Non-invasive evaluation of endothelial function, arterial mechanics and nitric oxide levels in children of hypertensive parents.

ABSTRACT

OBJECTIVE: To evaluate endothelial function, arterial mechanics and nitric oxide levels in apparently healthy children of hypertensive parents. DESIGN: Analytical observational study. SETTING: Tertiary Care hospital. MATERIAL: The group comprised 40 non-obese normotensives (11-18 years). Out of these, 20 were children of parents (one or both) with hypertension (systolic >140 mm Hg, diastolic > 90 mm Hg) while the rest were children of normotensive parents (controls). High resolution ultrasonography was performed to measure flow mediated and glyceryltrinitrate induced dilatation in the brachial artery and arterial mechanics in the common carotid artery. Fasting blood was assayed for nitric oxide by the Griess method. RESULTS: Flow mediated dilatation (FMD) was decreased in children of hypertensive parents as compared to controls (0.016 + 0.007 cm vs 0.075 vs 0.075 7plus; 0.130 cm, p < 0.05) the difference being statistically significant. But subsequently, the post glyceryl-trinitrate (GTN) dilation was comparable in both with no statistical significant difference being noted. Arterial mechanics (carotid intima-media thickness-C-IMT) were comparable in both the groups. Similarly nitric oxide levels estimated in platelet rich and platelet poor plasma were comparable in both the groups, with no statistical significance. CONCLUSIONS: Flow mediated vasodilatation (FMD) in the brachial artery was decreased in children of hypertensive parents as compared to controls. Subsequent post GTN vasodilatation was comparable in both the groups because, GTN acts directly on vascular muscle and not on endothelium. Similarly, arterial mechanics (C-IMT) and nitric oxide estimation in platelet rich and platelet poor plasma were comparable in both the groups. It is, therefore, concluded that children of hypertensive parents have evidence of endothelial dysfunction, as shown by the decrease in flow mediated dilatation, which could be an early marker for the development of coronary artery disease.