Discontinuation of metformin to prevent metformin-induced high colonic FDG uptake: is 48 h sufficient?

Objective: In this retrospective, single-center observational study, we investigated whether discontinuing metformin for at least 48 h prevents metformin-induced [F]fluorodeoxyglucose (FDG) uptake in all segments of the colon.

Methods: Patients with type 2 diabetes who were using metformin before undergoing an FDG PET/CT scan were included. Two groups were created: patients who discontinued metformin for less than 48 h (< 48 h group) and patients who discontinued metformin for between 48 and 72 h (≥ 48 h group).