Effects of diet, activities, environmental exposures and trimethylamine metabolism on alveolar breath compounds: protocol for a retrospective case-cohort observational study

摘要: ABSTRACT Background Exhaled breath contains thousands of volatile organic compounds (VOCs) that reflect on biochemical and biophysical activities both outside within the human body. Breath analysis could provide non-invasive, cost-effective, real time early disease diagnosis monitoring therapeutic responses. Objectives The primary objective this study was to assess effectiveness alveolar testing in diagnosing idiopathic systemic body odors. Key secondary objectives were if tests can reliably differentiate subtypes malodor different environments dietary regimens, map metabolites biomedical functions pathways. Study Design basic design measure a cohort odor order identify potential molecular correlates with genotypic phenotypic variables. Participants subdivided several ways allowing for cases controls cohort, using prior later test results observations. Thus, an observational retrospective case-cohort/nested case-control study. Setting/Participants recruited online via MEBO TMAU support groups site, during 3rd Annual Research conference held at Miami South Beach June 23, 2012 local meetups (Miami, Florida; New York, York; Chicago, Illinois, US Birmingham, England). population is individuals self-reporting production. Inclusion criteria good general health, desire ability travel one participating sites pay lab fee. Exclusion Criteria medical conditions prevent participation age under 18. Interventions Measures main procedure application rapid point-of-care system collect concentrate VOCs sorbent trap, collection apparatus (BCA) 5.0. Samples sent central laboratory analyzed gas chromatography mass spectroscopy. In addition, participants filled out food frequency questionnaires offered use Aurametrix, software tool based participant-initiated ecological momentary assessment approach, recall events any later. intakes, environmental exposures individual aggregate level data. endpoint composition samples, while diet activity data, alternative assessments endpoints. outcome diagnostic accuracy differentiating profiles two pre-defined sub-cohorts. Index concordance accuracy, sensitivity, specificity, positive predictive value negative will be reported. A number factors assessed confounding.