Infant cortisol concentrations do not differ by group in a randomized controlled trial of lipid based nutrient supplements among mothers and infants in Malawi

Authors: STEWART, CHRISTINE - University Of California; OAKS, BRIETTA - University Of California; ASHORN, PER - University Of Tampere; DEWEY, KATHRYN - University Of California; Laugero, Kevin

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2017
Publication Date: 9/8/2017
Citation: Stewart, C.P., Oaks, B.M., Ashorn, P., Dewey, K.G., Laugero, K.D. 2017. Infant cortisol concentrations do not differ by group in a randomized controlled trial of lipid based nutrient supplements among mothers and infants in Malawi . Journal of Nutrition. doi: 10.1186:s12884.015.0793.8.
DOI: https://doi.org/10.3390/nu10111606

Interpretive Summary: Poor nutrition during pregnancy can lead to abnormally high or low circulating levels of a key hormone, cortisol, throughout the body and brain of the offspring. Abnormally high or low levels of cortisol can lead to disturbances in metabolism, behavior, and overall health. Diet and overall nutrition may affect the levels of circulating cortisol in the body and brain. In this study of rural Malawian women, a low-income population with high rates of malnutrition, we tested whether a micronutrient (vitamins and minerals, including iron-folic acid) supplement during pregnancy and post-partum affected levels of circulating cortisol in the offspring, at 6, 12, and 18 months of age. One test group received a micronutrient supplement alone, another test group received a micronutrient + energy in the form of fat, and the third test group received only iron-folic acid supplementation. Maternal supplementation with micronutrients did not generally affect cortisol in the infants. Our results suggest that, in this setting, supplementation with micronutrients may have limited impact on child cortisol concentrations.

Technical Abstract: Background: Prenatal malnutrition and stress have been associated with the regulation of the offspring hypothalamic-pituitary-adrenal (HPA) axis. Objective: To evaluate whether maternal and infant nutritional supplementation was associated with salivary cortisol concentrations in Malawian infants. Methods: 1391 pregnant women were enrolled and randomized to receive either lipid-based nutrient supplements (LNS), multiple micronutrient (MMN), or iron-folic acid (IFA) supplements. Supplementation in the LNS and MMN groups continued through 6 months postpartum. Infants in the LNS group received LNS from 6 to 18 mo of age while infants in the MMN and IFA groups received no intervention. Maternal salivary cortisol was measured at enrollment and 36 wk gestation. At 6, 12, and 18 mo of age, infants’ salivary cortisol was measured at arrival at each clinic visit and, at 6 and 18 mo, also 20 min after a scheduled venipuncture blood draw. Results: Cortisol was measured at least once among 641 infants. Mean ± SD cortisol concentrations were 5.29 ± 4.81 nmol/L at 6 mo, 4.54 ± 5.69 nmol/L at 12 mo, and 4.61 ± 4.98 nmol/L at 18 mo, and did not differ by group at any time. Cortisol response to venipuncture also did not differ between groups. We found significant interactions between maternal cortisol and intervention group. Among mothers with high cortisol at 36 wk gestation, infants in the IFA group had a blunted response to venipuncture at 6 mo (+0.17 nmol/L) as compared to infants in the LNS (+0.58 nmol/L) or MMN (+0.83 nmol/L) groups. Infants in the MMN group had the lowest cortisol concentration at 18 mo (IFA: 4.85 nmol/L; LNS: 5.35 nmol/L; MMN: 3.65 nmol/L). There was no difference between groups among those whose mothers had low cortisol concentrations in late pregnancy. Conclusions: Maternal supplementation with micronutrients has limited impact on child cortisol concentrations in this setting.