Abstract 5418: Structural Alterations in Subcutaneous Small Resistance Arteries May Predict Changes of the Renal Function in Hypertensive Patients

Abstract

We have previously demonstrated that structural alteration of subcutaneous small resistance arteries of hypertensive patients, as indicated by an increased media to lumen (M/L) ratio, has a strong prognostic significance. Among the predictors of M/L indicators of renal function are those more closely correlated. Aim of the present study was to assess whether M/L ratio can predict subsequent changes in renal function in hypertensive patients. Sixty patients (33 males; 27 females; 15 normotensives and 45 hypertensives) underwent a biopsy of subcutaneous fat at a mean age of 56 years. Resistance-sized arteries were dissected and mounted on a wire myograph according to Mulvany-Halpern technique, and M/L was measured. Patients were re-evaluated after a mean time period of 8.5 years; serum creatinine, blood urinary nitrogen (BUN) and uric acid were measured, and glomerular filtration rate (GFR) was calculated according to MDRD formula. At baseline, we observed significant correlations between M/L and serum creatinine (r=0.32; p=0.013), GFR (r= −0.26; p=0.047), BUN (r=0.37; p=0.009), systolic (r=0.45, p<0.001), diastolic (r=0.29, p=0.02), mean blood pressure (r=0.38, p=0.002) and pulse pressure (r=0.40, p=0.002). In addition, we observed significant correlations between M/L and creatinine at follow up (r=0.57; p<0.001), % changes in serum creatinine (r=0.46; p<0.001), GFR at follow up (r= −0.43; p<0.001); % changes in GFR (as ml/min r= −0.33; p=0.008), as well as yearly changes (r= −0.34, p=0.007), BUN at follow up, (r=0.55; p<0.001), as well as uric acid at follow up (r=0.35; p=0.026). A multivariate analysis in which all common cardiovascular risk factors were included, showed that M/L is the most potent predictor of changes in renal function. In conclusion, our data suggest that structural alterations of subcutaneous small resistance arteries (which may be present also in other vascular beds), may predict the time-course of changes of renal function during a follow-up period of about 9 years.