Small-intestine calcium infusion to change gut function and blood sugar in men with type 2 diabetes
Effects of Intraduodenal Calcium on Plasma Glucose, Glucoregulatory Hormones and Gastric Emptying in Response to a Mixed-nutrient Drink in Humans With Type 2 Diabetes
This trial will test whether delivering calcium directly into the upper small intestine during short clinic visits changes gut function and blood sugar in men with type 2 diabetes.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 8 (estimated) |
| Ages | 18 Years to 70 Years |
| Sex | Male |
| Sponsor | University of Adelaide Academic / other |
| Locations | 1 site (Adelaide, South Australia) |
| Trial ID | NCT06942195 on ClinicalTrials.gov |
What this trial studies
In a randomized, double-blind, crossover design, participants attend three separate 4–6 hour clinic visits to receive a 75-minute intraduodenal infusion of either saline (control), 500 mg CaCl2, or 1000 mg CaCl2. A nasal catheter is passed into the duodenum and correct placement is confirmed electrically, while blood samples, breath tests for gastric emptying, and symptom questionnaires are collected before, during, and after the infusion. Visits are separated by 4–10 days and participants withhold glucose medications for 48 hours before each visit. The study measures plasma glucose, glucoregulatory hormones, gastric emptying, and gastrointestinal symptoms to see how intraduodenal calcium alters gut and glucose responses.
Who should consider this trial
Good fit: Men with type 2 diabetes who have BMI 28–38 kg/m², HbA1c 6.5–7.9%, stable weight, and who can withhold glucose medications and tolerate nasal catheter placement are ideal candidates.
Not a fit: People with significant gastrointestinal disease or prior GI surgery, current gallbladder or pancreatic disease, cardiovascular or respiratory disease, women, or those outside the BMI/HbA1c ranges are not likely to fit or benefit from this protocol.
Why it matters
Potential benefit: If successful, this approach could help improve post-meal blood sugar control or gut hormone responses that support diabetes management.
How similar studies have performed: Small mechanistic studies have shown that delivering nutrients to the small intestine can alter gut hormones and glucose, but intraduodenal calcium specifically is a relatively novel, not widely tested, approach.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Males with type 2 diabetes mellitus (T2DM). Diagnosis of T2DM will be based on WHO criteria. Only males will be included to avoid the confounding effects of the menstrual cycle on gastric emptying. * BMI: 28-38 kg/m². * HbA1c \>=6.5 - \<=7.9% at screening. * Blood glucose medications will be required to be withheld for 48 hours prior to each study day. * Weight-stable (i.e. \<5% fluctuation) at study entry, which will be ascertained by a stable body weight in the preceding 3 months. Exclusion Criteria: * Significant GI symptoms, or history of GI disease or surgery * Current gallbladder or pancreatic disease * Cardiovascular or respiratory diseases * Any other illnesses (except type 2 diabetes) as assessed by the investigator - (including chronic illnesses not explicitly listed above) * Use of prescribed or non-prescribed medications (including vitamins and herbal supplements) which may affect energy metabolism, GI function, bodyweight 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) * Individuals with low ferritin levels (\<30 ng/mL), or who have donated blood in the 12 weeks prior to taking part in the study * High performance athletes * Current intake of \> 2 standard drinks on \> 5 days per week (\>140g/week) * Current smokers of tobacco (cigarettes, cigars, pipes, sheesha, chewing, vaping etc.) * Current use of recreational drugs, e.g. marijuana * Current intake of any illicit substance * Vegetarians * Inability to tolerate nasoduodenal tube * Inability to comprehend study protocol * HbA1c \<6% or \>7.9% * Estimated glomerular filtration rate \<45 ml/min * Any patient whose medication cannot be withheld for 48 hours for medical reasons
Where this trial is running
Adelaide, South Australia
- Clinical Research Facility, Adelaide Health and Medical Sciences Building — Adelaide, South Australia, Australia (Recruiting)
Study contacts
- Principal investigator: Prof Christine Feinle-Bisset — Adelaide Medical School University of Adelaide Level 5 Adelaide Health and Medical Sciences Building, Cnr George St and North Tce, Adelaide, SA 5005
- Study coordinator: Prof Christine Feinle-Bisset
- Email: christine.feinle@adelaide.edu.au
- Phone: +61 8 8313 6053
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.