Ignite Creation Date:
2025-12-24 @ 11:28 PM
Ignite Modification Date:
2025-12-31 @ 4:21 PM
Study NCT ID:
NCT07013656
Status:
NOT_YET_RECRUITING
Last Update Posted:
2025-06-24
First Post:
2025-06-02
Is NOT Gene Therapy:
True
Has Adverse Events:
False
Brief Title:
Effects of Combined Administration of Calcium and L-tryptophan on Gut Functions and Blood Glucose in Healthy Humans
Sponsor:
University of Adelaide
Organization:
Study Overview
Official Title:
Effects of Combined Intraduodenal Administration of Calcium and L-tryptophan on Plasma Glucose, Glucoregulatory Hormones and Gastric Emptying in Response to a Mixed-nutrient Drink in Healthy Adult Males
Status:
NOT_YET_RECRUITING
Status Verified Date:
2025-06
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
The intervention in this study consists of 75-minute intraduodenal infusions of isosmotic solutions containing either saline (control), L-tryptophan, or calcium combined with L-tryptophan. Participants enrolled into the study will receive, in a randomised, double-blind fashion either (i) saline (control), (ii) L-tryptophan at a rate of 0.1 kcal/minute, (iii) combination of L-tryptophan (0.1 kcal/minute) + 500 mg calcium, or (iv) combination of L-tryptophan (0.1 kcal/minute) + 1000 mg calcium in four separate sessions, each of which will be separated by at least 4 (and up to 10) days. Each study session will be 4-6 hours. Studies will be carried out in the Clinical Research Facility of the Adelaide Medical School, the University of Adelaide, by staff and students trained in the required techniques.
Detailed Description:
Each participant will be required to consume a standardised dinner meal (beef lasagne; total energy content: 602 kcal; McCain Food, Wendouree, Victoria, Australia) on the night before each visit by 7 pm. After fasting overnight for \~ 13.5 hours and refraining from exercise and alcohol during the previous 24 hours, the participant will arrive in the laboratory at 8.30 am. After confirming adherence to the study requirements, vital signs ( blood pressure, heart rate and body temperature) will be measured to establish baseline values for safety, and they will be monitored throughout the study. Then, a manometric catheter will be inserted through an anaesthetised nostril and allowed to pass through the stomach and into the duodenum by peristalsis. The infusion port will be positioned \~ 14 cm distal to the pylorus. The correct positioning of the catheter will be monitored continuously by measurement of the transmucosal potential difference in the stomach (\~ -40 mV) and the duodenum (\~ 0 mV). Once the catheter has been positioned correctly, an intravenous cannula will be placed into a forearm vein for regular blood sampling. At time = -30 minute, a baseline blood sample (6 ml), visual analogue scale (VAS) questionnaire to assess gastrointestinal (GI) symptoms, and breath sample to assess gastric emptying will be collected. Then the infusion of one of the study treatments, i.e. (i) saline, (ii) L-tryptophan, (iii) L-tryptophan + 500 mg calcium, or (iv) L-tryptophan + 1000 mg calcium, will commence and continue for 75 minutes (times = -30 to 45 minutes). At time = -1 minute, participants will consume, within 1 minute, a mixed-nutrient drink (350 mL, containing 500 kcal, 74 g carbohydrates) labelled with 100 mg 13C-acetate for measurement of gastric emptying by non-invasive breath sampling at regular intervals, for subsequent analysis of 13CO2 levels. Blood samples for the measurement of plasma glucose and hormone concentrations, and VAS questionnaires, will be collected before and after the mixed-nutrient drink. At time = 240 minute, after collecting final blood and breath samples and VAS questionnaire, the intravenous cannula will be removed and the participant will be served a light lunch, after which they will be allowed to leave the laboratory. A total of 84 mL of blood (14 sampling time points, 6 mL each) will be taken on each study day (study total of 344 mL, including screening).
Study Oversight
Has Oversight DMC:
False
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?: