ABSTRACT
Aflatoxin exposure, malnutrition and growth impairment in children present significant public health problems in low- and middle-income countries. Recent epidemiology studies show that exposure to aflatoxins through dietary sources in early life contributes to growth retardation among children. However, the findings remain inconclusive due to limited comparative studies in high versus low aflatoxin exposure regions. This cross-sectional study presents aflatoxin exposure levels among children aged 6 to 12 years, and further evaluates the association between aflatoxin exposure levels, malnutrition and growth impairment in Kenya, East Africa. AFB1-lysine adducts are validated biomarkers of exposure and were quantified using HPLC with fluorescence detection. All children (n = 746) had detectable levels of AFB1-lysine adducts in serum, range 0.65-518.9 pg/mg albumin with a geometric mean (GM) of 10.5 (95%CI 9.4-11.7) pg/mg albumin. The Geometric Means (GM) of AFB1-lysine adducts were 14.0 (95%CI 12.5, 15.7) pg/mg albumin and 8.2 (95%CI 7.6, 8.8) pg/mg albumin (p-value < 0.001), among children recruited from Makueni and Siaya Counties, respectively. While the study confirms higher human exposure levels in Makueni county, it provides an initial data set for aflatoxin exposure levels among children recruited from Siaya County. In multivariate analysis, after adjusting for socio-economic indicators, farming practices, and household dietary patterns, increasing one unit of log AFB1-lysine was associated with decreasing Weight-for-age z-score (WAZ) by -0.13, p-value = 0.019 among all children aged 6-12 years. Among children 6 to 9 years, WAZ decreases by -0.11 (-0.54, -0.01), p-value = 0.049. Additional growth parameters Height-for-age z-score (HAZ) and Weight-for-height z-score (WHZ) do not reach statistical significance. HAZ decreases by -0.08, p-value = 0.337 and WHZ decreases by -0.17, p-value = 0.437 with every increase in log AFB1-lysine. These data suggest that efforts must be put in place to control for aflatoxin exposure in order to achieve better growth outcomes.