Effects of small intestinal L-phenylalanine infusions on gut motility, gut hormone release and blood glucose control in humans.

Not Applicable

Completed

• Conditions: Obesity; Healthy Human Physiology; Diet and Nutrition - Obesity; Oral and Gastrointestinal - Normal oral and gastrointestinal development and function

• Registration Number: ACTRN12612000846820
• Lead Sponsor: Christine Feinle-Bisset

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Study Start: 2012-08-13
• Last Update Posted: 13 January 2020

Recruitment & Eligibility

• Status: Completed
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

Male and female (BMI 18 to 25 kg/m2) subjects, aged between 18 to 50 years, will be included in the study. All subjects will be required to be weight-stable (ie less than 5 % fluctuation in their body weight) at study entry, as determined by their self-reported weight in the preceding 3 months, and will be required to maintain their normal physical activity over the course of the study.

Exclusion Criteria

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, orlistat, green tea extracts, Astragalus, St Johns Wort etc.) Lactose intolerance/other food allergy, diabetes mellitus, as defined by fasting glucose higher than 6.9 mmol/l and/or glycated haemoglobin higher than 6.2 %, epilepsy, cardiovascular or respiratory diseases, current intake of more than 2 standard drinks on more than 5 days per week, current smokers of cigarettes/cigars/marijuana, restrained eaters (score more than 12 on the three factor eating questionnaire), vegetarians, in female subjects, pregnancy or lactation. Phenylketonuria (PKU) ie missing the enzyme phenylalanine hydroxylase, which is needed to break down phenylalanine.

Study & Design

• Study Type: Interventional
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Antropyloroduodenal motility (number of antral, duodenal and isolated pyloric pressure waves, and basal pyloric pressure)[Using a manometri assembly and catheter, antropyloroduodenal pressures will be continously monitored from intubation until 90 minutes (end of infusion) for all three infusion sessions.];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 -10, 0, 15, 30, 45, 60, 75, 90 & 120 minutes for all three infusion sessions.]

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) and macronutrient and total energy intake at the buffet meal[VAS questionnaires are taken at t -10, 0, 15, 30, 45, 60, 75, 90 & 120 minutes for all three infusion sessions. The buffet meal will be presented at 90 minutes when the infusion ends and the subject will be allowed to freely consume food until comfortably full for 30 minutes (until t 120 minutes).]