Abstract
BACKGROUND: Apelin (APLN), elabela (ELA), and nitric oxide (NO) have effects on physiological and behavioural properties in biological systems. This study was designed to determine APLN, ELA and NO levels in schizophrenia patients and assess whether these molecules are of diagnostic value. METHODS: A total of 33 schizophrenic patients and 32 ageand sex-adjusted healthy participants were included in the study. ELA, APLN and NO levels were measured using ELISA methods. RESULTS: Although the ELA and NO levels of the patients were lower than the control group, APLN levels were higher (p = 0.039, p = 0.019, p = 0.048, respectively). There was a significant negative correlation between APLN levels and triglyceride (TG) and body mass index (BMI) levels (r = -0.426, p = < 0.001 and r = -0.330, p = 0.007, respectively). Respectively, the areas under the receiver-operating characteristic (ROC) curves of the ELA/APLN, ELA/NO and APLN/NO ratios were 0.628, 0.590 and 0.709, 95% confident intervals (CI): 0.491-0.764, 0.450-0.730 and 0.579-0.840. CONCLUSIONS: Decreased levels of ELA and NO and increased APLN levels in schizophrenia suggest that these molecules may be involved in its etiopathology. The APLN/NO ratio also seems to show promise in the diagnosis of the disease and may be used in future.