Changes in soluble transferrin receptor and hemoglobin concentrations in Malawian mothers are associated with those values in their exclusively breastfed, HIF-exposed infants

Authors: WIDEN, ELIZABETH - University Of North Carolina; BENTLEY, MARGARET - University Of North Carolina; KAYIRA, DUMBANI - University Of North Carolina; CHASELA, CHARLES - University Of North Carolina; DAZA, ERIC - University Of North Carolina; KACHECHE, ZEBRONE - University Of North Carolina; TEGHA, GERALD - University Of North Carolina; JAMIESON, DENISE - University Of North Carolina; KOURTIS, ATHENA - University Of North Carolina; VAN DER HORST, CHARLES - University Of North Carolina; Allen, Lindsay - A; Shahab-Ferdows, Setti; ADAIR, LINDA - University Of North Carolina

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/12/2013
Publication Date: 12/13/2013
Citation: Widen, E.M., Bentley, M.E., Kayira, D., Chasela, C.S., Daza, E.J., Kacheche, Z.K., Tegha, G., Jamieson, D.J., Kourtis, A.P., Van Der Horst, C.M., Allen, L.H., Shahab-Ferdows, S., Adair, L.S. 2013. Changes in soluble transferrin receptor and hemoglobin concentrations in Malawian mothers are associated with those values in their exclusively breastfed, HIF-exposed infants. Journal of Nutrition. 144(3):367-74. doi: 10.3945/jn.113.177915.

Interpretive Summary: While it is now recognized that the iron status of the infant at birth is directly related to the mother’s iron status during pregnancy, there is little information on how maternal and infant status are related in exclusively breastfed young infants. The objective was to determine whether maternal hemoglobin (Hb) and iron status (transferrin receptors [TfR], and ferritin) were associated with these measures in infants in the Breastfeeding, Antiretrovirals and Nutrition Study (BAN) conducted in Lilongwe, Malawi. HIV-infected women were randomly assigned to receive lipid-based micronutrient supplements (LNS) or no LNS, maternal antiretroviral drugs (ARV) or no ARVs, and infant ARVs or no ARVs (a 2X3 factorial design) from 2 to 24 wk postpartum. In a larger longitudinal sample of 1926 with Hb measures and controlling for the values at baseline, a 1 g/L increase in maternal Hb at 12, 18 and 24 wk was associated with a 0.06 g/L (p=0.01), 0.10 g/L (p<0.001), and 0.06 g/L (p=0.01) respectively higher infant Hb. In a subsample with iron status measures in both mothers and infants, at 2 wk postpartum (n=352) or 6 wk (n=167), and at 24 wk (n=537), controlling for status measures at baseline an increase in maternal log TfR and Hb was associated with a respective increase in infant values [log TfR ß = 0.18 mg/L, p<0.001; Hb ß = 0.13 g/L, p=0.01] showing that maternal and infant iron status were still related. Given the observed influence of maternal and initial infant values, optimizing maternal iron status is important to protect infant iron status.

Technical Abstract: Background: Infant iron status at birth is influenced by maternal iron status during pregnancy; however there are few data on the extent to which maternal iron status is associated with infant iron status during exclusive breastfeeding. Objective: We evaluated how maternal and infant hemoglobin (Hb) and iron status [transferrin receptors (TfR) and ferritin] were related during exclusive breastfeeding in HIV-infected women and their infants. Design: The BAN (Breastfeeding, Antiretrovirals and Nutrition) Study was a randomized controlled trial in Lilongwe, Malawi, in which HIV-infected women were assigned with a 2 x 3 factorial design to lipid-based nutrient supplements (LNS), or no LNS, and maternal antiretroviral (ARV), infant ARV or no ARV regimen, and followed for 24 wk of exclusive breastfeeding. Longitudinal models were used to relate maternal Hb (n=1926) to concurrently measured infant Hb. In a subsample of mother-infant pairs, change in infant iron status (Hb, log ferritin, log TfR) between 2 (n=355) or 6 wk (n=167), and 24 wk (n=532) was regressed on corresponding change in maternal indicator. Results: A one-unit higher maternal Hb at 12, 18 and 24 wk was associated with a 0.06 g/L (p=0.01), 0.10 g/L (p<0.001), 0.06 g/L (p=0.01) respectively higher infant Hb. In the subsample, an increase in maternal TfR and Hb was associated with a respective increase in infant values (TfR ß: 0.18 mg/L, p<0.001; Hb ß: 0.13 g/L, p=0.01). Initial infant values were predictors of later infant Hb and iron status (all p-values <0.001). Conclusions: Given the observed influence of maternal and initial infant values, optimizing maternal iron status is important to protect infant iron status.