Effect of Metformin Use on Vitamin B12 Deficiency Over Time (EMBER): A Real-World Evidence Database Study.

Area of Science:

• Endocrinology and Metabolism
• Nutritional Science
• Pharmacology

Background:

• Metformin is a first-line treatment for type 2 diabetes mellitus (T2DM).
• Vitamin B12 deficiency is a potential concern with metformin therapy.
• The long-term impact of metformin on vitamin B12 levels requires further investigation.

Purpose of the Study:

• To investigate the association between metformin use and vitamin B12 deficiency in T2DM patients.
• To evaluate the risk of developing vitamin B12 deficiency with prolonged metformin use.
• To assess the impact of metformin on borderline vitamin B12 deficiency.

Main Methods:

• Analysis of the All of Us database for adult T2DM patients with documented metformin use.
• Exclusion of participants with pre-existing vitamin B12 deficiency.
• Logistic regression models to assess the association between metformin duration and B12 deficiency risk.

Main Results:

• Over 36,000 T2DM participants were analyzed; 16.9% used metformin.
• Metformin users showed a higher incidence of B12 deficiency (7.5%) compared to non-users (6.3%).
• Long-term metformin use (≥4 years) significantly increased the odds of B12 deficiency (41.0%) and borderline deficiency (27.0%).

Conclusions:

• Long-term metformin use is linked to an elevated risk of vitamin B12 deficiency in T2DM patients.
• The risk of vitamin B12 deficiency increases progressively with the duration of metformin therapy.
• Clinicians should monitor vitamin B12 levels in patients on long-term metformin treatment.