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Objective Fatigue is a common symptom in systemic lupus erythematosus (SLE), and engaging in physical activity (PA) may reduce fatigue. We aimed to characterize relationships between fatigue, other health status measures assessed with the Patient Reported Outcomes Measurement Information System (PROMIS) instruments, and accelerometer-based PA measurements in patients with SLE. The internal consistency of each PROMIS measure in our SLE sample was also evaluated. Methods This cross-sectional study analyzed 123 adults with SLE. The primary fatigue outcome was Fatigue Severity Scale (FSS) score. Secondary outcomes were Patient Reported Outcomes Measurement Information System (PROMIS) standardized T-scores in seven health status domains. Accelerometers were worn for seven days, and mean daily minutes of light, moderate/vigorous, and bouted (10 minutes) moderate/vigorous PA were estimated. Cronbach’s alpha was determined for each PROMIS measure to assess internal consistency. Relationships between FSS, PROMIS, and PA were summarized with Spearman partial correlation coefficients (r), adjusted for average daily accelerometer wear time. Results Mean FSS (4.3, SD 1.6) was consistent with clinically relevant levels of fatigue. Greater daily and bouted moderate/vigorous PA minutes correlated with lower FSS (r=−0.20, p=0.03 and r=−0.30, p=0.0007, respectively). For PROMIS, bouted moderate/vigorous PA minutes correlated with less fatigue (r=−0.20, p=0.03). PROMIS internal consistency was excellent, with Cronbach’s alpha >0.90 for each domain. Mean PROMIS T-scores for fatigue, pain interference, anxiety, sleep disturbance, sleep-related impairment, and physical function were worse than reported for the general U.S. population. More moderate/vigorous PA minutes were associated with less pain interference (r=−0.22, p=0.01). Both light PA and moderate/vigorous PA minutes correlated with better physical function (r=0.19, p=0.04 and r=0.25, p=0.006, respectively). Conclusion More time spent in moderate/vigorous PA was associated with less fatigue (FSS and PROMIS), less pain interference, and better physical function (PROMIS). PROMIS had excellent internal consistency in our SLE sample, and six of seven PROMIS measures indicated poorer average health status in SLE patients compared to the general U.S. population.

Objective Most estimates of physical activity (PA) patterns in systemic lupus erythematosus (SLE) are based on subjective self-report measures prone to error. The aims of this study were to obtain objective measurements of PA using an accelerometer and estimates of energy expenditure based on the self-reported International Physical Activity Questionnaire (IPAQ), and to describe their relationship. Methods The “Activity in Lupus To Energize and Renew” (ALTER) study, a cross-sectional study of PA, included 129 persons with SLE. Accelerometer measures over 7 days included total daily activity counts and minutes of moderate-vigorous physical activity (MVPA). Each person completed the IPAQ via telephone interview. Spearman correlations (r) and 95% confidence intervals (CIs) assessed associations between accelerometer and IPAQ. Results Daily PA means (SD) from accelerometer measures were total daily activity counts, 502,910 (118,755) and MVPA, 40 (30) minutes. The median (interquartile range) MET-min per day for IPAQ intensities were: total 400 (159–693); walking, 83 (26–184); and moderate-vigorous, 231 (77–514), and domains were: work 0 (0–73); active transportation 28 (0–85); domestic and garden 77 (26–231); and leisure 57 (0–213). Associations between accelerometer measures and IPAQ were: 1) total daily count vs. IPAQ total, r=0.21, 95% CI: (0.03, 0.37); and 2) MVPA vs. IPAQ moderate-vigorous, r=0.16, 95% CI: (-0.02, 0.33). Conclusion Accelerometer measures and IPAQ energy expenditure estimates were moderately correlated. IPAQ provided descriptive PA data whereas accelerometers captured all daily activities and can help assess guideline attainment. The choice of IPAQ versus accelerometer measure should consider the purpose for which PA is measured.

Physical activity ameliorates fatigue in systemic lupus erythematosus (SLE) patients by an unknown mechanism. Adipokines, which are influenced by adiposity and physical activity, may be associated with patient-reported fatigue. We describe cross-sectional associations between adipokines and fatigue, physical activity, and SLE disease activity. We measured adipokines, self-reported fatigue, and objective physical activity in 129 SLE patients. Fatigue was assessed with the Fatigue Severity Scale (FSS) and Patient Reported Outcomes Measurement Information System (PROMIS) Fatigue score. Disease activity was measured with the Safety of Estrogens in Systemic Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI). Participants wore an accelerometer for 7 days to measure physical activity. Leptin, adiponectin, and resistin were measured in stored serum with a Luminex bead-based assay. Multivariable regression models assessed relationships between fatigue and adipokines, and Spearman correlation coefficients summarized associations between adipokines, physical activity, and SELENA-SLEDAI. Median adipokine levels were: leptin 30.5 ng/ml (Interquartile Range 14.0, 56.6), adiponectin 11.6 μg/ml (7.2, 16.8) and resistin 1.4 ng/ml (1.0, 2.2). Associations between adipokines and FSS or PROMIS fatigue were not significant. Body mass index (BMI) ≥ 30 kg/m was associated with FSS and PROMIS fatigue in regression analyses (p < 0.05). Weak correlations between leptin, adiponectin, leptin/adiponectin (L/A) ratio, and physical activity and between adiponectin and SELENA-SLEDAI score were not significant after adjusting for BMI. Adipokines were not associated with fatigue in SLE. Adipokines were correlated with physical activity (leptin, adiponectin, L/A ratio) and SLE disease activity (adiponectin), but most of these associations were explained by BMI.