Effects of drinking water, sanitation, handwashing and nutritional interventions on stress physiology, oxidative stress, and epigenetic programming in young children living in rural Bangladesh: A randomized clinical trial
Authors: Lin Audrie , Mertens Andrew N. , Rahman Md. Ziaur , Tan Sophia , Il’yasova Dora , Spasojevic Ivan , Ali Shahjahan , Stewart Christine P. , Fernald Lia C. H. , Kim Lisa , Yan Liying , Meyer Ann , Karim Md. Rabiul , Shahriar Sunny , Shuman Gabrielle , Arnold Benjamin F. , Hubbard Alan , Famida Syeda Luthfa , Akther Salma , Hossen Md. Saheen , Mutsuddi Palash , Shoab Abul K. , Shalev Idan , Rahman Mahbubur , Unicomb Leanne , Heaney Christopher D. , Kariger Patricia , Colford John M. , Luby Stephen P. , Granger Douglas A. 
Published: November 2021

Importance

A regulated stress response is essential for healthy trajectories, but the integrated effects of early childhood environmental and nutritional interventions on stress physiology are unknown.

Objective

To assess the effects of a combined nutritional, water, sanitation, and handwashing intervention on physiological stress response, oxidative stress, and DNA methylation.

Design, Setting, and Participants

In a trial in rural Bangladesh, we randomized geographical clusters of pregnant women and their in-utero children into either the combined nutritional, water, sanitation, and handwashing intervention or the control group. Physiological stress response, oxidative stress, and methylation levels of 757 children were measured at ages one and two years. Analysis was intention-to-treat.

Interventions

The intervention group received combined nutritional counseling and lipid-based nutrient supplements, chlorinated drinking water, upgraded sanitation, and handwashing with soap (N+WSH). The control group did not receive interventions.

Main Outcomes and Measures

We measured four isomers of urinary F2-isoprostanes [iPF(2α)-III; 2,3-dinor-iPF(2α)-III; iPF(2α)-VI; 8,12-iso-iPF(2α)-VI] at year one. At year two, we measured pre- and post-stressor concentrations of salivary alpha-amylase and cortisol, overall methylation of the glucocorticoid receptor (NR3C1) exon 1F promoter including methylation levels at the nerve growth factor-inducible protein A (NGFI-A) binding site, mean arterial pressure, and resting heart rate.

Results

Children in the N+WSH group had lower levels of F2-isoprostanes compared to controls (difference -0.16 to -0.19 log ng/mg of creatinine, P<0.01). Compared to the control group, post-stressor cortisol levels were elevated (0.24 log μg/dl; 95% CI, 0.07 to 0.4; P<0.01) and the residualized gain score for cortisol was higher (0.06 μg/dl; 95% CI, 0.01 to 0.12; P=0.023) in the N+WSH group. Children in the N+WSH group exhibited decreased logit-transformed methylation of the NGFI-A transcription factor binding site (−0.04; 95% CI, -0.08 to 0; P=0.037).

Conclusions and Relevance

A nutritional, water, sanitation, and handwashing intervention reduced oxidative stress, enhanced hypothalamic-pituitary-adrenocortical axis activity, and reduced methylation levels in a transcription factor binding site of the glucocorticoid receptor gene. A targeted environmental and nutritional intervention affected the set point, reactivity, and regulation of the physiological stress system in early childhood, which may have implications for long-term health and developmental trajectories.

Trial Registration

ClinicalTrials.govNCT01590095

Key Points

Question

Do intensive nutritional and environmental interventions alter physiological stress response, oxidative stress levels, and epigenetic programming during the first two years of life?

Findings

In this cluster randomized clinical trial of 757 children, a combined nutritional, drinking water, sanitation, and handwashing intervention significantly reduced oxidative stress, enhanced the cortisol response, and reduced methylation levels in a transcription factor binding site of the glucocorticoid receptor gene.

Meaning

The integrated nutritional, drinking water, sanitation, and handwashing intervention enhanced adaptive responses of the physiological stress system in early childhood, which may have implications for long-term health and developmental trajectories.