Estudos de fisiopatologia da hipertensão arterial em populações especiais

Abstract

Arterial Hypertension is a prevalent and silent disease intimately related to cardiovascular risk, kidney disease and mortality, characterized by blood pressure measurements repeatedly above currently accepted levels. Despite countless studies evaluating high blood pressure, a precise blood pressure cutoff - at which might start cardiovascular damage or kidney injury – has yet to be defined. The current thesis aims to evaluate diverse organs systems and some metabolic pathways that may relate to arterial hypertension, in certain groups affected by multiple and complex mechanisms of blood pressure imbalance: kidney transplant and pregnancy. The first study was entitled “Renin Angiotensin Aldosterone Axis and Blood Pressure in the Kidney Transplant”, and was conducted at Hospital São Lucas and at the Kidney and Hormones Laboratory. At Mayo Clinic, in Minnesota, United States, the second project “Preeclampsia and Mechanisms of Vascular Dysfunction in Interleukine 10 Knockout Model” took place. The first study prospectively enrolled 133 first kidney transplant individuals, who underwent evaluation for some aspects of the renin-angiotensin-alsdosterone (RASS) system – genotypic distribution of angiotensin converting enzyme (ACE), enzyme serum and urinary activity, and urinary expression of the 90 kDa isoform. No statistic differences in the examined variables could be demonstrated, comparing normal and hypertensive individual. Two distinctive RASS profiles for patients using Cyclosporine and Tacrolimus appeared. Factors associated with changes in blood pressure along the time were depicted using Generalized Estimating Equations (GEE). In the second part of this work, the author examined specific aspects of pregnancy hypertension pathophysiology. Some articles written in collaboration were added to demonstrate how different mechanisms may lead to endothelial damage and blood pressure imbalance in such distinct study population.