Dysregulation of Orexin-A and Implications for Renal Function Assessment in Chronic Kidney Disease

Abstract Background: Chronic kidney disease (CKD) is a long-standing kidney condition in which the kidneys are gradually damaged. It usually has multiple symptoms and is often accompanied by complications, such as hormonal imbalances, high blood pressure, anemia, and sleep disorders. Orexin, occasionally mentioned as hypocretin, is a neuropeptide that is mostly generated by orexin-containing neurons in the hypothalamus. Their receptors are found in a variety of tissues, such as the brain and kidney. This study aims to evaluate the impact of renal function on orexin-A levels in CKD. Materials and Methods: The study included 44 adult patients diagnosed with CKD, and their results were compared with 44 healthy participants of the same age and sex. An enzyme-linked immunosorbent assay kit was used to measure orexin-A, while urea, creatinine, and lipid profile were measured using spectrophotometric methods. Association with orexin-A was performed using Pearson’s correlation analysis. Results: The results showed a significant decrease in serum orexin-A ( P < 0.001) in patients with CKD. Correlation analysis showed that orexin-A in CKD patients was positively correlated with serum creatinine ( r = 0.353, P = 0.018) and high-density lipoprotein ( r = 0.354, P = 0.017), while negatively correlated with glomerular filtration rate (GFR) ( r = −0.424, P = 0.004). Conclusions: Orexin-A levels decreased in patients with CKD, and this decrease reflects the disruption of the orexin system, which was inversely related to the GFR and directly related to creatinine and high-density lipoprotein levels.