RESUMO
OBJECTIVE: Hypertension has become a global medical and public health issue even in childhood. It is well accepted that hypertension is associated with impaired endothelium-dependent vascular reactivity in adult patients. However, there is a lack of data on hypertension-related endothelial dysfunction in hypertensive children. Thus, present study aimed to evaluate the association of primary hypertension in the pediatric population with macro- and microvascular function, and to assess the potential role of oxidative stress in that connection. METHODS: Fifty-two children were enrolled in this study; 26 normotensive (NT) and 26 with primary hypertension (HT), both sexes, 9-17âyears old. In addition to anthropometric, hemodynamic and biochemical measurements, peripheral microvascular responses to occlusion (postocclusive reactive hyperemia, PORH), local heating (local thermal hyperemia, LTH), iontophoretically applied acetylcholine (AChID) and sodium nitroprusside (SNPID) were evaluated by laser Doppler flowmetry (LDF). Furthermore, brachial artery flow-mediated dilation (FMD) was measured and biomarker of oxidative stress was determined. RESULTS: PORH, AChID and LTH were impaired in hypertensive compared to normotensive children, while SNPID did not differ between groups. FMD was decreased in hypertensive compared to normotensive children. Serum concentration of 8-iso-PGF2α was significantly elevated in hypertensive compared to normotensive children. CONCLUSION: Even in childhood, primary hypertension is associated with attenuated endothelial function and reduced endothelium-dependent responses to various physiological stimuli. Juvenile hypertension is related to increased level of vascular oxidative stress. All changes are independent of BMI.