Short-term fine particulate matter (PM2.5) exposure has been linked with increased QT interval duration, a marker of ventricular repolarization and a risk factor for cardiac arrhythmia and sudden death, in several studies. Only one previous study evaluated whether long-term PM exposure is related to the QT interval. We aim to evaluate whether subchronic and long-term exposure to PM2.5 at home is linked with QT duration in an elderly cohort.
We measured heart-rate corrected QT interval duration among 404 participants from the Greater Boston area between 2003 and 2011. We modeled residential PM2.5 exposures using a hybrid satellite- and land use-based model. We evaluated associations between moving averages of short-term (1–2 days), subchronic (3–28 days), and long-term (1 year) pollutant exposures and corrected QT duration using linear mixed models. We also evaluated effect modification by oxidative stress genetic score using separated regression models and interaction terms.
We observed positive associations between subchronic and long-term PM2.5 exposure and corrected QT duration, with the strongest results for longer-term exposures. For example, a one standard deviation increase in 1-year PM2.5 was associated with a 6.3 ms increase in corrected QT (95% confidence interval: 1.8, 11). We observed somewhat greater effects among subjects with higher (8.5 ms) rather than lower (3.1 ms) oxidative stress allelic profiles (P interaction = 0.25).
PM2.5 was associated with increased corrected QT duration in an elderly cohort. While most previous studies focused on short-term air pollution exposures, our results suggest that longer-term exposures are associated with cardiac repolarization.
Supplemental Digital Content is available in the text.
From the aExposure, Epidemiology, and Risk Program, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA; bDepartment of Geography and Environmental Development, Ben-Gurion University of the Negev, Beer Sheva, Israel; cDepartment of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA; dVA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, Boston, MA; and eChanning Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA.
Submitted 1 March 2015; accepted 23 November 2015.
Supported by the US Environmental Protection Agency Grants R832416 and RD 83479801 and by the National Institute of Environmental Health Sciences Grants ES015172-01 and ES000002. The VA Normative Aging Study is supported by the Cooperative Studies Program/Epidemiology Research and Information Center of the US Department of Veterans Affairs and is a component of the Massachusetts Veterans Epidemiology Research and Information Center, Boston, MA.
The authors report no conflicts of interest.
Supplemental digital content is available through direct URL citations in the HTML and PDF versions of this article (www.epidem.com).
Correspondence: Irina Mordukhovich, Exposure, Epidemiology and Risk Program, Department of Environmental Health, Harvard T.H. Chan School of Public Health. Landmark Center, 401 Park Dr., Boston, MA 02215. E-mail: firstname.lastname@example.org.