Even the exact mechanism how proinsulin is involved in the pathogenesis of atherosclerosis is not completely recognized, it was already shown that PAI-1 activity increases after proinsulin administration in vitro, and there is increasing evidence that the atherogenic effects of proinsulin might be linked to increasing plasminogen activator inhibitor-1 (PAI-1) levels with subsequent inhibition of fibrinolysis and an augmented thrombogenic potency.