Abstract
Purpose::
To study associations between serum levels of inflammatory markers and proliferative retinopathy in type 1 diabetic patients.
Methods::
Type 1 diabetic patients (n=128) with different degrees of retinopathy underwent stereo fundus photography and retinopathy grading according to the Early Treatment Diabetic Retinopathy Study (ETDRS) scale, and were divided into two retinopathy groups, no or non-proliferative retinopathy (NDR/NPDR) (ETDRS levels 10-53; n=62), and proliferative retinopathy (PDR) (ETDRS levels >53; n=66). Serum levels of TNF-α, IL-1b, IL-6, Vascular Cellular Adhesion Molecule-1 (VCAM-1), Intercellular Adhesion Molecule -1 (ICAM-1), P-selectin and high-sensitive C-reactive protein (hsCRP) were analysed. Statistical analysis was performed by non-parametric Mann-Whitney U-test for significant differences between groups.
Results::
Patients with PDR had higher levels of TNF-α (6.5; 3-17 pg/ml vs. 5.0; 3-25 pg/ml; p=0.009), VCAM-1 (860; 360-2120 ng/ml vs. 700; 310-1820 ng/ml; p<0.001), and P-selectin (180; 39-400 ng/ml vs. 150; 42-440 ng/ml; p=0.017) (median; range). There were no differences in serum levels of ICAM-1 or hsCRP. IL-1ß was not detectable in any patient serum and IL-6 in 22.7% only. In multivariate logistic regression analysis TNF-α was the only independent determinant inflammatory marker for PDR.
Conclusions::
The association between the inflammatory marker TNF-α and PDR in type 1 diabetic patients suggest that inflammation might play a role in the pathogenesis of proliferative diabetic retinopathy.
Keywords: diabetic retinopathy • cytokines/chemokines • proliferation