Diabetic Retinopathy Risk Factors: Plasma Erythropoietin as a Risk Factor for Proliferative Diabetic Retinopathy

PURPOSE: The purpose of this study was to evaluate whether any stage of diabetic retinopathy (DR) is associated with levels of plasma erythropoietin and other plasma parameters. METHODS: It was examined a representative sample of 180 type 2 diabetes patients aged 40 to 79 years. Ophthalmic examination including a funduscopic examination, performed by an experienced ophthalmologist and the retinal finding were classified according to the grading system for diabetic retinopathy of ETDRS (Early Treatment Diabetic Retinopathy Study). It was measured the levels of plasma erythropoietin, cholesterol, triglyceride, apolipoproteins A and B, C-reactive protein, fasting blood glucose and hemoglobin A1C (HbA1C) in 88 DR patients and 92 controls without DR. Risk factors correlated with DR were compared between groups. RESULTS: The study group of 180 patients included 72 males and 108 females. The mean age of the patients with and without DR was 57.36 ± 8.87 years and 55.33 ± 8.28 years, respectively. Of the 88 patients with DR, only 9 (10%) had proliferative DR and the rest suffered from non-proliferative DR. The mean plasma levels of erythropoietin in proliferative DR group showed a significant difference in comparison to other groups. The mean plasma levels of cholesterol, triglyceride, apolipoproteins A and B, C-reactive protein, and fasting blood glucose were not significantly different in the three groups except for HbA1C. The absolute relative risk (ARR) also showed that erythropoietin was an increasing risk for proliferative DR (ARR, 1.17; 95% confidence interval, 1.060 to 1.420; odds ratio,1.060). CONCLUSIONS: Of the factors studied, erythropoietin level showed significant increase in proliferative DR group. The stepwise raised in mean plasma erythropoietin level which demonstrates significant correlation with proliferative DR versus remaining two groups, will be an indication of its role in proliferative DR.

Evaluation of antioxidant properties of silymarin and its potential to inhibit peroxyl radicals in vitro

Silymarin [milk thistle] has been used for centuries as a natural remedy for diseases of liver and biliary tract. The present study was carried out to evaluate the in vitro free radical scavenging activity and antioxidant properties of silymarin. Antioxidant properties of silymarin were evaluated by four methods: 1] FARP assay for total antioxidant capacity; 2] DPPH radical scavenging assay; 3] the inhibitory effect on RBC hemolysis induced by peroxyl radicals from APPH; 4] the inhibitory effect on plasma oxidation induced by Cu2+. But total phenolic compound was evaluated by Folin-Ciocalteu method. Total polyphenol compounds of silymarin was 0.484 +/- 0.017 mg Gallic acid equivalent per mg in comparison to that of green tea which is 0.313 +/- 0.095. High Antioxidant properties and significant protective effect of silymarin were in a concentration dependent manner in all methods. Therefore, silymarin is a powerful antioxidant herbal drug which can protect biological systems against the oxidative stress. It is suggested that silymarin may be used in preventing free radical-related diseases as a dietary natural antioxidant supplement