Associations Between Serum Adipokine, Antipsychotic Exposure, and Clinical Characteristics in Chronic Schizophrenia: A Cross‐Sectional Study

BACKGROUND: Previous meta-analyses have reported lower serum adiponectin levels in patients with schizophrenia treated with second-generation antipsychotics. However, the relationships among serum adipokines, psychiatric symptoms, and antipsychotic use remain unclear. This study aimed to clarify associations between serum adipokines, psychiatric symptoms, and antipsychotic treatment in patients with chronic schizophrenia compared with healthy controls. METHODS: The study included 37 inpatients with schizophrenia and 39 age- and gender-matched healthy controls. Fasting blood samples were collected, and serum adipokine levels were measured using enzyme-linked immunosorbent assays. Psychiatric symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS), and antipsychotic doses were converted to chlorpromazine equivalents. Correlations were examined using regression and multivariate analyses, including adjustment for body mass index (BMI). RESULTS: No significant case-control differences were observed in total or high-molecular weight adiponectin levels. Female patients had a significantly higher leptin/adiponectin ratio than female controls (p = 0.041). In the schizophrenia group, adiponectin levels were positively correlated with chlorpromazine equivalents (r = 0.684, p < 0.001). This association remained statistically significant after adjustment for BMI, gender and hospitalization period. Adiponectin levels were not significantly associated with psychiatric symptom severity. CONCLUSION: In this cross-sectional sample, serum adiponectin levels are associated with antipsychotic dosage but not with symptom severity. These findings suggest that adipokine regulation in patients with schizophrenia may be influenced by treatment-related and demographic factors. Longitudinal studies incorporating comprehensive metabolic assessments are needed to explore the clinical significance of these relationships.