Dose-dependent accumulation of glucose in the intestinal wall and lumen induced by metformin as revealed by F-labelled fluorodeoxyglucose positron emission tomography-MRI.

AIM

To investigate the relationships between various clinical variables and the metformin-induced accumulation of fluorodeoxyglucose (FDG) in the intestine, with distinction between the intestinal wall and lumen, in individuals with type 2 diabetes who were receiving metformin treatment and underwent F-labelled FDG ([ F]FDG) positron emission tomography (PET)-MRI.

MATERIALS AND METHODS

We evaluated intestinal accumulation of [ F]FDG with both subjective (a five-point visual scale determined by two experienced radiologists) and objective analyses (measurement of the maximum standardized uptake value [SUV ]) in 26 individuals with type 2 diabetes who were receiving metformin and underwent [ F]FDG PET-MRI. [ F]FDG accumulation within the intestinal wall was discriminated from that in the lumen on the basis of SUV .

RESULTS

SUV for the large intestine was correlated with blood glucose level (BG) and metformin dose, but not with age, body mass index, HbA1c level or estimated glomerular filtration rate (eGFR). SUV for the small intestine was not correlated with any of these variables. Visual scale analysis yielded essentially similar results. Metformin dose and eGFR were correlated with SUV for the wall and lumen of the large intestine, whereas BG was correlated with that for the wall. Multivariable analysis identified metformin dose as an explanatory factor for SUV in the wall and lumen of the large intestine after adjustment for potential confounders including BG and eGFR.

CONCLUSIONS

Metformin dose is an independent determinant of [ F]FDG accumulation in the wall and lumen of the large intestine in individuals treated with this drug.