Impact of Metformin on Leptin Transport in Cerebrospinal Fluid of Obese Patients

We hypothesize that the alteration of leptin transport into the CSF of obese patients could be modulated by drugs such as metformin which is widely used worldwide to treat diabetes. This study is monocentric, prospective, one-arm type and interventional. The main objective isto evaluate the impact of metformin on the transport of leptin into the CSF of obese patients. We propose to show a variation of CSF leptin / serum leptin before and after metformin treatment and study its association with changes in hypothalamic metabolic activity, cognitive and appetite-related behaviors and ratio of other metabolic signals. This would support the hypothesis of modulation of resistance to peripheral leptin by metformin and thus uncover a new indication for metformin treatment towards the management of obesity. For this purpose, volunteers will be subjected to blood sampling via venipuncture, CSF collection via lumbar puncture, MRI assessments and questionnaires (cognitive tests, food survey and feeding behavior) before and after a 3-month metformin treatment.