Impairment of heart rate recovery index in autosomal-dominant polycystic kidney disease patients without hypertension

BACKGROUND: We aimed to determine the status of the autonomic nervous system in patients with autosomal-dominant polycystic kidney disease (ADPKD) who were normotensive and had normal renal function. METHODS: A total of 28 normotensive ADPKD patients with normal renal function and 30 healthy control subjects consented to participate in the study. Heart rate recovery (HRR) indices were defined as the reduction in heart rate from the rate at peak exercise to the rate at the 1st, 2nd, 3rd and 5th minutes after the cessation of the exercise stress test; these results were indicated HRR(1), HRR(2), HRR(3) and HRR(5), respectively. RESULTS: The 1st- and 2nd-minute HRR indices of patients with ADPKD were significantly lower than those of the healthy control group (27.1±7.9 vs 32.0±7.9; p=0.023 and 46.9±11.5 vs 53.0±9.0; p=0.029, respectively). Similarly, HRR indices after the 3rd and 5th minutes of the recovery period were significantly lower in patients with ADPKD when compared with indices in the control group (56.7±12.0 vs 65.1±11.2; p=0.008 and 62.5±13.8 vs 76.6±15.5; p =0.001, respectively). CONCLUSION: Impaired HRR index is associated with normotensive early-stage ADPKD patients. Increased renal ischemia and activation of the renin-angiotensin-aldosterone system (RAAS) may contribute to impairment in the autonomic nervous system in these patients before the development of hypertension. Even if ADPKD patients are normotensive, there appears to be an association with autonomic dysfunction and polycystic kidney disease.