Thrombotic tendency in diabetes mellitus. Revisiting and revising a study initiated 30 years ago.

Studies initiated 30 years ago emphasized that dilute blood clot lysis time was longer in obese diabetic patients than in normal weight diabetics. It was also later reported that when compared to obese women with gluteal and femoral adiposity, the age matched men with abdominal obesity displayed a more delayed clot lysis, higher triglyceride levels and higher cholinesterase activity, as well as more increased concentration of plasminogen activator inhibitor-1 (PAL-1). According to authors' investigations and data in the literature, impaired fibrinolysis in overweight hypertriglyceridemic subjects are mainly due to increased plasma levels of coagulation factor XIII and PAI-1. It could also be demonstrated that plasma clotting factors VII and VIII activities as well as plasma fibrinogen and von Willebrand factor levels were higher in patients with type 2 diabetes and abdominal obesity than in diabetics without obesity. Such findings are supporting data in the literature, insisting on the pathogenic relevance of intraabdominal obesity and of the subsequently enhanced release of fatty acids and of proinflammatory cytokines in the portal flow. Surprisingly anticoagulant plasma proteins C and S levels were found to be increased in overweight and hyperlipidemic patients considered to be at risk for thrombotic complications. Recent data in the literature had however demonstrated that circulating protein C zymogen acquires anticoagulant activity only after its binding to specific receptors on endothelial cell membrane, while proinflammatory cytokines may disrupt this activating interaction with vascular endothelia.