Determinants of the structure of resistance-sized arteries in hypertensive patients

Abstract

Objective: It has been previously demonstrated that structural alterations of subcutaneous small resistance arteries of hypertensive patients, as indicated by an increased media to lumen (M/L) ratio, is the most potent predictor of cardiovascular events. The aim of the present study was to identify possible determinants of small resistance artery structure that may be evaluated with non-invasive approaches.

Materials and methods: One hundred and ninety-nine subjects (normotensives, essential hypertensives and patients with secondary hypertension) were included in the present study. All subjects were submitted to a biopsy of subcutaneous fat from the gluteal or the anterior abdominal region. Small resistance arteries were dissected and mounted on an isometric myograph, and M/L ratio was measured. All patients underwent standard biochemical tests, clinic blood pressure measurement, standard echocardiography and 24-h ambulatory blood pressure measurement. Glomerular filtration rate (GFR) was calculated according to MDRD study formula and Cockroft's formula.

Results: Significant correlation was found between M/L ratio and, respectively: GFR calculated both with MDRD study formula and Cockroft-Gault formula, creatinine serum, blood urea nitrogen, glycaemia, circulating sodium, clinical pulse pressure, stroke volume to pulse pressure ratio, clinical systolic, diastolic and mean arterial pressure, daytime pulse pressure. However, in a multivariate regression analysis, only serum creatinine remained in the model, and proved to be an independent predictor of small artery structure.

Conclusions: Indices of renal function and, probably, of large artery distensibility may be related to small arteries remodelling in hypertension.