ABSTRACT
Malnutrition, sarcopenia, and cachexia–anorexia syndrome (CAS) are complex challenges for researchers and clinicians in daily practice. CAS occurs in a variety of seemingly disparate illnesses, including cancer, acquired immune deficiency syndrome, heart failure, human immunodeficiency virus, tuberculosis, malaria, rheumatoid arthritis, chronic obstructive pulmonary disease, kidney failure, and liver failure. Variation in diagnostic criteria for cachexia will of course alter its clinical prevalence. Several domains of CAS are associated with poor prognosis, including decreased appetite, nutrition impact symptoms, weight loss, changes in body composition (BC), and sarcopenia. Sarcopenia is considered primary or age related when no other specific cause is evident and secondary when factors other than or in addition to aging, such as cancer, are evident. Imaging is useful for assessment of BC and diagnosing sarcopenia. CAS is characterized by a complex interplay of various mechanisms, leading to loss of muscle and fat as well as poor appetite.
