C34-14 The Association of Oxylipins on Asthma Morbidity and Effect Modification by Body Mass Index

Abstract Rationale Asthma and obesity are common comorbidities, both driven by inflammation and oxidative stress. Oxylipins are derivatives of polyunsaturated fatty acids that regulate the onset and resolution of inflammation. Oxylipin profiles are altered in obesity and have been shown to differentiate asthma from non-asthma; however, the association between oxylipins and asthma outcomes and the impact of obesity is not known. This study aims to identify differences in serum oxylipins associated with asthma morbidity and evaluate the effect modification by BMI. Methods We analyzed 150 participants in the Best African American Response to Asthma Drugs (BARD) clinical trial. Ninety oxylipins were quantified using liquid chromatography tandem mass spectroscopy from serum obtained at the time of randomization. Oxylipins found to be above the limit of detection in 80% of samples were log-transformed and included in the analysis. Asthma severity measures included past 12-month systemic corticosteroid use for asthma exacerbation, spirometry, asthma control and asthma quality of life questionnaires (AQLQ). The associations between oxylipins and asthma outcomes were tested using multivariable regression models adjusted for sex, age, BMI, absolute eosinophil count, percent African ancestry, and child vs adult/adolescent cohort. A false discovery rate (FDR) of 0.1 is used to determine statistical significance. Results Of the 90 oxylipins measured, 42 (46.7%) were detected in 80% of all samples and included in the analysis. In multivariable models, the pro-inflammatory arachidonic acid (AA) derivative 5,6-DiHETrE was associated with decreased odds of past 12-month systemic corticosteroid use (FDR-adjusted p-value 0.0628). AA derivatives TXB2, PGF2a, and 6-α-prostaglandin were associated with increased FEV1/FVC (FDR-adjusted p-values=0.0925). Thirteen oxylipins were associated with decreased asthma-related quality of life in multivariable models, including AA metabolites 5S-HETE, 5-KETE, 14,15-EET, LTB4, and Lipoxin A4; dihomo-gamma-linoleic acid metabolites 5-HETrE and 15-HETrE; linoleic acid metabolites 3-OxoODE and 9-OxoODE; and eicosapentaenoic acid metabolites 15-HEPE and 17,18-EpETE, all with FDR-adjusted p-values0.05. Oxylipin-BMI interaction was significant only in the AQLQ models. In all but LTE4, increased concentrations of oxylipins were associated with a decreased quality of life in individuals with higher BMI (Figure). Six of these oxylipins are products of lipoxygenase activity. Conclusions In this study, we find decreased quality of life with increasing concentrations of pro-inflammatory and resolving oxylipins among those with obesity. These oxylipins are primarily produced via lipoxygenases and may represent an important inflammatory pathway in obesity-associated asthma. Quantification of sputum oxylipins and correlation with serum levels will be important in understanding potential mechanisms and is forthcoming. This abstract is funded by: K12TR004412, R01HL123385, U10HL098075, Parker B. Francis Fellowship, 2L30HL159725