Endothelium-dependent vasodilation in normotensive subjects with a familial history of essential hypertension and in young subjects with borderline hypertension

OBJECTIVE: To investigate if young normotensive subjects with a familial history of essential hypertension (FHH) or young borderline-hypertensive (BHT) subjects have a defect endothelial function. METHODS: Fifteen young (26 +/- 4 years) healthy normotensive (115 +/- 8/71 +/- 6 mmHg) subjects with a FHH, 31 matched healthy normotensive subjects without FHH and seven BHT (143 +/- 12/92 +/- 2 mmHg), otherwise healthy, young males underwent evaluation of endothelium-dependent vasodilation (EDV) and endothelium-independent vasodilation (EIDV), by means of local intra-arterial infusions of methacholine (MCh, evaluating EDV) and sodium nitroprusside (SNP, evaluating EIDV) in the forearm. Forearm blood flow (FBF) was measured by venous occlusion plethysmography. RESULTS: Although there was no significant difference between normotensive subjects with and without a FHH regarding FBF during vasodilation induced by MCh or SNP, the subjects with a FHH presented a significantly suppressed endothelial function index, calculated as the ratio between EDV and EIDV, when compared to subjects without FHH (1.04 +/- 0.15 vs. 1.24 +/- 0.23, p < 0.01). Also in the group of BHT subjects, the endothelial function index was suppressed (1.01 +/- 0.18, p < 0.01), in this case due to a significantly attenuated EDV (p < 0.05), when compared to male subjects without a FHH. CONCLUSION: The present findings suggest an early occurrence of endothelial dysfunction in the development of essential hypertension.