Prevalence and determinants of solid and liquid gastric emptying in unstable type I diabetes - Relationship to postprandial blood glucose concentrations

OBJECTIVE - To compare postprandial blood glucose levels with gastric emptying (GE) time after intake of a solid and a nutrient liquid meal in patients with unstable, type I diabetes. RESEARCH DESIGN AND METHODS - The subjects studied were 15 patients with long-standing type I diabetes who during the last year repeatedly reported unexplained episodes of instability in their blood glucose regulation, including postprandial hypoglycemia. All patients were on a meal-administered, fast-acting insulin regimen. As control group, 19 healthy subjects were studied. GE was measured at two separate occasions, using a gamma camera after intake of either a solid or a nutrient liquid, isotope-labeled meal. Measurement of GE was done directly after meal completion and at 30-min intervals for 2 h. Insulin was taken 30 min before intake of the meal. Blood glucose was measured 30 min before the meal, after meal completion and at 30, 60, 90, and 120 min after start of the meal. All patients were evaluated for evidence of autonomic neuropathy and were asked for signs of gastrointestinal motor dysfunction. RESULTS - Seven (44%) of the patients had significantly delayed emptying of the solid meal (three men, four women) (P < 0.01), of whom one woman also had delayed emptying of the liquid meal compared with the healthy control subjects. Changes in blood glucose concentration were correlated to GE time with, in the group with delayed GE, a significant fall after the solid meal compared with the liquid meal (P < 0.05). The lag phase was prolonged in the women compared with the men, reaching significance in the patient group (P < 0.01). The women, patients as well as control subjects, had throughout the study a prolonged emptying time compared with the men after both the solid and the liquid meal. No correlation between GE and blood glucose concentration could be found. CONCLUSIONS - Delayed GE of a solid meal is commonly found in patients with type I diabetes and may be one cause of unstable blood glucose regulation. Women, patients as well as control subjects, seem to have a more prolonged GE than men. Awareness of gastric function in patients with type I diabetes is essential, especially in patients treated with meal-administered, fast-acting insulin.