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Research Article

Fine Particulate Air Pollution and the Progression of Carotid Intima-Medial Thickness: A Prospective Cohort Study from the Multi-Ethnic Study of Atherosclerosis and Air Pollution

  • Sara D. Adar mail,

    sadar@umich.edu

    Affiliations: Department of Epidemiology, University of Michigan, Ann Arbor, Michigan, United States of America, Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America

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  • Lianne Sheppard,

    Affiliations: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America, Department of Biostatistics, University of Washington, Seattle, Washington, United States of America

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  • Sverre Vedal,

    Affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America

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  • Joseph F. Polak,

    Affiliation: Department of Radiology, Tufts Medical Center, Boston, Massachusetts, United States of America

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  • Paul D. Sampson,

    Affiliation: Department of Statistics, University of Washington, Seattle, Washington, United States of America

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  • Ana V. Diez Roux,

    Affiliation: Department of Epidemiology, University of Michigan, Ann Arbor, Michigan, United States of America

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  • Matthew Budoff,

    Affiliations: Los Angeles Biomedical Research Institute, Los Angeles, California, United States of America, Division of Cardiology, University of California Los Angeles, Los Angeles, California, United States of America

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  • David R. Jacobs Jr,

    Affiliation: Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, Minnesota, United States of America

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  • R. Graham Barr,

    Affiliation: Departments of Medicine and Epidemiology, Columbia University Medical Center, New York, New York, United States of America

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  • Karol Watson,

    Affiliation: Division of Cardiology, University of California Los Angeles, Los Angeles, California, United States of America

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  • Joel D. Kaufman

    Affiliations: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America, Departments of Epidemiology and Medicine, University of Washington, Seattle, Washington, United States of America

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  • Published: April 23, 2013
  • DOI: 10.1371/journal.pmed.1001430
  • Featured in PLOS Collections

Reader Comments (2)

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Air Pollution and Other Causes of Increased Testosterone Result in Increased Carotid Intima-Media Thickness and Cardiovascular Disese

Posted by jamesmhoward on 26 Apr 2013 at 12:43 GMT

I suggest the findings of Adar, et al., may be explained by low testosterone initially caused by increased testosterone.

It is known that low testosterone is connected to atherosclerosis / increased carotid intima-media thickness (Endocr J. 2012 Sep 30;59(9):809-15). Adar, et al., cite the connection of “age, sex, race/ethnicity, smoking, and socio-economic indicators” as cofounders of increased CIMT. A case may be made for increased testosterone, followed by decreased testosterone, in each of these cofounders of increased CIMT.

Air pollution has been found to increase testosterone in rats (Inhal Toxicol. 2009 Aug;21(10):803-11).
I suggest that “age, sex, race/ethnicity, smoking, and socio-economic indicators,” as well as air pollution all increase testosterone. These increases in testosterone all result in an earlier decline of testosterone in adulthood. Therefore, all of these, including air pollution, cause an earlier onset of atherosclerosis / increased carotid intima-media thickness with ageing because of earlier loss of testosterone.

It is my hypothesis that the “secular trend,” the increase in size and earlier puberty in children is caused by increasing testosterone within the population. This results in an early decrease in testosterone. Therefore, we are witnessing the negative consequences of increased and decreased testosterone. The early decline in testosterone, however, is generating much more pathology.

No competing interests declared.

RE: Air Pollution and Other Causes of Increased Testosterone Result in Increased Carotid Intima-Media Thickness and Cardiovascular Disese

sadar replied to jamesmhoward on 14 Aug 2013 at 22:38 GMT

Thank you for your feedback on our manuscript. In your comment, you suggest that the observed associations between air pollution and the progression of atherosclerosis may be attributable to testosterone.

To address your concern, we conducted a sensitivity analysis in which we controlled for hormone levels, including testosterone, collected at the MESA baseline examination. These analyses indicated qualitatively robust findings with slightly stronger associations for air pollution after control for these hormones. This suggests that lower levels of testosterone in this older adult population are not likely to explain our observed findings.

No competing interests declared.