564 Longitudinal Study of Arterial Stiffness and Vessel Hemodynamics Post- Exercise in Young, Healthy Smokers and Non-Smokers

Abstract

BACKGROUND: Long-standing smokers have stiffer arteries at rest, and arterial stiffness remains unchanged in healthy populations in yearly follow-ups. However, the longitudinal effect of smoking on the ability of the vascular system to respond to increased demands (e.g. exercise) has not been investigated. This study aims to estimate the longitudinal effect of chronic smoking on arterial stiffness and subendocardial viability ratio (SEVR) in young healthy smokers. METHODS: Upon study entry (baseline), healthy moderate smokers (n 34) and non-smokers (n 62) underwent measurements of carotid-femoral pulse wave velocity (cfPWV) and SEVR. The measurements were performed at rest, and at 2, 5, 10, 15, and 20 minutes following an exercise test to volitional exhaustion (Bruce treadmill protocol). The tests were repeated at a 6-month follow-up in smokers and nonsmokers. Magnitude of differences in cfPWV and SEVR between 6-month follow-up and baseline assessments were compared between smokers and non-smokers. RESULTS: To date, 7 smokers and 27 non-smokers have completed both the baseline and 6 month follow-up assessments. Smokers demonstrated an overall significantly greater change than non-smokers in cfPWV between baseline and 6-month follow-up (6 month follow-up Baseline) at 5 minutes (P 0.041), 15 minutes (P 0.031) and 20 minutes (P 0.031) post-exercise (Table. 1). Similarly (6moFU BL), smokers displayed significantly greater net increase in SEVR compared to non-smokers at 5 minutes (P 0.021), 15 minutes (P 0.019) and 20 minutes (P 0.015) post-exercise. Of note, smokers ran for a shorter duration than the non-smokers at both baseline and 6-month follow-up assessment (13.9 2.4 and 15.2 3.4, vs. 15.1 1.7 and 17.2 2.5 minutes). There were no group differences in net change of resting (pre-exercise) measurements at baseline to 6-month follow-up between smokers and non-smokers.