Skeletal Muscle Regulates Metabolism via Interorgan Crosstalk: Roles in Health and Disease

Abstract

Skeletal muscle is recognized as vital to physical movement, posture, and breathing. In a less known but critically important role, muscle influences energy and protein metabolism throughout the body. Muscle is a primary site for glucose uptake and storage, and it is also a reservoir of amino acids stored as protein. Amino acids are released when supplies are needed elsewhere in the body. These conditions occur with acute and chronic diseases, which decrease dietary intake while increasing metabolic needs. Such metabolic shifts lead to the muscle loss associated with sarcopenia and cachexia, resulting in a variety of adverse health and economic consequences. With loss of skeletal muscle, protein and energy availability is lowered throughout the body. Muscle loss is associated with delayed recovery from illness, slowed wound healing, reduced resting metabolic rate, physical disability, poorer quality of life, and higher health care costs. These adverse effects can be combatted with exercise and nutrition. Studies suggest dietary protein and leucine or its metabolite β-hydroxy β-methylbutyrate (HMB) can improve muscle function, in turn improving functional performance. Considerable evidence shows that use of high-protein oral nutritional supplements (ONS) can help maintain and rebuild muscle mass and strength. We review muscle structure, function, and role in energy and protein balance. We discuss how disease- and age-related malnutrition hamper muscle accretion, ultimately causing whole-body deterioration. Finally, we describe how specialized nutrition and exercise can restore muscle mass, strength, and function, and ultimately reverse the negative health and economic outcomes associated with muscle loss.

Role of thyroid hormone in skeletal muscle physiology

“…SM is the primary organ responsible for glucose uptake in response to insulin and in high energy-demanding conditions, such as disease. In these situations, muscular protein catabolism can be stimulated to maintain an energy supply to other organs (Argilés et al 2016). Therefore, reducing the anabolic response mediated by TH in SM could favour energy conservation during illness.…”

Sarcolipin: A Key Thermogenic and Metabolic Regulator in Skeletal Muscle

“…Therefore, future research should explore how NST in muscle can be exploited to regulate whole body energy metabolism. Recent discoveries have uncovered the importance of cross talk between muscle and other organs in the regulation of energy metabolism both under healthy and diseased conditions [51, 74]. Muscle also has enormous flexibility in substrate utilization and can switch back and forth between fat and carbohydrate to accommodate energy demand and substrate availability during various patho-physiological conditions.…”

Disrupted Skeletal Muscle Mitochondrial Dynamics, Mitophagy, and Biogenesis during Cancer Cachexia: A Role for Inflammation

“…However, skeletal muscle relies heavily on lipids as a fuel source during rest and low-intensity activities and contributes to over 20% of whole body fatty acid metabolism [14]. This oxidative metabolism dependence underscores the muscle mitochondria's critical role in metabolic homeostasis [14, 15]. The analysis of muscle oxidative metabolism involves the quantification of mitochondria content, respiratory capacity, and the efficiency of the Krebs cycle and electron transport chain (ETC) [16, 17].…”