RESUMO
Patients with prehypertension suffer endothelial dysfunction and are at increased cardiovascular risk. Ankle-brachial index (ABI) constitutes an efficient tool for diagnosing peripheral arterial disease; but also an ABI < 0.9 is an independent and positive predictor of endothelial dysfunction and is associated with increased cardiovascular risk and mortality. The aim of this study was testing whether ABI was decreased in prehypertensive patients when compared with normotensive subjects. Methods We included 70 prehypertensive patients older than 19 years, in whom the ABI was registered with a 5 megahertz Doppler (Summit Doppler L250, Life Dop., USA). The highest ankle systolic pressure was divided by the highest brachial systolic pressure. We also included 70 normotensive subjects in whom the ABI was registered in the same way. The measurements were performed by the same physician who was blinded about the study. Statistical analysis was performed with odds ratio and student t-test. Results The ABI values in normotensive subjects were 1.023 ± 0.21, whereas prehypertensive patients significantly had lower ABI (0.90 ± 0.14p = 0.00012). We found ABI <0.9 in 30 prehypertensive patients (42.85%) and 13 normotensive patients (18.5%). The odds ratio of ABI <0.90 in prehypertensive patients was 3.288 (IC95 1.5–7.0, p = 0.0023). A regression analysis failed to show any independent association between ABI values and any other clinical parameter. Conclusions Prehypertensive patients had lower ABI and higher prevalence of peripheral artery disease when compared with normotensive subjects; this fact increases their cardiovascular risk. ABI must be included in global evaluation of prehypertensive subjects.