Measurements of Water in Breath and Saliva

Study Overview
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Brief Summary
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This study proposes to demonstrate the feasibility of measuring 2H:1H and 18O:16O in saliva and breath by comparing the natural abundances of 2H:1H and 18O:16O in saliva and urine of un-dosed humans.

Detailed Description
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The scientific premises for this line of research are 1) challenges related to costs, the complexity of sample collection and preparation, and the level of technical skills required for Isotope-ratio mass spectrometry (IRMS) analysis have limited the adoption of the doubly labeled water (DLW) method; and 2) the investigators preliminary data demonstrates that Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS) provides a valid, more rapid, and less technically challenging approach to isotopic analysis of human samples.

Official Title
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Rapid Measurements of Water Isotopes in Human Breath and Saliva for Doubly Labeled Water Analysis

Conditions
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Human Energy Expenditure

Intervention / Treatment
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* Procedure: Feasibility of measuring 2H:1H and 18O:16O in saliva and breath.


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy adult men and women, aged 18-45 yrs Exclusion Criteria: Obesity (body mass index (BMI) > 30 kg/m2) Pregnant or lactating women Self-reported acute or chronic disease (diabetes, heart diseases, thyroid diseases)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Interventional Model Description: Healthy adults (18-45 yrs.) will be recruited from the local Denver area. The investigators have elected to study a relatively homogenous sample to limit the impact of age, weight, and chronic disease on isotope fractionation in breath.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Healthy adults (18-45 yrs.)<br>Healthy adults (18-45 yrs.) will be recruited from the local Denver area. The investigators have elected to study a relatively homogenous sample to limit the impact of age, weight, and chronic disease on isotope fractionation in breath. | Procedure: Feasibility of measuring 2H:1H and 18O:16O in saliva and breath.<br>* The investigators propose to demonstrate the feasibility of measuring 2H:1H and 18O:16O in saliva and breath. The natural abundances of 2H:1H and 18O:16O of urine, saliva, and breath samples will be determined from samples obtained simultaneously from 50 relatively healthy human subjects. We will also measure 2H:1H and 18O:16O enrichments in urine, saliva, and breath of 10 relatively healthy human subjects obtained after consuming a standard DLW dose and compare the estimates of TDEE using these different matrices.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Natural abundances of 2H:1H and 18O:16O in humans | Evaluation of the natural abundances of 2H:1H and 18O:16O in urine, saliva, and breath of humans. | Baseline |