Abstract 13344: Higher Ambient Fine Particulate Matter Air Pollution and Temperature Levels Adversely Impact Cardiopulmonary Exercise Performance Among Patients Beginning Cardiac Rehabilitation

Abstract

Introduction: Fine particulate matter (PM 2.5 ) air pollution increases the risk for acute cardiovascular (CV) events. Extreme levels of ambient temperature (T) have also been linked to heightened CV risk. While several mechanisms have been proposed, no large-scale study has assessed the effect of PM 2.5 and T on directly-measured aerobic functional capacity among high-risk patients. Methods: We evaluated the effects of ambient PM 2.5 and T levels (during the prior 1 to 7 days at a local monitoring station) on cardiopulmonary exercise testing results performed among 2078 patients during enrollment into a cardiac rehabilitation program at the University of Michigan (from January 2003 to August 2011) using multiple linear regression analyses (controlling for age, sex, body mass index). Results: Peak exercise oxygen consumption (VO 2peak ) was significantly decreased by approximately 14.9% per 10 μg/m 3 increase in ambient PM 2.5 levels (lag days 6-7) (Figure). Increases in PM 2.5 were also related to significant decreases in anaerobic threshold (AT) (lag days 5-7), peak heart rate (lag days 2-3) and increases in peak systolic blood pressure (lag days 4-5). A 10°C increase in T was associated with reductions in VO 2peak (20.6% to 27.3%) (Figure) and AT (22.9% to 29.2%) during all 7 lag days. While PM 2.5 results were attenuated by adjusting for T due to co-linearity, the effects of ambient T remained significant after adjusting for same-day PM 2,5 and accounting for season. Conclusions: Short-term elevations in ambient PM 2.5 and/or T were associated with detrimental effects upon several aerobic exercise parameters among this cohort of cardiac rehabilitation patients. Both environmental factors may thus be important public health risk factors for an impaired exercise performance linked to an adverse quality of life and worse CV prognosis.