DIFFERENCES BETWEEN NISOLDIPINE AND LISINOPRIL ON GLOMERULAR-FILTRATION RATES AND ALBUMINURIA IN HYPERTENSIVE IDDM PATIENTS WITH DIABETIC NEPHROPATHY DURING THE FIRST YEAR OF TREATMENT

Our objective was to compare the effect of a long-acting calcium antag onist (nisoldipine) versus an ACE inhibitor (lisinopril) on albuminuri a, arterial blood pressure, and glomerular filtration rate (GFR) in hy pertensive IDDM patients with diabetic nephropathy. We performed a 1-y ear, double-blind, double-dummy, randomized, controlled study comparin g nisoldipine (20-40 mg once daily) with lisinopril (10-20 mg once dai ly) in 52 hypertensive IDDM subjects with diabetic nephropathy. Three patients dropped out, and results for the remaining 49 (25 nisoldipine , 24 lisinopril) are presented. Diuretics were required in 10 nisoldip ine- and 8 lisinopril-treated patients. Every 3 months, 24-h ambulator y blood pressure (TM2420, A&D, Tokyo, Japan) and albuminuria in three 24-h samples (enzyme immunoassay) were measured; GFR (Cr-51-EDTA plasm a clearance) was recorded every 6 months. Mean arterial blood pressure (24 h) was reduced from (mean +/- SE) 108 +/- 3 mmHg at baseline to 1 01 +/- 2 in average during treatment in the lisinopril group and from 105 +/- 2 to 103 +/- 2 in the nisoldipine group (P = 0.06 comparing ch anges in the two groups). Albuminuria was reduced 47% (95% CI 21-65) i n the lisinopril group versus an increase of 11% (-3 to 27) in the nis oldipine group (P = 0.001). Fractional albumin clearance was reduced 3 7% (95% CI 4-59%) in the Lisinopril versus an increase of 35% (8-69%) in the nisoldipine group (P < 0.01). GFR decreased from 85 +/- 5 ml . min(-1) . 1.73 m(-2) to 73 +/- 5 in the lisinopril group and from 84 /- 6 to 80 +/- 7 in the nisoldipine group (P < 0.05). The effect of st udy medication on albuminuria and GFR was independent of changes in sy stemic blood pressure and baseline variables in multiple regression an alyses. In summary, lisinopril reduced albuminuria, but also GFR, to a greater extent than did nisoldipine in hypertensive IDDM patients wit h diabetic nephropathy during the 1st year of treatment. Longer follow -up is required to clarify whether these drugs have different renoprot ective effects.