Distinguishing Between Cachexia, Sarcopenia and Protein Energy Wasting in End-Stage Renal Disease Patients on Dialysis

Patients with end-stage renal disease (ESRD) receiving dialysis can have altered nutritional status and body composition due to dietary restrictions, level of physical activity, co-morbidities, metabolic alterations and inflammation.1 As such, weight loss or wasting is common among this population with up to 75% of adults with ESRD undergoing maintenance dialysis displaying some evidence of wasting.2 There are several forms of loss of lean muscle mass or wasting in ESRD, including ‘protein energy wasting’, ‘cachexia’, and ‘age-related sarcopenia’ and these terms are often used interchangeably alongside ‘malnutrition’ in current care. Limited understanding of the differences between such terms is arguably a barrier to accurate recognition and management of these disorders in patients with ESRD. For instance, a recent European study of over 700 dietetic participants concluded that only 13% of health care professionals who could differentiate between malnutrition, starvation, cachexia and sarcopenia.3 Such knowledge is pertinent as for example, loss of muscle mass is a key feature in both sarcopenia and cachexia, but most patients with sarcopenia are not cachectic,4 as muscle wasting occurs with aging