Georgian Med News. 2026 Mar;(372):6-12.
ABSTRACT
STUDY OBJECTIVE: The study aimed to assess the prevalence of vitamin B12 deficiency in patients with type 2 diabetes mellitus treated with metformin, determine the relationship between serum vitamin B12 and homocysteine concentrations, and evaluate the diagnostic value of vitamin B12 for identifying elevated homocysteine levels.
MATERIAL AND METHODS: The study included 126 patients with type 2 diabetes mellitus, whose age ranged from 31 to 71 years (mean age 55.57±7.14 years). All patients were treated with metformin. Serum vitamin B12 and homocysteine concentrations were determined by direct chemiluminescent enzyme immunoassay (CLEIA) using a MAGLUMI X3 analyzer. HbA1c and other clinical parameters were also assessed. Correlation and linear regression analyses were used to assess the relationship between metformin dose, vitamin B12, and homocysteine levels. ROC analysis was used to determine the diagnostic efficiency, based on which optimal cutoff values, sensitivity, specificity, and area under the curve (AUC) were determined. Statistical analysis was performed using SPSS 23 software, and values of p<0.05 were considered statistically significant.
RESULTS: Vitamin B12 deficiency or insufficient levels were detected in 50.79% of patients. A weak, but statistically significant positive correlation was found between the daily dose of metformin and homocysteine concentration. At the same time, a strong and statistically significant negative correlation was observed between vitamin B12 and homocysteine concentrations (β=-0.760, p<0.001). ROC analysis showed that vitamin B12 concentration has a high diagnostic ability for detecting elevated homocysteine levels (AUC=0.904; 95% CI: 0.845-0.964). It was determined that a vitamin B12 value of <443.8 pg/mL represents the optimal cutoff for identifying elevated homocysteine levels, with a sensitivity of 84.97% and a specificity of 85.0%.
CONCLUSION: Vitamin B12 deficiency is widespread in patients with type 2 diabetes mellitus treated with metformin, and it is closely associated with increased homocysteine levels. The results indicate that reduced vitamin B12 concentrations play an important role in the increase in homocysteine. Assessment of vitamin B12 levels can be used for the early detection of metabolic disorders associated with increased homocysteine. Therefore, joint monitoring of vitamin B12 and homocysteine in patients treated with metformin will contribute to a more effective assessment of metabolic and cardiovascular risks.
PMID:42107930