High Serum Homocysteine Levels Correlate with a Decrease in the Blood Flow Velocity of the Ophthalmic Artery in Highway Toll Collectors

Abstract

Highway workers, such as policemen, automotive service companies, and toll collectors, are placed at risk of the accelerated atherosclerotic process, since recent studies have suggested that exposure to exhaust particles and ambient air pollution increases carotid intima-media thickness and reduces ocular blood flow velocity. Therefore, we assessed the relationship between serum homocysteine, a potential parameter for atherosclerosis, and the ocular blood flow velocity and the resistivity index in highway toll collectors. The peak systolic and end diastolic flow velocities and the resistivity index were measured in 22 toll collectors and 24 control subjects by color Doppler ultrasonography. The resistivity index, which is an indirect measure of the atherosclerotic process, was calculated: resistivity index = (peak systolic velocity -end diastolic velocity)/peak systolic velocity. Serum homocysteine levels were determined by fluorometric high-performance liquid chromatography. In the highway toll collectors, the serum homocysteine level (14.4 ± 4.8 μ mol/l; p < 0.005) and the resistivity index of the ophthalmic artery (0.741 ± 0.015; p < 0.05) were higher and the ophthalmic blood flow velocity (33.0 ± 3.0 cm/s; p < 0.001) was lower than those in the controls (10.6 ± 3.1 μ mol/l; 0.728 ± 0.023; 36.8 ± 2.2 cm/s; respectively). There were significant correlations between the serum homocysteine level and ophthalmic artery resistivity index in both highway toll collectors ( p < 0.001) and controls ( p < 0.005). Exposure to exhaust particles might increase the serum homocysteine level, which in turn could lead to the decreased ocular blood flow and the increased resistivity index.homocysteine; ocular blood flow; highway toll collectors; color Doppler ultrasonography

A curve model for association of serum homocysteine with carotid artery hemodynamics

“…The findings of this research are consistent with the results of Memisogullari et al [13], and demonstrate that Hcy is associated with hemodynamics. Factor such as blood pressure is reported to be related to hemodynamics [14].…”

“…However, results obtained by Memisogullari et al [13] in a previous study on correlation between Hcy and hemodynamics in ophthalmic artery of highway toll collectors revealed a linear pattern, in which high Hcy level was related to the decreased EDV and RI. However, Memisogullari et al based their study on the ophthalmic artery and only 22 toll subjects, while the current study focused on the carotid artery, and used a far greater number of subjects.…”

A Systematic Review of Occupational Exposure to Particulate Matter and Cardiovascular Disease

“…The studies were conducted in underground railroad workers [43], boilermaker construction workers [44–53], highway toll collectors [54], vehicle maintenance workers [55], highway patrol officers [56], traffic policemen [57], automobile mechanics [58], and a panel of healthy volunteers exposed to welding fumes [59]. Three studies focused on identifying effect modifiers [44,50,51] (Table 5) and four re-analyzed data to identify PM 2.5 sources and components responsible for observed associations [47,53,60,61].…”

“…Direct personal measurements of airborne PM concentrations were used to assign exposure in the boilermaker construction workers [44–53], vehicle maintenance workers [55], and highway patrol officers [23], while controlled exposures were studied in the panel of healthy volunteers exposed to welding fumes [59]. Job title was used in the other cohorts which were studied using a cross-sectional design [43,54,57,58] (Table 7). Because of the smaller number of participants, which generally makes it more feasible to collect more detailed information on a larger number of covariates, control or evaluation of important potential confounders such as smoking was conducted in all of the studies of intermediate cardiovascular outcomes, either through study design or in analysis.…”

“…To assess the chronic effects of exposure, four cross-sectional studies investigated the association between exposure as measured by job title and levels of circulating inflammatory markers [43], cardiovascular abnormalities [57], and measures of pre-clinical atherosclerosis [54,58] while controlling for smoking and a number of potentially important confounders (Table 7). In underground railway workers with relatively high exposure to PM 2.5 , increased baseline levels of PAI-1 and CRP were found as compared to low-exposed workers, suggesting a chronic systemic inflammatory effect of PM exposure [43].…”