Expression of angiopoietin-like protein 8 correlates with VEGF in patients with proliferative diabetic retinopathy.

ABSTRACT

PURPOSE: To investigate the vitreous and serum levels of angiopoietin-like protein 8 (ANGPTL-8) and vascular endothelial growth factor (VEGF) in patients with proliferative diabetic retinopathy (PDR). The serum levels of these factors were also analyzed in patients with diabetes and no diabetic retinopathy (NDR) and with non-proliferative diabetic retinopathy (NPDR), to detect the possible correlation between the ANGPTL-8 levels and hyperlipidemia. METHODS: Vitreous samples were obtained from 28 patients with PDR and from 12 patients without diabetes and with idiopathic macular hole (IMH). Serum samples were also obtained from 26 patients with NDR and 22 patients with NPDR. ANGPTL-8 levels and other factors were determined using an enzyme-linked immunosorbent assay. RESULTS: The ANGPTL-8 and VEGF levels in the vitreous and serum of the patients with PDR were higher than those in the patients with IMH, and were significantly correlated. The vitreous and serum ANGPTL-8 levels were more correlated with the triglyceride and low-density lipoprotein cholesterol levels than with the high-density lipoprotein cholesterol or total cholesterol levels in the patients with PDR. CONCLUSIONS: The vitreous and serum ANGPTL-8 levels were both upregulated in patients with PDR. There was an association between the elevation in the ANGPTL-8 levels and angiogenic and hyperlipidemic factors in the patients with PDR. These results suggest that ANGPTL-8 is a potential new diagnostic marker and therapeutic target for PDR treatment.