Upregulation of Monocyte Tissue Factor Activity is Significantly Associated with Carotid Intima-Media Thickness in Patients with Metabolic Syndrome

AIMS: Metabolic syndrome (MS) represents a cluster of cardiovascular risk factors and an increased risk of cardiovascular events. The carotid intima-media thickness (CIMT) is correlated with coronary and carotid atherosclerosis, and is a significant predictor of cardiovascular events. Tissue factor (TF) is an initiator of the extrinsic coagulation cascade and is expressed on peripheral blood monocytes and macrophages in atherosclerotic plaques. TF plays important roles in both thrombosis and atherosclerosis. No study has investigated the relationship between monocyte TF activity and CIMT in MS patients. METHODS: Peripheral blood mononuclear cells (PBMCs) were collected from 39 normal subjects and 110 patients with MS. The procoagulant activity (PCA) in monocytes was measured using a one-stage clotting assay and is expressed as the mean±SD (mU TF/10(6) PBMCs). RESULTS: The PCA in monocytes in MS patients was significantly higher than in normal subjects (86.2 ±69.5 vs. 52.4±9.9 mU TF/10(6) PBMCs, p < 0.001). In multivariate analysis, patient age (β coefficient= 0.373, p < 0.001), high-density lipoprotein cholesterol (β coefficient=-0.307, p = 0.001) and PCA (β coefficient= 0.422, p =0.002) were each significantly and independently associated with CIMT. CONCLUSIONS: These data indicate that the upregulation of monocyte TF activity is significantly associated with CIMT in MS patients.