Endothelial dysfunction in normotensive Chinese with a family history of essential hypertension.

Endothelial dysfunction is seen in patients with essential hypertension. However, it is still debated whether impaired endothelial function occurs before the development of hypertension. The aim of our study was to investigate whether endothelial dysfunction occurs in genetically vulnerable normotensive Chinese, and whether the endothelial dysfunction is worse as essential hypertension progresses. Endothelial function was assessed by high-resolution vascular ultrasound (7.5 MHz). The diameters of brachial arteries were measured at rest, during reactive hyperemia, and after sublingual administration of nitroglycerine (GTN) in 58 subjects with a mean age of 46.7 +/- 10.1 years. Among them, 18 patients had essential hypertension (Group 2), 20 normotensive subjects had a family history of hypertension (Group 3), and 20 normotensive subjects without a family history of cardiovascular diseases served as controls (Group 1). There was no difference in age among the three groups (Group 1: 46.5 +/- 10.5 versus Group 2: 46.7 +/- 9.5 versus Group 3: 44.50 +/- 11.21 years, P = NS). Flow-mediated dilatation of brachial arteries was significantly reduced in Group 2 and 3 as compared with Group 1 (Group 1: 13.2 +/- 5.9% versus Group 2: 8.0 +/- 3.6 versus Group 3: 4.86 +/- 3.5, both p < .01). On the other hand, nonflow mediated vasodilatation in response to GTN did not differ among the three groups. Endothelium-dependent vasodilatation is impaired not only in normotensive subjects with a family history of hypertension, but also becomes worse in the hypertensive patients.