Background and Aims: Vitamin B12 is an essential micronutrient required for optimal hemopoetic, cardiovascular and neuro-cognitive functions. There are some literature data that Metformin induces vitamin B12 malabsorption, which may increase the risk of developing vitamin B12 deficiency and subsequently elevation of homocysteine levels. High concentrations of homocysteine has been associated with higher risk of coronary artery disease, arterial hypertension, hip and other bone fractures, rheumatoid arthritis, diabetes, and other serious chronic diseases. As first line therapy, Metformin is the most frequently prescribed medication in cases of hyperinsulinism and type 2 diabetes. It is one of a few antihyperglycaemic agents, associated with improvement in cardiovascular morbidity and mortality. Metformin acts by reducing the amount of glucose, produced by the liver, as well as increasing patient's sensitivity to insulin.
Methods: Twenty five children with obesity aged between 10 and 17 years were included in the study. Levels of B12 and homocysteine were measured in the participants. All of them had BMI > 97th centile. Oral glucose tolerance test was performed and hyperinsulinism was diagnosed in the children. The patients were treated with Metformin 850 mg twice daily for a period of 1 to 3 years.
Results: Ten patients had levels of B12 within the laboratory reference range and recommended homocysteine concentration <7.2 µmol/l. In 15 of the participants we found insufficient levels of vitamin B12 <200 pg/ml and elevated homocysteine levels
Conclusions: Our results are consistent with literature data that Metformin is associated with low levels of vitamin B12. These are the first results of an ongoing study in our department. We recommend that vitamin B12 levels should be assessed regularly in patients treated with Metformin longer than a year.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology