Association of advanced oxidation protein product, thiobarbituric acid reactive substances and total sulfhydryl groups with retinal blood vessels caliber

Abstract

Introduction/Objective Intensive oxidative stress is proven in patients with diabetes mellitus and important in the development of a microvascular complication of type 2 diabetes mellitus. The aim of the study was to investigate the relationship between morphometric parameters of retinal blood vessels in patients with diabetic retinopathy (DR) and the levels of parameters of oxidative stress: advanced oxidation protein product (AOPP), thiobarbituric acid reactive substances (TBARS), and total sulfhydryl (SH) groups in blood samples. Methods The patients (the group with DR and controls) were sex-and age-matched. Glycaemia, hemoglobin A1C HbA1C, total cholesterol and its fractions, and triglycerides were measured in blood samples. AOPP and total SH groups were determined in the plasma by specific methods. Modification of the thiobarbituric acid method was used for the determination of TBARS. The number and diameter of retinal blood vessels, as morphometric parameters on digital retinal photography, was determined by using the ImageJ software. Student's t-test was used as the statistical method for the evaluation of differences between the morphometric and blood test parameters. The significance of differences in morphometric parameters of retinal blood was establish by one-way ANOVA. Results Significantly higher levels of parameters of oxidative stress (AOPP and TBARS) were in the group of patients with DR than in the controls. This difference was also present among the patients with mild and severe forms of DR (AOPP F 77.03, p < 0.001) (TBARS F 63.28, p < 0.001). The diameter of retinal blood vessels correlated with levels of AOPP, but only in patients with mild DR. Conclusion Parameters of oxidative stress, AOPP and TBARS, may be important for the follow-up of DR. In early stages in diabetic retinopathy, AOPP can be a valuable biomarker.