The Effect of Resistance Exercise on Inflammatory and Myogenic Markers in Patients with Chronic Kidney Disease

Background: Patients with Chronic Kidney Disease (CKD) experience muscle wasting which is associated with morbidity and mortality. Exercise can provide physiological and psychological benefits for CKD patients, however the molecular response to exercise is unknown. The aim of our study was to investigate the molecular response to resistance exercise before and after training in patients with CKD. Methods: This is a secondary analysis of a randomized trial that investigated the effect of 8-week progressive resistance training on muscle mass and strength compared to non-exercising controls. A sub-set of the cohort consented to vastus lateralis skeletal muscle biopsies in which we have studied molecular events relating to protein degradation, myogenesis, inflammation and oxidative stress. Results: Untrained, a single bout of exercise resulted in blunted phosphorylation of Akt and reduced mRNA expression of MyoD and myogenin, which was somewhat restored after 8 weeks of resistance training. We also observed a heightened and prolonged inflammatory response to unaccustomed exercise, which was reduced after training. There was no evidence that resistance exercise training created a prolonged oxidative stress response within the muscle, or increased catabolism suggesting that the exercise was not damaging. Conclusions: These results indicate that resistance exercise training may help restore the anabolic environment that is usually created by a bout of exercise, but is initially absent in these patients. These data also suggest that if patients are similarly limited in their response to other anabolic stimuli such as feeding, this may provide part of the explanation why patients lose muscle mass.