stay can last from a couple of days to a couple of weeks. ICU patients are often in pain, in fragile health condition, and connected to various devices such as a ventilator, intravenous drip, and monitoring equipment. The resulting lack of mobilization, makes patients lose 1-3% of muscle power for each day they are in the ICU. Within 2 weeks, patients can lose up to 50% of their muscle mass. Early mobilization of ICU patients reduces their time on a respirator and their hospital length of stay. Because of this, ICUs have started early mobilization physical therapy. However, there is a lack of solutions for patients that properly handle fear of movement, are sufficiently personalized to the possibilities and needs of the individual and motivate recurring use in this context. Meanwhile, various technological advances enable new solutions that might bring benefits for this specific use case. Hospitals are experimenting with screens and projections on walls and ceilings to improve their patients’ stay. Standalone virtual reality and mixed reality headsets have become affordable, available and easy to use. In this project, we want to investigate: How can XR-technologies help long-stay ICU patients with early mobilization, with specific attention to the issues of fear of movement, personalization to the individual’s possibilities, needs and compliance over multiple sessions? The research will be carried out in co-creation with the target group and will consist of a state-of-the-art literature review and an explorative study.
