Uremic Sarcopenia: Clinical Evidence and Basic Experimental Approach

Abstract

Sustained physical activity extends healthy life years while a lower activity due to sarcopenia can reduce them. Sarcopenia is defined as a decrease in skeletal muscle mass and strength due not only to aging, but also from a variety of debilitating chronic illnesses such as cancer and heart failure. Patients with chronic kidney disease (CKD), who tend to be cachexic and in frail health, may develop uremic sarcopenia or uremic myopathy due to an imbalance between muscle protein synthesis and catabolism. Here, we review clinical evidence indicating reduced physical activity as renal function deteriorates and explore evidence-supported therapeutic options focusing on nutrition and physical training. In addition, although sarcopenia is a clinical concept and difficult to recapitulate in basic research, several in vivo approaches have been attempted, such as rodent subtotal nephrectomy representing both renal dysfunction and muscle weakness. This review highlights molecular mechanisms and promising interventions for uremic sarcopenia that were revealed through basic research. Extensive study is still needed to cast light on the many aspects of locomotive organ impairments in CKD and explore the ways that diet and exercise therapies can improve both outcomes and quality of life at every level.

Mitochondrial Dysfunction in Kidney Disease and Uremic Sarcopenia

“…The mitochondrial dysfunction in human skeletal muscle was also associated with poor physical activity performance when evaluated with a 6-min walk test. This result indicates that uremic sarcopenia is already progressing even before CKD advances ( Nishi et al, 2020 ; Ryan, 2020 ).…”

Uremic Sarcopenia and Its Possible Nutritional Approach

“…Secondary analysis from the ExTra CKD study showed that supervised physical exercise in CKD patients under conservative therapy is able to significantly improve the volume of the quadriceps femoris [ 150 ]. Furthermore, studies conducted on CKD non-dialysis patients demonstrated that aerobic exercise, intermittent exercise, and resistance training are able to enhance VO 2 peak [ 151 , 152 , 153 ].…”

Depression and low physical activity are related to sarcopenia in hemodialysis: a single-center study

“…In addition, uremic sarcopenia has been proposed as skeletal complication, e.g., muscle wasting, in CRF ( Fujita et al, 2006 ). Mitochondrial dysfunction in skeletal muscle in patients with CRF play an important role in promoting the uremic sarcopenia ( Nishi et al, 2020 ). The induced mitochondrial damage can promote inflammation or cause the release of cytochrome; resulting in apoptosis and reduced ATP synthesis leads to cell damage.…”