Early deterioration of iron status among a cohort of Bolivian infants

Abstract

Iron deficiency (ID) and iron deficiency anemia (IDA) are major contributors to infant and maternal morbidity worldwide. There is limited longitudinal data on iron status in young infants and on methods to adjust iron biomarkers for inflammation. We aimed to quantify the prevalence of inflammation-adjusted ID, anemia, and IDA over the first year in a cohort of Bolivian infants and their mothers. Healthy mother-infant dyads were recruited from two peri-urban hospitals. Infants provided three blood draws (2, 6-8, and 12-18 months; N = 160); mothers provided two blood draws (1 and 6-8 months postpartum [plus third anemia measurement at 12-18 months]; N = 250). Blood was analyzed for hemoglobin, ferritin, soluble transferrin receptor, C-reactive protein (CRP), and alpha(1)-acid glycoprotein (AGP). Iron biomarkers were adjusted for inflammation using CRP and AGP; hemoglobin cutoffs were adjusted for altitude. Inflammation (elevated CRP or AGP) was 17% among toddlers 12-18 months of age. ID (inflammation-adjusted ferritin) increased with age (<1%, 56%, and 79% at each blood draw), as did anemia and IDA (anemia: 70%, 76%, and 81%; IDA: <1%, 46%, and 68%). Maternal ID declined from the first to second assessment (39% vs. 27%). Inflammation-adjusted ID prevalence was up to 15 percentage points higher than unadjusted estimates. The high prevalence of ID, anemia, and IDA in this cohort of Bolivian infants beginning at 6-8 months of age suggests that early interventions may be necessary in vulnerable populations.