Purpose: To evaluate the effects of aerobic exercise on patient-reported outcomes (PROs) in women with systemic lupus erythematosus (SLE), and whether changes in cardiorespiratory fitness (CRF) mediate the changes in PROs.
Methods: A total of 58 women with SLE were assigned to either an exercise group (EG; n = 26) or a control group (CG; n = 32) in this non-randomized clinical trial. The EG comprised 12 weeks of aerobic exercise (2 sessions/week) between 40%-75% of the individual's heart rate reserve. At baseline, and at week 12, CRF (Bruce test) and PROs were assessed including psychological stress (Perceived Stress Scale), sleep quality (Pittsburg Sleep Quality Index), fatigue (Multidimensional Fatigue Inventory), depressive symptoms (Beck Depression Inventory), and quality of life (36-item Short-Form Health Survey).
Results: In comparison to the CG, the EG showed a significant reduction in general fatigue (mean difference (MD) -2.86 units; 95%CI -5.70 to -0.01; p = 0.049), physical fatigue (MD -4.33 units; 95%CI -7.02 to -1.65; p = 0.002) and a non-significant reduction of reduced motivation (MD - 1.29 units; 95%CI -2.60 to 0.03; p = 0.055). There were no significant between-group differences in the changes in psychological stress, sleep quality, depressive symptoms, quality of life, or other fatigue dimensions (all p > 0.05). Changes in CRF mediated the effects of the exercise intervention on general fatigue by 53.8%.
Conclusion: The results suggest that 12 weeks of progressive aerobic exercise might improve relevant dimensions of fatigue in women with SLE, despite the absence of effects on other PROs. Improvements in CRF seem to mediate the effect of exercise on general fatigue.Implications for rehabilitationAerobic exercise could be safely introduced in rehabilitation programs for inactive patients with SLE with mild disease activity.Including physical activity recommendations as part of rehabilitation could improve relevant aspects of fatigue in women with SLE.When rehabilitation aims at reducing fatigue, cardiorespiratory fitness improvements derived from physical activity might enhance benefits.
Keywords: Physical activity; SLE; aerobic capacity; fatigue; mental health; quality of life.