RESULTS: The mean duration of diabetes was 8.4 years (±5.8); mean duration of metformin use was 64.1 months (±43.2), with a meanmetformindose of 1,306 mg/day. A sufficient cobalamin level was independently associated with a decreasedrisk of depression (OR 0.42; 95 % CI 0.23-0.78) and better cognitiveperformance (β = 1.79; 95 % CI 0.07-3.52) adjusted for confounders. This indicates that cobalamin-deficient patients had a 2.4 times higher chance of depression and a 1.79 point lowercognitiveperformance score. HoloTCII was not associated with any outcome.
CONCLUSIONS: Cobalamin deficiency was associated with an increasedrisk of depression and worse cognitiveperformance, while holoTCII was not. Screening for cobalamin deficiency may be warranted in diabetespatients using metformin. Physicians should consider a cobalamin deficiency in diabetespatients using metformin with a depression or cognitive decline.