3B.04

Abstract

Objective: To evaluate endothelial function in normotensive adolescents with exaggerated blood pressure response during exercise. Design and method: This was a cross-sectional study conducted with 157 high school students (80 boys and 77 girls), aged between 13 to 18 years old (15.0 ± 1.6), normotensive, without smoking habits, non-obese, normolipidemic and normal glucose. An exaggerated blood pressure response was defined as a systolic pressure rise of more than 70 mm Hg, during the treadmill test with Bruce protocol. The endothelial function was assessed through endothelium-dependent vasodilation with reactive hyperemia test by high-resolution vascular ultrasound. The cohort was split into quartiles, according to flow-mediated dilation (FMD). The study comparison was made between the lowest quartile versus the rest of them. Results: An exaggerated blood pressure response was observed in 13 adolescents (8.3%), 10 (13.0%) females and 3 (3.8%) males (P = 0.036). For adolescents in the lowest FMD quartile, a higher prevalence of exaggerated blood pressure response was observed, in comparison with the others quartiles (17.5 vs 5.1%, respectively; P = 0.014). Even after adjustment for factors known to affect endothelial function, the logistic regression analysis revealed that an exercise-induced hypertension was a predictor of impaired FMD (OR = 3.924; I.C. 95%: 1.233–12.488). Conclusions: Normotensive adolescents with exercise-induced hypertension have impaired endothelium-dependent vasodilation. Exercise blood pressure may thus be a useful marker of nitric oxide bioactivity, and hence an important cardiac prognostic factor.