Conceptual Models of Frailty: The Sarcopenia Phenotype

Population aging has redefined cardiovascular medicine toward multifaceted patient-oriented care, with frailty emerging as a fundamental concept. The definition of frailty is ardently debated between opposing constructs: phenotypic criteria and accumulated deficits. Phenotypic criteria revolve around age-related loss of muscle mass and strength, known as sarcopenia. Skeletal muscle is crucial for functioning, mobility, energetics, and is the body's primary reservoir for amino acids. Sarcopenia can be assessed objectively, serving as an incremental predictor of adverse health outcomes and a therapeutic target for muscle-building interventions. Thus, the sarcopenia phenotype should be the central focus of frailty assessment and intervention.