Cross-sectional association of soluble thrombomodulin with mild peripheral artery disease; the ARIC study

Thrombomodulin, an endothelial membrane glycoprotein, is an essential part of the protein C anti-coagulant pathway. It may also have a role in the regulation of fibrinolysis. We carried out a cross-sectional study to assess the association of soluble thrombomodulin (sTM) with peripheral artery disease (PAD) in a stratified random sample (n = 863) of otherwise healthy black and white participants of the Atherosclerosis Risk in Communities (ARIC) Study. PAD was more common in black than in white participants and associated with classical risk factors in an expected manner; positively with age, smoking, hypertension, diabetes (P = 0.05), and LDL-cholesterol, and inversely with HDL-cholesterol. Significant positive associations were observed also with fibrinogen and white blood cell count. Overall, the sTM concentration was not a significant predictor of PAD. The association was, however, modified by the level of factor VIII:C in whites (P = 0.002 for the interaction), but not in blacks. Protein C was inversely associated with PAD prevalence (odds ratio 0.33, 95% CI 0.18-0.61, P = 0.0004). sTM was inversely associated with plasminogen, but no associations with t-PA, PAI-1, or D-dimer were seen. In conclusion, the present results provide some additional evidence on the role of thrombomodulin-protein C pathway in atherosclerotic disease and support our earlier observation on interaction between sTM and factor VIII:C.