Interpretation of serum ferritin concentrations as indicators of total-body iron stores in survey populations: The role of biomarkers for the acute phase response

John L. Beard, Laura E. Murray-Kolb, Francisco J. Rosales, Noel W. Solomons, Mary Lu Angelilli

Research output: Contribution to journalArticle

Abstract

Background: Nutritional surveys use acute phase protein (APP) biomarkers such as C-reactive protein (CRP) and α1-acid glycoprotein (AGP) to identify the influence of inflammation on the distribution of iron status biomarkers. Few, however, have examined which biomarker better identifies persons with spurious elevations in iron status markers. Objective: We explored the relations of APP biomarkers to iron-status biomarkers in infants and school-age children. Design: In screening surveys, we identified a sample of African American infants (n = 351) and Guatemalan school-age children (n = 375). We used a common set of APP and iron-status biomarkers to examine the association between the 2 sets of markers (laboratory variables). Results: The overall prevalence of either inflammation or iron deficiency was 50%. Serum ferritin - but not transferrin receptor, transferrin receptor index, or serum iron - was related to APP concentrations, but poor positive predictive value (1 geometric SD above the geometric mean were poorly predicted by either elevated AGP or CRP. Qualitative CRP analysis was not effective in identifying persons who had other indications of mild inflammation. Conclusions: These analyses show that a low prevalence of inflammation has little influence on the distribution of ferritin, and 2 common indicators of inflammation do not perform equally well in identifying persons who may have elevations in ferritin due to inflammation.

Original languageEnglish (US)
Pages (from-to)1498-1505
Number of pages8
JournalAmerican Journal of Clinical Nutrition
Volume84
Issue number6
StatePublished - Dec 1 2006
Externally publishedYes

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Keywords

  • α-acid glycoprotein
  • Acute phase proteins
  • C-reactive protein
  • Children
  • Ferritin
  • Guatemala
  • Iron deficiency
  • Transferrin receptor

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Food Science

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