Investigating physical inactivity and associated health parameters in patients with systemic lupus erythematosus

Background Physical inactivity, which is highly prevalent in patients with systemic lupus erythematosus (SLE), is an independent risk factor for cardiovascular events and causes many complications. This study aimed to investigate the effect of objective measurement and physical activity level on peripheral muscle strength, exercise capacity, pain, dyspnea, fatigue, anxiety, and depression in patients with SLE. Methods The present cross-sectional study analyzed 41 patients with SLE. Clinical and demographic characteristics of patients were recorded. Functional exercise capacity, peripheral muscle strength, dyspnea, pain, fatigue, anxiety, and depression were assessed. The physical activity level was assessed by a wearable activity tracker (Mi Band four smart band). Results The number of steps measured by the activity tracker was 4384.43 ± 1558.21 steps per day in patients with SLE. Patients with physical activity levels below 5000 steps exhibited elevated levels of fatigue, along with diminished functional exercise capacity and knee muscle strength, in comparison to those who were above the 5000-step threshold. Physical activity levels correlated with functional exercise capacity (6MWT), physiological parameters (maximum heart rate, Δ heart rate, Δ dyspnea, QFM fatigue, Δ QFM fatigue), and knee extension muscle strength. The functional exercise capacity and knee extension were identified as significantly and dependently associated with physical activity levels in SLE patients. Conclusion Physical activity level is associated with functional exercise capacity and knee muscle strength in patients with SLE.