Relationships between infection, inflammation and biomarkers of micronutrient among school-age children in Malawi.

BACKGROUND

Micronutrient deficiencies in vitamin A, iron and zinc continue to threaten the growth, immunity and cognitive development of school-age children (SAC) in low- and middle-income countries. However, infection-related distortion of micronutrient biomarkers and limited evidence leave the burden and determinants in Malawi insufficiently understood. This study investigated the relationships between infection, inflammation and indicators of micronutrient status including retinol-binding protein (RBP), ferritin and zinc among SAC in Malawi.

METHODS

A secondary analysis of cross-sectional data from the 2015-2016 Malawi Micronutrient Survey was conducted. Infection and inflammation were assessed using caregiver-reported illness, malaria testing, haematuria, C-reactive protein (CRP) and α-1-acid glycoprotein (AGP). Descriptive and inferential statistical analyses were performed. Multivariable generalized linear models were used to examine associations between infection and inflammation indicators and micronutrient biomarkers (RBP, inflammation-adjusted ferritin and serum zinc) while controlling for demographic, nutritional and household covariates. All analyses were conducted using R version 4.3.0.

RESULTS

Elevated CRP and AGP were significantly associated with lower RBP and zinc concentrations and with higher ferritin levels. Recent fever and malaria positivity were also associated with alterations in micronutrient biomarker concentrations. Older children (11-14 y) had higher RBP levels. Regional differences were observed, with children in the Central and Southern regions showing lower RBP and ferritin compared with those in the Northern region.

CONCLUSIONS

Infection and inflammation are important determinants of micronutrient biomarker concentrations among SAC in Malawi. These findings highlight the importance of adjusting micronutrient assessments for inflammation and strengthening integrated public health strategies that combine micronutrient interventions with infection prevention and control to improve child nutritional status.