cGMP: Metabolism and Appetite Modulation

January 20, 2025 updated by: Universidade Nova de Lisboa

Metabolic Effects of cGMP: From Amino Acid Absorption Kinetics to Appetite Modulation

Phenylketonuria is an inborn error of phenylalanine metabolism. Although the phenylalanine-restricted diet is recognized as the mainstay of therapy, little is known about the impact of protein substitutes on the metabolism of patients with phenylketonuria.

Therefore, the aim of this project is to study the impact of acute ingestion of casein glycomacropeptide supplemented with amino acids (cCGMP-AAs) alone or in combination with two different meals on amino acid absorption kinetics, glycaemic and insulinemic response, and on acute markers of appetite control.

The main findings of this project will bring new insights into the dietary management of these patients, which may lead to improvements in protein substitutes formulations.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
15

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Portugal
      • Lisboa, Portugal, 1169-056
        • NOVA Medical School|Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisboa,
        • Contact:
        • Contact:
        • Principal Investigator:
          • Júlio César Rocha, PhD
        • Principal Investigator:
          • Ana Faria, PhD
        • Principal Investigator:
          • Anita MacDonald, PhD
        • Sub-Investigator:
          • Conceição Calhau, PhD
        • Sub-Investigator:
          • Catarina Rodrigues, MSc

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Men or women
  • Adults (age ≥ 18 years)
  • Body Mass Index (BMI) between 18.5-25.0 kg/m2
  • Filling informed consent

Exclusion Criteria:

  • Clinically significant illness
  • Have changed frequency, duration, or intensity of physical activity in the last month
  • Taking protein supplements
  • Pregnant or breastfeeding
  • Smoking and drug use

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Meal A
Meal A - CGMP-AAs alone
Dietary supplement: cGMP-AAs alone (20 g of protein equivalent)
cGMP-AAs alone (20 g of protein equivalent)
Experimental: Meal B
Meal B - CGMP-AAs in combination with carbohydrates (including fibre)
Dietary supplement: cGMP-AAs (20 g of protein equivalent) + 50 g of low-protein bread + 160 g of unpeeled apple
cGMP-AAs (20 g of protein equivalent) + 50 g of low-protein bread + 160 g of unpeeled apple
Experimental: Meal C
Meal C - CGMP-AAs in combination with carbohydrates and fat
Dietary supplement: cGMP-AAs (20 g of protein equivalent) + 50 g of low-protein bread + 10 g of olive oil
cGMP-AAs (20 g of protein equivalent) + 50 g of low-protein bread + 10 g of olive oil

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Changes in the iAUC (mmol/L*min) for total amino acids
Time Frame: 180 minutes
Total amino acids will be measured in fasting and every 30 minutes up to 180 minutes. The iAUC (mmol/L*min) for amino acids will be calculated based on the concentration curve following consumption of the test meal.
180 minutes
Changes in the iAUC (pmol/L*min) for glucagon-like peptide-1 (GLP-1)
Time Frame: 180 minutes
GLP-1 will be measured in fasting and every 30 minutes up to 180 minutes. The iAUC (pmol/L*min) for GLP-1 will be calculated based on the concentration curve following consumption of the test meal.
180 minutes
Changes in the iAUC (pmol/L*min) for Cholecystokinin (CCK)
Time Frame: 180 minutes
CCK will be measured in fasting and every 30 minutes up to 180 minutes. The iAUC (pmol/L*min) for CCK will be calculated based on the concentration curve following consumption of the test meal.
180 minutes
Changes in the iAUC (pmol/L*min) for peptide YY (PYY)
Time Frame: 180 minutes
PYY will be measured in fasting and every 30 minutes up to 180 minutes. The iAUC (pmol/L*min) for PYY will be calculated based on the concentration curve following consumption of the test meal.
180 minutes
Changes in the iAUC (pmol/L*min) for Gastric inhibitory polypeptide (GIP)
Time Frame: 180 minutes
GIP will be measured in fasting and every 30 minutes up to 180 minutes. The iAUC (pmol/L*min) for GIP will be calculated based on the concentration curve following consumption of the test meal.
180 minutes

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Changes in glucose
Time Frame: 180 minutes
Glucose will be measured in fasting and every 30 minutes up to 3 hours. The iAUC (mmol/L*min) for glucose will be calculated based on the concentration curve following consumption of the test meal.
180 minutes
Changes in insulin
Time Frame: 180 minutes
Insulin will be measured in fasting and every 30 minutes up to 3 hours. The iAUC (mmol/L*min) for insulin will be calculated based on the concentration curve following consumption of the test meal.
180 minutes
Changes in C-peptide
Time Frame: 180 minutes
C-peptide will be measured in fasting and every 30 minutes up to 3 hours. The iAUC (mmol/L*min) for C-peptide will be calculated based on the concentration curve following consumption of the test meal.
180 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Universidade Nova de Lisboa

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 3, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 28, 2025

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 24, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 20, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 20, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 25, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 25, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 20, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • cGMP: Metabolism and Appetite

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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