Effects of acute and chronic exercise on cardiovascular responses in female smokers

Abstract

Among women, smoking is the leading cause of preventable death and disease. Endothelial dysfunction, measured by flow mediated dilation (FMD) and hyper-reactivity to neurovascular challenges are two potential mechanisms by which this may occur. It has been suggested that acute and chronic exercise may improve endothelial function and attenuate cardiovascular reactivity to neurovascular stressors. This research was conducted to determine the effect of acute (Study 1) and chronic (Study 2) moderate-intensity cycling exercise on FMD and cardiovascular responses to two neurovascular stressors (Stroop Color-Word conflict test (CWT) and forehead cold) among sedentary female smokers and non-smokers. FMD was determined by brachial arterial diameter, arterial velocity and blood flow measured by Doppler Ultrasonography; beat-to-beat finger blood pressure (BP), heart rate (HR), arterial velocity, arterial diameter, and blood flow were assessed in responses to forehead cold and the Stroop CWT. Acute exercise (Study 1) increased FMD, baseline HR, arterial velocity and blood flow; and reduced baseline systolic and diastolic BP, HR, arterial velocity, and blood flow in both groups. In addition, acute exercise decreased arterial velocity and blood flow responses during the Stroop CWT and forehead cold in both groups. In study 2, FMD was impaired and decreases in arterial diameter and blood flow during forehead cold were augmented at baseline among female smokers compared to non-smokers. Three weeks of cycle exercise training at a moderate intensity did not improve endothelial function measured by FMD or alter stress reactivity during neurovascular stress in smokers or non-smokers. Overall, acute moderate intensity exercise improves endothelial function and alters some aspects of stress reactivity, but these effects do not extend to 3-weeks of short-term exercise training.