INTRODUCTION AND AIMS:
The effect of Residual Renal Function (RRF) in patients with end stage renal disease in peritoneal dialysis and hemodialysis is extensively studied and is associated with significantly lower morbidity and mortality. RRF declines with time on dialysis and very few studies have investigated therapeutic interventions for preserving RRF in new hemodialysis patients. The effect of Angiotensin converting enzyme inhibitor (ACEi) on reducing the rate of decline of GFR in proteinuric nephropathies is well established. The aim of our study was to investigate whether enalapril, an ACEi, given in new dialysis patients, would provide the benefit of slowing the loss of residual renal function.
METHODS:
A prospective, randomized open label study was designed. Inclusion criteria were residual GFR >= 5 ml/min/1.73 m2, urine output >= 200 ml/day, not taking ACEi or ARBs for more than 3 months. Exclusion criteria were intolerance of ACEi and/or ARBs, blood pressure <120/70 mmHg, peritoneal dialysis as a previous dialysis mode, failing from transplantation, known history of congestive heart failure, cardiovascular disease and bilateral or unilateral renal artery stenosis. Within 4 years, 55 starting dialysis patients were screened, 42 met the inclusion criteria and were randomized in two groups: in treatment with enalapril (e.gr.) or no treatment at all (c.gr). ACEi and/or ARBs were discontinued 3 months prior enrolment. RRF was estimated at 0 (after the first week on dialysis), 3, 6, 9 and 12 months from initiation of dialysis.
RESULTS:
Both groups had similar clinical, laboratory, pre-study treatment characteristics and no differences concerning volume status, events of intradialytic hypotension, hospitalization days. 14% of the treatment group and 19% of the control group were anuric at the end of the study. After the 9th month, GFR declined more rapidly in the control group (p=0,013) and at the end of the study, GFR was 2 times higher than control group (2,50 +/-1,2 ml/min/1,73 m2 e.gr. vs 1,11 +/-0,5 ml/min/1,73 m2 c.gr., p=0,009) Urine volume declined as well. After the 6th month there was a faster decline in urine volume at the control group and a statistical difference between treatment and control group at the end of the study (570 +/-270 ml e.gr. vs 330 +/-160 ml c.gr. p=0,023).
CONCLUSIONS:
A very limited number of studies have investigated renoprotection after dialysis. Our study has proven that enalapril, given in a single morning dose in new dialysis patients has a significant effect on preserving RRF at least during the first 12 months. These data indicate the need not to withhold ACE inhibitors when GFR approximates levels requiring replacement therapy or when patients initiate dialysis. This intervention was safe and it wasn't associated with adverse side effects. Further studies are necessary in order to investigate the potential long term effect of ACEi on RRF, on morbidity and mortality in those patients.

Date: Saturday, June 26, 2010
Session Info: Oral Session: Pathophysiology of kidney disease