Soluble adhesion molecules are not involved in the development of retinopathy in type 2 diabetic patients

Raised serum levels of adhesion molecules are believed to reflect endothelial activation and may contribute to the development of diabetic vascular complications. The aim of this study was to clarify the association between soluble adhesion molecules levels and retinopathy in type 2 diabetic patients. Levels of soluble E-selectin, ICAM-1 and VCAM-1 were measured by enzyme-linked immunosorbent assay (ELISA) in 47 type 2 diabetic patients classified in two subgroups according to the presence (n=34) or absence (n=13) of retinopathy as determined by fundus ophthalmoscopy; 22 control subjects were also studied. Soluble E-selectin levels were significantly elevated in both diabetic subgroups compared to control subjects (p<0.01), while no significant difference was found in sICAM-1 and sVCAM-1 levels. However, sE-selectin, sICAM-1 and sVCAM-1 levels were comparable in diabetic subgroups. The progression of retinopathy was not associated with an increase in soluble adhesion molecules levels. Stepwise multiple regression analysis revealed that only diabetes duration and microalbuminuria were independent determinants of retinopathy (p<0.01). Our results confirm the contribution of endothelial activation in the development of diabetic complications as indicated by increased levels of soluble adhesion molecules. However, a direct implication of adhesion molecules in the pathogenesis or progression of type 2 diabetic retinopathy cannot be supported.