| Summary: | COPD is associated with chronic systemic inflammation that has been linked to an increased risk of atherosclerosis, ischemic heart disease, and stroke. Endothelial dysfunction, vascular remodeling and arterial stiffness are early processes in the pathogenesis of atherosclerosis and are predictive of future cardiovascular events. Aerobic exercise training can reduce the risk of cardiovascular disease in patients with other chronic conditions. However, little is known about the benefits of exercise for improving vascular health in patients with COPD. Ten non-smoking patients with COPD (mean age=69±9yr, FEV1%pred=67± 3%) and six healthy controls matched for age, sex, BMI and activity level underwent pulmonary function and cardiopulmonary exercise testing. Endothelial function was assessed by flow-mediated dilation (FMD) in response to reactive hyperemia in the brachial artery, and carotid artery intima-medial thickness (IMT) was measured by ultrasound. Central and peripheral pulse wave velocity (PWV), carotid compliance and beta stiffness index were determined by applanation tonometry and ultrasound. A venous blood sample was collected to measure systemic inflammation. Following completion of baseline testing, aerobic exercise was performed on lower and upper extremity cycle ergometers, 3x/week for 8 weeks. All baseline measurements were repeated upon completion of the exercise training. An improvement in peak O2-consumption (VO₂peak, 18.0±4.6 to 19.8±3.6 ml/kg/min, p<0.01) and peripheral PWV (7.6±2.5 to 6.8±1.8 m/sec, p=0.03) occurred with training in patients with COPD. However, there was no significant change in measures of FMD, central arterial stiffness, carotid IMT or biomarkers of systemic inflammation, (p>0.05). There was also an improvement in VO₂peak (19.8±2.6 to 26.0±4.1 ml/kg/min, p=0.03) in controls, with no other significant changes following training. This pilot study demonstrated that 8-weeks of aerobic training improved peak aerobic power and peripheral arterial stiffness but had little effect on other established markers of cardiovascular disease risk in patients with COPD. These findings suggest that a typical 8-week pulmonary rehabilitation program may not be long enough to greatly improve vascular function or structure or reduce the systemic inflammation associated with increased cardiovascular disease risk in patients with COPD. Larger randomized, controlled studies are now needed to confirm these preliminary findings. === Graduate Studies, College of (Okanagan) === Graduate
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