Could Regular Exercise Prevent Smoking-Induced Arterial Stiffening in
Hispanics?

Hirofumi Tanaka, University of Texas Department of Kinesiology and Health Education
Shirley Laffrey, University of Texas School of Nursing
Nell Gottrieb, University of Texas Department of Kinesiology and Health Education

Purpose: For most smokers, the single most important strategy for improving their cardiovascular health is learly and should be smoking cessation. However, sustained smoking cessation is very difficult to achieve due primarily to the addictive nature of nicotine. It has been recently recognized that ethnic minorities, including Hispanics, have less success in quitting smoking despite the fact that they are already at greater risk of developing CVD. Additionally, the adverse effects of smoking are even greater in minorities compared with Caucasians. As such, interventions targeted for reducing the risk of smoking-induced CVD, while ever increasing Hispanic smokers attempt to quit smoking, are critically needed. Emerging evidence indicates that smoking may exert its effects by decreasing the compliance of central arteries. In this context, regular exercise is emerging as an effective lifestyle modification for improving arterial compliance based primarily on the data obtained in healthy older adults. However, there is no information is available if regular exercise is associated with the prevention/attenuation of smoking-induced arterial stiffening.

Research Aims: The general hypotheses of the proposed project are that 1) endurance-trained smokers do not demonstrate a decrease in arterial compliance observed in sedentary smokers, 2) a lack of reduction in arterial compliance in endurance-trained smokers is accompanied by a corresponding functional benefit, and 3) these favorable adaptations are mediated by a decrease in sympathetic tone.

Methods: A total of 36 otherwise healthy sedentary and endurance-trained Hispanic smokers and non-smokers will be studied. Static and dynamic arterial compliance will be determined with a simultaneous application of high-resolution ultrasonography and carotid applanation tonometry. Additionally, arterial baroreflex sensitivity, muscle sympathetic nerve activity, vasoactive hormones, vascular endothelium-dependent vasodilation, arterial stiffness (pulse wave velocity and augmentation index) will be measured.