title: Oxidized Low-Density Lipoprotein Predicts the Development of Renal Dysfunction in Atrial Fibrillation.
abstract: OBJECTIVE
  To investigate the role of oxidative stress (OS) in the development of chronic kidney disease (CKD) in atrial fibrillation (AF).
  
  
  METHODS
  We compared OS burden, determined at study inclusion as plasma concentrations of oxidized low-density lipoprotein (oxLDL), between stable AF patients (n = 256, mean age: 62.8 ± 9.3 years; 60.9% males) with preserved renal function, defined as an estimated glomerular filtration rate (eGFR) ≥60 ml/min/1.73 m2, and a matched control group in sinus rhythm (n = 138, mean age: 61.5 ± 11.2 years; 60.9% males). During the prospective follow-up of AF patients, we investigated the association and prognostic validity of oxLDL for CKD development, diagnosed as a sustained decline in eGFR to <60 ml/min/1.73 m2.
  
  
  RESULTS
  AF patients had a higher mean oxLDL (76.2 ± 21.7 U/l) compared to sinus rhythm controls (61.6 ± 13.1 U/l; p < 0.001). AF presence independently predicted increased oxLDL levels in the study cohort [β = 14.7; 95% confidence interval (CI), 10.7-18.7; p < 0.001]. Over a median 4-year follow-up, 19.9% of AF patients developed CKD. Adjusting for all clinical covariates, oxLDL (per tertile) was associated with a hazard ratio of 2.17 for CKD occurrence (95% CI, 1.40-3.35; p < 0.001). AF patients in the upper oxLDL tertile (≥88.7 U/l) had a 3.70-fold (95% CI, 1.55-8.81) higher risk for CKD compared to the lower oxLDL tertile (<67.0 U/l) patients (p < 0.001). oxLDL improved discriminative validity (c-statistic increment: 0.041, 95% CI, 0.007-0.075, p = 0.017), and increased the net reclassification and integrated discrimination for CKD risk by 12.4 and 6.0%, respectively (both p < 0.001).
  
  
  CONCLUSIONS
  oxLDL is increased in AF patients compared to sinus rhythm controls. oxLDL has an independent association and an incremental predictive value that might complement clinical CKD risk assessment in AF patients following further research.
authors.affiliation: Cardiology Clinic, Clinical Center of Serbia, Belgrade, Serbia; School of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Marija
authors.initials: M
authors.lastname: Polovina
authors.affiliation: Cardiology Clinic, Clinical Center of Serbia, Belgrade, Serbia.
authors.forename: Ivana
authors.initials: I
authors.lastname: Petrović
authors.affiliation: Nephrology Clinic, Clinical Center of Serbia, Belgrade, Serbia; School of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Voin
authors.initials: V
authors.lastname: Brković
authors.affiliation: Cardiology Clinic, Clinical Center of Serbia, Belgrade, Serbia; School of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Milika
authors.initials: M
authors.lastname: Ašanin
authors.affiliation: School of Medicine, University of Belgrade, Belgrade, Serbia; Department of Medical Statistics and Informatics, Belgrade, Serbia.
authors.forename: Jelena
authors.initials: J
authors.lastname: Marinković
authors.affiliation: School of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Miodrag
authors.initials: M
authors.lastname: Ostojić
keywords: Atrial fibrillation; Chronic kidney disease; Glomerular filtration rate; Oxidative stress; Oxidized low-density lipoproteins; Renal dysfunction