Introduction

Muscular mass loss with or without a corresponding reduction in function (i.e., physical performance or muscle strength) can happen due to ageing naturally or as a result of acute and chronic illnesses.

Recent pooled analyses have shown that low muscle mass and sarcopenia (i.e., low muscle mass and function) are prevalent in community-dwelling and hospitalized older adults and patients with lung diseases, liver cirrhosis, cancer, and other diseases. However, the prevalence of these conditions may vary depending on the diagnostic criteria used.

Patients may also have muscle loss without changes in body weight or even in the context of obesity (sarcopenic obesity). Cachexia is a catabolic disorder that is further defined by extreme weight loss with or without loss of fat mass and inflammation brought on by underlying conditions, with catastrophic effects on patients. Low muscle mass is one of the distinguishing criteria of cachexia (1).