Effect of cardiac rehabilitation on the renal function in chronic kidney disease - Analysis using serum cystatin-C based glomerular filtration rate

Abstract

Background: Whether an individually determined appropriate level of cardiac rehabilitation (CR) has a favorable effect on the renal function still remains unclarified. The aim of this study was to confirm the effect of CR on the estimated glomerular filtration rate (eGFR) using cystatin C, which is known to be unaffected by physical exercise. Methods: The study population was comprised of 86 patients (61 males; average age 74 y/o) with a lower-moderate level of chronic kidney disease (CKD) who was admitted to our hospital for treatment of cardiovascular disease (CVD) and who participated in our 3-month CR program. The exercise capacity was assessed by cardiopulmonary exercise testing (CPX) and the eGFR was measured by a formula based on the serum cystatin C concentration (eGFRcys) in each patient both at the beginning and end of the CR. Results: In the CVD patients with CKD, both the peak oxygen uptake (VO2) and peak work rate (WR) improved significantly after CR (15.0 ± 3 to 15.8 ± 3 ml/min/kg, p = 0.002. 65.5 ± 21 to 70.2 ± 25 W, p = 0.001). Regarding the renal function, the eGFRcys improved (45.2 ± 11 to 47.3 ± 13 ml/min/1.73 m2, p = 0.023), however, the eGFR assessed by the serum creatinine (eGFRcr) did not improve after CR (45.1 ± 12 to 44.9 ± 13 ml/min/1.73 m2, p = 0.834). Conclusions: In CVD patients, a novel CR program significantly improved the exercise capacity. Further, CR was shown to have a favorable effect on the renal function when it was estimated by the eGFRcys. Keywords: Cardiac rehabilitation, Chronic kidney disease, Cardiovascular disease, Cystatin C, Estimated glomerular filtration rate, Exercise capacity