Associations Between Diabetic Retinopathy and Plasma Levels of High-sensitive C-reactive Protein or Von Willebrand Factor in Long-term Type 1 Diabetic Patients

Abstract

Purpose: To evaluate high-sensitive C-reactive protein (hs-CRP) and von Willebrand factor as possible plasma markers of diabetic retinopathy in a population-based cohort of type 1 diabetic patients.Materials and Methods: This was a cross-sectional study of 201 type 1 diabetic patients from a population-based cohort from Fyn County, Denmark. Plasma levels of hs-CRP and von Willebrand factor antigen were measured and related to the level of diabetic retinopathy (DR) as evaluated by dilated nine-field 45 degree monoscopic fundus photos captured by Topcon TRC-NWS6 and graded according to the Early Treatment Diabetic Retinopathy Study (ETDRS) adaptation of the modified Airlie House classification of DR.Results: Median age and duration of diabetes were 58.7 and 43 years, respectively. Median levels (10th–90th percentile) of hs-CRP and von Willebrand factor antigen were 1.31 mg/l (0.37–13.3 mg/l) and 1.27 IU/ml (0.79–2.07 IU/ml), respectively. No or minimal DR (ETDRS-levels 10–20) was found in 16.4%, mild DR (ETDRS-level 35) in 19.4%, moderate DR (ETDRS-levels 43–47) in 11.0%, and 53.2% had proliferative diabetic retinopathy (PDR) corresponding to ETDRS-level 60 or more. In an age- and sex-adjusted model, patients in the highest quartile of hs-CRP were more likely to have PDR than patients in the lowest quartile (odds ratio: 2.59; 95% confidence interval: 1.09–6.12). However, this was no longer statistically significant in a multivariate model. Von Willebrand factor was not associated with PDR in any model.Conclusions: Even though patients with higher levels of hs-CRP were more likely to have PDR in an age- and sex-adjusted model, this was no longer statistically significant in a multivariate model. This indicates the importance of other risk factors like duration of diabetes, glycemic regulation, and smoking. We did not find any association between von Willebrand factor and diabetic retinopathy.