Abstract

Background: Homocysteine is an emerging risk factor for cardiovascular and non-diabetic ocular vaso-occlusive diseases. However, studies of the relationship between homocysteine and diabetic retinopathy have reported inconsistent results.

Objective: The purpose of this study was to evaluate the relationship between plasma total homocysteine concentration and diabetic retinopathy.

Design: We assessed the homocysteine-retinopathy relationship in 168 men and women with type 2 diabetes in a community-based, cross-sectional study. We photodocumented diabetic retinopathy status and measured plasma total homocysteine concentration using a commercial FPIA enzymatic kit. Data for selected clinical/demographic variables and established risk factors for diabetic retinopathy were obtained from fasting blood samples and an interviewer-assisted lifestyle questionnaire.

Results: A higher mean (95% CI) plasma total homocysteine concentration was observed in diabetic individuals with retinopathy than in those without retinopathy (11.5 [10.4- 12.5] umol/L vs. 9.6 [9.1-10.2] umol/L, p = 0.001). Furthermore, the relationship between homocysteine and diabetic retinopathy was not explained by renal dysfunction and was independent of the other major risk factors for diabetic retinopathy [duration of diabetes, HbA1c, systolic blood pressure] and determinants of higher homocysteine concentrations [age, gender, red cell folate], (OR 1.20 [1.023-1.41], p = 0.024).

Conclusion: Plasma total homocysteine concentration may be a useful biomarker and/or a novel risk factor for increased risk of diabetic retinopathy in people with type 2 diabetes.