We performed this study to compare the endothelial function of the patients with newly diagnosed essential hypertension(EH) to age and sex-matched normal subjects or patients with known coronary artery disease(CAD) and to evaluate the effect of calcium channel blockers(amlodipine) on the endothelial dysfunction in patients with EH.

The endothelial function, expressed as percent brachial artery diameter changes at hyperemic phase compared to resting state, using high-resolution ultrasound was measured before taking amlodipine and 3 to 4 months after taking amlodipine(5 to 10 mg daily), when the high blood pressure(BP) was well controlled(129/83 mmHg), in patients with EH(mean age; 53 yrs, n=2). We also measured the endothelial function in normal subjects(mean age; 54 yrs, n=5) and patients with proven CAD(mean age; 56 yrs, n=0).

The mean BP of the patients with EH, CAD, and normal subjects were 172/108 mmHg, 110/69 mmHg, and 113/72 mmHg, respectively. There were no significant differences among the study groups in regard to the serum glucose and various lipid levels. The endothelial function of the patients with EH(6.6±2.3%) was significantly(p=.000) lowered when compared to the normal subjects(14.3±3.3%), but did not show any significant differences when compared to the patients with CAD(8.6±3.4%). The endothelial function in patients with EH was significantly(p=.007) improved from 6.6±2.3 % to 11.0±2.7 % 3 to 4 months after taking the amlodipine.

Calcium channel blockers, especially amlodipine, can improve endothelial dysfunction in patients with EH as well as controlling high BP.