Direct Measurement of Microstructure of Ingestive Behaviour After Initiation of GLP-1 Receptor Agonist Treatment at Maximum Dose (DIGRAT)

Condition(s) studied

Investigational drug(s) / intervention(s)

semaglutide 1 mg weekly injection: Initiation of semaglutide treatment with weekly injection. The patient starts at 0.25 mg for 4 weeks and then the dose escalates at 0.5 mg. The maximum dose of 1 mg is reached at week 12. The patients decided to undergo the treatment before they were recruited in the study.

Study summary

Ingestion of food instigates the release of a battery of enteroendocrine peptide hormones that help control gut motility and digestive secretion. Peptide hormone products of the enteroendocrine L-cell and GLP-1 in particular, play multiple roles in relation to the regulation of pancreatic islet function and gastric emptying and the induction of satiety pathways in the central nervous system The mechanism of action of GLP-1 RAs on food intake reduction is mainly mediated through both peripheral and central nervous system (CNS) pathways. GLP-1 RAs directly stimulates POMC neurons and inhibits neuropeptide-Y (NPY) and Agouti-related peptide (AgRP) neurons in the arcuate nucleus resulting in a reduction in hunger and increases in fullness4.

While there were studies which indirectly measured the changes of food preference and eating behaviour in humans after using GLP-1 RAs via visual analogue scales (VAS) or Patient's Experiences Questionnaires the investigators found there is a necessity to conduct the studies to do direct measurements of the changes of food preference and eating behaviour. Direct measures of an altered food selection in humans after using GLP-1 RAs have virtually not been performed likely due to the significant methodological and conceptual challenges they pose to researchers and study design. However, direct measures represent an essential component in the attempt to understand how GLP-1 RAs alters eating and diet selection which is the main reason of conducting this study. This innovative experiment will be a critical and a novel test of the explicit experience of humans with high-sugar high-fat fluids after using GLP-1 RAs and its potential role for the understanding of possible mechanisms determining post-treatment outcome such as weight loss.

Eligibility

Primary outcome measure(s)

• Energy Intake from Liquid Meal Consumption — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  Total energy intake (in kilocalories) from consumption of high-carbohydrate, high-sucrose, and high-fat lactose-free milk during each visit. Intake is measured using a drinkometer device that quantifies the exact volume consumed, which is then converted into kilocalories based on the known energy density of each meal type. The unit of measure is kilocalories (kcal).
• Macrostructure of Ingestive Behaviour (Rate of Energy Intake) — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  The rate of energy intake is calculated for each participant during the ingestion of each of the one stimuli, based on standardised measurements from the drinkometer system. This measure reflects the average caloric intake per second over the course of the test stimulus consumption. Energy intake is determined by the volume of liquid consumed, multiplied by the known caloric density of the test stimulus, and divided by the duration of the ingestion period. The unit of measure is kilocalories per second (kcal/s). This outcome is assessed during the five study visits, in which a one test stimulus is administered at each visit.
• Macrostructure of Ingestive Behaviour (Meal Duration) — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  Meal duration is defined as the total time taken by each participant to consume the liquid meal, measured using the standardised drinkometer system. The duration is recorded from the initiation of ingestion (first measurable suck) to the completion of consumption (last measurable suck). The unit of measure is seconds (s). This outcome is assessed during the five study visits. The test stimuli are offered to participants simultaneously.
• Macrostructure of Ingestive Behaviour (Number of Sucks) — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  The primary outcome is the number of sucks performed by each participant during the ingestion of the liquid meal as measured using a standardised drinkometer system. A "suck" is defined as a discrete negative pressure event generated by the participant to draw in liquid, as detected by the drinkometer's calibrated weight sensors. For the stimulus, the total number of sucks is recorded as a simple count, with the unit of measure being "number (n)." The outcome is assessed at each of the five study visits, each of which features a single test stimulus administered in a standardised fashion.
• Microstructure of Ingestive Behaviour (Suck Energy Intake) — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  Suck energy intake is defined as the total amount of energy (in kilocalories) consumed by the participant during each individual suck, measured for test stimuli using a standardised drinkometer system. For each test stimulus, the total caloric intake is calculated by multiplying the volume of liquid ingested by its caloric density and summing the values across all measured sucks. The unit of measure is kilocalories (kcal). This outcome is assessed during the five study visits, test stimuli are presented to the participant simultaneously.
• Microstructure of Ingestive Behaviour (Suck Duration) — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  Suck duration is defined as the time span of each individual suck performed by the participant during the ingestion the liquid meal test stimuli, as measured by a standardised drinkometer system. For each test stimulus, the duration of every suck is recorded from the initiation to the completion of the negative pressure event. The unit of measure is seconds (s). This outcome is assessed during the five study visits, where the stimulus of the liquid meal is administered at each visit. The test stimuli are presented simultaneously.
• Microstructure of Ingestive Behaviour (Suck Rate) — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  Suck rate is defined as the average energy intake of liquid ingested per second during each suck, measured for the test stimuli using a standardised drinkometer system. The energy intake consumed during each suck is divided by the corresponding suck duration to determine the rate of ingestion for that event. The unit of measure is kilocalories per second (kcal/s). This outcome is assessed during the five study visits, where the single test stimulus is administered at each visit. The test stimuli are presented simultaneously.
• Microstructure of Ingestive Behaviour (Suck Maximal Rate) — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  Suck maximal rate is defined as the highest instantaneous rate of liquid ingestion (in kilocalories per second) achieved during any single suck by the participant for the test stimuli, as measured using a standardised drinkometer system. For the test stimulus, the maximal rate is determined by identifying the suck with the greatest energy intake per unit time among all measured sucks during the ingestion period. The unit of measure is kilocalories per second (kcal/s). This outcome is assessed during the five study visits where the stimuli are presented simultaneously.
• Microstructure of Ingestive Behaviour (Burst Number) — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  Burst number is defined as the total count of distinct bursts performed by the participant during the ingestion of the stimuli, as measured using a standardised drinkometer system. A "burst" is operationally defined as a sequence of successive sucks separated by brief pauses, typically reflecting a rhythmic drinking pattern. For the stimulus, the number of such bursts is recorded as an integer value. The unit of measure is "number of bursts" (n). This outcome is assessed during the five study visits, where the test stimuli is presented simultaneously.
• Microstructure of Ingestive Behaviour (Burst Duration) — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  Burst duration is defined as the total elapsed time of each individual burst performed by the participant during the ingestion of the test stimuli, as measured using a standardised drinkometer system. A "burst" is operationally defined as a sequence of consecutive sucks separated by brief pauses. For each burst, the duration is measured from the onset of the first suck to the end of the last suck within the burst. The unit of measure is seconds (s). This outcome is assessed during the five study visits, where the test stimulus is presented simultaneously.
• Microstructure of Ingestive Behaviour (Burst Energy Intake) — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  Burst energy intake is defined as the total amount of energy intake (in kilocalories) consumed during each individual burst by the participant, measured for the test stimuli using a standardised drinkometer system. A "burst" is operationally defined as a sequence of consecutive sucks separated by brief pauses. For each burst, the energy intake is calculated by multiplying the volume of liquid ingested within the burst by the energy density of the test stimulus. The unit of measure is kilocalories (kcal). This outcome is assessed during the five study visits, where the test stimuli is offered simultaneously.
• Microstructure of Ingestive Behaviour (Burst Rate) — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  Burst rate is defined as the average rate of energy intake during each individual burst performed by the participant for the test stimuli, as measured using a standardised drinkometer system. For each burst, the total energy intake (in kilocalories) is divided by the duration of the burst (in seconds) to determine the average rate of energy intake for that burst. The unit of measure is kilocalories per second (kcal/s). This outcome is assessed during the five study visits, where the test stimuli are offered simultaneously.
• Microstructure of Ingestive Behavior (Number of Sucks per Burst) — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  The number of sucks per burst is defined as the average count of individual sucks occurring within each burst during the ingestion of the test stimuli, as measured using a standardised drinkometer system. A "burst" is operationally defined as a sequence of consecutive sucks separated by brief pauses. For each burst, the total number of sucks is recorded, and the outcome is typically reported as the mean number of sucks per burst. The unit of measure is "number of sucks per burst" (n). This outcome is assessed during the five study visits, where the test stimuli are presented simultaneously.
• Microstructure of Ingestive Behaviour (Inter-Burst Intervals) — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  Inter-burst interval is defined as the elapsed time between the end of one burst and the onset of the subsequent burst during the ingestion of the test stimuli, as measured using a standardised drinkometer system. A "burst" is operationally defined as a sequence of consecutive sucks separated by brief pauses. The inter-burst interval quantifies the temporal spacing between bursts and is recorded in seconds (s). This outcome is assessed during the five study visits, the stimulus is offered simultaneously.
• Microstructure of Ingestive Behaviour (Inter-Sucks Intervals) — At baseline, 4 weeks, 12 weeks, 24 weeks, 52 weeks
  Inter-suck interval is defined as the elapsed time between the end of one suck and the initiation of the subsequent suck during the ingestion of each of the test stimulus, as measured using a standardised drinkometer system. A "suck" is operationally defined as a discrete negative pressure event corresponding to the drawing in of liquid. The inter-suck interval quantifies the temporal spacing between individual sucks within a burst or throughout the test stimulus consumption, and is recorded in seconds (s). This outcome is assessed during the five study visits, where the test stimulus is presented simultaneously.

Trial sites (1)

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