Oxytocin prolongs the gastric emptying time in patients with diabetes mellitus and gastroparesis, but does not affect satiety or volume intake in patients with functional dyspepsia

BACKGROUND: Oxytocin is released in response to a fatty meal. Blockage of the oxytocin receptor led to slower gastric emptying whereas stimulation resulted in less satiety in healthy volunteers. Patients with diabetes mellitus and gastroparesis lack oxytocin elevation, and dyspepsia is partly caused by reduced fundus accommodation causing early satiety and related symptoms. The aim of this study was thus to examine the effect of oxytocin on gastric emptying, satiety and volume intake in patients with gastrointestinal pathology. RESULTS: Gastric emptying scintigraphy was performed twice in 12 patients with diabetic gastroparesis, once with oxytocin and once with saline as intravenous infusions. The patients scored their sensation of satiety using a visual analogue scale (VAS). The gastric emptying in patients with gastroparesis was prolonged during oxytocin infusion (p = 0.034) without affecting satiety. A slow satiety drinking test was performed in 14 patients with functional dyspepsia. The patients scored their satiety every five minutes until maximal satiety was reached, and the total volume was determined. The VAS was also completed 30 minutes afterwards. The test was performed twice, once with oxytocin and once with saline as intravenous infusions. There was no difference in satiety scores or volume of nutrient intake between saline and oxytocin infusions, either before, during or after the meal. CONCLUSIONS: Oxytocin prolongs gastric emptying in patients with diabetes mellitus and gastroparesis, but has no effect on volume of nutrient intake or satiety and other related symptoms in patients with functional dyspepsia.