Individuals with chronic kidney disease (CKD) exhibit impairments to skeletal muscle function when compared to age-matched healthy controls. The current study was designed to compare muscle strength, functional measures, and the levels of some biomarkers across the stages of CKD compared to age-matched healthy controls (HC). Thirty-nine individuals with either CKD stage 3 (n = 10, age = 69.7 ± 9.95), stage 4 (n = 10, age = 66.5 ± 6.95), or stage 5 (n = 9, age = 58.7 ± 13.01) or age-matched HC (n = 10, age = 62.3 ± 10.4) were recruited to participate in this study. After obtaining approval from a physician, participants came to the lab on two occasions. The first lab visit consisted of the completion of an informed consent form, a health screening form, and a medical history questionnaire. Anthropometric measurements were then taken, as well as a blood sample via venipuncture. Next, a familiarization trial with maximum voluntary isometric contractions (MVIC) was performed, in addition to the six-minute walk test (6MWT), and the short physical performance battery test (SPPB). Participants visited the lab for the second time after a minimum of 72 h had passed. During this visit, three MVICs were performed. Force was recorded using a load cell. Concentrations of uremic toxins indoxyl sulfate (IS) and p-cresyl sulfate (pCS), along with inflammatory markers interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-⍺) were analyzed using commercially available enzyme-linked immunosorbent assays per the manufacturer’s instructions. Uremic toxins IS and pCS, as well as the inflammatory marker IL-6 all increased significantly from HC to CKD stage 3, to CKD stage 4, and to CKD stage 5. TNF-⍺ increased significantly from HC to CKD stage 3, but not between the CKD groups. SPPB, MVIC, and 6MWT performance decreased significantly between HC to CKD stage 3, to CKD stage 4. No significant change was found in SPPB, MVIC, and 6MWT from CKD stage 4 to CKD stage 5. As CKD progresses, indices of muscular strength and functional measures decline compared to HC but the biomarkers, uremic toxins and markers of inflammation increase. These changes in biomarkers are associated with worsened skeletal muscle function. ‘. Not applicable.
Coker et al. (Tue,) studied this question.