APOB and atrial fibrillation: The lipid levels depended significantly on AF and APOE allele groups for TG, TC, LDL-C and Apo-B (all P < 0.001), and statistically significant interactions between AF and APOE allele were observed in the above 4 variables (TG, F = 4.478, P = 0.012; TC, F = 6.189, P = 0.002; LDL-C, F = 3.717, P = 0.025; Apo-B, F = 4.529, P = 0.011, respectively).