A nonlinear relationship between low-density-lipoprotein cholesterol levels and atrial fibrillation among patients with hypertension in China

Background: The association between low-density-lipoprotein cholesterol (LDL-C) and atrial fibrillation (AF) in hypertensive population remains controversial. Therefore, we explored the relationship between LDL-C and AF among patients with hypertension in a Chinese community. Methods: This is a retrospective cross-sectional study that enrolled 7808 hypertensive patients between January 2013 and December 2013 in Guangdong, China. AF was diagnosed by 12-lead electrocardiogram (ECG) or self-reported status. LDL-C value were categorized by quartiles. Univariate and multivariate logistic regression were performed to examine the relation between LDL-C and AF. LDL-C values were expressed in continuous (every 1 mg/dL increment) or categorical variables in each regression model. Results: Among 7,808 (47.1% man, with mean age 62.3 years) participants, 78 AF cases were identified. In multivariate logistic regression, when LDL-C was presented as continuous variable, it was inversely associated with the occurrence of new onset AF (OR = 0.99, 95% CI: 0.98, 1.00; P=0.018). Meanwhile, when LDL-C was presented as categorical variable, the negative association between LDL-C and AF was attenuated after adjusting for confounders. Adjusted restricted cubic spline demonstrated a non-linear correlation between LDL-C and AF. Conclusions: Lower levels of LDL-C was associated with increased incidence of AF in a Chinese community hypertensive population.