Child Aflatoxin Exposure is Associated with Poor Child Growth Outcomes: A Prospective Cohort Study in Rural Malawi
Andrew Matchado, Joshua W. Smith, Kerry Schulze, John D. Groopman, Emma Kortekangas, David Chaima, Charles D. Arnold, Kenneth Maleta, Ulla Ashorn, Per Ashorn, Kathryn G. Dewey, Christine P. Stewart
Abstract
Aflatoxin exposure is associated with child growth faltering in cross sectional studies with limited findings from longitudinal studies. To evaluate relationship between maternal aflatoxin B1-lysine adduct concentration, child aflatoxin B1-lysine adduct concentration and child growth in first 30 months of life. Aflatoxin B1-lysine adduct was measured in mother-child dyad plasma samples using isotope dilution mass spectrometry. Using linear regression, we assessed relationship between aflatoxin B1-lysine adduct concentration and child weight, height, head and mid-upper arm circumferences at 1 week, 6, 12, 18, 24 and 30 months of age. In adjusted models, maternal prenatal aflatoxin B1-lysine adduct (pg/μL) was positively associated with newborn anthropometric outcomes; largest beta coefficients for associations between standardized values were for newborn weight-for-age z score (β = 0.13; 95% CI: 0.02, 0.24; P < 0.05 and β = 0.11; 95% CI: 0.00, 0.22; P < 0.05 for second and third trimester aflatoxin, respectively). Child aflatoxin B1-lysine adduct (pg/μL) at 6 months was negatively associated with head circumference-for-age z-score at 6, 18, 24 and 30 months, with beta coefficients ranging from β = -0.15; 95% CI: -0.28, -0.02 to β = -0.17; 95% CI: -0.31, -0.03; P < 0.05); 18-month aflatoxin was negatively associated with anthropometric outcomes at 18, 24 and 30 months, most consistently with length-for-age z-score (β = -0.18; 95% CI: -0.32, -0.04, β = -0.21; 95% CI: -0.35, -0.07, β = -0.18; 95% CI: -0.32, -0.03 at 18, 24 and 30 months, respectively). Child aflatoxin exposure was associated with impaired child growth but maternal aflatoxin exposure was not. Exposure during infancy was linked to persistent deficit in head circumference, implying reduced brain size lasting beyond age of 2. Exposure at 18 months was linked to persistent linear growth deficit. Further research should elucidate mechanisms through which aflatoxin affects child growth.