Household air pollution and metabolomics among Honduran women

Abstract

Introduction: Household air pollution (HAP), primarily from solid fuel combustion in cookstoves, is the third leading risk factor for morbidity and mortality worldwide; however, direct evidence linking HAP with chronic disease endpoints is limited. Obtaining clinical disease measures in rural settings of low- and middle-income countries is logistically challenging; consequently, focus has been placed on subclinical indicators of risk. The ability to conduct broad non-targeted metabolomics profiling from dried blood spots (DBS) represents an innovative approach to identify biomarkers of exposure and health. Methods: We conducted a cross-sectional study among 107 women, aged 25-55 years, using wood-burning stoves in rural Honduras. Kitchen and personal 24-hour fine particulate matter (PM2.5) concentrations were collected via gravimetric sampling. DBS were collected via finger-stick. Global non-targeted metabolite profiling was performed using reverse phase ultra performance liquid chromatography and high resolution mass spectrometry. Analyses were conducted using open source XCMS, RAMclustR, and searchable spectral libraries for compound annotation. In separate linear models, we evaluated the relationship between PM2.5 and each metabolite, adjusting for age, BMI, physical activity, and socio-economic status and using a false discovery rate p-value correction for multiple testing. Results: PM2.5 exposures were associated with 27 metabolites, five were annotated (e.g., phenylalanine, terpene). Lysophosphatidylcholine 18:2, a metabolite previously identified as being protective for incident coronary heart disease, was inversely associated with kitchen PM2.5 levels. We will evaluate standards for annotated metabolites to quantify the PM2.5 relationships. Conclusion: The use of DBS could have far-reaching impacts on field-based sciences, such as HAP, by expanding the ability to discover new biomarkers and characterize metabolic profiles in populations previously inaccessible.