None listed
Conditions
Brief summary
We have previously demonstrated that consuming a mixture of whey protein and guar gum (a dietary fibre) before a meal (as a “preload”) can slow stomach emptying and improve blood sugar control after the meal in people with type 2 diabetes. In the current study, we want to compare the effects of the whey protein and guar gum given either separately or in combination in people with type 2 diabetes. The current study is designed to evaluate the acute effects of whey protein and guar gum given in advance of the main meal either alone or in combination, on postprandial glycaemia (glucose levels after a meal), gastric emptying, glucose absorption, and the release of gut hormones and insulin in patients with type 2 diabetes.
Interventions
On each study day, subjects will consume either (i) 20g whey protein concentrate, (ii) 5g guar gum, (iii) 20g whey protein concentrate + 5g guar gum each sweetened with 60mg sucralose or (iv) placebo (60mg sucralose alone) dissolved in 150 ml water (t = -20 min). 15 minutes later, subjects will eat a mixed standardized meal (65g powdered potato (Deb, Epping, NSW, Australia) reconstituted with 200ml water containing 20g glucose, 5g 3-O-methyl-glucose (3-OMG, a marker for glucose absorption), and
On each study day, subjects will consume either (i) 20g whey protein concentrate, (ii) 5g guar gum, (iii) 20g whey protein concentrate + 5g guar gum each sweetened with 60mg sucralose or (iv) placebo (60mg sucralose alone) dissolved in 150 ml water (t = -20 min). 15 minutes later, subjects will eat a mixed standardized meal (65g powdered potato (Deb, Epping, NSW, Australia) reconstituted with 200ml water containing 20g glucose, 5g 3-O-methyl-glucose (3-OMG, a marker for glucose absorption), and one egg yolk containing 100 microL 13C-octanoic acid, within 5 min (t = -5-0 min). Breath samples will be collected immediately before, and every 5 minutes after, meal ingestion in the first hour and every 15 minutes for a further 3 hours for the measurement of gastric emptying . Venous blood sample (10 ml each) will be collected at t= -15, 0, 15, 30, 60, 90, 120, 180, 240 min for the measurements of blood glucose, serum 3-OMG, and plasma GLP-1, insulin and glucagon concentrations using established assays of our laboratory. At the same intervals used for blood sampling, appetite and gastrointestinal sensations will be assessed by means of validated 100 mm visual analogue scales. Each study day is separated by a 4 day wash-out period. Patients will be supervised during consumption of the preload and the mashed potato meal.
Sponsors
Central Adelaide Local Health Network
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject)
Eligibility
Sex/Gender
All
Age
18 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
Male or female patients with a diagnosis of type 2 diabetes by WHO criteria (plasma glucose equal to 7.0 mmol/L fasting, or greater than 11.1 mmol/L two hours after a glucose challenge) or with a history of HbA1c greater than or equal to 6.5%, managed by diet or metformin * Age 18 – 75 years *Body mass index (BMI) 20- 40 kg/m2, and weight-stable *HbA1c greater than equal 6.0% and less than or equal to 7.9% at the time of screening *Haemoglobin above the lower limit of the normal range (i.e. greater than 135 g/L for men and 115 g/L for women), and ferritin above the lower limit of normal (i.e. greater than 10 mcg/L)
Exclusion criteria
*Requirement for antidiabetic medications other than metformin *Significant gastrointestinal symptoms, or history of gastrointestinal disease including known gastroparesis, or surgery (other than appendicectomy or cholecystectomy) *Intake of greater than 20 g alcohol on a daily basis, or cigarette smoking *Volunteers who have donated blood in the preceding 3 months *Current use of medications which are likely to affect gastrointestinal function or appetite (opiates, anticholinergics, levodopa, beta blockers, clonidine, nitrates, tricyclic antidepressants, selective serotonin re-uptake inhibitors, phosphodiesterase type 5 inhibitors, sumatriptan, metoclopramide, domperidone, cisapride, tegaserod, or erythromycin) *Females of childbearing age who are pregnant, or lactating , or have inadequate contraception *Vegetarians
Outcome results
None listed