Influence of retinopathy on plasma concentrations of total homocysteine and other biochemical parameters in algerian patients with type 2 diabetes mellitus

Abstract

Homocysteine (HCY) has been identified as a risk factor for vascular disease in the general population. Diabetic retinopathy (DR) itself rather than hyperhomocysteinemia is the leading cause of blindness among patients with type 2 diabetes mellitus (T2DM). Our study was conducted with 60 healthy control subjects and 178 subjects with T2DM. They were enrolled in the Diabetes Prevention Program from September 2007 to December 2008. Of the 178 patients, 121 cases (68%) had DR Mean plasma total HCY (tHCY) levels were found to be higher in T2DM patients compared to controls (p <0.001), and were also higher than that of the DR group (p <0.001). Plasma folic acid levels were lower in the DR group compared with T2DM without DR and the control group (p <0.001), but there were no significant differences between the latter and the controls. Moderate hyperhomocysteinemia was significantly associated with lower vitamin B12 and folic acid concentrations and older age. Concentrations of serum total cholesterol, LDL-cholesterol (LDL-C), and triglycerides (TG) were significantly raised (p <0.001) whereas the level of HDL-cholesterol (HDL-C) was decreased (p <0.001) in diabetic subjects as compared to controls. Logistic regression analysis showed that DR after adjustment was significantly associated with the following factors: cholesterol, HDL-C and TG. The analysis in DR patients after controlling for cholesterol and TG was independent of plasma tHCY concentrations (OR = 28.5 and OR = 11.9; respectively). In conclusion, results suggest a possible association between moderate hyperhomocysteinemia, traditional risk factors and folic acid deficiency could be an independent risk factor for DR.