Haemostatic variables were assessed in 43 patients, 28 insulin-dependent and 15 non insulin-dependent. Maximum aggregation by low concentrations of adenosine diphosphate (ADP) or arachidonic acid and elevated plasma concentrations of TxB2, Factor VIII, vWF:Ag, RCoF and fibronectin (Fnct) indicated a hypercoagulable state. The manifestation of vasculopathy was associated with elevated concentrations of RCoF, Fnct, Hbalc, cholesterol and triglycerides, while impaired fibrinolysis was demonstrated by decreased t-PA levels and the absence of crosslinked fibrin degradation products (XL-FDP).