RELATIONSHIP BETWEEN ORAL GLUCOSE-TOLERANCE AND GASTRIC-EMPTYING IN NORMAL HEALTHY-SUBJECTS

The relationships between gastric emptying and intragastric distribution of glucose and oral glucose tolerance were evaluated in 16 healthy volunteers. While sitting in front of a gamma camera the subjects drank 350 ml water containing 75 g glucose and 20 MBq Tc-99m-sulphur colloid. Venous blood samples for measurement of plasma glucose, insulin and gastric inhibitory polypeptide were obtained at - 2, 2, 5, 10, 15, 30, 45, 60, 75, 90, 105, 120 and 150 min. Gastric emptying approximated a linear pattern after a short lag phase (3.3 +/- 0.8 min). The 50% emptying time was inversely related to the proximal stomach 50% emptying time (r = -0.55, p < 0.05) and directly related to the retention in the distal stomach at 120 min (r = 0.72, p < 0.01). Peak plasma glucose was related to the amount emptied at 5 min (r = 0.58, p < 0.05) and the area under the blood glucose curve between 0 and 30 min was related to the amount emptied at 30 min (r = 0.58, p < 0.05). In contrast, plasma glucose at 120 min was inversely related to gastric emptying (r = - 0.56, p < 0.05) and plasma insulin at 30 min (r = - 0.53, p < 0.05). Plasma insulin at 120 min was inversely related (r = - 0.65, p < 0.01) to gastric emptying. The increase in plasma gastric inhibitory polypeptide at 5 min was related directly to gastric emptying (r = 0.53, p < 0.05). These results indicate in normal subjects that (i) gastric emptying accounts for about 34% of the variance in peak plasma glucose after a 75-g oral glucose load (ii) plasma glucose levels at 120 min are inversely, rather than directly, related to gastric emptying (iii) the distal stomach influences gastric emptying of glucose.