Traffic-Related Air Pollution Exposure and Altered Fatty Acid Oxidation among Adolescents and Young Adults – the Interplay with Obesity

Abstract

S01: Mapping the Air Pollution Metabolome: Applications, Limitations, and the Path Forward, Room 217, Floor 2, August 26, 2019, 10:30 AM - 12:00 PM Background/Aim: Air pollution exposure has been shown to increase the risk of obesity and metabolic dysfunction in animal models and human studies. However, the metabolic pathways altered by air pollution exposure are unclear, especially in adolescents and young adults who are at a critical period for developing cardio-metabolic diseases. The aim of this study was to examine the associations of exposures to traffic-related and regional air pollutants with indices of fatty acid and amino acid metabolism. Methods: A total of 173 young adults (18-23 years) from eight Children’s Health Study (CHS) Southern California communities were examined from 2014-2018. Exposures to traffic-related [freeway and non-freeway nitrogen oxides (NOx)] and regional air pollutants (nitrogen dioxide, ozone and particulate matter) were estimated based on participants’ residential addresses. Serum concentrations of 64 targeted metabolites including amino acids, acylcarnitines, ketones and total non-esterified fatty acid (NEFA) were measured in fasting serum samples. Principal component analysis (PCA) of metabolites was performed to identify metabolite clusters that represent key metabolic pathways. Mixed effects models were used to analyze the associations of air pollution exposure with metabolomic principal component (PC) scores and individual metabolite concentrations adjusting for potential confounders. Results: Higher long-term (lagged one-year average) exposure to non-freeway NOx was associated with higher concentrations of NEFA oxidation byproducts and higher NEFA-related PC score (all p’s<0.01). The effect sizes were larger among obese and Non-Hispanic White individuals (interaction p’s≤0.002). Among females, higher exposure to freeway NOx was associated with a higher NEFA-related PC score (p=0.006). Additionally, among all participants, higher exposure to freeway NOx was associated with a lower PC score for lower concentrations of short- and median-chain acylcarnitines (p=0.042). Conclusions: Results of this study indicate that traffic-related air pollution exposure is associated with altered fatty acid metabolism, which contributes to the metabolic perturbation in obese youth.