Endothelium-dependent vasodilatation in patients with and without essential hypertension.

Althogh previous studies suggested that vascular endothelial function may be impaired in patients (pts) with essential hypertension, a general consensus has not been reached. Aim of the study was to investigate as to whether different subsets of hypertensive pts might have different flow dependent endothelial responses. : 110 consecutive pts with essential hypertension and 22 control subjects were studied; 42 pts had nevar been treated and 68 pts had therapy witheld 4 days before the study. Mean age was 55 years (range 40-70); pts were current cigarette smokers; pts had cholesterol levels \gr 240 mg%; had type I and type II diabete mellitus. Using a linear array echo transducer driven at 10 Mhz, the brachial artery diameter was measured at baseline, during reactive hyperemia (as a rule associated with endothelium-dependent dilatation) and after sublingual nitroglycerin (GTN) (associated with endothelium-independent dilatation). : in the total population brachial artery diameter was 3.3 ± 0.1 mm (mean ± SEM) at baseline and increased by 6.1 ± 0.5% in response to an average flow increase of 771 ± 54% during reactive hyperemia and by 18.6 ± 1.3% after GTN. Flow mediated vasodilatation (FMD) was inversely related to baseline artery diameter (r = −0.51, p <0.01). FMD was 7.6 ± 1.4% in the control group, 6.3 ± 0.7% in previously treated hypertensive pts and 5.7 ± 0.8% in the group of pts who never received treatment (NS). Variance analysis with baseline diameter as covariate showed a significant interaction between smoke and age (p < 0.04): smoke did not affect FMD in pts <65 years while it decreased FMD in pts \gr65 years (8.6 ± 1.1% vs 0.4 ± 0.7%). Conclusions: FMD was not impaired in pts with essential hypertension. Cigarette smoking induced endothelial dysfunction in the elderly pts.