The Serum Irisin Level in Non-Diabetic Patients with Chronic Kidney Disease

OBJECTIVE: Metabolic activity in patients with chronic kidney disease (CKD) is characterized by increased energy expenditure, protein loss, and catabolic processes. Irisin is a recently discovered thermogenic protein that causes energy expenditure. We are in the opinion that the level of irisin may change in patients with CKD and this condition can contribute to the energy expenditure in CKD. The present study aimed to determine the level of serum irisin, in patients with CKD, and the association between CKD stage and the serum irisin level. MATERIAL and METHODS: The study included 90 patients with CKD (stages 2-4) and 32 healthy controls. Routine laboratory tests and measurement of the serum irisin level in all participants were performed. The serum irisin level was measured using the enzyme-linked immunosorbent assay method. RESULTS: The serum irisin level was significantly lower in the patients with CKD than in the control group (p < 0.05). The mean irisin level in the patient group decreased as the severity of CKD increased (stage 2: 22.1±6.3 ng/mL; stage 3: 17.5±3.4 ng/mL; stage 4: 12.9±3.2 ng/mL; p<0.001). There was a positive correlation between the serum irisin level and the glomerular filtration rate (r=0.625, p<0.001). In the regression analysis CKD stage was an independent predictor of the irisin level (β ± SE= –4.663±0.511, p<0.001). CONCLUSION: In the CKD patients the serum irisin level decreased as the severity of disease increased. Accordingly, the catabolic process, which occurs more frequently in the advanced stages of CKD, might also play a role in decreasing the serum irisin level.