Abstract
Twenty-four-hour excretion of D-xylose after oral administration in nine diabetic patients, and of 3-0-methyl-D-glucose in six patients, showed no significant change after treatment with metformin. There was, however, a significant reduction in mean fasting blood glucose levels in thirteen patients from 160 to 115 mg/100 ml (P <0·001), and the intravenous glucose tolerance improved in twelve of these patients (P <0·01), during treatment with metformin. It is concluded that the hypoglycaemic action of metformin does not depend primarily on an intestinal effect.