Calf blood flow and vascular resistance in middle-aged and elderly hypertensives.

Hypertension is associated with increased total peripheral vascular resistance. Calf blood flow and vascular resistance in two groups of hypertensives of different age has been evaluated: 85 middle-aged hypertensives (MH) and 25 elderly hypertensives (EH), and in two groups of 20 normotensive control subjects of similar age. Calf blood flow at rest (RF) and after ischaemia (PF) was determined by strain-gauge plethysmography. Basal (BVR) and minimal (MVR) vascular resistance were obtained by the mean blood pressure (MBP):RF and MBP:PF ratio. Blood flow at rest was reduced only in EH, while PF was significantly lower in MH and in EH in comparison with the respective controls. In parallel, BVR and MVR were higher in MH and in EH compared with controls. The increase of BVR and of MVR was more evident in EH. These results suggest that in EH there is an impairment of the calf maximal vasodilatation capacity, probably due to the long duration of hypertension.