Environmental Enteric Dysfunction, Aflatoxin Exposure, and Poor Growth Outcomes During the First 1,000 Days in Uganda
Lauer, Jacqueline.
2018
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Abstract:
Background: Stunting remains a pervasive form of undernutrition globally, affecting ~155
million children < 5 years of age. Growth failure frequently begins in utero and
continues until at least 24 months of life (called the "first 1,000 days"), after which
time its effects are largely irreversible. While inadequate diets and diarrheal disease
are commonly cited as immediate determi... read morenants, they fail to explain much of the burden.
Meanwhile, less is known about the role of chronic, asymptomatic gastrointestinal
inflammation (environmental enteric dysfunction, or EED) and/or aflatoxin (AF) exposure
during the first 1,000 days and their implications for poor child growth. Objectives:
The goal of this PhD thesis was to examine the associations among EED, AF exposure, and
poor growth outcomes during the first 1,000 days in Uganda. Specifically, the objective
of aim #1 was to examine the associations among poor household drinking water quality,
EED, and poor growth outcomes in children 12-16 months of age living in rural
southwestern Uganda. The objective of aims #2 and #3 were to examine the association
between EED biomarkers (aim #2) and AF exposure (aim #3) in pregnant women aged 18-45
and subsequent adverse birth outcomes in Mukono District, Uganda. Methods: For aim #1,
we conducted a cross-sectional, observational study within a longitudinal birth cohort
study. A lactulose: mannitol (L:M) test was performed on 385 children ages 12-16 months
living in 7 sub-counties of southwestern Uganda. Water quality data were obtained using
a compartment bag test, and safe water was defined as water lacking E. coli
contamination. Data on child anthropometry and covariates were extracted from an
existing birth cohort study. For aims #2 and #3, we conducted a prospective cohort study
in Mukono, Uganda with a sample of 258 pregnant women who were enrolled at their first
prenatal visit. We measured maternal EED biomarkers, namely L:M ratios and serum
anti-flagellin and anti-lipopolysaccharide (LPS) antibodies, as well as maternal
aflatoxin B1 (AFB1) concentrations. Data on maternal anthropometry and covariates were
obtained at enrollment and 3 weeks prior to participants' estimated date of delivery.
For all aims, statistical analyses were conducted using STATA 15 software and results
were obtained from multivariate linear regression models. Results: Aim #1: Children from
households with safe drinking water had significantly lower mean ln L:M ratios
(0.23-point difference, 95% CI: 0.09, 0.38) and significantly higher length-for-age
(LAZ) (β: 0.34, 95% CI: 0.07, 0.61) and weight-for-age (WAZ) (β: 0.24, 95%
CI: 0.10, 0.38) Z-scores at 12-16 months of age. Additionally, children with higher LAZ
at 6 and 9 months had significantly lower ln L:M ratios at 12-16 months of age (β:
-0.06, 95% CI: -0.13, 0.00 and β: -0.05, 95% CI: -0.10, -0.001, respectively). Aim
#2 and #3: Higher concentrations of maternal anti-flagellin IgG and anti-LPS IgG were
significantly associated with shorter length of gestation [(β: -1.35, 95% CI:
-2.64, -0.07) and (β: -0.89 [95% CI: -1.52, -0.25)] and with lower length at birth
[(β: -0.97, 95% CI: -1.79, -0.14) and (β: -0.45, 95% CI: -0.87, -0.02)] and
lower LAZ at in infants at birth [(β -0.52, 95% CI: -0.95, -0.08) and (β:
-0.25, 95% CI: -0.48, -0.03)]. Furthermore, elevations in maternal ln AFB1 levels were
associated with lower weight (β: -0.07; 95% CI: -0.13, -0.002), lower WAZ
(β: -0.16; 95% CI: -0.30, -0.03), smaller head circumference (β: -0.27; 95%
CI: -0.51, -0.03), and lower head circumference-for-age Z-score (HCZ) (β: -0.23;
95% CI: -0.41, -0.04) in infants at birth. Conclusions: Maternal and child EED and AF
exposure were associated with significant decreases in growth at birth, infancy, and
early childhood. Efforts to improve nutrition and reduce stunting may be enhanced by
simultaneously addressing EED and AF
exposure.
Thesis (Ph.D.)--Tufts University, 2018.
Submitted to the Dept. of Food Policy & Applied Nutrition.
Advisor: Shibani Ghosh.
Committee: Lynne Ausman, Christopher Duggan, Jeffrey Griffiths, and Patrick Webb.
Keywords: Nutrition, and Public health.read less - ID:
- k643bc587
- Component ID:
- tufts:24969
- To Cite:
- DCA Citation Guide EndNote
