Altered Flow-Mediated Vasodilatation, Low Paraoxonase-1 Activity, and Abnormal High-Density Lipoprotein Subclass Distribution in Takayasu's Arteritis

Background: Takayasu's arteritis (TA) is an idiopathic chronic inflammatory disease that causes occlusion of large arteries, but little is known about whether affected patients are characterized by endothelial dysfunction, different high-density lipoproteins (HDL) subclasses and paraoxonase-1 (PON1) activity. Methods and Results: In the present study, 30 patients with TA, 30 age- and gender-matched volunteers (controls) and 15 patients with essential hypertension were studied. Flow-mediated vasodilation (FMD) and maximal blood flow velocity, assessed in the brachial artery by high-resolution ultrasound, were significantly lower in patients. HDL subclass distribution was determined by polyacrylamide gradient gel electrophoresis. HDL-cholesterol, HDL3b subclass and PON1 activity, assessed spectrophotometrically using phenylacetate as the substrate, were also lower in patients compared with controls. In a multiple regression analysis, the use of prednisone and systolic blood pressure were independent variables that predicted the FMD. Conclusions: A low FMD, abnormal size distribution of HDLs, and low PON1 activity are observed in TA patients. These abnormalities appear independently and constitute a cluster that may contribute to the vascular dysfunction of TA arteritis. (Circ J 2009; 73: 760 - 766)