Acute exposure to diesel affects inflammation and vascular function.

Area of Science:

• Environmental Health
• Cardiovascular Physiology
• Toxicology

Background:

• Diesel exhaust fumes are a prevalent toxic air pollutant.
• The long-term effects of acute diesel exhaust exposure on inflammation and vascular health remain largely unknown.

Purpose of the Study:

• To investigate the prolonged impact of acute diesel exhaust fume exposure on vascular properties and inflammatory markers in healthy subjects.
• To assess changes in endothelial function, arterial stiffness, and heart rate variability following diesel exhaust exposure.

Main Methods:

• Healthy subjects underwent a 2-hour exposure to diesel exhaust fumes or filtered air.
• Vascular function (flow-mediated dilation, pulse wave velocity, augmentation index), heart rate variability (SDNN), and inflammatory/hemostatic markers (C-reactive protein, fibrinogen, protein C, protein S) were measured before and 24 hours post-exposure.

Main Results:

• Diesel exhaust exposure significantly impaired endothelial function, increased arterial stiffness, and reduced heart rate variability for up to 24 hours.
• Exposure led to elevated C-reactive protein and fibrinogen levels, alongside decreased protein C and protein S activity.
• Smokers exhibited higher C-reactive protein levels post-exposure compared to non-smokers.

Conclusions:

• Short-term diesel exhaust exposure has lasting adverse effects on vascular function, heart rate variability, and inflammatory markers.
• These findings elucidate mechanisms contributing to increased cardiovascular risk in individuals regularly exposed to diesel exhaust.