• Login
    View Item 
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Validation of bioimpedance spectroscopy to assess acute changes in hydration status

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_td_3145074_sip1_m.pdf
    Size:
    2.467Mb
    Format:
    PDF
    Download
    Author
    Higgins, Karen J.
    Issue Date
    2004
    Keywords
    Health Sciences, Nutrition.
    Advisor
    Howell, Wanda H.
    
    Metadata
    Show full item record
    Publisher
    The University of Arizona.
    Rights
    Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
    Abstract
    In this study bioimpedance spectroscopy (BIS) was validated as a field method for measuring short-term, small changes in hydration status by comparing extracellular water change (ΔECW) estimated by BIS with a criterion method (bromide dilution), dual energy X-ray absorptiometry (DXA) and body weight (BW). A secondary aim was to compare BW to bromide dilution as a method for estimating acute ΔECW. Finally, BIS was compared to DXA and single frequency bioimpedance analysis (SF-BIA) instruments to assess acute hydration effects on body composition estimates. During dehydration, no significant differences were found between bromide and BIS measures of ΔECW. The ΔECW measured by DXA (DXA-ΔECW) and BW (BW-ΔECW) was significantly different from bromide-estimated ΔECW (Br-ΔECW), but not from BIS estimates (BIS-ΔECW). During rehydration, there were no significant differences between Br-ΔECW and the other methods. When using BW as the reference, results were more consistent in that BW-ΔECW was significantly correlated with both BIS-ΔECW and DXA-ΔECW regardless of hydration status. These findings suggest that bromide may not be an appropriate criterion method for estimating short-term changes in hydration status. Regardless of hydration status, BIS provided accurate measures of fat-free mass (BIS-FFM) and fat mass (BIS-FM) that were comparable to, or better than, estimates by SF-BIA. At baseline and after dehydration BIS-FFM had the highest correlation with DXA estimates (DXA-FFM), although two SF-BIA instruments (Bio-Resistance Body Composition Analyzer from Valhalla Scientific and The Body Comp Scale from American Weights & Measures) produced good estimates of FFM. Rehydration appeared to affect the accuracy of FFM measurements by BIS and SF-BIA as evidenced by lower, more moderate correlations to DXA-FFM. Phase-dependent effects on percentage body fat (%BF) estimates were also apparent. In contrast, all methods performed reasonably well for estimates of FM, regardless of hydration status. In summary, BIS provides accurate estimates of ΔECW compared to either bromide dilution or BW, especially in the direction of dehydration. BIS also provides accurate estimates of FFM and FM regardless of hydration status. Further study of bromide dilution as a criterion measure is needed to validate its use in measuring ΔECW during acute shifts in hydration.
    Type
    text
    Dissertation-Reproduction (electronic)
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Graduate College
    Nutritional Sciences
    Degree Grantor
    University of Arizona
    Collections
    Dissertations

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.