Effect of Glycine in Cystic Fibrosis

October 30, 2014 updated by: Mario H. Vargas, Instituto Nacional de Enfermedades Respiratorias

Evaluation of the Capability of a Glycine Oral Supplement for Diminishing Bronchial Inflammation in Children With Cystic Fibrosis

The aim of this study is to evaluate if glycine, orally administered in a daily dose of 0.5 g/kg during 8 weeks, can ameliorate the airway inflammation in children with cystic fibrosis, as compared with placebo. During all of the study children will receive their usual treatment for cystic fibrosis.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Terminated

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.

Detailed Description

Background. Cystic fibrosis (CF) is a genetic disorder caused by a mutation in a gene that codifies for a chloride channel named "cystic fibrosis transmembrane regulator" (CFTR). In the lungs this results in thick and dehydrated mucus that tends to cause obstruction of the bronchial lumen. Neutrophils and proinflammatory substances have been detected in bronchoalveolar lavage fluid of children with CF who have no bacterial infection. This inflammation conditions a vicious circle in which airways are colonized by bacteria that further increase inflammation. Persistent inflammation leads to irreversible changes in airways, which become distorted. Therefore, a key step in CF treatment is reduction of airway inflammation, for which long-term use of corticosteroids, ibuprofen or macrolides may be indicated.

Glycine and its antiinflammatory effect. Glycine is the most simple aminoacid, but it is also an agonist of the glycine receptors (GlyR) that, when activated, cause that cells such as Kupffer cells, alveolar macrophages and neutrophils decrease their sensitivity to proinflammatory agents. Orally administered glycine has been used for some illnesses, and it has been noticed that it is well tolerated. Considering that children with CF have an intense inflammatory process in the airways, here we propose to use glycine as antiinflammatory agent.

Problem statement. Can a glycine oral supplement decrease the airway inflammation in children with CF?

Hypothesis. Compared with placebo, a daily supplement of glycine administered for 8 weeks to children with CF produce a statistically significant decrease of bronchial inflammation, measured by the concentration of neutrophils and inflammatory substances in sputum and peripheral blood, as well as by respiratory symptoms and spirometry.

Main objective: To determine whether a daily supplement of 0.5 g/kg glycine for 8 weeks significantly decrease the concentration, including neutrophils, interleukin(IL)-1β, IL-6, IL-8, tumor necrosis factor alpha (TNF-α), and myeloperoxidase, in sputum and peripheral blood of children with CF.

Secondary Objectives:

  1. To determine if glycine can improve respiratory symptoms, including decreased amount and better fluidity of sputum.
  2. To determine if glycine can improve spirometric variables.

Study design. This will be a randomized, placebo controlled, blinded, two-arms, cross-over clinical trial. Patients will receive glycine or placebo during the initial 8 weeks (initial phase), and after a 2 weeks washout period, they will receive the alternate treatment during another 8 weeks (second phase).

Material and methods: Children with CF fulfilling the selection criteria will be studied if their parents accept their participation. They will be randomly assigned to one of two groups. The experimental group will receive glycine and the control group will receive placebo (sugar glass), both at doses of 0.5 g/kg divided in 3 doses per os dissolved in any liquid. At study entry and at weeks 4, 8, 10, 14 and 18 we will collect a 2 ml blood sample and a sputum sample, and the children will be submitted to spirometry. A daily symptom questionnaire will be filled by the parents.

Statistical analysis: Each variable will be compared between experimental and control groups using Student's t test (or Mann Whitney U test if lacking normal distribution). Sample size: There are no previous studies that allow us to calculate a sample size. For convenience, it is estimated that 30 children can be included.

Time to complete: 24 months.

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 (Actual)

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.
13

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.
  • Phase 2

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

  • Mexico
      • Mexico DF, Mexico, 14080
        • Instituto Nacional De Enfermedades Respiratorias
      • Mexico DF, Mexico, 06720
        • Hospital Infantil de Mexico
      • Mexico DF, Mexico, 06720
        • Unidad de Investigación Médica en Enfermedades Respiratorias, Hospital de Pediatría, CMN SXXI, IMSS

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

1 year to 11 years (Child)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Children of either sex
  • Between 5 and 15 years of age
  • With CF diagnosed according to established criteria
  • Without changes in the CF treatment in the last 30 days
  • Without CF exacerbation in the last 30 days
  • Without acute respiratory infection (e.g., common cold) in the last 15 days
  • Informed consent letter signed by their parents or legal guardians

Exclusion Criteria:

  • Children with CF that had participated in a research protocol in the last 3 months
  • Presence of serious adverse effects attributable to glycine, in which case the result will be considered as therapeutic failure in the statistical analysis
  • Development of a CF exacerbation, in which case the available data so far collected will be included in the statistical analysis

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

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.
Active Comparator: Glycine
Patients will receive a daily oral supplement of 0.5 g/kg glycine dissolved in water.
Dietary supplement: Glycine
Daily oral supplement of glycine at a dose of 0.5 g/kg divided in three doses during 8 weeks
Other Names:
  • aminoacetic acid
Placebo Comparator: Placebo
Patients will receive a daily supplement of 0.5 g/kg sugar glass dissolved in water.
Dietary supplement: Placebo
Daily oral administration of placebo (sugar glass) at a dose of 0.5 g/kg divided in three doses during 8 weeks
Other Names:
  • sugar glass

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 Serum Concentration of Inflammatory Biomarkers (Other Than TNF-alpha)
Time Frame: 8 weeks
To correct for the baseline variability, all measurements were expressed as percentage of baseline (value at week 8 with respect to baseline value [beginning of the glycine or placebo period, respectively]). Then, percentages were log-transformed to adjust to a normal distribution.
8 weeks
Changes in Sputum Concentration of Inflammatory Biomarkers (Other Than IL-6 and G-CSF)
Time Frame: 8 weeks
To correct for the baseline variability, all measurements were expressed as percentage of baseline (value at week 8 with respect to baseline value [beginning of the glycine or placebo period, respectively]). Then, percentage change was log-transformed to adjust to a normal distribution.
8 weeks
Changes in Serum Concentration of Inflammatory Biomarkers (TNF-alpha)
Time Frame: 8 weeks
To correct for the baseline variability, all measurements were expressed as percentage of baseline (value at week 8 with respect to baseline value [beginning of the glycine or placebo period, respectively]). Then, percentages were log-transformed to adjust to a normal distribution.
8 weeks
Changes in Sputum Concentration of Inflammatory Biomarkers (IL-6)
Time Frame: 8 weeks
To correct for the baseline variability, all measurements were expressed as percentage of baseline (value at week 8 with respect to baseline value [beginning of the glycine or placebo period, respectively]). Then, percentage change was log-transformed to adjust to a normal distribution.
8 weeks
Changes in Sputum Concentration of Inflammatory Biomarkers (G-CSF)
Time Frame: 8 weeks
To correct for the baseline variability, all measurements were expressed as percentage of baseline (value at week 8 with respect to baseline value [beginning of the glycine or placebo period, respectively]). Then, percentage change was log-transformed to adjust to a normal distribution.
8 weeks

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 Clinical Data Scores (Other Than Sputum Production, Dyspnea and Global Symptoms)
Time Frame: 8 weeks

To correct for the baseline variability, all measurements were expressed as percentage of baseline (value at week 8 with respect to baseline value [beginning of the glycine or placebo period, respectively]).

Each respiratory symptom (Cough severity, Sputum features, Appetite, Dyspnea, and Energy perception) was evaluated in a 5-options Likert scale, ranging from 1 (better) to 5 (worse). The total score was computed by the simple sum of the five symptoms.
8 weeks
Changes in Score for Sputum Production, Dyspnea and Global Symptoms
Time Frame: 8 weeks

To correct for the baseline variability, all measurements were expressed as percentage of baseline (value at week 8 with respect to baseline value [beginning of the glycine or placebo period, respectively]).

In the symptoms questionnaire, each respiratory symptom (Cough severity, Sputum features, Appetite, Dyspnea, and Energy perception) was evaluated in a 5-options Likert scale, ranging from 1 (better) to 5 (worse). The total score was computed by the simple sum of the five symptoms.
8 weeks
Changes in Pulse Oximetry, FEV1/FVC, and FEF50.
Time Frame: 8 weeks
To correct for the baseline variability, all measurements were expressed as percentage of baseline (value at week 8 with respect to baseline value [beginning of the glycine or placebo period, respectively]).
8 weeks
Changes in FEV1, FEF25, and FEFmax
Time Frame: 8 weeks
To correct for the baseline variability, all measurements were expressed as percentage of baseline (value at week 8 with respect to baseline value [beginning of the glycine or placebo period, respectively]).
8 weeks
Changes in Other Spirometric Variables
Time Frame: 8 weeks
To correct for the baseline variability, all measurements were expressed as percentage of baseline (value at week 8 with respect to baseline value [beginning of the glycine or placebo period, respectively]).
8 weeks

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.
Instituto Nacional de Enfermedades Respiratorias

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Instituto Mexicano del Seguro Social
Hospital Infantil de Mexico Federico Gomez

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Mario H Vargas, MD, MSc, Instituto Nacional De Enfermedades Respiratorias

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

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Study Major Dates

Study Start

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.
March 1, 2012

Primary Completion (Actual)

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.
September 1, 2013

Study Completion (Actual)

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.
September 1, 2013

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).
August 15, 2011

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.
August 15, 2011

First Posted (Estimate)

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.
August 16, 2011

Study Record Updates

Last Update Posted (Estimate)

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.
November 5, 2014

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.
October 30, 2014

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.
October 1, 2014

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

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.
  • Glycine in CF

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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