The TROY (Testing Responses on Youth) cohort was established in 2007 to assess the association between lifetime exposure to outdoor air pollution (including particulate matter, nitrogen dioxide, and ozone) and cardiovascular disease progression, as measured by thickening of the carotid arterial wall (carotid intimamedia thickness, CIMT), several histological inflammatory markers (blood lipids, reactive proteins, and homocysteine levels), arterial stiffness, and other biochemical indicators of disease progression. Additional health endpoints measured include body mass index, systolic and diastolic blood pressure, health status (via self-administered questionnaire and personal interview), and lung function. The population is 860 nonsmoking USC college students since measured on one occasion. Through an ARRA supplement, approximately 350 participants will have a second measurement of CIMT taken a year or more after the first CIMT measurement.
TROY Participant Residential Locations.
The study aims to:
(1) assess carotid artery intima-media thickness (CIMT), lung function, lifetime residential history, time-activity patterns, C-reactive protein (CRP), lipids, diet, and other relevant cardio-respiratory covariates among 800 eligible non-smoking college students;
(2) geo-code all lifetime residential addresses and to assign estimates of monthly ambient concentrations of fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) to each residence;
(3) estimate the “exposure effective time” spent in these concentrations using individual and population based data of indoor and outdoor time-activity patterns, and to calculate time-weighted concentrations of PM2.5, NO2, and O3 for each subject’s lifetime;
(4) investigate the association between long-term exposure and CIMT and the modification of this association by lung function, C-reactive proteins, and low-density lipoproteins (LDL) through multilevel spatial regression and latent variable models.