Oxidized high-density lipoprotein associates with atrial fibrillation

Background: Atrial fibrillation (AF) is the most common heart arrhythmia and considered to be a progressive chronic disease associated with increased morbidity and mortality. Recent data suggest a link between inflammation, oxidative stress, and AF, although the underlying mechanisms are not fully understood. Because oxidized lipoproteins cause structural damage and electrophysiologic changes in cardiomyocytes, it is feasible that the transformation of atheroprotective high-density lipoprotein (HDL) into dysfunctional HDL contributes to the development of AF. Objective: The purpose of this study was to determine whether a reduced antioxidant function of HDL is associated with the presence of AF. Methods: In this multicenter cross-sectional cohort study, we assessed HDL function in sera of 1206 participants. Patients were divided into groups according to the presence of AF (n = 233) or no AF (n = 973). A validated cell-free biochemical assay was used to determine reduced HDL antioxidant function as assessed by increased normalized HDL lipid peroxide content (nHDL_ox). Results: Participants with AF had a 9% higher mean relative nHDL_ox compared to persons without AF (P = .025). nHDL_ox was strongly associated with AF in all models of logistic regression, including the analysis adjusted for age, sex, and risk factors for AF (all P ≤.01). Conclusion: Reduced antioxidant HDL function is associated with the presence of AF, which supports growing evidence that impaired lipoprotein function is linked to electrophysiological changes in cardiomyocytes. nHDL_ox is one of several contributors to the initiation and perpetuation of AF.