Proteinuria reduction and progression to renal failure in patients with type 2 diabetes mellitus and overt nephropathy.

Background: Little is known of the effects of blood pressure reduction by specific classes of antihypertensive drugs on the association between proteinuria reduction and progression of kidney insufficiency and development of end-stage kidney disease in patients with overt diabetic nephropathy in type 2 diabetes mellitus. Methods: Associations between baseline proteinuria and proteinuria reduction by either irbesartan, amlodipine, or control for similar decrements in blood pressure and the cumulative incidence of renal end points were examined using the Kaplan-Meier method in patients enrolled in the Irbesartan Diabetic Nephropathy Trial. Results: Risk for kidney failure doubled for each doubling of baseline proteinuria level (hazard ratio, 2.04; 95% confidence interval, 1.87 to 2.22; P < 0.001). For each halving of proteinuria level between baseline and 12 months with treatment, risk for kidney failure was reduced by more than half (hazard ratio, 0.44; 95% confidence interval, 0.40 to 0.49; P < 0.001). For the same proportional change in proteinuria, the reduction in risk for kidney failure was significantly greater for irbesartan compared with amlodipine (P = 0.048), but not control (P = 0.245). Proteinuria reduction in the first 12 months of therapy with irbesartan is associated with 36% of the total renoprotective effect observed. Conclusion: Baseline proteinuria is an important risk factor for kidney failure and provides a means to identify patients at greatest risk. Halving proteinuria halves the kidney risk. Proteinuria reduction using an angiotensin receptor-blocking agent, such as irbesartan, should be regarded as an important therapeutic goal in renoprotective strategies

Citrate- vs. acetate-based dialysate in bicarbonate haemodialysis: consequences on haemodynamics, coagulation, acid-base status, and electrolytes.

BACKGROUND: A concentrate for bicarbonate haemodialysis acidified with citrate instead of acetate has been marketed in recent years. The small amount of citrate used (one-fifth of the concentration adopted in regional anticoagulation) protects against intradialyser clotting while minimally affecting the calcium concentration. The aim of this study was to compare the impact of citrate- and acetate-based dialysates on systemic haemodynamics, coagulation, acid-base status, calcium balance and dialysis efficiency. METHODS: In 25 patients who underwent a total of 375 dialysis sessions, an acetate dialysate (A) was compared with a citrate dialysate with (C+) or without (C) calcium supplementation (0.25 mmol/L) in a randomised single-blind cross-over study. Systemic haemodynamics were evaluated using pulse-wave analysis. Coagulation, acid-base status, calcium balance and dialysis efficiency were assessed using standard biochemical markers. RESULTS: Patients receiving the citrate dialysate had significantly lower systolic blood pressure (BP) (-4.3 mmHg, p < 0.01) and peripheral resistances (PR) (-51 dyne.sec.cm-5, p < 0.001) while stroke volume was not increased. In hypertensive patients there was a substantial reduction in BP (-7.8 mmHg, p < 0.01). With the C+ dialysate the BP gap was less pronounced but the reduction in PR was even greater (-226 dyne.sec.cm-5, p < 0.001). Analyses of the fluctuations in PR and of subjective tolerance suggested improved haemodynamic stability with the citrate dialysate. Furthermore, an increase in pre-dialysis bicarbonate and a decrease in pre-dialysis BUN, post-dialysis phosphate and ionised calcium were noted. Systemic coagulation activation was not influenced by citrate. CONCLUSION: The positive impact on dialysis efficiency, acid-base status and haemodynamics, as well as the subjective tolerance, together indicate that citrate dialysate can significantly contribute to improving haemodialysis in selected patients