title: Traffic-Related Air Pollution, Blood Pressure, and Adaptive Response of Mitochondrial Abundance.
abstract: BACKGROUND
  Exposure to black carbon (BC), a tracer of vehicular-traffic pollution, is associated with increased blood pressure (BP). Identifying biological factors that attenuate BC effects on BP can inform prevention. We evaluated the role of mitochondrial abundance, an adaptive mechanism compensating for cellular-redox imbalance, in the BC-BP relationship.
  
  
  RESULTS
  At ≥ 1 visits among 675 older men from the Normative Aging Study (observations=1252), we assessed daily BP and ambient BC levels from a stationary monitor. To determine blood mitochondrial abundance, we used whole blood to analyze mitochondrial-to-nuclear DNA ratio (mtDNA/nDNA) using quantitative polymerase chain reaction. Every standard deviation increase in the 28-day BC moving average was associated with 1.97 mm Hg (95% confidence interval [CI], 1.23-2.72; P<0.0001) and 3.46 mm Hg (95% CI, 2.06-4.87; P<0.0001) higher diastolic and systolic BP, respectively. Positive BC-BP associations existed throughout all time windows. BC moving averages (5-day to 28-day) were associated with increased mtDNA/nDNA; every standard deviation increase in 28-day BC moving average was associated with 0.12 standard deviation (95% CI, 0.03-0.20; P=0.007) higher mtDNA/nDNA. High mtDNA/nDNA significantly attenuated the BC-systolic BP association throughout all time windows. The estimated effect of 28-day BC moving average on systolic BP was 1.95-fold larger for individuals at the lowest mtDNA/nDNA quartile midpoint (4.68 mm Hg; 95% CI, 3.03-6.33; P<0.0001), in comparison with the top quartile midpoint (2.40 mm Hg; 95% CI, 0.81-3.99; P=0.003).
  
  
  CONCLUSIONS
  In older adults, short-term to moderate-term ambient BC levels were associated with increased BP and blood mitochondrial abundance. Our findings indicate that increased blood mitochondrial abundance is a compensatory response and attenuates the cardiac effects of BC.
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.).
authors.forename: Jia
authors.initials: J
authors.lastname: Zhong
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.).
authors.forename: Akin
authors.initials: A
authors.lastname: Cayir
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.).
authors.forename: Letizia
authors.initials: L
authors.lastname: Trevisi
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.).
authors.forename: Marco
authors.initials: M
authors.lastname: Sanchez-Guerra
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.).
authors.forename: Xinyi
authors.initials: X
authors.lastname: Lin
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.).
authors.forename: Cheng
authors.initials: C
authors.lastname: Peng
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.).
authors.forename: Marie-Abèle
authors.initials: MA
authors.lastname: Bind
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.).
authors.forename: Diddier
authors.initials: D
authors.lastname: Prada
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.).
authors.forename: Hannah
authors.initials: H
authors.lastname: Laue
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.).
authors.forename: Kasey J M
authors.initials: KJ
authors.lastname: Brennan
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.).
authors.forename: Alexandra
authors.initials: A
authors.lastname: Dereix
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.).
authors.forename: David
authors.initials: D
authors.lastname: Sparrow
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.).
authors.forename: Pantel
authors.initials: P
authors.lastname: Vokonas
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.).
authors.forename: Joel
authors.initials: J
authors.lastname: Schwartz
authors.affiliation: From Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (J.Z., A.C., L.T., M.S.-G., C.P., M.-A.B., D.P., H.L., K.J.M.B., A.D., J.S., A.A.B.); Vocational Health College, Canakkale Onsekiz Mart University, Çanakkale, Turkey (A.C.); Singapore Institute for Clinical Sciences, Singapore (X.L.); Department of Statistics, Harvard University, Cambridge, MA (M.-A.B.); Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología, Mexico City, Mexico (D.P.); and VA Normative Aging Study, Veterans Affairs Boston Healthcare System and the Department of Medicine, Boston University School of Medicine, MA (D.S., P.V.). abaccare@hsph.harvard.edu.
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Baccarelli
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000009:adverse effects; D000397:Air Pollution / Q000009:adverse effects*; D001794:Blood Pressure / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000175:diagnosis / Q000209:etiology; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000378:metabolism*; D052638:Particulate Matter / Q000009:adverse effects; D011446:Prospective Studies; D053260:Soot / Q000009:adverse effects*; D001335:Vehicle Emissions
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D053260:Soot; D001335:Vehicle Emissions
keywords: air pollution; blood pressure; mitochondria; oxidative stress