Myostatin and Irisin Levels in Predicting the Outcome of Patients With Systemic Inflammation: A Prospective Observational Study

Systemic inflammatory response syndrome (SIRS) is associated with severe metabolic stress that can lead to rapid breakdown of skeletal muscle and the development of stress-related malnutrition. These processes often result in muscle weakness, delayed recovery, prolonged hospital stay, and increased morbidity and mortality in affected patients. In recent years, increasing attention has been paid to signaling molecules produced by skeletal muscles, known as myokines. Myokines influence not only muscle regeneration and muscle breakdown but also have a wide range of effects on other organs and tissues in the body, including the brain and gastrointestinal tract. Previous studies suggest that lower levels of certain myokines, such as myostatin and irisin, may be associated with worse outcomes in critically ill patients. The primary aim of this prospective observational study is to evaluate the association between the levels of selected myokines and prolonged hospital stay in patients with systemic inflammation. If such an association is confirmed, myokines could potentially serve as prognostic biomarkers for the development of muscle dysfunction and prolonged hospitalization. Secondary objectives include evaluating correlations between myokine levels and other indicators of systemic inflammation and muscle dysfunction. In addition, the study assesses the potential use of bedside ultrasound measurement of the quadriceps muscle to detect muscle catabolism and to help predict clinical outcomes in hospitalized patients.