A 12-month lifestyle intervention does not improve cardiac autonomic function in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) are at a high risk of future autonomic dysfunction and cardiovascular disease. The aim of this study was to examine the effects of a 12-month lifestyle intervention (LI) involving regular aerobic exercise on cardiac autonomic function in CKD patients.

Pooled exploratory analysis.

113 eligible patients with stage 3-4 CKD (eGFR 25-60 ml/min/1.75m²) participated in a LI program, including an 8-week individualised gym-based exercise program followed by a 10-month home-based program. The control (CON) group underwent standard nephrological care. The following parameters were assessed prior to and following the 12-month study period: cardiorespiratory fitness (VO₂peak) from a graded exercise test; cardiac autonomic function from time, frequency, and non-linear measures of heart rate variability (HRV), heart rate (HR) recovery following peak exercise, and chronotropic competence during exercise.

Compared to the CON group, the LI group significantly increased VO₂peak (CON = -1.0 vs. LI = +1.8 ml/kg/min, p < 0.01) while there was no significant improvement in any HRV measure (p = 0.85), HR recovery (p = 0.38) or chronotropic competence (p = 0.28). Changes in relative VO₂peak were significantly associated with changes in a non-linear HRV measure, α1 (p < 0.01), independent of age and eGFR (r² = 0.196, p = 0.03).

Despite the significant increase in cardiorespiratory fitness for the LI group, there were no changes in cardiac autonomic function. However, α1 may be a sensitive measure to assess VO₂peak changes in this clinical cohort. Further research is required to investigate the role of different modalities of exercise training to enhance cardiac autonomic function in patients with CKD.