Glycerophospholipid metabolism changes association with ozone exposure

Abstract

Exposure to ozone (O₃) has been associated with cardiovascular outcomes in humans, yet the underlying mechanisms of the adverse effect remain poorly understood. We aimed to investigate the association between O₃ exposure and glycerophospholipid metabolism in healthy young adults. We quantified plasma concentrations of phosphatidylcholines (PCs) and lysophosphatidylcholines (lysoPCs) using a UPLC-MS/MS system. Time-weighted personal exposures were calculated to O₃ and co-pollutants over 4 time windows, and we employed orthogonal partial least squares discriminant analysis to discern differences in lipids profiles between high and low O₃ exposure. Linear mixed-effects models and mediation analysis were utilized to estimate the associations between O₃ exposure, lipids, and cardiovascular physiology indicators. Forty-three healthy adults were included in this study, and the mean (SD) time-weighted personal exposures to O₃ was 9.08 (4.06) ppb. With shorter exposure durations, O₃ increases were associated with increasing PC and lysoPC levels; whereas at longer exposure times, the opposite relationship was shown. Furthermore, two specific lipids, namely lysoPC a C26:0 and lysoPC a C17:0, showed significantly positive mediating effects on associations of long-term O₃ exposure with pulse wave velocity and systolic blood pressure, respectively. Alterations in specific lipids may underlie the cardiovascular effects of O₃ exposure.

Keywords: Cardiovascular health; Glycerophospholipids metabolism; Mediation effect; Ozone exposure.