Effects of intragastric administration of L-amino acids on gastric emptying, gut hormone release, blood glucose and energy intake in healthy, normal weight and overweight or obese type 2 diabetic patients.

Not Applicable

Recruiting

• Conditions: Obesity; Type 2 Diabetes; Healthy Human Gastrointestinal Physiology; Diet and Nutrition - Obesity; Oral and Gastrointestinal - Normal oral and gastrointestinal development and function; Metabolic and Endocrine - Diabetes

• Registration Number: ACTRN12614000837628
• Lead Sponsor: Christine Feinle-Bisset

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Study Start: 2014-08-07
• Last Update Posted: 13 January 2020

Recruitment & Eligibility

• Status: Recruiting
• Sex: All
• Target Recruitment: 320

Inclusion Criteria

A total of 20 healthy, lean (BMI 19-25 kg/m2) and 20 obese T2DM (BMI 30-35 kg/m2) male and female Caucasian subjects, aged between 18 - 55 years, will be included in each sub-study i) - ix). T2DM diagnosis will be based on WHO criteria. HbA1c will be >=6.5 - <=7.9% at screening. Patients will be diet-controlled, with or without metformin (<2 g/d). All subjects will be required to be weight stable (ie <5% fluctuation) at study entry, which will be ascertained by a stable body weight in the preceeding 4 weeks. Subjects will be required to maintain their normal physical activity over the course of the study, which will be assessed using diaries.

Exclusion Criteria

All subjects: Significant gastrointestinal symptoms, disease or surgery; use of prescribed or non-prescribed medications (including vitamins and herbal supplements) which may affect energy metabolism, gastrointestinal function, body weight or appetite (eg domperidone and cisapride, anticholinergic drugs (eg 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 less than 15 ng/mL, males less than 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 greater than 2 standard drinks on greater than 5 days per week; current smokers of cigarettes/cigars/marijuana; current intake of any illicit substance; vegetarians; inability to comprehend study protocol; unable to tolerate naso-gastric tube; in female subjects, pregnancy or lactation; phenylketonuria (only applies to the part involving L-phenylalanine).

Healthy subjects only: fasting glucose >6.9 mmol/l or HbA1c >=6.5%; restrained eaters (score >12 on the three factor eating questionnaire).

Obese T2DM subjects only: HbA1c <6.5% - >7.9%; metformin medication >2g/d; estimated glomerular filtration rate <45ml/min. The degree of eating restraint will be assessed, but not used as an exclusion criteria, as obese often have some degree of eating restraint.

Study & Design

• Study Type: Interventional
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Gastric Emptying (measurement of 13CO2 in breath samples, and 2D ultrasound of the antral area).[Breath samples will be collected at t = -20 min and every 5 minutes from t = 0 to 60 min. 2D ultrasound will be taken at t = -20 min, t = -2 min, and every 15 minutes from t = 0 to 60 min. ];Plasma concentrations of gastrointestinal hormones (e.g. CCK, GLP-1, PYY, GIP and ghrelin), insulin and glucose.[Gut hormone release will be assessed by Enzyme-linked Immunosorbent Assay (ELISA) or Radio Immnunosorbent Assay (RIA) from blood samples taken at t = -20 min, every 15 minutes from t = 0 to 60 min, and a final sample taken after a 1/2 hr lunch period immediately following each study visit (t = 90 min). ]

Secondary Outcome Measures

Name	Time	Method
Appetite sensations using a Visual Analogue Scale (VAS) (satiety, hunger, fullness, thirst, desire to eat and amount of food desired to eat).[VAS questionnaires are taken at t = -20 min, t = -2 min, and every 15 minutes from t = 0 to 60 min. A final VAS is administered at the end of a 1/2 hr lunch period immediately following each study visit (t = 90 min).];Macronutrient and total energy intake at the buffet meal measured using the computer software program FoodWorks.[A buffet meal will be presented immediately following each study visit. The subject will be allowed to freely consume food until comfortably full for 30 minutes.]