【論文摘要】The Association of Long-term PM2.5 Absorbance Exposure with Carotid-intima-media Thickness in Young Taiwanese

Abstract

Background/Synopsis: The contribution of long-term air pollution exposures to subclinical atherosclerosis in young age has not been fully studied. Objectives/Purpose: This study is to evaluate to assess the associations of carotid intima-media thickness (CIMT) values in adolescents or young adults with one-year exposures to different sizes of particulate matter (PM) and traffic-related exhausts. Methods/Results: We recruited 789 school age subjects who resided in Taipei City and participated in the YOung TAiwanese (YOTA) Cohort between 1992 and 2000. Of all study subjects, 303 subjects were elevated blood pressures (EBP) and 486 subjects had normal BP (NBP) in the childhood. The CIMT values at different segments were measured at the age of 12-30 in the follow-up health examination from 2006 to 2008. Land-use regression models were used to estimate participants' one-year exposures to particulate matter (PM) of different sizes and traffic-related exhausts, including PM2.5 absorbance, nitrogen oxides, and nitrogen dioxides. Generalized linear regression was applied to assess the associations of CIMT values in adolescents or young adults with one-year exposures to six air pollutants. Our findings indicate one-year exposure to PM2.5 absorbance is associated with increased mean and maximum CIMT at different carotid segments. Specifically, exposure to PM2.5 absorbance among subjects who exhibited elevated childhood blood pressure is associated with an increases in mean CMIT at common carotid artery by 3.94% (95%CI: 0.24, 7.64), carotid bulb by 7.77% (95%CI: 2.95, 12.95), and internal carotid artery by 4.75% (95%CI: 0.67, 8.84). Similar increases in the maximum CIMT values were evident at the aforementioned sites. Moreover, older age, gender and health status (overweight, elevated blood pressure, hyperglycemia and hypercholesterolemia), coupled with high level exposure to PM2.5 absorbance (≥2.18 10-5 m-1; 75th percentile), are particularly at risk for developing increased CIMT. Conclusion: Long-term exposure to PM2.5 absorbance is positively associated with subclinical atherosclerosis in adolescents or young adults. The atherosclerosis developed since early childhood depending on individual cardiovascular risk factors including overweight, hypertension, hyperglycemia, or hypercholesterolemia, and can be modified by PM2.5 absorbance concentration.