Abstract:
Vascular endothelial growth factor (VEGF) plays an important role in the development of diabetic retinopathy. Previous studies have suggested that angiotensin converting enzyme inhibitor therapy (ACE inhibitor) may reduce vitreous VEGF concentration in diabetic retinopathy and maculopathy. In addition to the cholesterol–lowering effect of statins, they also improve endothelial function, and might therefore be protective in diabetic retinopathy by influencing vitreous VEGF concentration. We studied the effect of statin medication and /or ACE inhibitor medication on the vitreous VEGF concentration in patients with proliferative diabetic retinopathy or diabetic maculopathy.
The study population consisted of 56 diabetic patients (with type I or type II diabetes) and 43 non–diabetic subjects who underwent vitreous surgery. The study subjects were interviewed about their ACE inhibitor or statin medications and undiluted vitreous samples (200 to 500 µl) were collected at the beginning of classic three–port pars plana vitrectomy. Plasma and vitreous VEGF concentrations were assessed using a chemiluminiscent human VEGF immunoassay.
Diabetic patients had significantly higher vitreous VEGF concentration than control subjects (828.2 pg/ml vs.48.2 pg/ml, p<0.001). The diabetic group was divided into four subgroups according to ACE inhibitor (A) or statin (S) medication: A–S–, A+S–, A–S+ and A+S+. These four groups did not differ significantly in concentration of fasting blood glucose, glycated hemoglobin, blood pressure or in duration of diabetes. No significant changes in vitreous VEGF concentration were found in diabetic group when divided according to diabetes type or type of retinopathy.
Current results show for the first time that statin therapy is not associated with changes in vitreous VEGF concentration, and on the contrary to previous reports, vitreous VEGF is not affected by ACE inhibitor therapy.
Keywords: diabetic retinopathy • growth factors/growth factor receptors • vitreous