Epidemiology of sarcopenia and frailty in CKD

Abstract

Chronic kidney disease (CKD) is very common in the elderly. CKD-related metabolic derangements increase the risk of skeletal muscle wasting, so the prevalence of sarcopenia and frailty are substantially higher in CKD patients compared to the general population. Sarcopenia is defined according to the Asian Working Group for Sarcopenia (AWGS), while frailty according to the Japanese version of the Cardiovascular Health Study (J-CHS) in Japan. Sarcopenia and frailty are closely associated with protein-energy wasting. Frailty is also more prevalent in female than in male in CKD patients. Sarcopenia and frailty are both related to survival prognosis and accelerated progression to end-stage kidney disease in patients with non-dialysis-dependent CKD. In dialysis patients, low muscle strength rather than muscle mass volume is more strongly associated with physical inactivity, inflammation, and total mortality. Frailty is also an independent predictor of cognitive impairment, hospitalization, and mortality in the dialysis population. Given the convincing relationship between sarcopenia, frailty, and adverse clinical outcomes, we should be more aware of the concept of sarcopenia and frailty and prevent their progressions especially in older patients with advanced CKD.