405Acute and short-term effects of diesel exhaust fumes exposure on arterial wall properties, inflammatory process and fibrosis-fibrinolysis status

Abstract

Abstract Introduction Exhaust fumes from diesel engines are a complex mixture of toxic compounds with a wide variety of harmful effects. The acute effects of diesel exhaust fumes on the cardiovascular system are well-known. However, their short-term impact has not been thoroughly studied. Purpose To study the acute and short-term (24 h) effects of diesel exhaust particles (DEPs) on endothelial function, arterial wall properties, inflammatory process and fibrosis-fibrinolysis status. Methods In this blind cross over study, 40 healthy volunteers (median age 40 years old) have been exposed to diesel exhaust particles (DEPs) and then to filtered air (FA) over a 2-hour session with a wash out period of 4 weeks. Exposure to DEPs was calibrated based on the mass of microparticles less than 2,5 microns in diameter (PM 2,5). Flow-mediated-dilation (FMD) was used to estimate endothelial function. Pulse wave velocity (PWV) and augmentation index (AIx) assessed central aortic stiffness and arterial reflected waves respectively. C reactive protein (CRP) was measured to determine the inflammatory status, as well as fibrinogen and protein C levels to evaluate the impact on the coagulation cascade. All measurements were performed before each session (T0), at the end of the 2 hours exposure session (T2) and 24 hours after completion of each session (T24). Variables with normal distribution are presented as mean±SD otherwise as median±SEM. Results At T0 of DEP and FA exposure there was no significant difference in FMD, PWV, AIX, CRP, protein C and fibrinogen levels. Exposure to DEP decreased significantly FMD (T0: 11.97±4.61% vs T2: 7.71±3.36% vs. T24: 6.17±3.19%, p<0.001) and increased PWV (T0: 6.09±1.03m/sec vs T2: 7.22±1.31m/sec vs. T24: 6.90±1.03m/sec, p<0.001), AIx (T0: 8.17±3.19% vs T2: 12.71±3.36% vs. T24: 13.17±4.61%, p<0.001), CRP (T0: 1.41±0.18 mg/L vs T2: 1.99±0.21mg/L vs. T24: 2.08±0.24mg/L, p=0.04) and fibrinogen levels (T0: 269±44 mg/dL vs T2: 331±75 mg/dL vs. T24: 307±51 mg/dL, p=0.002). Protein C was significantly reduced (T0: 121±26% vs T2: 104±21% vs. T24: 105±20%, p=0.003). Exposure to FA had no significant impact on the study parameters. Graph of results Conclusion Exposure to diesel exhaust fumes may have significant adverse effects on the cardiovascular system with impairment of endothelial function, arterial wall properties, inflammatory status and fibrosis-fibrinolysis parameters not only during the exposure period but as far as 24 hours after exposure. Acknowledgement/Funding None