Evaluating the relationship between glucagon-like peptide 1 (GLP-1), TNF-α levels, and metabolic parameters with symptom severity in newly diagnosed major depressive disorder patients

AIM: The aim of the study was to evaluation of the relationship of Glucagon-Like Peptide 1(GLP-1), TNF-α level and metabolic parameters with symptom severity in patients with newly diagnosed majör depressive disorder. METHODS: Between the dates of October 30, 2022, and July 15, 2023, a total of 57 patients who presented to the Psychiatry Outpatient Clinic of Balıkesir University Hospital, underwent SCID-5-CV assessment, were diagnosed with major depressive disorder according to DSM-V criteria, had not previously received medical treatment for this condition, and did not have any accompanying metabolic diseases were included in the study. Additionally, 48 healthy volunteers with similar sociodemographic characteristics were recruited. After obtaining consent from the patients, a sociodemographic data form, the Hamilton Depression Scale, and the Hamilton Anxiety Scale were administered. Fasting blood glucose, HbA1c, HDL, LDL, total cholesterol, and triglyceride values were assessed in order to evaluate metabolic parameters, along with GLP-1 and TNF-α levels in the blood. Blood samples for GLP-1 and TNF-α were collected from the patients and stored at -80 degrees Celsius until the time of analysis. The analyses were performed using the ELISA method with commercial kits. RESULTS: The median value of TNF-α was found to be significantly lower in the patient group (132.28 pg/mL) compared to the control group (592.40 pg/mL) with a significant p-value of 0.00. Similarly, the median value of GLP-1 was significantly lower in the patient group (30.74 ng/mL) compared to the control group (103.28 ng/mL) with a p-value of 0.00. To investigate the relationship between HAM-D scores and GLP-1 as well as TNF-α levels in both patient and control groups, a correlation analysis was conducted. In the patient group, a significant negative correlation was observed between HAM-D scores and both GLP-1 and TNF-α values (r: -0.41, p=0.001 for GLP-1; r: -0.31, p=0.016 for TNF-α). Similarly, in the control group, there was a significant negative correlation between HAM-D scores and both GLP-1 and TNF-α values (r: -0.34, p=0.017 for GLP-1; r: -0.39, p=0.005 for TNF-α). CONCLUSION: This study supports the possibility that GLP-1 could be associated with the severity of major depressive disorder symptoms and may have a role in the pathophysiology of major depressive disorder.