Skin blood flow and veno-arteriolar response in essential hypertension]

High arteriolar resistance and vasoconstriction are considered an important factor in essential hypertension. In 98 patients with essential hypertension and 60 normals we evaluated skin flow at rest (RF) and the veno-arteriolar response (VAR = the vasoconstriction due to leg dependency) using laser-Doppler flowmetry. Measurements were repeated after four weeks in normals and after treatment with nifedipine (10 mg tid) in hypertensives. At the beginning of the study in hypertensives RF and VAR were lower than in normals. After nifedipine treatment a decrease in blood pressure was associated with an increase in RF and VAR. A difference was also observed between responders and non responders (16.3%). RF and VAR at the beginning of the study were both higher in non responders and did not change after treatment indicating that the degree of vasoconstriction in these patients was lower. In conclusion microcirculation changes in hypertension may be quantified by laser-Doppler flowmetry and used to evaluate vasoconstriction and the effects of drugs.