Effect of Exercise Training on Estimated GFR, Vascular Health, and Cardiorespiratory Fitness in Patients With CKD: A Pilot Randomized Controlled Trial

Abstract

Background: Exercise capacity, which is predictive of all-cause mortality and cardiovascular disease risk, is reduced significantly in patients with non-dialysis-dependent chronic kidney disease. This pilot study examined the effect of moderate-intensity exercise training on kidney function and indexes of cardiovascular risk in patients with progressive chronic kidney disease stages 3 to4. Study Design: Single-blind, randomized, controlled, parallel trial. Setting & Participants: 20 patients (aged 18-80 years; 17 men) randomly assigned to rehabilitation (n=10) or usual care (n=10). Participants were included if they were 18 years or older and had evidence of rate of decline in creatinine-based estimated glomerular filtration rate (eGFRcr)≥2.9mL/min/1.73m2 per year for 12 months preintervention. Patients were excluded if they had unstable medical conditions or had recently started regular exercise. Intervention: The rehabilitation group received resistance and aerobic training (3 days per week) for a 12-month period. The usual care group received standard care. Outcomes: Kidney function assessed by comparing mean rate of change in eGFRcr (mL/min/1.73m2 per year) from a 12-month preintervention period against the 12-month intervention period. Pulse wave velocity (PWV), peak oxygen uptake (Vo 2peak), and waist circumference assessed at 0, 6, and 12 months. Measurements: eGFR assessed using creatinine, cystatin C (eGFRcys), and a combination of both values (eGFRcr-cys). Results: 18 participants (rehabilitation, 8; usual care, 10) completed the study. A significant mean difference in rate of change in eGFRcr (+7.8±3.0 [95% CI, 1.1-13.5] mL/min/1.73m2 per year; P =0.02) was observed between the rehabilitation and usual care groups, with the rehabilitation group demonstrating a slower decline. No significant between-group mean differences existed in absolute eGFRcr, eGFRcr-cys, or eGFRcys at 12 months of study intervention. Significant between-group mean differences existed in PWV (-2.30 [95% CI,-3.02 to-1.59] m/s), waist circumference (-7.1±12.8 [95% CI,-12.4 to-3.2] cm), and Vo 2peak (5.7 [95% CI, 1.34-10.10] mL/kg/min). Change in eGFRcr was correlated inversely with PWV (r =-0.5; P =0.04) at 12 months. Limitations: Small sample size, inconsistency between primary and secondary measures of kidney function. Conclusions: The effect of a 1-year exercise intervention on progression of kidney disease is inconclusive. A larger study with longer follow-up may be necessary.