The carotid intima-media thickness in workers with high and low exposure to air pollution

Background: The exposure to chronic air pollution is associated with cardiovascular morbidity and mortality through atherosclerosis acceleration and progression. Carotid intima-media thickness (CIMT) is an important subclinical sign of atherosclerosis. Objective: To analyze the difference of CIMT between chemical industry workers with high and low exposure to air pollution. Method: There were 66 male subjects who consisted of 33 chemical industry workers in the production division and other 33 non-industry workers who have worked for more than 1 year. The subjects underwent the examination of CIMT in left and right carotid artery. Results: The mean of left CIMT test was 0.97 ± 0.08 mm in industry workers and 0.75 ± 0.15 mm in office workers. The mean of left CIMT test was 1.01 ± 0.09 mm in industry workers and 0.72 ± 0.10 mm in office workers. On the other hand, the mean of left and right CIMT test was 0.99 ± 0.07 mm in industry workers and 0.74 ± 0.11 mm in office workers. The difference analysis of left CIMT between two groups was examined by using unpaired t-test. There was no significant difference of CIMT value between subjects who worked in industry and office (p < 0.05; 9% CI 0.16 – 0.28). On the other hand, the difference analysis between left CIMT and the mean of left and right CIMT was measured by Mann-Whitney test. The results showed that there was a significant difference between two groups (p< 0.05). Conclusion: There was no significant difference between subjects with high and low exposure to air pollution (p < 0.05).