Serum Homocysteine Levels in Highway Toll Collectors and the Relationship with Intima-Media Thickness of the Carotid Artery

Aim: A relationship between air pollution and increased intima–media thickness (IMT) has been recently reported, but its etiology is not yet well understood. We aimed to determine whether exposure to exhaust particles, which are important air pollutants, is associated with increased serum homocysteine (Hcy) levels and whether elevated Hcy levels are associated with increased IMT.Materials and Methods: Serum Hcy levels were measured by fluorometric high performance liquid chromatography in 65 male highway toll collectors (HTCs) and 43 healthy male volunteers. IMT was measured with Doppler sonography by an experienced radiologist.Results: Serum Hcy levels (14.5 ± 4.9 mmol/L, P 0.005) and IMT (0.757 ± 0.18 mm, P 0.001) werehigher in the HTC group than in controls (12.0 ± 2.8 mmol/L and 0.612 ± 0.11 mm, respectively). A positivecorrelation was found between Hcy level and IMT both in the HTC group (r = 0.36; P 0.005) and in the control group (r = 0.36; P 0.05).Conclusions: Exposure to exhaust particles may cause an increase in oxidative stress because of an increasein serum Hcy levels, which consequently may lead to an increase in IMT. Nevertheless, further studies on the subject are needed before drawing a firm conclusion.