Dihydropyridine calcium antagonists and renal function in hypertensive kidney transplant recipients.

Objective: To investigate whether calcium antagonists are nephroprotective in hypertensive cyclosporine-treated renal allograft recipients.

Methods: We studied 50 hypertensive and 17 normotensive renal transplants (eight females, nine males; 14-54 years, mean age 38.8 +/- 3.5 years). Hypertensive patients were randomized to be treated with (+Ca; 11 females, 13 males; 20-65 years, mean age 43.1 +/- 3 years) or without (-Ca; 15 females, 11 males; 25-60 years, mean age 41.3 +/- 2.5 years) a calcium antagonist (nitrendipine or nifedipine). Additional antihypertensives were given stepwise according to a standardized protocol: beta1-adrenoceptor blocker, diuretic alpha1-adrenoceptor blocker or vasodilator. Data were analysed at 0, 1, 2 and 3 years on an intention-to-treat basis.

Results: Hypertensive patients had a higher body mass index at 0/3 years (23.7 +/- 0.6/25.1 +/- 0.6 kg/m2) than normotensive patients (22.2 +/- 0.6/22.1 +/- 0.7 kg/m2). During the study, blood pressure in normotensive transplants was always slightly, but not significantly, lower than that of transplants with treated hypertension. There was no difference between the groups (+Ca) and (-Ca). Cr51-ethylenediaminetetracetic acid (EDTA) clearance (0/2 years) was 58 +/- 4/57 +/- 6 ml/min in normotensives, 52 +/- 4/47 +/- 4 ml/min in hypertensives (+Ca) and 47 +/- 4/49 +/- 6 ml/min in hypertensives (-Ca). Proteinuria (0/3 years) was 0.16 +/- 0.04/0.15 +/- 0.02 g/24 h in normotensive, 0.26 +/- 0.08/0.23 +/- 0.05 g/24 h in hypertensives (+Ca) and 0.26 +/- 0.07/0.22 +/- 0.05 g/24 h in hypertensives (-Ca).

Conclusions: Post-transplant hypertension is associated with higher body mass index and poor renal function. No difference in the course of Cr51-EDTA clearance, serum creatinine, proteinuria or blood pressure was observed between groups treated with or without calcium antagonists. Calcium antagonists and conventional antihypertensive treatment have the same nephroprotective effect in hypertensive renal transplants, when treatment is started 3 months after transplantation.