Multisystem derangements in frailty and sarcopenia

Multisystem derangements, encompassing metabolic, musculoskeletal and stress-response systems, occur during aging and are associated with the development of physical frailty and sarcopenia. These modular changes are relevant sources for the identification of biomarkers for the two conditions. Here, we provide an up-to-date overview on existing biomarkers of physical frailty and sarcopenia and discuss emerging approaches for biomarker discovery.Inflammatory, metabolic and hematologic markers are shared between physical frailty and sarcopenia. Gut microbial derivatives and damage-associated molecular patterns transferred via extracellular vesicles have been indicated as possible gut-muscle axis regulators and candidate markers of physical frailty and sarcopenia.Mediators of metabolic, musculoskeletal and stress-response system dysregulation are shared by physical frailty and sarcopenia and indicate the existence of common pathophysiological pathways. Multiplatform biomarker analyses have been proposed as an innovating approach for tracking the multifaceted and dynamic nature of physical frailty and sarcopenia. Upon validation, the identified biomarkers may support diagnostic makeup and tracking of the two conditions in both research and clinical settings.