Exhaled Carbon Monoxide and Red Blood Cell Turnover
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|ClinicalTrials.gov Identifier: NCT03288233|
Recruitment Status : Recruiting
First Posted : September 20, 2017
Last Update Posted : September 20, 2017
|Condition or disease||Intervention/treatment|
|Diabetes Mellitus Healthy||Diagnostic Test: Breath carbon monoxide measurement|
Recently Investigators have demonstrated that RBC lifespan has substantial inter-individual variation even in people without diabetes or obvious hematologic diseases affecting RBC lifespan (5,6). Investigators combined Endocrinology-Hematology research group has taken a leading role in applying state-of-the-art methods for RBC survival measurement.The published articles articles are now cited when investigators refer to the state of the art understanding of true RBC lifespan (7). Using a biotin labeling method that involves ex vivo labeling of cells with biotin and then re-infusion of those cells, Investigators were able to demonstrate that RBC lifespan is sufficiently heterogeneous even in the hematologically normal population with normal reticulocyte count to significantly affect HbA1c interpretation (5). Recognizing the limitations of the safe but relatively invasive biotin technique, Investigators more recently developed a stable isotope (SI) in which RBC heme is labeled with orally administered 15N-glycine (6). This is a benign and noninvasive technique and expands the scope of RBC lifespan studies to sizable epidemiologic and physiologic studies, a number of which investigators are initiating and planning.
However, the feasibility of making the findings translatable to widespread patient care has been perceived as a limitation to the merit of answering these scientific questions. The SI approach still requires multiple blood measurements over months (6). This proposed project is designed to test the feasibility of a method to satisfy the unmet clinical need for measuring RBC survival easily, noninvasively, and inexpensively. The goal is to access most individuals with or at risk for diagnosis of diabetes in or near most doctors' offices. Over the next year Investigators intend to determine whether exhaled alveolar carbon monoxide (eCO), a measure of heme breakdown and hence of RBC turnover, can be used in this manner to provide a single point measure of RBC lifespan. Interestingly, heme metabolism is the only known endogenous source of carbon monoxide in people (8) and there are recent studies by others suggesting its potential for measuring RBC lifespan (9,10) Now that technology has advanced to measure CO with sufficient sensitivity and cost, investigators will explore the use of instrumentation at the same time investigators expand their studies using the SI approach. The results from this method will be compared with a previous small population of subjects that had lifespan measured by biotin and/or SI technique.
|Study Type :||Observational|
|Estimated Enrollment :||30 participants|
|Official Title:||Measurement of Exhaled Lower Respiratory Carbon Monoxide and Correlation With Previous Measures of Red Cell Lifespan|
|Actual Study Start Date :||April 2015|
|Estimated Primary Completion Date :||May 2018|
|Estimated Study Completion Date :||August 2018|
Diagnostic Test: Breath carbon monoxide measurement
Participants will be asked to breath in designed breathing circuits or hold their breath for short period of time and then their breath samples will be collected in special bags and the carbon monoxide and carbon dioxide will be measured with electrochemical techniques.
- Average end expiratory alveolar concentration of Carbon monoxide (ppm) in morning before breakfast [ Time Frame: four consecutive weeks ]In this preliminary phase of the study we use a device that has not been used in the United States before (Carbolyzer II, Taiyo, Japan) as a surrogate marker for red blood cell (RBC) removal or turnover in human subjects. Published studies and the company literature for the Carbolyzer mBA-2000 would suggest sufficient capability for the purposes of such measurements. This project will test more rigorously the validity of these specifications for this application. First, the detector will be standardized in more detail with measurement of the CO content of defined mixtures in the range needed for sufficient sensitivity. The device will calibrated prior with known concentrations of a mixture of carbon monoxide in air at three points (0-3-12 ppm). In addition, investigators will evaluate alternative CO detection devices for suitability which do not alter the experience of the participating subject or the accompanying risks and benefits.
- Average end expiratory alveolar concentration of CO (ppm) in morning 30 min after breakfast [ Time Frame: four consecutive weeks ]similar to outcome 1
- Average end expiratory alveolar concentration of CO (ppm) 30 min after lunch [ Time Frame: one day sampling ]similar to outcome 1
- Average end expiratory alveolar concentration of CO (ppm) 5 hours after lunch [ Time Frame: one day sampling ]similar to outcome 1
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03288233
|Contact: Shahriar Arbabi, MDemail@example.com|
|United States, Ohio|
|University of Cincinnati||Recruiting|
|Cincinnati, Ohio, United States, 45220|
|Contact: Colleen Rogge, BSN 513-475-6478 firstname.lastname@example.org|
|Contact: Stephanie Donnelly, MBA 513-558-2639 email@example.com|
|Principal Investigator: Robert Cohen, MD|
|Principal Investigator:||Robert Cohen, MD||University of Cincinnati|