The Relationship between Serum Homocysteine Levels and Nonproliferative Diabetic Retinopathy in Type 2 Diabetes Mellitus

Abstract

Objective: To evaluate the relationship between serum homocysteine levels and the presence of nonproliferative diabetic retinopathy (NPDR) in type 2 Diabetes Mellitus (T2DM) patients Methods: One-hundred patients with a diagnosis of T2DM and 30 healthy control subjects whose age and sex were similar were included in this study. In diabetic patients retinopathy was assessed by ophthalmological examination. Homocysteine, fasting glucose, HbA1C, triglyceride, total cholesterol, high density lipoprotein and low density lipoprotein levels were analyzed in the blood samples in both groups. Also microalbumin levels were analyzed in 24-hour urine samples. T2DM patients were further divided into two groups according to the presence of retinopathy as patients with NPDR (Group 1, n=32) and without retinopathy (Group 2, n=68). Results: There was no statistically significant difference in the homocysteine levels between the T2DM group and the control group (13.13±4.35μmol/l and 12.29±4.81μmol/l, respectively, p>0.05). Although homocysteine levels were higher in the patients with diabetic retinopathy (Group 1) than the diabetic patients without any diabetic complication (Group 2), the difference was not statistically significant (13.21±4.23mmol/l and 12.96±4.60mmol/l, respectively, p>0.05). Conclusion: There was no increase in serum homocysteine levels in T2DM when there was no additional diabetic or cardiovascular complication other than NPDR. Our study, by demonstrating that serum homocysteine level was irrelevant to the presence of NPDR, suggests that homocysteine does not play a role at the early stages of retinopathy.