Weight loss is the hallmark of any progressive acute or chronic disease state. In its extreme form, it involves a significant lean body mass (including skeletal muscle), and fat loss. Skeletal muscle provides a fundamental basis for human function, enabling locomotion and respiration. Muscle wasting is related to a poor quality of life and increased morbidity/ mortality.
Two common but distinct conditions characterized by a loss of skeletal muscle mass are sarcopenia and cachexia. Sarcopenia, cachexia, and anorexic disorders (protein-energy malnutrition) represent the major causes of muscle-wasting disorders.
It has been known for millennia that muscle and fat wasting leads to poor outcomes including deaths in chronic disease states.
It is usually accompanied by physical inactivity, decreased mobility, slow gait, and poor physical endurance which are also common features of the frailty syndrome.
Both cachexia and sarcopenia are characterized by an important muscle dysfunction that leads to increased morbidity and mortality.
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