Iron status biomarkers and C-reactive protein in children aged 19 to 72 months in Chile

Abstract

Background. The Chilean Ministry of Health has combated iron deficiency through the delivery of fortified milk by the National Complementary Feeding Program (NCFP). Objective. To assess iron status and associations between biomarkers of iron status and serum C-reactive protein (CRP) in 218 beneficiaries of the NCFP aged 19 to 72 months in Santiago and Valparaiso, Chile. Methods. Blood was collected from a cross-sectional representative sample. Iron status (measured by hemoglobin, zinc protoporphyrin, and serum ferritin levels) and inflammation (according to CRP level) were determined. Results. Serum CRP level was positively associated with serum ferritin and zinc protoporphyrin levels (r = 0.16 and r = 0.15; p = .0168 and p = .0290, respectively). Serum ferritin was higher among children with high CRP (> 10 mg/dL) than among those with low CRP (≤ 10 mg/dL) (p = .003). After adjustment for 10, 6, and 5 mg/L CRP, the prevalence of low serum ferritin changed from 56.4% without adjustment to 60.6%, 61.5%, and 42.7%, respectively, and the prevalence of high zinc protoporphyrin changed from 22.9% to 21.6%, 17.4%, and 17.9%, respectively. There were no differences between regions in biomarkers of iron status. There was no association between consumption of fortified milk and the prevalence of abnormal serum ferritin (< 15 μg/L) after adjustment for sex, age, and breastfeeding (OR, 1.00; 95% CI, 0.99 to 1.01; p = .288). After adjustment for 10 mg/L CRP, 5.5% were classified as having iron-deficiency anemia, 42.7% as having iron-deficiency erythropoiesis, 17.9% as having depleted iron stores, and 35.8% as having normal iron status. Conclusions. CRP level was positively associated with serum ferritin and zinc protoporphyrin levels. Chilean children aged 19 to 72 months from Santiago and Valparaiso who were beneficiaries of the NCFP had a low prevalence of iron-deficiency anemia, a high prevalence of iron-deficiency erythropoiesis, and a moderate prevalence of depleted iron stores.