The patients’ heart-rate recovery was defined as the difference between heart rate at the peak of exercise and one and two minutes post-exercise. The women with SLE had significantly lower heart-rate recovery after exercise at both intervals. Dr. Prado and her colleagues concluded that the “SLE patients present an abnormal heart rate response to exercise, namely chronotropic incompetence and a delayed heart-rate recovery.”
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Explore This IssueFebruary 2011
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Exercise as a Protectant
Fortunately, SLE patients might be able to reduce their risk of cardiovascular disease (CVD) through exercise. Edgard T. Reis Neto, MD, of the rheumatology division of the Federal University of São Paulo, Brazil, noted that improvements in SLE treatment in the past 20 years have led to increased patient survival. As a result, cardiovascular disease has become a larger cause of morbidity and mortality for SLE patients. Endothelial dysfunction has been implicated in the pathogenesis of CVD, and SLE patients have been shown to have endothelial function impairment, even in the absence of other cardiovascular risk factors. But physical exercise can act as an endothelial protectant by increasing blood flow, which reduces platelet activation and coagulation, and increases nitric oxide bioavailability.
Dr. Reis Neto sought to study the effect of supervised physical exercise on endothelial function as well as quality of life, fatigue, exercise tolerance, and body composition in SLE patients. The study group exercised for one hour three times a week for 16 weeks, including 40 minutes of walking at a heart rate at the ventilatory anaerobic threshold. Endothelial function was assessed through an ultrasound of the brachial artery.
The results were encouraging, Dr. Reis Neto said. Flow-mediated dilation, a measure of endothelial function, increased significantly in the exercise group. The exercise group also exhibited significant increases in exercise tolerance, functional capacity (a quality-of-life measure), and vitality.
Researchers had found challenges with recruitment, however. Although more than 400 patients were invited to participate and nearly 200 manifested interest, 109 were excluded (mostly due to candidates being over 45 years of age, taking statins, in menopause, or suffering from kidney failure) and 53 dropped out for personal reasons. Ultimately, only 21 were included in the study and 19 completed evaluations (12 in the exercise group and seven in the control group).
Although this study was small and not randomized, Dr. Reis Neto said, it was the first to demonstrate that supervised physical exercise can improve endothelial function in SLE patients. It suggests that exercise can help to prevent cardiovascular morbidity and mortality in these patients.