Platelet aggregation and intraplatelet adenine nucleotides in diabetic retinopathy.

Twenty non-diabetic controls, 50 diabetics without retinopathy and 29 diabetics with retinopathy, all well-matched age groups, were studied in males and females, respectively. Moreover, diabetic patients with retinopathy were divided into the following two subgroups: mild retinopathy and severe retinopathy. Platelet aggregation was elevated in the male diabetics with mild or severe retinopathy. There was no difference in platelet volume between the groups. Intraplatelet ADP contents were significantly decreased in the female diabetics with severe retinopathy showing no high platelet aggregability. There was no significant difference in intraplatelet ATP contents between groups. These results indicated not only that platelet aggregation might be generally high in the diabetics with retinopathy, but also that dense granule release might occur readily in vivo in the female diabetics with severe retinopathy and therefore platelet aggregation was not elevated in the group.