Vitamin B12, sleep, and metformin: Untangling the diabetes connection

Background: Insomnia is highly prevalent in patients with type 2 diabetes mellitus (T2DM). Recent experimental studies have demonstrated that micronutrient levels in the body, especially Vitamin B12 (VitB12), may affect the activity of presynaptic neurons and the synthesis of sleep-regulating neurotransmitters such as serotonin, melatonin, and glutamate, though its exact role remains inconclusive. Aims and Objectives: This study therefore evaluated the associations between serum VitB12 and insomnia in patients with T2DM. Materials and Methods: Between September 2023 and October 2023, a total of 160 T2DM patients with or without insomnia were recruited. Clinical and biochemical parameters such as serum VitB12 levels were measured in each participant. Insomnia was evaluated using the Athens Insomnia Scale (AIS), with a score ≥6 indicating the presence of insomnia. Serum VitB12 levels were measured using the ADVIA Centaur Vitamin B12 assay. Statistical analysis was performed using the Statistical Package for the Social Sciences (v20) software. Results: Among the total diabetic population under study, 46.6% males and 52.9% females were found to be suffering from insomnia. It was also found that there was a significantly higher mean value of serum VitB12 levels among people with insomnia (307 pg/mL) than those without it (371 pg/mL) with a P=0.018. However, there was no significant correlation between AIS scores and VitB12 levels, as the Pearson correlation coefficient was found to be 0.074 and P=0.356 (>0.05). Conclusion: This study suggests that elevated serum VitB12 level is independently associated with the incidence of insomnia in diabetic people but there is no correlation between the degree of insomnia and serum VitB12 levels.