Coagulation factors of contact phase of haemostasis are normal in well-controlled type-I diabetic patients despite presence of diabetic retinopathy.

Alterations of plasma coagulation factors have been reported in diabetic patients with severe microangiopathy and metabolic derangement. No information is available, however, for well-controlled type-I diabetic patients. Thus, we studied coagulation factors of the contact phase and inhibitors in 80 fairly well-controlled diabetics (42 female, 38 male, age 28 +/- 11 SD years). Mean HbA1c in these patients was 6.6 +/- 1.0 SD, duration of diabetes ranged from 6 months to 30 years, and 36% had retinopathy shown by fluorescein angiography. The well-controlled diabetic patients did not differ from controls in terms of the activity of prekallikrein, factor XII, high molecular weight kininogen, kallikrein inhibitor, C-1-esterase inhibitor and antithrombin III. Only alpha-2-macroglobulin, an inhibitor of the contact phase of blood coagulation, was elevated significantly in these patients (p less than 0.05). Diabetics with retinopathy had similar activities of prekallikrein, factor XII, high molecular weight kininogen, kallikrein inhibitor, c-1-esterase inhibitor and antithrombin III when compared with patients without retinopathy and controls respectively. alpha-2-macroglobulin did not differ in patients with and without diabetic retinopathy but were significantly elevated in both groups compared with controls. Correlation analysis showed significant positive correlation between HbA1c and the activity of high molecular weight kininogen, kallikrein inhibitor and alpha-2-macroglobulin. In patients with poor metabolic control (n = 11; 6 female, 5 male; age 25 +/- 5 SD years; HbA1C 10.7 +/- 0.9) prekallikrein (p less than 0.05), kallikrein inhibitor (p less than 0.005) and alpha-2-macroglobulin (p less than 0.005) were significantly elevated compared to the controls.(ABSTRACT TRUNCATED AT 250 WORDS)