Intervention Effects on Musculoskeletal Health and Physical Function in CKD-MBD Using a Rat Model

Abstract

Chronic kidney disease (CKD) is a systemic condition that affects approximately 14% of adults in the United States. Kidney damage disrupts biochemical concentrations which can lead to a condition known as CKD-mineral bone disorder (CKD-MBD). CKD-MBD consists of altered biochemistries, vascular calcification, and bone abnormalities. Skeletal muscle impairments have also been observed in those with CKD. Bone abnormalities lead to an increased risk of fracture that is 2-100 times higher in the CKD population than the non-CKD population. In CKD, muscular atrophy in combination with muscle weakness and/or poor physical function (i.e., sarcopenia) occurs in 4-63% of patients while muscular weakness alone (i.e., dynapenia) has a prevalence of 18-46%. The collective musculoskeletal impairments lead to a reduction in physical function, increased risk of hospitalization, and increased mortality. Exercise is commonly used to treat impaired bone and skeletal muscle in non-CKD populations. However, in CKD, exercise has demonstrated inconsistent results which are likely due to the varying exercise prescriptions reported in the literature. Additionally, the prescription of exercise necessary to cause musculoskeletal adaptation may be too intense for CKD patients in the mid-to-late stages of disease, especially since many were sedentary prior to diagnosis. This suggests that exercise alone may not be sufficient to elicit the desired muscle and bone outcomes. The use of nutraceuticals such as carnitine and pharmaceuticals that act as “exercise mimetics” are becoming more popular, however their impact on musculoskeletal health in CKD has not been extensively researched.