Metabolites in Blood and Breath in Metabolic Conditions

August 7, 2026 updated by: Johannes Haeberle, University Children's Hospital, Zurich

Measurement of Metabolites in the Breath and Blood in Patients With Altered Metabolism and Healthy Individuals

In patients with inborn errors of metabolism (IEM) and in those requiring a ketogenic diet for the treatment of medical conditions, relevant biochemical analytes are routinely and regularly measured in venous or capillary blood samples. Repeated venipuncture for blood collection is invasive, burdensome, and resource-intensive. As an alternative, capillary blood sampling can provide some relief for the measurement of a limited number of metabolites. Nevertheless, the frequent finger pricks required to obtain capillary blood samples can still be uncomfortable for patients. Therefore, patients could benefit if non-invasive breath measurements were to replace the currently invasive biochemical monitoring methods in the future.

In this study, the usability of metabolite measurements across matrices (venous blood, capillary blood, breath captured by a handheld sensor and breath in a collection bag) in IEM patients, individuals prescribed special health-related diets, and healthy volunteers will be investigated. The usability of a handheld breath sensor for remote monitoring of patients will also be tested. Lastly, exploratory investigations will be performed to identify new disease biomarkers in breath.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Estimated)

100

Contacts and Locations

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

Study Contact

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

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Patients who are routinely cared for at the study site will be invited to participate. Healthy volunteers will be recruited through communication with healthy family members accompanying patients to hospital visits and the general population through flyers.

Description

Inclusion Criteria:

  • Patients aged 4-20 years old with refractory epilepsy on a ketogenic diet, or
  • Patients aged 4 years old and above with a confirmed diagnosis of urea cycle disorders, organic acidurias, amino acidopathies and fatty acid oxidation defects, or
  • healthy adults and
  • informed consent

Exclusion Criteria:

  • Physical findings at screening that would compromise safety of the participant or quality of study data. Examples include presentation of fever, pulmonary complications, presence of disease comorbidities that might interfere with study result and inability to comply with study procedures.

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Patients or healthy adult volunteers
Other: Observational Study
no intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Concentration (μmol/L) of metabolites of clinical interest in venous blood, capillary blood and breath of participants.
Time Frame: Baseline
  1. Concentration of beta-hydroxybutyrate in venous and capillary blood
  2. Concentration of acetone in exhaled breath
  3. Concentration of ammonia in venous blood and exhaled breath
  4. Concentration of amino acids (alanine, arginine, asparagine, aspartic acid, citrulline, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, ornithine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine) in venous blood, capillary blood and exhaled breath.
Baseline

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation of metabolite concentrations in different matrices
Time Frame: Baseline
  1. Correlation between concentration of beta-hydroxybutyrate in venous and capillary blood and concentration of acetone in exhaled breath captured directly by a handheld device with a chemiresistor sensor and breath captured in a collection bag and measured by mass spectrometry
  2. Correlation between concentration of ammonia in venous blood and exhaled breath captured directly by a handheld device with a chemiresistor sen
  3. Correlation between concentration of amino acids in venous and capillary blood and in exhaled breath captured directly by a handheld device with a chemiresistor sensor and breath captured in a collection bag and measured by mass spectrometry
Baseline
Participant self-report questionnaire on a 4-point Likert scale on the burden of each sampling method
Time Frame: Baseline
Likert scale: 1, Strongly Agree. 2, Agree. 3, Disagree. 4, Strongly Disagree. The lower the score, the lower the burden of sampling method.
Baseline
Participant self-report questionnaire on a 4-point Likert scale on the usability of the handheld breath sensor for remote measurements of metabolites
Time Frame: Baseline
Likert scale: 1, Strongly Agree. 2, Agree. 3, Disagree. 4, Strongly Disagree. The lower the score, the higher the acceptance of using the handheld breath sensor.
Baseline
Untargeted SESI-based mass spectrometry analysis of exhaled breath captured in a bag
Time Frame: Baseline
abundance (parts per million) of all detectable and identifiable metabolites in exhaled breath
Baseline

Collaborators and Investigators

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

Sponsor

University Children's Hospital, Zurich

Collaborators

ETH Zurich (Switzerland)

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)

October 1, 2026

Primary Completion (Estimated)

October 1, 2036

Study Completion (Estimated)

October 1, 2037

Study Registration Dates

First Submitted

July 2, 2026

First Submitted That Met QC Criteria

July 9, 2026

First Posted (Actual)

July 15, 2026

Study Record Updates

Last Update Posted (Actual)

August 12, 2026

Last Update Submitted That Met QC Criteria

August 7, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2026-00730

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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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