Acute exposure to diesel exhaust increases muscle sympathetic nerve activity in humans

Gregory D. Rankin, Mikael Kabéle, Rachael Brown, Vaughan G. Macefield, Thomas Sandström, Jenny A. Bosson

Research output: Contribution to journalArticleResearchpeer-review

16 Citations (Scopus)

Abstract

BACKGROUND: Diesel exhaust (DE) emissions are a major contributor to ambient air pollution and are strongly associated with cardiovascular morbidity and mortality. Exposure to traffic-related particulate matter is linked with acute adverse cardiovascular events; however, the mechanisms are not fully understood. We examined the role of the autonomic nervous system during exposure to DE that has previously only been indirectly investigated. METHODS AND RESULTS: Using microneurography, we measured muscle sympathetic nerve activity (MSNA) directly in the peroneal nerve of 16 healthy individuals. MSNA, heart rate, and respiration were recorded while subjects rested breathing filtered air, filtered air with an exposure mask, and standardized diluted DE (300 µg/m3) through the exposure mask. Heart rate variability was assessed from an ECG. DE inhalation rapidly causes an increase in number of MSNA bursts as well as the size of bursts within 10 minutes, peaking by 30 minutes (P<0.001), compared with baseline filtered air with an exposure mask. No significant changes occurred in heart rate variability indices during DE exposure; however, MSNA frequency correlated negatively with total power (r2=0.294, P=0.03) and low frequency (r2=0.258, P=0.045). Heart rate correlated positively with MSNA frequency (r2=0.268, P=0.04) and the change in percentage of larger bursts (burst amplitude, height >50% of the maximum burst) from filtered air with an exposure mask (r2=0.368, P=0.013). CONCLUSIONS: Our study provides direct evidence for the rapid modulation of the autonomic nervous system after exposure to DE, with an increase in MSNA. The quick increase in sympathetic outflow may explain the strong epidemiological data associating traffic-related particulate matter to acute adverse cardiovascular events such as myocardial infarction. REGISTRATION: URL: https://www.clini​caltr​ials.gov; Unique identifier: NCT02892279.

Original languageEnglish
Article numbere018448
Number of pages18
JournalJournal of the American Heart Association
Volume10
Issue number10
DOIs
Publication statusPublished - 18 May 2021
Externally publishedYes

Keywords

  • Air pollution
  • Autonomic nervous system
  • Diesel
  • Heart rate variability
  • Muscle sympathetic nerve activity
  • Sympathoexcitation

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