Endothelial Dysfunction in Prehypertension and Associated Factors

Abstract

Background: Endothelial dysfunction precedes structural abnormalities and atherosclerosis clinical manifestations, and thus it is considered an early marker of cardiovascular diseases. The objectives of this cross-sectional study were to determine the frequency of endothelial dysfunction in prehypertensive subjects and its association with demographic, anthropometric and clinical characteristics of the population studied. Methods and Results:Endothelial function was assessed by flowmediated vasodilation (FMD) of the brachial artery in 60 non-smoking and non-diabetic prehypertensive subjects aged 30-70 years who were recruited from the community. Variables analyzed were gender, age, race, sedentary lifestyle, dyslipidemia, body mass index, abdominal circumference and blood pressure. In order to evaluate the relationship between endothelial dysfunction and study variables, Student t, Mann-Whitney and chi-square tests were used. Multivariate logistic regression of variables analyzed with respect to endothelial dysfunction was applied in unadjusted as well as adjusted models (p<0.20). Significance level was set at 5%. Mean age of prehypertensive subjects was 42.6±9.2 years; 60% were females, 33.3% were Black, 61.6% were overweight, and 68.3% had a sedentary lifestyle. Endothelial dysfunction was detected in 36.7% of the population; its frequency was higher for Black subjects (45%). Association was established between endothelial dysfunction and males as well as obesity, the latter even after adjustment of the model (p=0.010). Conclusions:In conclusion, frequency of endothelial dysfunction as determined by FMD was high in the population under study, even IntroductionEndothelial dysfunction is associated with atherosclerosis progression and complications, and thus it is an early marker of cardiovascular disease (CVD). [1] Endothelial dysfunction as detected by flow-mediated vasodilation (FMD) of the brachial artery was related to the presence of coronary artery disease in 122 subjects undergoing coronary angiography, with 71% sensitivity and 81% specificity.[2] The positive predictive value of abnormal brachial dilation with respect to coronary endothelial dysfunction is 95%.[3] Therefore, assessment of endothelial function can help in the identification of early changes in asymptomatic subjects with CVD risk factors, such as prehypertension.Despite controversies over the use of the term 'prehypertension', studies have demonstrated that this clinical condition is an independent risk factor for the development of systemic arterial hypertension (SAH) and arteriosclerotic vascular disease. [4][5][6][7] Weil et al [8] have shown that, regardless of other CVD risk factors, prehypertension is associated with decreased blood flow in the forearm in response to acetylcholine infusion, suggesting less endotheliumdependent vasodilation. Moreover, it is known that increased age is associated to decreased endothelium-dependent vasodilation in humans and such reduction occurs earlier in males than females. [9,10] Neverthel...