Increased hematocrit and reduced blood pressure following control of glycemia in diabetes.

In this study we determine the effects of reducing blood glucose on mean arterial blood pressure (MAP) and hematocrit (Hct) in patients with type 2 diabetes who are not responding to conventional treatment in an intensive treatment program 1 year after initiation of treatment. Data on MAP, glucose and Hct was obtained from 21 diabetic type 2 individuals subjected to personalized treatment and compared (paired statistics) to pretreatment conditions. Exclusion criteria were severe retinopathy, diabetic nephropathy, amputation of diabetic foot and increased glucose>50 mg/dl. Treatment was the combined administration of glibenclamide and metformin dosed to obtain a reduction of glucose levels. Exercise and strict adherence to a prescribed diet were prescribed in all cases. One year after initiation of therapy, glucose decreased from 219 +/- 87 to 158+/-51 mg/dl (p<0.002), Hct increased from 41.6 +/- 3.2 to 44.7+/-2.9% (p<0.001) and MAP decreased from 100.6 +/- 11.0 to 94.3+/-7.2 mmHg (p<0.001). There were no statically significant changes in cholesterol and triglyceride concentrations. The patients lost weight (72.5+/-12.6 to 70.3+/-13.0 kg, p<0.001) and lowered blood creatinine concentration from 1.04+/-0.24 to 0.95+/-0.25 mg/dl, p<0.05. The increase in Hct should correspond to an increase in blood viscosity of about 12%, however blood pressure, and presumably vascular resistance, decreased by 6%. It is proposed that these effects are in part related to improved kidney function resulting in increased Hct and blood viscosity which increases vascular wall shear stress and NO bioavailability leading to a vasodilator effect.