title: Metformin reduces the rate of small intestinal glucose absorption in type 2 diabetes.
abstract: In rodents, metformin slows intestinal glucose absorption, potentially increasing exposure of the distal gut to glucose to enhance postprandial glucagon-like peptide-1 (GLP-1) secretion. We evaluated the effects of metformin on serum 3-O-methylglucose (3-OMG; a marker of glucose absorption) and plasma total GLP-1 concentrations during a standardized intraduodenal infusion of glucose and 3-OMG in patients with type 2 diabetes. A total of 12 patients, treated with metformin 850 mg twice daily or placebo for 7 days each in a double-blind, randomized, crossover design (14 days' washout between treatments), were evaluated on days 5 or 8 of each treatment (6 subjects each). On each study day, 30 minutes after ingesting 850 mg metformin or placebo, patients received an infusion of glucose (60 g + 5 g 3-OMG, dissolved in water to 240 mL) via an intraduodenal catheter over the course of 120 minutes. Compared with placebo, metformin was associated with lower serum 3-OMG ( P < .001) and higher plasma total GLP-1 ( P = .003) concentrations. The increment in plasma GLP-1 after metformin vs placebo was related to the reduction in serum 3-OMG concentrations ( P = .019). Accordingly, metformin inhibits small intestinal glucose absorption, which may contribute to augmented GLP-1 secretion in type 2 diabetes.
authors.affiliation: Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia.|Centre of Research Excellence in Translating Nutritional Science to Good Health, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Tongzhi
authors.initials: T
authors.lastname: Wu
authors.affiliation: Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia.|Centre of Research Excellence in Translating Nutritional Science to Good Health, University of Adelaide, Adelaide, South Australia, Australia.|Medical School, Southeast University, Nanjing, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Xie
authors.affiliation: Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia.|Centre of Research Excellence in Translating Nutritional Science to Good Health, University of Adelaide, Adelaide, South Australia, Australia.|Medical School, Southeast University, Nanjing, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Wu
authors.affiliation: Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia.|Centre of Research Excellence in Translating Nutritional Science to Good Health, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Karen L
authors.initials: KL
authors.lastname: Jones
authors.affiliation: Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia.|Centre of Research Excellence in Translating Nutritional Science to Good Health, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Horowitz
authors.affiliation: Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia.|Centre of Research Excellence in Translating Nutritional Science to Good Health, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Rayner
mesh_terms: D019325:3-O-Methylglucose / Q000378:metabolism*; D000368:Aged; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D004311:Double-Blind Method; D052216:Glucagon-Like Peptide 1 / Q000187:drug effects* / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007408:Intestinal Absorption / Q000187:drug effects*; D007421:Intestine, Small / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008687:Metformin / Q000494:pharmacology*; D008875:Middle Aged; D019518:Postprandial Period
chemical_list: D007004:Hypoglycemic Agents; D019325:3-O-Methylglucose; D052216:Glucagon-Like Peptide 1; D008687:Metformin; D005947:Glucose
keywords: 3-O-methylglucose; glucagon-like pepetide-1; intestinal glucose absorption; metformin