Reduced Albuminuria During Early and Aggressive Antihypertensive Treatment of Insulin-dependent Diabetic Patients with Diabetic Nephropathy

Abstract

Urinary albumin excretion rate (radial immunodiffusion), glomerular filtration rate (GFR) (single-shot ⁵¹Cr-EDTA technique), and arterial blood pressure (BP) were measured in 12 juvenile-onset, insulin-dependent diabetic patients with persistent proteinuria (> 0.5 g/day) due to diabetic nephropathy. Mean age of the patients was 30 yr. All patients had a diastolic blood pressure ≥95 mm Hg. Metoprolol, hydralazine, and furosemide or thiazide were used as antihypertensives. During the 12-mo treatment period, BP decreased from 151/104 to 133/85 mm Hg (P < 0.001), the urinary albumin excretion rate diminished from 1447 to 613 μg/min (P < 0.005), and GFR declined from 96 to 89 ml/min/1.73 m² (P < 0.01). A linear relationship between mean blood pressure and the logarithm of the albuminuria was found (r = 0.48, P < 0.01). Arterial hypertension is an early feature of diabetic nephropathy in young insulin-dependent patients. Early and aggressive treatment of that condition decreases albuminuria, probably due to reduced intraglomerular filtration pressure. Whether sustained reduction in arterial blood pressure to near-normal levels during several years also reduces the rate of decline in GFR in diabetic nephropathy remains to be established.