Session/Event: Climate, Environment, Agriculture and Food Supply (Oral 3)

(OR03-06-22) Associations Between Ambient Temperature and Circulating Maternal One-carbon and Amino Acid Metabolites in Pregnancy

On Demand

Presenting Author(s)

Kartik Shankar, PhD

Professor
University of Colorado Denver Anschutz Medical Campus
Aurora, Colorado, United States

Disclosure: Disclosure(s): No relevant financial relationship(s) with ineligible companies to disclose.

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Co-Author(s)

Sarah J. Borengasser, PhD

Assistant Professor
University of Colorado Denver Anschutz Medical Campus
Aurora, Colorado, United States
SA

Sumera A. Ali, MBBS

Aga Khan University
Karachi, Sindh, Pakistan
SJ

Saleem Jessani

Aga Khan University
Stephanie P. Gilley, MD, PhD

Postdoctoral Fellow
University of Colorado
Aurora, Colorado, United States
JK

Jennifer F. Kemp, MS

Senior Professional Research Assistant
University of Colorado Anschutz Medical Campus
Aurora, Colorado, United States
PJ

Purevsuren Jambal, MS

University of Colorado
Aurora, Colorado, United States
JW

Jamie E. Westcott, MS

University of Colorado School of Medicine
Aurora, Colorado, United States
SS

Sarah Saleem, MBBS, DCH, MSc

Aga Khan University
Karachi, Sindh, Pakistan
RG

Robert L. Goldenberg

Columbia University
KH

K. Michael Hambidge, MD, ScD

University of Colorado School of Medicine
Aurora, Colorado, United States
Nancy F. Krebs, MD, MS

Professor of Pediatrics, Head, Section of Nutrition
University of Colorado Anschutz Medical Campus
Aurora, Colorado, United States

Objectives: Excessive ambient temperature closely linked to climate change is an imminent threat to the health of mothers and children globally. Recent studies have shown detrimental associations between high temperatures during pregnancy and birth outcomes. The goal of this study was to examine relationships between circulating metabolites in the mother and environmental temperature in a resource-limited setting.

Methods: The study was a secondary analysis employing data from the Women First (WF) trial conduced in Thatta, Pakistan. As part of the trial, women of child-bearing age either consumed a comprehensive maternal nutritional supplement (MNS) prior to conception until delivery (Arm 1), from 12 wk gestation until delivery (Arm 2); or were not supplemented with MNS Arm 3. Daily maximum air temperatures were acquired from the closest surface observation systems (n = 131). Average daily maximum temperatures (T_max) for a 90-day window representing the 1^st trimester of pregnancy was calculated for each participant. The number of days in this period when the T_max was >39° C was computed to assess ‘heat stress days’. Maternal blood was collected on dried blood spot (DBS) cards at 34 wk gestation. A targeted metabolomics assay measuring concentrations of 23 metabolites was performed on DBS samples using LC-MS/MS.

Results: Linear regression was employed to assess the associations between ambient temperature in the 1^st trimester and metabolite levels (z-scores). Models were adjusted for MNS supplementation. Significant associations between Tmax in the 1^st trimester and 7 metabolites were observed (FDR p-values < 0.05). Of these, maternal choline concentrations were negatively correlated with maximal temperature in the 1^st trimester (β = -0.063, p = 4.3e-10). Concentrations of glutamine, histidine, arginine, symmetrical-dimethylarginine, methionine and cysteine were positively associated (p < 0.05) with daily maximal temperature.

Conclusions: Collectively, the findings indicate that exposure to excessive heat stress in the first trimester is associated with lower choline levels and other metabolites important in blood pressure regulation. While the findings are associative, our results point to underlying mechanistic alterations in maternal circulation in concert with environmental heat stress.

Funding Sources: Bill & Melinda Gates Foundation; NIH/ NICHD/ODS