Blood lipid profiles and risk of atrial fibrillation: A systematic review and meta-analysis of cohort studies

Background: There is an increasing body of evidence associating traditional cardiovascular risk factors with atrial fibrillation (AF), but the relationship between blood lipid profiles and the risk of AF remains controversial. Objective: This study aimed to conduct a systemic review and meta-analysis of large cohort studies to evaluate the relationship between blood lipid profiles and incident AF. Methods: PubMed and Embase were searched up to January 31, 2019, for cohort studies that reported the relationship between blood lipid levels and incident AF. The hazard ratios or odds ratios of the highest vs lowest categories of lipid levels were extracted to calculate pooled estimates. Sensitivity analysis and meta-regression were performed to explore potential sources of heterogeneity. Results: Eleven studies were included in the meta-analysis, including 9 studies for total cholesterol (TC), 5 for low-density lipoprotein cholesterol (LDL-C), 8 for high-density lipoprotein cholesterol (HDL-C), and 8 for triglyceride. Serum TC and LDL-C levels were inversely related to AF risk (relative risk [RR] = 0.81, 95% confidence interval [CI]: 0.72–0.92; RR = 0.79, 95% CI: 0.70–0.88, respectively). Likewise, elevated HDL-C levels were associated with a reduced AF risk (RR = 0.86, 95% CI: 0.76–0.97), whereas no significant association was observed between triglyceride levels and incident AF (RR = 1.02, 95% CI: 0.90–1.17). Conclusions: Our meta-analysis of large cohort studies found an inverse relationship between serum TC, LDL-C, and HDL-C levels and AF risk, although there was no significant association between TG levels and incident AF. Future studies regarding AF risk stratification may take these blood lipids into consideration, and further efforts are needed to investigate the potential mechanisms.