Abstract 5152: Normotensive and Hypertensive Obese Patients Show the Presence of Structural and Functional Alterations in Subcutaneous Small Resistance Arteries
Structural alterations of subcutaneous small resistance arteries of hypertensive patients, as indicated by an increased media to lumen (M/L) ratio, are frequently present in hypertensive and or/diabetic patients, and may represent the earliest alterations that may be observed. In addition, M/L of small arteries have a strong prognostic significance. However, no data are available about the structure and endothelial function of small resistance arteries of obese patients. Therefore, we have investigated 16 patients with severe obesity. Six of them were normotensive, and 10 hypertensive. We compared results obtained with those observed in 12 normotensive lean controls and in 12 hypertensive lean patients. Systolic and diastolic blood pressure were evaluated by a standard sphygmomanometric approach, using appropriate cuff for obese patients. All patients underwent a biopsy of subcutaneous fat before or during surgical intervention of gastric banding or intestinal derivation. Subcutaneous small resistance arteries were dissected and mounted on a wire myograph, according to Mulvany-Halpern technique, and M/L, media thickness, media cross-sectional area were measured. A concentration-response curve to acetylcholine (10 –9 –10 –5 Mol/l) was performed, in order to evaluate endothelial function. The results are summarized in the Table⇓. Obese patients, independently from the presence of hypertension, diabetes and dyslipidemia, show the presence of an increased M/L and of an increased media cross-sectional area. Preliminary data suggest the presence of endothelial dysfunction, as indicated by a reduced endothelium-dependent vasodilatation, especially in hypertensive obese patients. In conclusion, our data suggest that the presence of obesity is associated to structural alterations of subcutaneous small resistance arteries, mainly characterized by hypertrophic remodeling.