A comparative study on indicators of vitamin A status and risk factors for sensitivity and specificity of the methods to detect vitamin A deficiency

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Abstract

Background

Serum retinol (SR) and retinol-binding protein (RBP) are commonly used indicators, but they are affected by infections and inflammation. This study aimed to assess the sensitivity and specificity of VA indicators to detect vitamin A deficiency (VAD) in 36–59-month-old children living in a rural area in Burkina Faso.

Methods

In a community-based study, two cross-sectional surveys were carried out from November 2016 to September 2017 in the health district of Dandé in Burkina Faso. The surveys included 115 children 36–59 months old. Indicators of VA and inflammation assessed in all children included SR, RBP and total liver VA reserves (TLR) estimated by retinol isotope dilution, and inflammation markers (C-reactive protein (CRP) and alpha 1-acid glycoprotein (AGP)). We calculated the sensitivity, specificity, positive and negative predictive values. In addition, the effects of inflammation, helminth infection, and season on sensitivity and specificity were assessed.

Results

The prevalence of VAD assessed by SR (< 0.7 µmol/L), RBP (< 0.7 µmol/L), and TLR (< 0.1 µmol/g liver) were, respectively, 30.9%, 33.3%, and 0%. Compared to TLR, the specificity, positive predictive value, and negative predictive value of SR were 71.1%, 0%, and 100%, and of RBP, were 68.9%, 0%, and 100%, respectively. The sensitivity was indeterminable for SR and RBP. The specificity of SR and RBP was lower during the dry season. Elevated CRP (> 5.0 mg/L) and AGP (> 1.0 g/L) were detected in 1.9% and 28.6% of children, respectively. The adjustment of VA indicators for inflammation improved SR’s specificity to 75.9% and decreased RBP’s specificity to 67.8%.

Conclusion

No cases of VAD were identified by TLR. However, (inflammation-adjusted) SR and RBP had varying accuracy in the estimation of VAD.

Trial registration

The study was registered, retrospectively, on 22 March 2018 as a clinical trial with the Pan African Clinical Trials Registry under the number Cochrane South Africa; PACTR201803002999356.

Related collections

Most cited references 32

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Constructing socio-economic status indices: how to use principal components analysis.

S Vyas, L Kumaranayake (2006)

Theoretically, measures of household wealth can be reflected by income, consumption or expenditure information. However, the collection of accurate income and consumption data requires extensive resources for household surveys. Given the increasingly routine application of principal components analysis (PCA) using asset data in creating socio-economic status (SES) indices, we review how PCA-based indices are constructed, how they can be used, and their validity and limitations. Specifically, issues related to choice of variables, data preparation and problems such as data clustering are addressed. Interpretation of results and methods of classifying households into SES groups are also discussed. PCA has been validated as a method to describe SES differentiation within a population. Issues related to the underlying data will affect PCA and this should be considered when generating and interpreting results.

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Measures of Diagnostic Accuracy: Basic Definitions

Ana-Maria Šimundić (2009)

Diagnostic accuracy relates to the ability of a test to discriminate between the target condition and health. This discriminative potential can be quantified by the measures of diagnostic accuracy such as sensitivity and specificity, predictive values, likelihood ratios, the area under the ROC curve, Youden's index and diagnostic odds ratio. Different measures of diagnostic accuracy relate to the different aspects of diagnostic procedure: while some measures are used to assess the discriminative property of the test, others are used to assess its predictive ability. Measures of diagnostic accuracy are not fixed indicators of a test performance, some are very sensitive to the disease prevalence, while others to the spectrum and definition of the disease. Furthermore, measures of diagnostic accuracy are extremely sensitive to the design of the study. Studies not meeting strict methodological standards usually over- or under-estimate the indicators of test performance as well as they limit the applicability of the results of the study. STARD initiative was a very important step toward the improvement the quality of reporting of studies of diagnostic accuracy. STARD statement should be included into the Instructions to authors by scientific journals and authors should be encouraged to use the checklist whenever reporting their studies on diagnostic accuracy. Such efforts could make a substantial difference in the quality of reporting of studies of diagnostic accuracy and serve to provide the best possible evidence to the best for the patient care. This brief review outlines some basic definitions and characteristics of the measures of diagnostic accuracy.

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Adjusting plasma ferritin concentrations to remove the effects of subclinical inflammation in the assessment of iron deficiency: a meta-analysis.

David Thurnham, Linda D McCabe, Sumanto Haldar … (2010)

The World Health Organization recommends serum ferritin concentrations as the best indicator of iron deficiency (ID). Unfortunately, ferritin increases with infections; hence, the prevalence of ID is underestimated. The objective was to estimate the increase in ferritin in 32 studies of apparently healthy persons by using 2 acute-phase proteins (APPs), C-reactive protein (CRP) and alpha(1)-acid glycoprotein (AGP), individually and in combination, and to calculate factors to remove the influence of inflammation from ferritin concentrations. We estimated the increase in ferritin associated with inflammation (ie, CRP gt 5 mg/L and/or AGP gt 1 g/L). The 32 studies comprised infants (5 studies), children (7 studies), men (4 studies), and women (16 studies) (n = 8796 subjects). In 2-group analyses (either CRP or AGP), we compared the ratios of log ferritin with or without inflammation in 30 studies. In addition, in 22 studies, the data allowed a comparison of ratios of log ferritin between 4 subgroups: reference (no elevated APP), incubation (elevated CRP only), early convalescence (both APP and CRP elevated), and late convalescence (elevated AGP only). In the 2-group analysis, inflammation increased ferritin by 49.6% (CRP) or 38.2% (AGP; both P lt 0.001). Elevated AGP was more common than CRP in young persons than in adults. In the 4-group analysis, ferritin was 30%, 90%, and 36% (all P lt 0.001) higher in the incubation, early convalescence, and late convalescence subgroups, respectively, with corresponding correction factors of 0.77, 0.53, and 0.75. Overall, inflammation increased ferritin by ap 30% and was associated with a 14% (CI: 7%, 21%) underestimation of ID. Measures of both APP and CRP are needed to estimate the full effect of inflammation and can be used to correct ferritin concentrations. Few differences were observed between age and sex subgroups.

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Author and article information

Contributors

Olivier O. Sombié: ouahaminolivier.sombie@ugent.be , sombieolivier@yahoo.fr

Journal

Journal ID (nlm-ta): Nutr Metab (Lond)

Journal ID (iso-abbrev): Nutr Metab (Lond)

Title: Nutrition & Metabolism

Publisher: BioMed Central (London )

ISSN (Electronic): 1743-7075

Publication date (Electronic): 16 November 2023

Publication date PMC-release: 16 November 2023

Publication date Collection: 2023

Volume: 20

Electronic Location Identifier: 49

Affiliations

[1 ]GRID grid.457337.1, ISNI 0000 0004 0564 0509, Unité Nutrition et Maladies Métaboliques, , Institut de Recherche en Sciences de la Santé/Direction Régionale de l’Ouest, ; Bobo-Dioulasso, Burkina Faso

[2 ]Department of Public Health and Primary Care, Faculty of Medicine and Health Sciences, Ghent University, ( https://ror.org/00cv9y106) Ghent, Belgium

[3 ]GRID grid.457337.1, ISNI 0000 0004 0564 0509, Unité Nutrition et Maladies Métaboliques, , Institut de Recherche en Sciences de la Santé/Direction Générale, ; Ouagadougou, Burkina Faso

[4 ]Department of Translational Physiology, Infectiology and Public Health, Faculty of Veterinary Medicine, Ghent University, ( https://ror.org/00cv9y106) Ghent, Belgium

[5 ]Department of Nutritional Sciences, University of Wisconsin-Madison, ( https://ror.org/01y2jtd41) Madison, USA

Article

Publisher ID: 768

DOI: 10.1186/s12986-023-00768-7

PMC ID: 10652566

PubMed ID: 37974246

SO-VID: 83a7efd2-e0ba-4082-8e21-ff1f1a3ff744

License:

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

History

Date received : 18 August 2023

Date accepted : 7 November 2023

Custom metadata

ScienceOpen disciplines: Nutrition & Dietetics

Keywords: sensitivity,specificity,total liver reserve,serum retinol,retinol-binding protein,vitamin a deficiency,children,burkina faso

Data availability:

ScienceOpen disciplines: Nutrition & Dietetics

Keywords: sensitivity, specificity, total liver reserve, serum retinol, retinol-binding protein, vitamin a deficiency, children, burkina faso