Coagulation pathways and diabetic retinopathy: abnormal modulation in a selected group of insulin dependent diabetic patients

Aims-To investigate whether diabetic retinopathy (DR), already associated w ith microvascular alterations, ischaemia, and endothelial dysfunction, was also characterised by abnormal modulation of coagulation pathways. Methods-Plasma samples, collected from 67 type 1 diabetics comparable for a ge, duration of disease (DD), and metabolic control (MC), were processed fo r prothrombin degradation products (F1+2) and factor VII coagulant activity (FVII:c). 50 normal subjects served as a control group. The ETDRS-Airlie H ouse Classification of DR was used. Results-A significant correlation between FVII:c and F1+2 plasma concentrat ions was observed (p <0.05). FVII:c (p <0.005) and F1+2 (p <0.0001) levels were higher in diabetics than in controls, especially in patients with prol iferative DR (FVII:c p <0.0001; F1+2 p<0.005). However, cases without retin al lesions and healthy subjects did not differ significantly (FVII:c and F1 +2 p >0.05). Conclusions-These findings pointed out the presence of a hypercoagulable st ate associated with endothelial dysfunction in patients with insulin depend ent diabetes mellitus (IDDM), demonstrated both by increased FVII:c and F12 plasma levels. Moreover, the observation of different DR related degrees of procoagulant activity, despite comparable DD and IMC, strengthens the hy pothesis of multiple risk factors in the pathogenesis of DR.