title: Relation of long-term exposure to air pollution to brachial artery flow-mediated dilation and reactive hyperemia.
abstract: Long-term exposure to ambient air pollution has been associated with cardiovascular morbidity and mortality. Impaired vascular responses may, in part, explain these findings, but the association of such long-term exposure with measures of both conduit artery and microvascular function has not been widely reported. We evaluated the association between residential proximity to a major roadway (primary or secondary highway) and spatially resolved average fine particulate matter (PM2.5) and baseline brachial artery diameter and mean flow velocity, flow-mediated dilation%, and hyperemic flow velocity, in the Framingham Offspring and Third Generation Cohorts. We examined 5,112 participants (2,731 [53%] women, mean age 49 ± 14 years). Spatially resolved average PM2.5 was associated with lower flow-mediated dilation% and hyperemic flow velocity. An interquartile range difference in PM2.5 (1.99 μg/m(3)) was associated with -0.16% (95% confidence interval [CI] -0.27%, -0.05%) lower flow-mediated dilation% and -0.72 (95% CI -1.38, -0.06) cm/s lower hyperemic flow velocity%. Residential proximity to a major roadway was negatively associated with flow-mediated dilation%. Compared with living ≥400 m away, living <50 m from a major roadway was associated with 0.32% lower flow-mediated dilation (95% CI -0.58%, -0.06%), but results for hyperemic flow velocity had wide confidence intervals -0.68 cm/s (95% CI -2.29, 0.93). In conclusion, residential proximity to a major roadway and higher levels of spatially resolved estimates of PM2.5 at participant residences are associated with impaired conduit artery and microvascular function in this large community-based cohort of middle-aged and elderly adults.
authors.affiliation: Cardiovascular Epidemiology Research Unit, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts. Electronic address: ewilker@bidmc.harvard.edu.
authors.forename: Elissa H
authors.initials: EH
authors.lastname: Wilker
authors.affiliation: Cardiovascular Epidemiology Research Unit, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden.
authors.forename: Petter L
authors.initials: PL
authors.lastname: Ljungman
authors.affiliation: Cardiovascular Epidemiology Research Unit, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Pulmonary and Critical Care Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Mary B
authors.initials: MB
authors.lastname: Rice
authors.affiliation: Department of Geography and Environmental Development, Ben-Gurion University of the Negev, Beer Sheva, Israel.
authors.forename: Itai
authors.initials: I
authors.lastname: Kloog
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts.
authors.forename: Joel
authors.initials: J
authors.lastname: Schwartz
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts.
authors.forename: Diane R
authors.initials: DR
authors.lastname: Gold
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts.
authors.forename: Petros
authors.initials: P
authors.lastname: Koutrakis
authors.affiliation: NHLBI and Boston University's Framingham Heart Study, Framingham, Massachusetts; Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Vita
authors.affiliation: Cardiovascular Engineering Inc., Norwood, Massachusetts.
authors.forename: Gary F
authors.initials: GF
authors.lastname: Mitchell
authors.affiliation: NHLBI and Boston University's Framingham Heart Study, Framingham, Massachusetts; Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts; Sections of Preventive Medicine and Epidemiology and Cardiology, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Ramachandran S
authors.initials: RS
authors.lastname: Vasan
authors.affiliation: NHLBI and Boston University's Framingham Heart Study, Framingham, Massachusetts; Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Emelia J
authors.initials: EJ
authors.lastname: Benjamin
authors.affiliation: NHLBI and Boston University's Framingham Heart Study, Framingham, Massachusetts; Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Naomi M
authors.initials: NM
authors.lastname: Hamburg
authors.affiliation: Cardiovascular Epidemiology Research Unit, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts.
authors.forename: Murray A
authors.initials: MA
authors.lastname: Mittleman
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D001916:Brachial Artery / Q000503:physiopathology*; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000503:physiopathology; D015331:Cohort Studies; D016001:Confidence Intervals; D004108:Dilatation, Pathologic / Q000139:chemically induced* / Q000503:physiopathology; D004777:Environment; D005260:Female; D006801:Humans; D006940:Hyperemia / Q000139:chemically induced* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D052638:Particulate Matter / Q000009:adverse effects; D011237:Predictive Value of Tests; D018570:Risk Assessment; D013997:Time Factors
chemical_list: D052638:Particulate Matter