Effect of sympathetic and plasma renin activity on hemodialysis hypertension.

BACKGROUND: The reasons for poor control of blood pressure in hemodialysis (HD) patients are not clear, while patients have achieved their desirable dry weight and excess weight are not different between the hypertensive and normotensive patients. A link between sympathetic activity and HD hypertension could be an alternative explanation. PATIENTS AND METHODS: We studied the effect of sympathetic and plasma renin-aldosterone activity of 10 hypertensive patients, 5 men and 5 women, aged from 30 to 60 years. The results were compared to those of another 10 normotensive hemodialysis patients. Blood samples were taken before HD and at the end of a 4-hour HD session for plasma aldosterone (ALDO), renin activity (PRA), adrenaline and noradrenaline determination. One month dialysis records, which includes 13 dialysis sessions and 26 blood pressure readings for each patient were used, for pre-dialysis and post dialysis mean arterial blood pressure (MAP) measurement. RESULTS: Pre-dialysis plasma adrenaline was 124.12 +/- 12.93 pg/ml vs. 121.12 +/- 14.71 pg/ml and plasma noradrenaline was 260.88 +/- 140.86 pg/ml vs. 138.11 +/- 122 +/- 32 pg/ml for hypertensive and normotensive patients, respectively. Post-dialysis plasma adrenaline and noradrenaline levels were 119.37 +/- 8.81 pg/ml vs. 120.62 +/- 15.35 pg/ml and 210.44 +/- 126.71 pg/ml vs. 94.88 +/- 64.05 pg/ml for hypertensive and normotensive patients, respectively. Pre-dialysis PRA was 8.70 +/- 6.37 ng/ml/h vs. 2.77 +/- 1.8 ng/ml/h and plasma ALDO was 457.07 +/- 245.54 pg/ml vs. 197.74 +/- 87.46 pg/ml for hypertensive and normotensive patients, respectively. Pre-MAP was 109.76 +/- 5.21 mmHg vs. 99.28 +/- 7.13 mmHg and post-MAP was 107.22 +/- 6.74 mmHg, vs. 91.61 +/- 7.27 mmHg for hypertensive and normotensive patients, respectively. Plasma ALDO and fluid volume removed by ultrafiltration were found to be significantly correlated (p < 0.05). PRA and plasma adrenaline-noradrenaline levels were not correlated with MAP or body weight alterations. CONCLUSIONS: It is suggested that sympathetic activity, as it was expressed by plasma catecholamine alterations, is not associated with hemodialysis hypertension.

Renal hemodynamics in hypertensive renal allograft recipients: effects of calcium antagonists and ACE inhibitors.

Hypertension present in more than 50% of successfully renal transplanted patients and its prevalence has slightly increased since the introduction of cyclosporine A. Twenty patients, 9 women and 11 men aged from 30 to 58 years, with stable cadaveric renal allograft function and moderate to severe hypertension, were included in the study. Renal artery graft stenosis causing hypertension were excluded. All patients were given triple drug immunosuppressive treatment with methylprednisolone, azathioprine and cyclosporine A (CsA) and their hypertension was treated with a nifedipine dose of 20 mg twice daily. To evaluate the effect of ACE inhibitors on renal hemodynamics and hypertension, a 4 mg/daily dose of perindopril was added to the above regimen for two months. Effective renal plasma flow (ERPF) decreased from 208 +/- 54 to 168 +/- 61 ml/min and renal vascular resistance (RVR) increased from 75 +/- 12 to 88 +/- 17 mm Hg/ml/min (P < 0.05 and P < 0.01, respectively). Mean blood pressure was significantly (P < 0.001) reduced by the combination of both agents in comparison to the blood pressure control by monotherapy with nifedipine. It is suggested that the combination of both antihypertensive agents was more effective than monotherapy with nifedipine in controlling blood pressure, but less favorable on the renal hemodynamic response in hypertensive renal transplant patients who were maintained on CsA.

Management of moderate to severe hypertension and proteinuria by nifedipine retard and perindopril after renal transplantation.

Clinical studies of treatment with angiotensin converting enzyme (ACE) inhibitors in patients with glomerular disease have shown the clinical efficacy of these agents. Fifteen renal transplant hypertensive and proteinuric patients on triple drug treatment with cyclosporin (CSA), azathioprine and methylprednisolone entered the therapeutic protocol of this study. All patients followed up last year had stable graft function (serum creatinine less than 2 mg/dl). Hypertension was treated by nifedipine retard and occasionally by furosemide. Patients with a renal artery graft stenosis, at least as judged by technetium-scan imaging were excluded. In order to evaluate the possible role of ACE inhibitors on hypertension and proteinuria, perindopril 4 mg/daily was added for two months to the above regimen. Two patients, who showed a reversible deterioration of renal function during treatment and three who did not comply to the therapeutic protocol were excluded. Systolic and diastolic blood pressure as well as 24 h urine protein was found to be significantly (p < 0.01) reduced at the end of the two-month combined treatment with perindopril and nifedipine retard in comparison to the result of monotherapy with nifedipine retard. GFR and ERPF showed no significant difference (NS) between the two modes of treatment. It is suggested that the combined treatment with nifedipine retard and perindopril is more effective than the monotherapy with nifedipine retard in the management of moderate to severe post-transplant hypertension and proteinuria of renal transplant patients.