HUMAN PLACENTAL GLUCOSE-UPTAKE AND TRANSPORT ARE NOT ALTERED BY THE ORAL ANTIHYPERGLYCEMIC AGENT METFORMIN

OBJECTIVE: Our purpose was to determine whether the biguanide oral ant ihyperglycemic agent metformin increases human placental uptake and tr ansport of glucose to the fetal circulation. STUDY DESIGN: The human s ingle-cotyledon model was used to compare transport of tritiated gluco se in the maternal to fetal direction in eight human placentas between control placentas and those exposed to metformin in vitro. Transport was calculated from the serial perfusate glucose levels obtained in ea ch 3-hour experiment, and placental uptake was determined from homogen ates of the perfused cotyledon. Liquid scintillation spectrometry meas ured levels of both glucose and the reference substance antipyrine. Tr ansport was compared by the Mann-Whitney U test. RESULTS: Mean materna l and fetal glucose levels were 77.5 +/- 4.9 mg/dl and 61.3 +/- 5.9 mg /dl, respectively, in the metformin group and 83.8 +/- 4.3 mg/dl and 6 0.4 +/- 12.4 mg/dl, respectively, in controls at 2 hours. Placental gl ucose uptake was 91.1 +/- 42.2 mu g/gm placenta in the metformin exper iments and 104.9 +/- 76.9 mu g/gm placenta in controls. No difference in placental glucose uptake or transport could be demonstrated. CONCLU SION: Metformin does, not affect human placental glucose uptake or tra nsport.