Stage-Specific Changes in Irisin, Nesfatin-1, and Oxidative Stress Markers in Brucellosis

Background Brucellosis is a globally prevalent foodborne zoonotic disease transmitted primarily through the ingestion of unpasteurized dairy products or undercooked meat. While its infectious etiology is well recognized, the metabolic and oxidative stress-related alterations associated with the disease remain insufficiently characterized. Objectives This study aimed to investigate stage-specific changes in serum irisin and nesfatin-1 levels, alongside markers of oxidative stress, in patients with acute, subacute, and chronic brucellosis. Methods A total of 90 patients diagnosed with brucellosis at different clinical stages and 30 healthy controls were included. Serum levels of irisin, nesfatin-1, total oxidant status (TOS), total antioxidant status (TAS), and the oxidative stress index (OSI; TOS/TAS ratio) were determined using enzyme-linked immunosorbent assay (ELISA). Intergroup comparisons were performed using one-way ANOVA and paired t-tests. Results Serum irisin and nesfatin-1 levels were significantly reduced in brucellosis patients compared to controls, with variations dependent on disease stage (p < 0.05). Concurrently, a significant increase in TOS and OSI values and a decrease in TAS levels were observed across all stages of brucellosis (p < 0.05). Conclusions Brucellosis induces distinct alterations in energy-regulating hormones and redox balance, extending beyond its infectious profile. Reduced levels of irisin and nesfatin-1, in parallel with elevated oxidative stress, suggest potential roles for these hormones as biomarkers in disease staging and metabolic monitoring. These findings underscore the need to incorporate hormonal and oxidative profiling into the clinical evaluation of brucellosis. To our knowledge, this is the first study to evaluate irisin and nesfatin-1 responses across different clinical stages of brucellosis.