Hypotensive Therapy Reduces Microvascular Albumin Leakage in Insulin‐dependent Diabetic Patients with Nephropathy

The effect of hypotensive therapy on the transcapillary escape rate of albumin (TERalb) was studied in eight hypertensive insulin-dependent diabetic patients (mean age 29, range 19-42 years) with nephropathy and retinopathy. Transcapillary escape rate of albumin (initial disappearance of intravenously injected 125I-labelled human serum albumin), urinary albumin excretion rate (radial immunodiffusion), and glomerular filtrate rate (single bolus 51-Cr-EDTA technique) were measured. After hypotensive treatment (mean duration, 23 months, range 7-39 months) with combinations of metoprolol, hydralazine, and frusemide or thiazide diuretics, arterial blood pressure fell from 152/103 +/- 18/6 mmHg (mean +/- SD) to 133/81 +/- 12/10 mmHg (p less than 0.01), transcapillary escape rate of albumin from 10.2 +/- 1.8 to 8.1 +/- 1.8% of intravascular mass of albumin/h (p less than 0.01), albuminuria from 1803 (370-5066) micrograms/min to 940 (101-2676) micrograms/min (median and range, p less than 0.05), and glomerular filtration rate from 103 +/- 23 to 84 +/- 22 ml/min/1.73 m2 (p less than 0.01). Our study suggests that effective hypotensive treatment reduces the abnormally elevated albumin leakage characteristically found in insulin-dependent diabetic patients with clinical microangiopathy. This may be due to a reduction in the hydrostatic pressure in the microcirculation.