None listed
Conditions
Brief summary
The purpose of this trial is to investigate the acute dose-related effects of intraduodenal administration of calcium on gastrointestinal functions, associated with the regulation of appetite and energy intake, in healthy participants.
Interventions
The intervention in this study consists of a 75-min intraduodenal infusion of either a calcium chloride (CaCl2) or control solution.
Participants enrolled into the study will receive, in randomised, double-blind fashion
(i) Saline (control),
(ii) 500 mg CaCl2,
(iii) 1000 mg CaCl2,
each occurring at separate visits. Each visit will last 4-6 hours in duration and will be separated by 3-7 days. To ensure adherence to the intervention, research staff will closely supervise the participants through
The intervention in this study consists of a 75-min intraduodenal infusion of either a calcium chloride (CaCl2) or control solution. Participants enrolled into the study will receive, in randomised, double-blind fashion (i) Saline (control), (ii) 500 mg CaCl2, (iii) 1000 mg CaCl2, each occurring at separate visits. Each visit will last 4-6 hours in duration and will be separated by 3-7 days. To ensure adherence to the intervention, research staff will closely supervise the participants throughout the study visit. Visits 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. Participants will be asked to consume a standardised dinner meal (Beef lasagne; total energy content: 602kcal; McCain Food, Wendouree, Victoria, Australia) the night before each visit by no later than 7 pm. After fasting for 14 hours overnight and refraining from exercise and alcohol for 24 hours, participants will arrive at the laboratory at 8 am. Upon arrival, participants will be intubated with a 17-channel manometric catheter that will be inserted through an anaesthetised nostril and allowed to pass through the stomach and into the duodenum by peristalsis. The manometric catheter consists of 16 side holes, spaced at 1.5 cm intervals, will be used for measuring pressures in the antrum, pylorus, and duodenum. An additional channel (with the side hole positioned approx 14 cm distal to the pylorus when the catheter is in the correct position) will be used for intraduodenal infusions. The correct positioning of the catheter will be maintained by continuous measurement of the transmucosal potential difference between the most distal antral channel and the most proximal duodenal channel. All manometric channels will be perfused with degassed, distilled water, except for the two channels that will be perfused with degassed 0.9% saline, at 0.15 ml/min. An intravenous cannula will be placed into a forearm vein for regular blood sampling. Once the catheter has been positioned correctly, fasting motility will be monitored continuously, and immediately after the end of phase III activity of the fasting migrating motor complex, during a period of motor quiescence, baseline antropyloroduodenal (APD) pressures will be recorded for 10 min (t = -10-0 min), and at t = 0 min after collecting baseline blood sample and visual analogue scale (VAS), one of the three intraduodenal infusions (ie i) saline, ii) 500 mg or iii) 1000 mg CaCl2) will commence. APD pressures will be measured continuously for 75 min (t = 0-75 min). Vital signs (blood pressure, heart rate) will be measured at regular time intervals using a sphygmomanometer/blood pressure meter. At t = 75 min, the manometric assembly will be removed and participants will be presented with a standardised, buffet-style meal to assess energy intake. Participants will be allowed 30 min to freely consume food until they feel comfortably full. At t = 105 min, a final blood sample and VAS questionnaire will be collected. The intravenous cannula will then be removed and participants will be allowed to leave the laboratory. A total of 80 mL of blood will be taken on each study day (study total of 248 mL, including screening test).
Sponsors
Christine Feinle-Bisset
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to 55 Years
Healthy volunteers
Yes
Inclusion criteria
Healthy Lean weight (BMI 19-25 kg/m2)
Exclusion criteria
Each participant will be questioned prior to the study to exclude: • significant GI symptoms, disease or surgery • use of prescribed or non-prescribed medications (including vitamins and herbal supplements) which may affect energy metabolism, GI function, body weight or appetite (e.g. domperidone, cisapride, anticholinergic drugs (e.g. atropine), metoclopramide, erythromycin, hyoscine, orlistat, green tea extracts, Astragalus, St Johns Wort etc.) • lactose intolerance/other food allergy(ies) • current gallbladder or pancreatic disease • cardiovascular or respiratory diseases • individuals with low ferritin levels (females <15 ng/mL, males <30 ng/mL), or who have donated blood in the 12 weeks prior to taking part in the study • any other illnesses as assessed by the investigator (including chronic illnesses not explicitly listed above) • high performance athletes • current intake of > 2 standard drinks on > 5 days per week • current smokers of tobacco (cigarettes, cigars, pipes, sheesha, chewing, vaping etc.) • recreational drug use, e.g marijuana • current intake of any illicit substance • vegetarians • inability to tolerate nasoduodenal tube • inability to comprehend study protocol • restrained eaters (score >12 on the 3-factor eating questionnaire)
Outcome results
None listed