Effects of Calcium on Gut Functions and Blood Glucose in Humans With Type 2 Diabetes

Официальное название

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

Обзор

The intervention in this study consists of a 75-min intraduodenal infusion of an isotonic solution containing either of calcium chloride (CaCl2) or control (saline). Participants enrolled into the study will receive, in randomised, double-blind fashion (i) Saline (control), (ii) 500 mg CaCl2, or (iii) 1000 mg CaCl2 in three 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.

Подробное описание

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 (7 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) 500 mg CaCl2 or iii) 1000 mg CaCl2), 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 98 mL of blood (14 sampling time points, 7 mL each) will be taken on each study day (study total of 310 mL, including screening and glucose tolerance test samples).

Вмешательства

• Другое Ca-1000
  Calcium, an essential mineral and a key component of dairy, is a regular part of our daily diet. Recent studies have shown that calcium, at doses of 1000 mg, stimulates gut hormones and motility, will be 'higher dose' in this condition.
• Другое Ca-500
  Calcium, an essential mineral and a key component of dairy, is a regular part of our daily diet. Recent studies have shown that calcium, at doses of 500 mg, stimulates gut function. In this condition, it will be considered 'lower dose.'
• Другое Control
  Saline (an isotonic solution containing 2.8 g of sodium chloride (NaCl), dissolved in 225 mL of distilled water).

Первичные конечные точки

• Plasma glucose concentrations [Срок оценки: Blood samples will be collected over 4.5 hours: at baseline (time = -30 minutes), then at regular intervals before and after drink administration (times = -25, -15, 0, 10, 20, 30, 45, 60, 75, 90, 120, 180, 240 minutes).]

Вторичные конечные точки (3)

• Gastric emptying [Срок оценки: Breath samples will be collected in sealed tubes over 4.5 hours: at baseline (time = -30 minutes) (prior to treatment administration), every 5 minutes after the drink (times = 0 to 60 minutes), then every 10 minutes until 240 minutes post-drink.]
• Plasma concentrations of glucoregulatory hormones e.g. glucagon-like peptide (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), C-peptide, glucagon, insulin and cholecystokinin (CCK) [Срок оценки: Blood samples will be collected over 4.5 hours: at baseline (time = -30 minutes), then at regular intervals before and after the drink (times = -25, -15, 0, 10, 20, 30, 45, 60, 75, 90, 120, 180, 240 minutes).]
• GI symptoms (nausea and bloating) will be assessed as a composite secondary outcome. [Срок оценки: Visual Analogue questionnaires will be collected over 4.5 hours: at baseline (time = -30 minutes), at regular intervals before and after the drink (times = -25, -15, 0, 20, 30, 45 minutes), then every 10 minutes until 240 minutes.]

Критерии участия

Критерии включения

• 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.

Критерии исключения

• 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

Критерии приведены из реестра в оригинале (на английском). Окончательную оценку соответствия проводит исследовательский центр.

Здоровые добровольцы: Нет

Дизайн исследования

Распределение

Рандомизированное

Модель

Перекрёстный дизайн

Маскирование

Тройное слепое

Основная цель

Другое

Центры проведения

Австралия · 1 центр

• Clinical Research Facility, Adelaide Health and Medical Sciences Building — Adelaide

Идентификаторы

NCT: NCT06942195 · 13243-1

Первоисточники (государственные реестры)

• ClinicalTrials.gov (NIH, США)

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