title: Association Between Particulate Air Pollution and QT Interval Duration in an Elderly Cohort.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: 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.
authors.forename: Irina
authors.initials: I
authors.lastname: Mordukhovich
authors.forename: Itai
authors.initials: I
authors.lastname: Kloog
authors.forename: Brent
authors.initials: B
authors.lastname: Coull
authors.forename: Petros
authors.initials: P
authors.lastname: Koutrakis
authors.forename: Pantel
authors.initials: P
authors.lastname: Vokonas
authors.forename: Joel
authors.initials: J
authors.lastname: Schwartz
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000368:Aged; D000369:Aged, 80 and over; D000397:Air Pollution / Q000706:statistics & numerical data*; D001145:Arrhythmias, Cardiac / Q000453:epidemiology*; D053840:Brugada Syndrome / Q000453:epidemiology*; D000075224:Cardiac Conduction System Disease; D002374:Catalase / Q000235:genetics; D015331:Cohort Studies; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D005721:Glutamate-Cysteine Ligase / Q000235:genetics; D051547:Heme Oxygenase-1 / Q000235:genetics; D006801:Humans; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000235:genetics; D018384:Oxidative Stress; D052638:Particulate Matter; D012307:Risk Factors; D013696:Temperature; D013997:Time Factors
chemical_list: D052638:Particulate Matter; D000080242:8-Hydroxy-2'-Deoxyguanosine; D002374:Catalase; C496541:HMOX1 protein, human; D051547:Heme Oxygenase-1; D016660:NAD(P)H Dehydrogenase (Quinone); C447479:NQO1 protein, human; C546365:GCLM protein, human; D005721:Glutamate-Cysteine Ligase; D003849:Deoxyguanosine