Abstract
<title>Abstract</title> <p> Background. Diabetic retinopathy (DR) is a major complication of diabetes mellitus and a leading cause of visual impairment in adults. The study aimed to evaluate Hcy as a potential biomarker for DR in type 1 diabetes mellitus (T1DM) and investigate its association with DR severity. Methods. A case–control study included adult patients with T1DM, stratified into two groups according to the presence (DR group, n = 60) or absence (non-DR group, n = 58) of DR. Plasma Hcy, folate, and vitamin B12, creatinine, urinary microalbumin, and glycated hemoglobin were measured using automated methods. Estimated glomerular filtration rate (eGFR) was calculated according to the CKD-EPI formula. Multivariate analyses were performed to determine independent predictors for DR and plasma Hcy. Results. Diabetes duration, HbA1c, microalbuminuria, and folate were higher, whereas eGFR was lower in the DR group. Plasma Hcy was higher in the DR group than in the non-DR group (12.6 ± 5.40 <italic>vs.</italic> 9.51 ± 3.58 µmol/L; p < 0.001), and hyperhomocysteinemia was more prevalent in the DR group than the non-DR group (25% <italic>vs</italic> . 10.3%; p = 0.037); mean Hcy did not differ between the NPDR and PDR subgroups, but HHC was more prevalent in the PDR subgroup than the NPDR subgroup (33.3% <italic>vs</italic> . 16.7%; p = 0.041). In multivariate analysis, Plasma Hcy was increased in the DR group independently of diabetes duration and control, and renal function [OR (95% CI), 1.13 (1.022–1.257); p = 0.018]. Glycated hemoglobin, microalbuminuria, and eGFR were the other independent predictors for DR in T1DM patients. Conclusions. The findings support plasma Hcy as a clinically relevant biomarker for DR screening and suggest that targeting its metabolism may be a therapeutic option. Prospective studies and clinical trials are needed to confirm the results. </p>