Small uncontrolled studies of dialysis-dependent CKD (chronic kidney disease) patients have demonstrated abnormalities of cardiovascular autonomic control and vascular compliance, which may contribute to adverse cardiovascular morbidity in this population. However, there is little information utilizing newer non-invasive techniques in pre-dialysis patients with increasing degrees of uraemia. In the present study, 55 non-dialysis-dependent non-diabetic CKD patients with mean GFR (glomerular filtration rate) of 27 ml·min −1 ·m −2 were studied. All patients underwent a 10-min period of electrocardiographic and non-invasive blood pressure monitoring. Cardiac BRS (baroreceptor sensitivity) was calculated from the combined α-index. PWV (pulse wave velocity) measurement and determination of arterial wave reflexion by applanation tonometry was performed in all patients. Mean (S.D.) cardiac BRS was 10.8 (7.1) ms/mmHg and mean (S.D.) PWV was 8.6 (1.7) m/s. Reduced GFR was correlated with increased PWV and decreased cardiac BRS. On logistic regression analysis with adjustment for clinical significant risk factors, severely impaired renal function (assessed by GFR <15 ml·min −1 ·m −2 ) was associated with increased large artery stiffness [odds ratio for PWV=3.14 (95% confidence intervals, 1.03–9.53); P =0.04] and increased cardiovascular autonomic dysfunction [odds ratio for BRS=0.87 (95% confidence intervals, 0.75–1.80); P =0.06]. In conclusion, non-dialysis dependent non-diabetic CKD patients with decreasing GFR have reduced cardiac BRS and increased large artery stiffness. This may have important prognostic and therapeutic consequences for the management of vascular disease in a pre-dialysis population.

Cardiac BRS (baroreceptor reflex sensitivity) is impaired following ischaemic stroke and predicts the risk of subsequent long-term death and disability. Impaired cardiac BRS may be due to impaired central processing of baroreceptor information following stroke or reduced baroreceptor activity due to increased large artery stiffness. We evaluated the relationship between large (aortic) artery stiffness and cardiac BRS during the acute phase of ischaemic stroke and in comparison with a group of stroke-free control subjects. Thirty-one ischaemic stroke patients were studied within 48 h of onset and again on day 14, along with 26 control subjects free of cerebrovascular disease. Cardiac BRS (determined by spectral analyses) and arterial stiffness estimated by PWVcf (carotid–femoral pulse wave velocity) using applanation tonometry were obtained. At baseline, cardiac BRS was lower in the stroke compared with the control group (4.3±2.3 compared with 6.5±4.2 ms/mmHg; P <0.05). Cardiac BRS values were correlated with PWVcf at <48 h ( r =−0.51, P <0.01) and on day 14 ( r =−0.54, P <0.01), but not in the control group ( r =−0.27, P =not significant). In quantile regression models, taking into account the effect of all cardiovascular variables, cardiac BRS was independently related to PWVcf at baseline and on day 14 in the stroke patients, but stroke was not related to cardiac BRS level when other cardiovascular variables were considered. Wall stiffness of the arterial vessels involved in the baroreflex arc may account for, at least in part, the reduced cardiac BRS observed in acute stroke patients.