Insulin resistance adds to endothelial dysfunction in hypertensive patients and in normotensive offspring of subjects with essential hypertension.
OBJECTIVE
To evaluate whether endothelium-dependent (nitric oxide-mediated) dilation of the brachial artery (BA) is impaired in patients being treated for essential hypertension (EH), and whether this abnormality can be detected in normotensive offspring of subjects with EH (familial trait, FT); and to investigate the interrelationship between flow-mediated vasodilation (FMD) and hyperinsulinaemia/insulin resistance.


METHODS
Cross-sectional study.


METHODS
Angiology department at a teaching hospital.


METHODS
The study encompassed 172 subjects, of whom 46 were treated hypertonics aged 40-55 (49) years, and 44 age-matched, normotensive volunteers as controls. We also investigated 41 normotonics with FT aged 20-30 (25) years and 41 age-and sex-matched controls without FT.


METHODS
Using high-resolution ultrasound, BA diameters at rest, during reactive hyperaemia (endothelium-dependent dilation) and after sublingual glyceryl trinitrate (GTN) application (endothelium-independent dilation) were measured.


RESULTS
In hypertonics FMD was significantly lower than in controls [2.4 (2.9) vs. 7.4 (2.5)%; P < 0.00005], as was GTN-induced dilation [12.1 (4.3) vs. 16.1 (4.6)%; P=0.0007]. In subjects with FT, FMD was also decreased compared with the control group [5.8 (4.1) vs. 10.0 (3.0)%; P < 0.00005]. The response to GTN was comparable in both groups of young subjects. FMD was negatively related to insulin concentration in all subjects studied (P < 0.00005).


CONCLUSIONS
In treated patients with EH, flow-mediated dilation of the BA as well as endothelium-independent dilation are decreased. In individuals with FT the endothelial function of the peripheral arteries is also altered in the absence of elevated blood pressure. Endothelial dysfunction is related to hyperinsulinaemia/insulin resistance, which could be one of the pathogenetic determinants of EH and its complications.
Zizek
B
B
Department of Angiology, University Medical Centre, Ljubljana, Slovenia. jelka.kos@trnovo.kclj.si
Poredos
P
P
D000328:Adult; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005260:Female; D006439:Hemodynamics; D006801:Humans; D006946:Hyperinsulinism / Q000503:physiopathology*; D006973:Hypertension / Q000188:drug therapy / Q000235:genetics / Q000503:physiopathology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000502:physiology*; D014463:Ultrasonography; D014664:Vasodilation
D009569:Nitric Oxide