Particulate air pollution and risk of ST-segment depression during repeated submaximal exercise tests among subjects with coronary heart disease: the Exposure and Risk Assessment for Fine and Ultrafine Particles in Ambient Air (ULTRA) study

Circulation. 2002 Aug 20;106(8):933-8. doi: 10.1161/01.cir.0000027561.41736.3c.

Abstract

Background: Daily variations in ambient particulate air pollution have been associated with cardiovascular mortality and morbidity. We therefore assessed the associations between levels of the 3 main modes of urban aerosol distribution and the occurrence of ST-segment depressions during repeated exercise tests.

Methods and results: Repeated biweekly submaximal exercise tests were performed during 6 months among adult subjects with stable coronary heart disease in Helsinki, Finland. Seventy-two exercise-induced ST-segment depressions >0.1 mV occurred during 342 exercise tests among 45 subjects. Simultaneously, particle mass <2.5 microm (PM2.5) and the number concentrations of ultrafine particles (particle diameter 10 to 100 nm [NC(0.01-0.1)]) and accumulation mode particles (100 to 1000 nm [NC(0.1-1)]) were monitored at a central site. Levels of particulate air pollution 2 days before the clinic visit were significantly associated with increased risk of ST-segment depression during exercise test. The association was most consistent for measures of particles reflecting accumulation mode particles (odds ratio 3.29; 95% CI, 1.57 to 6.92 for NC(0.1-1) and 2.84; 95% CI, 1.42 to 5.66 for PM2.5), but ultrafine particles also had an effect (odds ratio 3.14; 95% CI, 1.56 to 6.32), which was independent of PM2.5. Also, gaseous pollutants NO2 and CO were associated with an increased risk for ST-segment depressions. No consistent association was observed for coarse particles. The associations tended to be stronger among subjects who did not use beta-blockers.

Conclusions: The present results suggest that the effect of particulate air pollution on cardiovascular morbidity is at least partly mediated through increased susceptibility to myocardial ischemia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Air Pollutants / adverse effects*
  • Air Pollutants / analysis
  • Coronary Disease / diagnosis*
  • Electrocardiography
  • Environmental Exposure
  • Exercise Test
  • Female
  • Finland / epidemiology
  • Humans
  • Humidity
  • Male
  • Myocardial Ischemia / diagnosis
  • Myocardial Ischemia / epidemiology*
  • Myocardial Ischemia / etiology
  • Particle Size
  • Risk Assessment
  • Risk Factors
  • Temperature

Substances

  • Air Pollutants