Background: Systemic inflammation and protein-energy malnutrition may be associated with poor outcomes in kidney disease.
Methods: We studied 26 adults (age, 65 +/- 10 [SD] years) with chronic kidney disease, not on dialysis therapy. Subjects were randomly assigned to resistance training (n = 14) or a control group (n = 12) for 12 weeks, while counseled to consume a low-protein diet (protein, approximately 0.6 g/kg/d). We determined whether resistance training reduces levels of inflammatory mediators (serum C-reactive protein [CRP] and interleukin-6 [IL-6]), in addition to previously reported improvements in nutritional and functional status in this same subject population.
Results: Serum CRP levels were reduced in subjects undergoing resistance training (-1.7 mg/L) compared with controls (1.5 mg/L; P = 0.05). Similarly, IL-6 levels were reduced in the resistance-exercise group versus controls (-4.2 versus 2.3 pg/mL; P = 0.01). Resistance training lead to skeletal muscle hypertrophy, shown by increases in type I (24% +/- 31%) and type II (22% +/- 41%) muscle fiber cross-sectional areas, compared with control subjects (-14% +/- 34% and -13% +/- 18%, respectively; P < 0.05). Muscle strength also improved with resistance training (28% +/- 14%) compared with controls (-13% +/- 22%; P = 0.001).
Conclusion: Resistance training reduced inflammation and improved nutritional status in individuals with moderate chronic kidney disease consuming a low-protein diet. These results need to be investigated further in larger cohorts of patients with varying stages of kidney disease to determine whether resistance training can improve disease outcomes long term.