Post-exercise heart rate recovery across stages of non-dialysis chronic kidney disease

Chronic kidney disease (CKD) is associated with increased cardiovascular morbidity and mortality, partly mediated by autonomic dysfunction. Heart rate recovery (HRR), particularly during the first minute after exercise (HRR1), reflects early parasympathetic reactivation and provides an integrative measure of cardiovascular autonomic regulation. However, data across non-dialysis CKD stages remain limited. In this prospective observational study, 120 patients with CKD stages 1–4 and 30 age- and sex-matched healthy controls underwent symptom-limited treadmill exercise testing. HRR was calculated at 1, 2, 3, and 5 min after peak exercise. Associations between HRR indices and CKD stage were assessed using ANOVA and age- and sex-adjusted general linear models. Within the CKD cohort, multivariable linear regression was performed to identify independent predictors of HRR1. Baseline and peak heart rates were comparable across CKD stages and controls. In contrast, HRR values declined progressively with advancing CKD stage (HRR1 overall P < 0.001). Compared with controls, HRR1 was significantly reduced from stage 2 onward. After adjustment for age and sex, CKD stage remained associated with HRR1; however, in an expanded CKD-only model additionally including cardiometabolic comorbidities, this association was attenuated. Within the CKD cohort, HRR1 correlated positively with eGFR (r = 0.36, P < 0.001), and both age (β = −0.326, P = 0.001) and eGFR (β = 0.212, P = 0.024) independently predicted HRR1. Post-exercise heart rate recovery declines progressively across CKD stages and is independently associated with renal function in non-dialysis patients. These findings suggest that impaired HRR1 reflects early cardiovascular autonomic dysregulation across non-dialysis CKD.