Study of Vitamin B12 Status among Older Adult Iraqi Patients with Diabetic Retinopathy

Background: Diabetic retinopathy (DR), a typical consequence of diabetes mellitus (DM). is the main cause of vision loss in middle-aged and older adults. Unchecked and severe cases of DR could lead to blindness. DR is categorized into nonproliferative and proliferative variants based on the existence or absence of ocular neovascularization. The association between serum levels of vitamin B12 and various indicators, such as body mass index (BMI), fasting blood sugar (FBS), HOMA-β, fasting insulin (FI), HOMA-IR, and HbA1c, is studied in patients with DM and DR. Method and Results: In this study, thirty healthy individuals and sixty patients were examined. Two subgroups were divided for the patients: thirty with DM and thirty with DR. For each group, serum levels of vitamin B12, FBS, FI, HOMA-β, HOMA-IR, and HbA1c have been investigated. Levels of vitamin B12 in serum demonstrated a significant decrease for each DM and DR with healthy subjects (391.57 ± 90.67 vs. 660.23 ± 168.01, P = 0.001) and (263.27 ± 79.15 vs. 660.23 ± 168.01, P = 0.001), respectively, and also demonstrated a significant decrease between DM and DR (391.57 ± 90.67 vs. 263.27 ± 79.15, P = 0.001). The correlation between vitamin B12 and other clinical indicators has been examined. Through these results, it is observed that vitamin B12 exhibited a significant negative association with age (r = -0.673) and a significant positive correlation with FI (r = 0.513), HOMA-β HOMA-IR (r = 0.333), and HOMA-IR (r = 0.268), while it revealed a non-significant negative correlation with BMI (r = -0.082), FBS (r = -0.108), and HbA1c (r = -0.172). Conclusion: The results of this investigation showed that serum levels of vitamin B12 were significantly lower in individuals with DR than in the healthy subjects and those with DM.