Childhood traffic-related air pollution and adverse changes in subclinical atherosclerosis measures from childhood to adulthood

Abstract

Background Chronic exposure to air pollutants is associated with increased risk of cardiovascular disease (CVD) among adults. However, little is known about how air pollution may affect the development of subclinical atherosclerosis in younger populations. Carotid artery intima-media thickness (CIMT) is a measure of subclinical atherosclerosis that provides insight into early CVD pathogenesis. Methods In a pilot study of 70 participants from the Southern California Children’s Health Study, we investigated CIMT progression from childhood to adulthood. Using carotid artery ultrasound images obtained at age 10 and follow-up images at age 21–22, we examined associations between childhood ambient and traffic-related air pollutants with changes in CIMT over time and attained adult CIMT using linear mixed-effects models adjusted for potential confounders. Average residential childhood exposures (i.e., birth to time of measurement at 10–11 years) were assigned for regional, ambient pollutants (ozone, nitrogen dioxide, particulate matter, interpolated from regulatory air monitoring data) and traffic-related nitrogen oxides (NOx) by road class (modeled using the CALINE4 line source dispersion model). Traffic density was calculated within a 300-m residential buffer. Results For each 1 standard deviation (SD) increase in childhood traffic-related total NOx exposure, we observed greater yearly rate of change in CIMT from childhood to adulthood (β: 2.17 μm/yr, 95% CI: 0.78–3.56). Increases in annual rate of CIMT change from childhood to adulthood also were observed with freeway NOx exposure (β: 2.24 μm/yr, 95% CI: 0.84–3.63) and traffic density (β: 2.11 μm/yr, 95% CI: 0.79–3.43). Traffic exposures were also related to increases in attained CIMT in early adulthood. No associations of CIMT change or attained level were observed with ambient pollutants. Conclusions Overall, we observed adverse changes in CIMT over time in relation to childhood traffic-related NOx exposure and traffic density in our study population. While these results must be cautiously interpreted given the limited sample size, the observed associations of traffic measures with CIMT suggest a need for future studies to more fully explore this relationship.

Exposure to particulate matter: a brief review with a focus on cardiovascular effects, children, and research conducted in Turkey

“…Besides blood pressure, one prospective pilot study ( 83 ) with 70 children aged 6–18 investigated their carotid artery intima-media thickness (CIMT; a measure of carotid plaque build-up and atherosclerosis) progression and established its association with traffic-related exposure to NO x but not PM and O 3 .…”

Long-term air pollution exposure and markers of cardiometabolic health in the National Longitudinal Study of Adolescent to Adult Health (Add Health) Study

“…For example, a 2021 study of children in Los Angeles, CA, observed that children with higher exposure to traffic-related air pollution had greater annual change in carotid artery intima-media thickness, a measure indicative of subclinical atherosclerosis. 21 Jerrett et al examined traffic pollution around children's residences and observed that higher levels of traffic-related air pollution were associated with higher body mass index (BMI) in children 10-18 years, particularly in females. 22 Li et al studied adults aged 18 to 29 and found that high concentrations of some air pollutants were associated with impairments in highdensity lipoprotein (HDL) functionality, 23 and McGuinn et al found that long-term PM2.5 exposure was associated with lipoprotein increases in adults.…”

Associations of Time-Weighted Individual Exposure to Ambient Particulate Matter with Carotid Atherosclerosis in Beijing, China

“…Long-term exposure to PM was demonstrated as an important risk factor for CIMT in both cross-sectional and longitudinal studies among late midlife women [14] or women transitioning through menopause [15], adolescents or young adults [16], children [17], general population [18,19] and even HIV-positive adolescents [20]. But such association was not found in some other studies for either PM 2.5 [21,22] or PM 10 [16]. PM exposure was associated with the prevalence and progression of carotid plaque, but not with those of CIMT [23].…”