Interaction between factor V Leiden and serum LDL cholesterol increases the risk of atherosclerosis.

We investigated the association between the factor V Leiden gene variant and carotid atherosclerosis in a cross-sectional study and explored possible associations between this gene variant and coronary artery disease (CAD) in a case-control study.The presence (n=1696) or absence (n=703) of carotid atherosclerosis were sonographically assessed among participants of the population-based Study of Health in Pomerania (SHIP). The case-control study included 1021 patients with severe CAD and 2791 healthy SHIP participants. The factor V Leiden gene variant was determined by PCR and MnlI digestion.Multivariable analyses revealed no independent association between the factor V Leiden gene variant per se and carotid atherosclerosis or CAD. In the cross-sectional study, there was an interaction between the factor V Leiden gene variant and serum LDL cholesterol in non-diabetics with respect to the risk of carotid atherosclerosis. In the case-control study a similar interaction was found for CAD. In both studies the atherosclerotic risk increased with rising serum LDL cholesterol concentrations in carriers of the factor V Leiden gene variant.The co-existence between the factor V Leiden gene variant and high serum LDL cholesterol is independently associated with the risk of atherosclerosis.