PERIPHERAL HEMODYNAMICS IN TYPE-II DIABETES - EFFECT OF ANGIOTENSIN-CONVERTING ENZYME-INHIBITION

The aim of this study was to investigate the effect of angiotensin con verting enzyme inhibition on forearm haemodynamics in normotensive and hypertensive Type II (non-insulin dependent) diabetic patients compar ed to non-diabetic patients with essential hypertension. The study was pet-formed on 16 Type II (non-insulin dependent) diabetic patients of whom 8 were normotensive and 8 hypertensive, and on another 8 non-dia betic patients with essential hypertension. Before and after a weeks o f enalapril administration, blood pressure, metabolic control, B.M.I., insulin levels, plasma and urinary Na and K and renal function were a ssessed. On the examination day each patient tvas placed in a supine p osition until blood pressure and heart rate stabilized and a venous bl ood sample was drawn for the determination of plasma renin activity, a ldosterone and plasma norepinephrine. Peripheral haemodynamics was det ermined by means of basal forearm blood flow and vascular resistance, maximum forearm blood flow and minimum vascular resistance after 10 mi ll of ischaemia, venous distensibility at 30 mmHg above minimum occlud ing pressure. Plasma renin activity increased and aldosterone decrease d in the three treatment groups after ACE-inhibition. Blood pressure a nd forearm vascular resistance were reduced whereas maximum arterial v asodilating capacity and venous distensibility increased in all groups . Metabolic parameters, B.M.I., insulin levels, electrolyte balance an d renal function were not modified by enalapril treatment. This study demonstrates that ACE-inhibitors exert haemodynamic changes on periphe ral circulation not only in non-diabetic hypertensive patients hut als o in Type II diabetic patients. The vasodilating capacity might repres ent an additional positive feature of this drug in patients with diabe tes.