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

Abstract

AIMS To investigate whether diabetic retinopathy (DR), already associated with 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 age, duration of disease (DD), and metabolic control (MC), were processed for prothrombin degradation products (F1+2) and factor VII coagulant activity (FVII:c). 50 normal subjects served as a control group. The ETDRS-Airlie House Classification of DR was used.

RESULTS A significant correlation between FVII:c and F1+2 plasma concentrations 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 proliferative DR (FVII:c p <0.0001; F1+2 p<0.005). However, cases without retinal 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 state associated with endothelial dysfunction in patients with insulin dependent diabetes mellitus (IDDM), demonstrated both by increased FVII:c and F1+2 plasma levels. Moreover, the observation of different DR related degrees of procoagulant activity, despite comparable DD and MC, strengthens the hypothesis of multiple risk factors in the pathogenesis of DR.