Introducing a Clinically Applicable Ultrasound Method for the Study of Gastric Emptying in Health and Disease. A Study in Healthy Subjects and Patients with Diabetes Mellitus

Sammanfattning: Abnormal gastric motor function, a frequent complication among the increasing diabetic population of the world, also includes other patient groups such as those many patients with functional dyspepsia. These facts stress the need for a reliable, safe, cost-effective, and simple technique for measuring gastric emptying. To date the ultrasound technique for measuring gastric emptying has been regarded as time-consuming and laborious, making it less favoured for clinical use. The aim of the thesis was to simplify and standardize a well-tolerated and clinically applicable ultrasound method for the assessment of gastric emptying rate in order to diagnose delayed gastric emptying in patients with suspected gastroparesis. Using a single section of the stomach at a specified level, to assess the change in the antral cross-sectional area at 15 and 90 min postprandially, as an estimate of gastric emptying, the ultrasound method has been simplified, standardized and adapted for clinical use. Good agreement in inter-observer and intra-observer variability and an ability to discriminate gastric emptying between healthy subjects and type 1 diabetic patients with suspected delayed gastric emptying, indicates that the method has good clinical applicability. A comparison of ultrasonographic measurements of changes in antral area, as an estimate of antral emptying, with scintigraphic measurements of total stomach emptying, showed good agreement. Using the present, standardized ultrasound method, it was possible to elucidate the relationship between delayed gastric emptying rate and cardiac autonomic neuropathy, showing a significantly lower gastric emptying rate in type 1 diabetic patients with cardiac autonomic neuropathy than in those without this complication, and unrelated to symptoms of gastroparesis. By means of ultrasound, the effect of different food factors on gastric emptying was also studied, thereby showing that the addition of locust bean gum to the meal delayed the emptying rate, and that the ingestion of bread with added sodium propionate reduced the postprandial glucose and insulin responses because of the resultant reduction in the rate of gastric emptying.