Traffic-Related Air Pollution and Self-Reported Hypertension among Hispanics of Mexican Origin: Moderation by Neighborhood-Level Stressors
The incidence of hypertension, a major risk factor for cardiovascular diseases, has been growing in the U.S., especially among Hispanic populations. Studies have shown an association between traffic-related air pollution (TRAP) and hypertension, and there is growing interest in the potential role that psychosocial stressors play in the association. We investigated the hypothesis that greater exposure to TRAP, as indicated by NO2 exposure and distance to nearest major roadway, increases the risk of hypertension in Hispanics of Mexican origin, while also exploring the potential modifying effects of neighborhood-level stressors on the associations. We used baseline data from a cohort study of Mexican Americans in Houston, Texas, along with data on individual- and neighborhood-level psychosocial factors. To estimate TRAP, we obtained data from air monitoring sites in the Houston-Galveston-Brazoria region and performed inverse distance weighting to calculate individual exposures to nitrogen dioxide (NO2 ) for the year preceding enrollment into the cohort. We also utilized roadway data from the U.S. Census Bureau and geocoded residential locations to measure residential distances to nearest major roadway. Logistic regression models were used to examine relationships between TRAP exposure and hypertension and stratified analyses were conducted to examine potential interacting effects of selected neighborhood-level stressors. Results were largely null for the associations between NO2 exposure and hypertension; adjusted prevalence odds ratios (PORs) and 95% confidence intervals (CIs) were 0.92 (0.71-1.21), 1.04 (0.80-1.36), and 0.85 (0.64-1.13) for the 2nd, 3rd, and 4th quartiles of NO2 exposure, respectively, as compared to the 1st quartile. Increased odds of hypertension were observed for those who lived <150 meters>(POR=1.02; 95% CI [0.63-1.62]), 150-<300 meters>(POR=1.09; 95% CI [0.76-1.56]), or 300-<1000 meters away from a major roadway>(POR=1.10; 95% CI [0.89-1.34]), compared to those who lived ≥1000 meters away. All results were statistically insignificant. Stratified analyses by neighborhood-level stressors yielded inconclusive results. In stratified analyses, the highest level of stress about safety in the home or neighborhood and unknown people in the neighborhood generated the highest PORs across all NO2 quartiles. The highest level of stress about unknown people in the neighborhood generated the highest PORs across all distance categories. This study generated mixed results regarding the association of TRAP with hypertension in a Mexican American population, consistent with several studies from the literature. While results from stratified analyses were inconclusive, they suggest that stressors related to perceptions of safety in the neighborhood may be of interest as potential effect modifiers and warrant future investigation. Future studies may use more robust methods to expand upon this work and further examine the impact of TRAP on hypertension in vulnerable study populations.
Environmental Health|Public health|Hispanic American studies|Epidemiology
Chee, Allyson, "Traffic-Related Air Pollution and Self-Reported Hypertension among Hispanics of Mexican Origin: Moderation by Neighborhood-Level Stressors" (2017). Texas Medical Center Dissertations (via ProQuest). AAI10687631.