The association between peptic ulcer disease and depression risk: The role of serotonin as a diagnostic biomarker in a case-control study.
AIM To evaluate serum serotonin levels in patients with peptic ulcer disease (PUD) and assess its potential as a biomarker associated with depressive symptoms in patients with PUD. METHODS This case-control study included 50 adult male patients with endoscopically confirmed PUD and 50 apparently healthy male controls. Serum serotonin levels were measured using enzyme-linked immunosorbent assay (ELISA). Depression was diagnosed by a psychologist and assessed using the Patient Health Questionnaire-9 (PHQ-9). Statistical analyses included the Mann-Whitney U test, chi-square test, multivariate logistic regression, and receiver operating characteristic (ROC) curve analysis. RESULTS Patients with PUD had higher PHQ-9 scores than controls, with a median score of 13.5 (7.0-16.6) versus 4.0 (2.0-8.0) (p<0.001). Serum serotonin levels were lower in patients with PUD than in controls, with a median of 530.086 (435.7-592.8) pg/mL versus 1008.763 (874.89-1120.43) pg/mL (p<0.001). In the adjusted model, lower serotonin levels remained independently associated with comorbid PUD-depression status (OR=0.992; 95% CI 0.988-0.996; p<0.001). ROC analysis showed high diagnostic performance for serotonin in the full sample (AUC=0.920; 95% CI 0.870-0.970; cut-off 803.131 pg/mL; sensitivity 85.0%; specificity 100%). CONCLUSION Serum serotonin levels were lower in male patients with PUD and depressive symptoms than in healthy controls. Serotonin may have diagnostic value as a biomarker associated with depressive symptoms in patients with PUD, but longitudinal studies including women and PUD patients without depression are required.