The Impact of Pulmonary and Peripheral Vascular Change from Particulate Matter Inhalation on Exercise Performance

Abstract

Particulate matter (PM) inhalation has been associated with increased morbidity and mortality among susceptible populations, however, only recently has athletic performance among healthy subjects been investigated. PM inhalation has been shown to result in vasoconstriction of both the pulmonary and peripheral vasculature, yet no present study has investigated the effects of PM inhalation on both performance and the vasculature. PURPOSE: Examine the effect of PM inhalation on exercise performance, pulmonary arterial pressure (PAP), and flow-mediated vasodilation (FMD). METHODS: Sixteen volunteer participants were randomly assigned to two consecutive workouts (separated by 24 hr) in either high PM (HPM) (number count = 343,000 particles·cm3 ± 215,443; geometric mn = 26.6 nm ±7.44) or low PM (LPM) (number count = 2,170 particles·cm3 ± 2,066 conditions; geometric mn = 25.4 nm ± 6.61). HPM conditions were created through freshly generated PM from a 4-cycle gasoline engine. Following a seven day washout period, subjects returned to complete a second set of exercise bouts in a different condition. The participants' PAP and FMD were assessed before and after each exercise bout. RESULTS: Total work accumulated in HPM conditions decreased by 2.87% compared to LPM conditions (108.0 kJ ± 14.8 (LPM), 104.9 kJ ± 15.2 (HPM), p = 0.019). PAP was significantly increased (18.0 mmHg ± 1.39 pre, 18.8 mmHg ± 1.28 post, p = 0.043) after a single bout of exercise in HPM conditions among participants with baseline PAP exceeding 16.00 mmHg, while PAP was significantly greater (17.3 mmHg ± 1.80 pre, 18.9 mmHg ± 1.71 post, p < 0.001) among all participants after the second bout of exercise in HPM compared to the initial baseline measurement taken approximately 24 hr prior. FMD taken after the second bout of exercise in HPM was significantly decreased (9.37% ± 3.43 pre, 4.79% ± 3.01 post, p = 0.023) compared to the initial baseline. CONCLUSION: Exercise performance declined in HPM conditions. This appears to be due in part to impaired vasodilation in the pulmonary and peripheral vasculature which was most evident 24 hr. after exposure. It also appears that those with increased baseline PAP's are more susceptible to the effects of HPM inhalation.