Next Article in Journal
Sprouted Grains: A Comprehensive Review
Previous Article in Journal
The Obemat2.0 Study: A Clinical Trial of a Motivational Intervention for Childhood Obesity Treatment
Article Menu
Issue 2 (February) cover image

Export Article

Open AccessArticle

Iron Status of Kenyan Pregnant Women after Adjusting for Inflammation Using BRINDA Regression Analysis and Other Correction Methods

1
Division of Human Nutrition, Wageningen University and Research, P.O. Box 9101, 6700HB Wageningen, The Netherlands
2
Training and Research Unit of Excellence, Department of Public Health, College of Medicine, University of Malawi, Private Bag 360, Chichiri, Blantyre 3, Malawi
3
Centre for Public Health Research, Kenya Medical Research Institute (KEMRI), P.O. Box 54840 00200, Nairobi, Kenya
4
Danone Nutricia Africa & Overseas, Kenrail Towers, Ring Road Parklands, Nairobi, Kenya
5
Laboratory for Clinical Chemistry, Meander Medical Centre, Maatweg 3, 3813 TZ Amersfoort, The Netherlands
6
Cell Biology and Immunology Group, Wageningen University and Research, P.O. Box 338, 6700AH Wageningen, The Netherlands
7
MRC Unit, The Gambia, Atlantic Boulevard, Fajara, Republic of Gambia
8
MRC International Nutrition Group, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
9
Danone Nutricia Research, route de la Vauve, 91120 Palaiseau, France
*
Author to whom correspondence should be addressed.
Nutrients 2019, 11(2), 420; https://doi.org/10.3390/nu11020420
Received: 27 December 2018 / Revised: 7 February 2019 / Accepted: 13 February 2019 / Published: 16 February 2019
  |  
PDF [533 KB, uploaded 27 February 2019]
  |  

Abstract

Serum ferritin concentration is the preferred biomarker to assess population iron status in the absence of inflammation. Interpretation of this biomarker is complicated in populations with a high burden of infection, however, because inflammation increases serum ferritin concentration independently of iron status. We aimed to compare estimates of iron status of Kenyan pregnant women, with circulating ferritin concentrations adjusted for inflammation using newly proposed methods by the BRINDA project, or using previously proposed adjustment methods. We re-analyzed data from pregnant Kenyan women living in a rural area where malaria is highly endemic (n = 470) or in an urban area (n = 402). As proposed by the BRINDA group, we adjusted individual ferritin concentration by internal regression for circulating concentrations of C-reactive protein (CRP) and α1-acid glycoprotein (AGP). Other adjustment methods comprised: (a) arithmetic correction factors based on CRP or AGP; (b) exclusion of subjects with inflammation (CRP >5 mg/L or AGP >1 g/L); and (c) higher ferritin cut-off value (<30 μg/L). We additionally adjusted for Plasmodium infection as appropriate. Lastly, we assessed iron status without adjustment for inflammation. All correction methods increased prevalence of iron deficiency compared to the unadjusted estimates. This increase was more pronounced with the internal regression correction method. The iron deficiency prevalence estimate increased from 53% to 87% in rural Kisumu study and from 30% to 41% in the urban Nairobi study after adjusting for inflammation (CRP and AGP) using the BRINDA internal regression method. When we corrected for both inflammation and Plasmodium infection using the regression correction, it resulted in lower prevalence estimates compared to uninfected women. Application of linear regression methods to adjust circulating ferritin concentration for inflammation leads to markedly decreased point estimates for ferritin concentration and increased estimates for the prevalence of iron deficiency in pregnancy. View Full-Text
Keywords: acute-phase proteins; C-reactive protein; α1-acid glycoprotein; ferritin; inflammation; Kenya; pregnant women acute-phase proteins; C-reactive protein; α1-acid glycoprotein; ferritin; inflammation; Kenya; pregnant women
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Supplementary material

SciFeed

Share & Cite This Article

MDPI and ACS Style

Mwangi, M.N.; Echoka, E.; Knijff, M.; Kaduka, L.; Werema, B.G.; Kinya, F.M.; Mutisya, R.; Muniu, E.M.; Demir, A.Y.; Verhoef, H.; Bourdet-Sicard, R. Iron Status of Kenyan Pregnant Women after Adjusting for Inflammation Using BRINDA Regression Analysis and Other Correction Methods. Nutrients 2019, 11, 420.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Nutrients EISSN 2072-6643 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top