Oxidized LDL to autoantibodies against oxLDL ratio - The new biomarker associated with carotid atherosclerosis and cardiovascular complications in dialyzed patients

Objective: To investigate the role of autoantibodies against oxidized LDL (oxLDL-Ab) in clearing of oxLDL from circulation in dialyzed uremic patients, as well as the significance of this process in the carotid atherosclerosis and cardiovascular complications. Methods: oxLDL, oxLDL-Ab and intima-media thickness (IMT) were measured in 132 uremic patients on hemodialysis (HD), peritoneal dialysis (PD) or conservative treatment both with and without cardiovascular disease (CVD) and in 29 healthy controls. The ratio of oxLDL to oxLDL-Ab (oxLDL/oxLDL-Ab), reflecting the balance between in vivo oxidative LDL modification and the clearance of oxLDL from circulation was also calculated. Results: oxLDL were lower, whereas oxLDL-Ab were higher in patients without CVD compared to those with CVD. oxLDL/oxLDL-Ab ratio was also significantly lower in dialyzed subjects without CVD compared to their counterparts with CVD and healthy controls. IMT values were significantly higher in uremic patients compared with controls, and patients with CVD had particularly elevated IMT compared with those without CVD. The inverse correlation was between IMT and oxLDL-Ab, whereas the IMT was strongly and positively associated with oxLDL/oxLDL-Ab ratio. There was the weak inverse relationship between oxLDL and oxLDL-Ab levels in dialyzed patients. Multiple stepwise regression analysis identified oxLDL/oxLDL-Ab ratio as one of the predictors of IMT in the whole dialyzed group. Conclusions: oxLDL/oxLDL-Ab ratio could be a new biomarker significantly and independently associated with carotid atherosclerosis in dialyzed patients. A titer of oxLDL-Ab and oxLDL/oxLDL-Ab ratio seem to play an important role for distinguishing patients with and without cardiovascular complications. (C) 2012 Elsevier Ireland Ltd. All rights reserved.