Antihypertensive treatment can slow down the decline in glomerular filtration rate (GFR) with time. In patients with
diabetic nephropathy,
angiotensin converting enzyme (ACE) inhibition has been shown to be more effective in this regard than conventional
antihypertensive therapy. Whether this applies to the much larger population of patients with
essential hypertension is not yet known. In the present study, the effects of two different
antihypertensive therapies on the loss of GFR with time, determined with Cr51-EDTA clearance after 6, 12 and 24 months of treatment, were assessed in a prospective, randomised, double-blind trial in 257 patients with
essential hypertension. All had normal renal function and none had
diabetes mellitus or glucosuria.
Proteinuria (dipstick positive or trace) was detected in 7 patients initially. The two therapeutic modalities were the
ACE inhibitor cilazapril and the beta-
adrenoceptor blocking agent
atenolol. Both
therapies were equally effective in lowering systolic blood pressure (e.g. from 168 mmHg to 152 mmHg with
cilazapril and from 170 mmHg to 155 mmHg with
atenolol after 6 months, p < 0.001 for both). However,
atenolol was slightly but significantly more effective in lowering the diastolic blood pressure at 6, 12 and 24 months. The decline in GFR with time was significantly smaller with
cilazapril than with
atenolol. After 6 months the reduction in GFR was 1.0 vs. 4.0 ml/min x 1.73 m2, p = 0.008 (
cilazapril vs.
atenolol) and after 12 months the corresponding changes were 2.0 vs. 4.5 ml/min x 1.73 m2, p = 0.04 and after 24 months 3.0 vs. 4.0 ml/min x 1.73 m2, respectively (n.s.).(ABSTRACT TRUNCATED AT 250 WORDS)