Influence of a Cardiac Rehabilitation Program on Renal Function in Patients With Cardiovascular Disease in a One-Year Follow-Up

Background: Exercise training may improve renal function in patients with chronic kidney disease (CKD). The effect of cardiac rehabilitation (CR) with exercise training on renal function has not yet been established. We evaluated the effects of CR on renal function in patients with cardiovascular disease (CVD). Methods: Twenty-three CVD patients in a 1-year CR program (CR group) who had ischemic heart disease (IHD) and/or heart failure were compared with 26 age-and gender-matched CVD patients without CR (non-CR group, standard pharmacological care alone). At baseline and after 1 year, urea nitrogen (UN), creatinine (Cr), potassium (K), estimated glomerular filtration rate (eGFR) and hematocrit (Hct) in blood were assessed. Results: There were no differences in the patient characteristics at baseline between the CR and non-CR groups except for the percentages of heart failure and the use of calcium channel blocker. After 1 year, there were no significant changes in UN, Cr, K, eGFR or Hct in either the CR or non-CR groups. The patients in the CR group were divided into two groups according to the eGFR level at baseline: low (n = 12, eGFR < 51 mL/minute/1.73 m(2), indicating mild-to-moderate CKD) and high (n = 11, eGFR = 51 mL/minute/1.73 m(2)) eGFR groups. Although there were no differences in the patient characteristics at baseline between the low and high eGFR groups, the low eGFR group showed a significant increase in eGFR after the 1-year CR program. Conclusions: CR may improve renal function in patients with mild-to-moderate CKD.