Estimated cardiorespiratory fitness as a predictor of fatigue in patients with primary Sjoegren's syndrome

Primary Sjoegren’s syndrome (pSS) is a systemic autoimmune disease characterized by lymphocyte infiltration and gradual destruction of exocrine glands. Additionally, the inflammatory process can affect organs such as the kidneys, lungs, and heart, leading to renal decline, dyspnea, and cardiac symptoms. Sicca, particularly dry eyes and mouth, is present in 95% of patients. Moreover, 65-70% of patients report fatigue. Fatigue, described as a subjective and unpleasant sensation ranging from tiredness to exhaustion, is the most significant challenge for pSS patients. Till now, no therapeutics have been approved for the treatment of fatigue. Studies have shown that pSS patients with lower physical activity, higher activity avoidance, and greater somatic focus display a higher level of fatigue. Potentially, interventions to increase aerobic capacity and levels of physical activity may improve fatigue symptoms of pSS patients. The overarching aim of the project is to analyze whether the estimated cardiorespiratory fitness serves as a predictor of fatigue by assessing the daily physical activity from the patients with the use of accelerometers in their home environment. Since fatigue is an early symptom in autoimmune diseases, especially in pSS, understanding the underlying mechanisms and the impact of high or low cardiorespiratory fitness could inform the development of effective interventions to improve long-term patient outcomes and potentially delay the progression of autoimmune diseases.