Effect of enalapril on hemorheology in hypertensive patients with renal disease.

Abstract

An open, prospective study was undertaken to investigate the effects of enalapril on hemorheology in patients with renal disease and complicating hypertension. Cellular and plasma determinants of blood viscosity and renal function were measured in 19 patients at baseline and 2, 60 and 120 days after treatment with enalapril (mean dose 5.4; range 2.5-20 mg/day). Within 2 days of starting enalapril there was a significant decrease in apparent blood viscosity measured at high shear rate (-0.15 mPa.s; p < 0.05) which fell further by day 60. The decrease in blood viscosity was primarily the result of hemodilution, as evidenced by a concurrent fall in plasma albumin concentration and plasma viscosity. A small, but significant decrease, in hemoglobin concentration (-7.4g/l; p = 0.03), and a trend of improved red blood cell (RBC) and white blood cell (WBC) rheological properties may have also contributed to the decrease in blood viscosity. We conclude that enalapril had a beneficial effect on hemorheology in patients with renal disease. The mechanism of the rheological changes appeared to be multifactorial and would be expected to decrease vascular resistance to blood flow.