ATLANTA—Systemic lupus erythematosus (SLE) exacts a major physical and emotional toll on patients. Leading researchers explored this impact in a concurrent abstract session titled “Issues in Lupus” at the 2010 ACR/ARHP Annual Scientific Meeting in Atlanta. [Note: This session was recorded and is available via ACR SessionSelect at www.rheumatology.org.]
Test of Family Functioning
Family functioning likely is influenced greatly by this disabling condition, said Afton L. Hassett, PsyD, associate research scientist in the department of anesthesiology at the University of Michigan Medical School in Ann Arbor. Recent research has found that many patients with SLE have lower levels of social support than healthy controls, leading to lower quality of life and possibly even affecting disease activity.1-4 But the topic is rarely studied.
Dr. Hassett and her team developed a new instrument for assessing family functioning for patients with SLE. They began the project with semistructured interviews of 20 patients. This study resulted in the following main findings:
- Fatigue, even more than pain, affected patients’ ability to spend time with their families;
- Patients shied away from outdoor family activities;
- The disease affected the families’ mental health, as well as that of the patient;
- Many patients felt isolated; and
- Many patients suffered from a loss of sexual and emotional intimacy.
A group of rheumatologists, researchers, and patients brainstormed 16 questions to address each of these issues. In a pilot study, the team narrowed the questions to one item for each issue. (In their research, the team found that many patients defined “family” to include neighbors, friends, and even pets.) To test the instrument, 52 patients with SLE completed the new six-item SLE-FAMILY. For validation purposes, the patients also filled out the Sheehan Disability Scale, Fatigue Severity Scale, Multidimensional Scale of Negative Affect Scale, and the Systemic Lupus Activity Questionnaire.
The SLE-FAMILY had good test–retest reliability and internal consistency. However, reliability analysis of individual items found a weakness of the performance of one. The team revised the item after finding that several patients overlooked the fact that its scoring was reversed from the others. The SLE-FAMILY appears to be a promising new instrument for robust measurement of family functioning, Dr. Hassett concluded.
Fatigue and Body Composition
While fatigue is acknowledged as a major concern in rheumatoid arthritis, less attention has been paid to its role in SLE, noted Patricia Katz, PhD, professor of medicine (rheumatology) and health policy at the University of California, San Francisco (UCSF). Nor is there an abundance of research on the relationship between fatigue and body composition in rheumatic disease. Such obesity-related factors as sleep disorders and muscle weakness could contribute to fatigue in patients with rheumatic disease. Dr. Katz sought to examine the role of body composition and muscular weakness in fatigue among women with SLE.
The team recruited patients from the UCSF Lupus Outcomes Study, an ongoing, longitudinal panel study. Body composition and regional body fat distribution were measured with a lunar prodigy, dual-energy X-ray absorptiometry system (DEXA). This analysis yielded measures of total, as well as regional, body fat and lean mass, each of which was adjusted for height to create a fat mass index (FMI) and a lean mass index (LMI). Lower extremity strength and lower right knee flexion and extension were measured. Fatigue was measured with the severity subscale of the Multidimensional Assessment of Fatigue.
The analysis focused on the 115 women for whom all data were available. Mean total-percent body fat was 41%, and the mean fatigue rating was 5.9 on the fatigue scale. Controlling for age, disease duration, and disease activity, neither total fat mass index nor lean mass index were significantly associated with fatigue severity. However, when appendicular and trunk FMI were examined separately, greater trunk FMI was significantly associated with greater fatigue. Muscle weakness also was significantly and independently associated with greater fatigue. High doses of prednisone were associated both with fatigue and abdominal obesity. Dr. Hassett also noted that fatigue could have other causes not accounted for in the study, such as physical inactivity, sleep problems, or inflammation.
[The study] was the first to demonstrate that supervised physical exercise can improve endothelial function in SLE patients.
Heart-Rate Variability
Premature coronary disease is known to be a major cause of morbidity and mortality in lupus, noted Danilo M.L. Prado, PhD, in the rheumatology division of the University of São Paulo Medical School in Brazil. This is mediated not only by traditional risk factors (e.g., diabetes and hypertension), but also by risk factors associated with the disease itself (e.g., disease activity and drugs). And another risk factor is starting to emerge: Patients with SLE are known to have lower heart-rate variability, suggesting impaired autonomic modulation.
“Attenuated heart-rate response to exercise, also known as chronotropic incompetence, has been shown to be predictive of mortality in heart disease even after adjustment for age, physical fitness, and standard cardiovascular risk factors,” Dr. Prado said. Studies associate low heart-rate recovery with attenuated parasympathetic reactivation and sympathetic overactivity following the termination of exercise.
Dr. Prado hypothesized that SLE patients would present an atypical chronotropic response. Eighteen women with SLE, but without other cardiopulmonary issues, were compared to 17 healthy controls. All subjects performed a progressive treadmill cardiopulmonary test until exhaustion in order to determine their maximal aerobic capacity. The women with SLE had significantly greater resting heart-rate levels, lower peak workload levels, and lower aerobic fitness (as measured by peak VO2) when compared with the controls.
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.”
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.
Richard Sine is a medical journalist based in Atlanta.
References
- Archenholtz B, Burckhardt CS, Segesten K. Quality of life of women with systemic lupus erythematosus or rheumatoid arthritis: Domains of importance and dissatisfaction. Qual Life Res. 1999;8:411-416.
- Zheng Y, Ye DQ, Pan HF, et al. Influence of social support on health-related quality of life in patients with systemic lupus erythematosus. Clin Rheumatol. 2009;28:265-269.
- Alarcón GS, McGwin G, Bertoli AM, et al. Effect of hydroxychloroquine on the survival of patients with systemic lupus erythematosus: Data from LUMINA, a multiethnic US cohort (LUMINA L). Ann Rheum Dis. 2006;66:1168-1174.
