Diabetic Retinopathy and Homocysteine Study

Diabetic retinopathy is a major vascular complication of diabetes mellitus (DM), often leading to low vision and blindness. In a recent study, researchers reported that high homocysteine is associated with nonproliferative diabetic retinopathy in patients with type 2 diabetes.

The study findings were published in the journal Diabetic & Metabolic Syndrome: Clinical Research & Review on December 01, 2021.

A few studies have suggested that the level of plasma and vitreous Hcy is a risk factor for diabetic retinopathy, while others have refuted this link. Therefore, Dr. Tomislav Bulum and his team conducted a study to assess the role of plasma homocysteine (Hcy) in the development of nonproliferative diabetic retinopathy (NPDR) in patients with type 2 diabetes (T2DM) without chronic kidney disease.

In this cross-sectional study, the researchers included a total of 94 T2DM patients. They evaluated Hcy, serum 25-hydroxy (25-OH) Vitamin D, vitamin B12, and folate using the CMIA method. They determined NPDR according to the EURODIAB retinal photography methodology and optical coherence tomography (OCT) of the macula.

Key findings of the study:

• When compared to patients without NPDR, the researchers found that the patients with NPDR had longer diabetes duration (p < 0.001), higher Hcy (p < 0.001), lower vitamin B12 (p = 0.028) and lower estimated glomerular filtration rate (eGFR).
• They also found a positive association with NPDR and diabetes duration, HbA1c and Hcy and a negative association with vitamin B12 and eGFR.
• Upon logistic regression analyses, they noted that the diabetes duration (OR = 1.13), Hcy (OR = 1.06), and eGFR (OR = 0.96) were the main predictors of NPDR in T2DM.
• Using stepwise regression analyses, they observed that the best model for predicting Hcy (R² = 0.104) included vitamins B12 and D.

The authors concluded, "Higher Hcy is associated with NPDR and may play a role as a risk factor for its development in T2DM. Vitamins B12 and D seem to modify this association."

For further information:

DOI: https://doi.org/10.1016/j.dsx.2021.102355