Acute and Long‐term Renal Effects of Angiotensin Converting Enzyme Inhibition in Normotensive, Normoalbuminuric Insulin‐dependent Diabetic Patients

Abstract

Glomerular filtration rate (GFR) (thalamate clearance), renal plasma flow (RPF) (hippuran clearance), and urinary albumin excretion rate (AER) were measured in 10 normoalbuminuric, normotensive insulin‐dependent diabetic patients and 8 normal subjects before and during acute angiotensin converting enzyme (ACE) inhibition by means of enalapril (10 mg IV). The effect of placebo versus enalapril (30 mg day⁻¹) was also studied for 3‐month treatment periods in the insulin‐dependent diabetic patients. Acute ACE‐inhibition caused a decline in filtration fraction (FF) from 0.259±0.011 (±SE) to 0.237±0.013 (2ppppp−1 (2p−6 to 0.92±0.12 times 10⁻⁶ (2p−1 min⁻¹) and significant changes in GFR, RPF, mean arterial pressure or HbA_1c were not observed. Thus, acute and long‐term ACE‐inhibition in normotensive normoalbuminuric insulin‐dependent diabetic patients are associated with changes in renal haemodynamics and albumin excretion rate, probably as a result of a reduction in glomerular capillary hydrostatic pressure.