The VitMin Lab Sandwich-ELISA Assays for Iron and Inflammation Markers Compared Well with Clinical Analyzer Reference-Type Assays in Subsamples of the Nepal National Micronutrient Status Survey.

BACKGROUND: The low cost and small specimen volume of the VitMin Lab ELISA assays for serum ferritin (Fer), soluble transferrin receptor (sTfR), C-reactive protein (CRP), and α-1-acid glycoprotein (AGP) have allowed their application to micronutrient surveys conducted in low-resource countries for ∼2 decades. OBJECTIVES: We conducted a comparison between the ELISA and reference-type assays used in the US NHANES. METHODS: Using the Roche clinical analyzer as a reference, we measured random subsets of the 2016 Nepal National Micronutrient Status Survey (200 serum samples from children aged 6-59 mo; 100 serum samples from nonpregnant women) for Fer, sTfR, CRP, and AGP. We compared the combined data sets with the ELISA survey results using descriptive analyses. RESULTS: The Lin's concordance coefficients between the 2 assays were ≥0.89 except for sTfR (Lin's ρ = 0.58). The median relative difference to the reference was as follows: Fer, -8.5%; sTfR, 71.2%; CRP, -19.5%; and AGP, -8.2%. The percentage of VitMin samples agreeing within ±30% of the reference was as follows: Fer, 88.5%; sTfR, 1.70%; CRP, 74.9%; and AGP, 92.9%. The prevalence of abnormal results was comparable between the 2 assays for Fer, CRP, and AGP, and for sTfR after adjusting to the Roche assay. Continued biannual performance (2007-2019) of the VitMin assays in CDC's external quality assessment program (6 samples/y) demonstrated generally acceptable performance. CONCLUSIONS: Using samples from the Nepal survey, the VitMin ELISA assays produced mostly comparable results to the Roche reference-type assays for Fer, CRP, and AGP. The lack of sTfR assay standardization to a common reference material explains the large systematic difference observed for sTfR, which could be corrected by an adjustment equation pending further validation. This snapshot comparison together with the long-term external quality assessment links the survey data generated by the VitMin Lab to the Roche assays used in NHANES.

Barriers to and Facilitators of Iron and Folic Acid Supplementation within a School-Based Integrated Nutrition and Health Promotion Program among Ghanaian Adolescent Girls.

BACKGROUND: Anemia is a moderate public health problem among adolescent girls in Ghana. OBJECTIVES: We aimed to evaluate the barriers to and facilitators of program fidelity to a school-based anemia reduction program with weekly iron and folic acid (IFA) supplementation. METHODS: Authors analyzed directly observed weekly IFA consumption data collected longitudinally and cross-sectional data from a representative survey of 60 secondary schools and 1387 adolescent girls in the Northern and Volta regions of Ghana after 1 school year (2017-2018) of the intervention (30-36 wk). A bottleneck analysis was used to characterize the levels of IFA coverage and used adjusted generalized linear mixed-effects models to quantify the school and student drivers of IFA intake adherence. RESULTS: Of girls, 90% had ever consumed the tablet, whereas 56% had consumed ≥15 weekly tablets (mean: 16.4, range: 0-36), indicating average intake adherence was about half of the available tablets. Among ever consumers, 88% of girls liked the tablet, and 27% reported undesirable changes (primarily heavy menstrual flow). School-level factors represented 75% of the variance in IFA consumption over the school year. Total IFA tablets consumed was associated with the ability to make up missed IFA distributions (+1.4 tablets; 95% CI: +0.8, +2.0 tablets), junior compared with senior secondary school (+5.8; 95% CI: +0.1, +11.5), educators' participating in a program-related training (+7.6; 95% CI: +2.9, 12.2), and educator perceptions that implementation was difficult (-6.9; 95% CI: -12.1, -1.7) and was an excessive time burden (-4.4; 95% CI: -8.4, -0.4). CONCLUSIONS: Although the program reached Ghanaian schoolgirls, school-level factors were barriers to adherence. Modifications such as expanded training, formalized make-up IFA distributions, sensitization (awareness promotion), and additional support to senior high schools may improve adherence. Spreading the responsibility for IFA distribution to other teachers and streamlining monitoring may reduce the burden at the school level. Strengthening the health education component and improving knowledge of IFA among students may also be beneficial.

Obese women less likely to have low serum ferritin, Nicaragua.

OBJECTIVE: To examine the association between overweight and obesity and serum ferritin among women of reproductive age (15-49 years) in Nicaragua, considering the effect of α1-acid glycoprotein (AGP), a marker of inflammation. DESIGN: We analysed data from the 2004-05 Nicaraguan Integrated Surveillance System for Nutrition Interventions. Three logistic regression models were analysed with low serum ferritin (<15 µg/l) as the dependent variable: (i) overweight or obese status and covariates; (ii) model 1 plus AGP; and (iii) model 1 restricted to only women with normal AGP levels (≤1.0 g/l). SETTING: Nicaragua. SUBJECTS: Included in this analysis were 832 non-pregnant mother/caregivers (15-49 years) surveyed in 2004-2005. RESULTS: In the sample, prevalence of overweight and obesity was 31.8 % and 19.2 %, respectively, and 27.6 % had low serum ferritin. In model 1, the adjusted OR of low serum ferritin was 0.74 (95 % CI 0.52, 1.05) for overweight women and 0.42 (95 % CI 0.26, 0.65) for obese women. In model 2, AGP was significantly independently associated with low serum ferritin (adjusted OR=0.56, 95 % CI 0.34, 0.92) while the adjusted OR for overweight and obesity were largely unchanged. Excluding women with elevated AGP did not appreciably affect the relationship between overweight or obesity and low serum ferritin (model 3). CONCLUSIONS: Overall, in this population of reproductive-age women, obese women were less likely to have low serum ferritin levels, and this was independent of inflammation as measured by AGP.

Association of elevated α1-acid glycoprotein (AGP) and the prevalence of anemia in Nicaraguan preschool children.

BACKGROUND: Anemia status is frequently assessed in cross-sectional surveys. Recently, the assessment of acute phase proteins (APPs) has become more common, primarily for iron and vitamin A biomarkers. Although the so-called "anemia of infection" has been known for years, the relationship between APPs and anemia has been infrequently presented. OBJECTIVE: To assess the relationship between elevated α1-acidglycoprotein (AGP) and the prevalence of anemia among preschool children. METHODS: A nationally representative household-based cross-sectional survey was conducted in 2003-05 in Nicaragua. Blood samples were collected from preschool children 6 to 59.9 months of age and tested for hemoglobin and AGP. Data were also obtained on sex, weight, height, use of iron supplements, maternal education, and urban or rural status. RESULTS: Among the 1420 children assessed, the overall prevalence of anemia was 20.2% and the prevalence of elevated AGP was 24.0%. Children with elevated AGP had an anemia prevalence of 27.9%, compared with 17.8% among those with a normal AGP, for a crude prevalence odds ratio (POR) of 1.8 (p = .010). Accounting for age, maternal educational level, and year of survey using logistic regression, the adjusted POR for the association between elevated AGP and anemia was 1.5 (p = .053). CONCLUSIONS: Children in this survey with an elevated AGP had a higher prevalence of anemia, although after controlling for covariates the p-value did not indicate a statistically significant difference (p = .053). It may be helpful to account for APPs, when this information is available, for purposes of comparing anemia prevalence across populations or within a population over time.