Molecular and Cardiometabolic Characteristics of Different Types of Skeletal Muscle

Skeletal muscle is one of the body’s largest endocrine organs and displays marked heterogeneity in fiber-type composition. Slow oxidative (type I) and fast glycolytic/oxidative (type II) fibers differ in mitochondrial capacity, substrate utilization, insulin sensitivity, glucose uptake, and regulation of protein synthesis and degradation. These molecular distinctions shape postprandial glucose disposal, lipid metabolism, and whole-body energy homeostasis, positioning muscle fiber composition as a key determinant of systemic metabolic regulation.Beyond contractile function, skeletal muscle secretes myokines, metabolites, and extracellular vesicles that influence pancreatic, hepatic, adipose, vascular, and inflammatory pathways. Aging, sarcopenia, muscle atrophy, and physical inactivity drive fiber-type shifts linked to insulin resistance and increased cardiometabolic risk. Understanding fiber-type–specific endocrine mechanisms is therefore essential for promoting metabolic resilience and healthy longevity.This Research Topic aims to elucidate how distinct skeletal muscle fiber types differentially regulate endocrine and metabolic homeostasis in health, aging and disease. We welcome studies examining fiber-type–specific effects on hormonal signaling, insulin sensitivity and resistance, postprandial glucose uptake, lipid metabolism, and protein turnover, including mechanisms underlying muscle atrophy and sarcopenia during aging. Contributions exploring muscle–organ endocrine cross-talk and targeted interventions to enhance muscle phenotype and cardiometabolic health are particularly encouraged. Topics of interest include, but are not limited to:• Fiber-type–specific endocrine and secretory functions• Myokines and muscle-derived signaling factors• Insulin sensitivity, insulin resistance, and glucose uptake across fiber types• Protein synthesis, protein degradation, muscle atrophy, and sarcopenia• Muscle–pancreas, –liver, and –adipose cross-talk• Hormonal regulation of muscle phenotype• Exercise and targeted interventions modulating endocrine signaling• Fiber-type interactions and fiber type transitions in obesity, type 2 diabetes, cardiovascular disease, atherogenic blood lipids, inflammation, some cancers, and aging Topic editors: Marc Hamilton, Zhen Yan, Theodore Zderic, Vihang Narkar Source: https://www.frontiersin.org/research-topics/80141/molecular-and-cardiometabolic-characteristics-of-different-types-of-skeletal-muscle