Relation of risperidone-induced changes in body weight, serum leptin concentration and leptin gene with psychosis

Objective: To analyze the relation of serum leptin concentration and leptin gene -2548G/A polymorphism with risperidone-induced body weight change and treatment response. Methods: We recruited 66 Chinese Han-nationality patients with schizophrenia or schizophrenia-like psychosis. Waistline and body mass index (BMI) were measured on admission and every 2 weeks subsequently for all the patients; plasma leptin level was also measured on admission, at 4-week and 10-week treatment. The polymorphism of leptin gene was determined with PCR-RFLP technique in the patients. The Positive and Negative Symptom Scale (PANSS) was used for the evaluation of the improvement of clinical symptoms. Results: After 10 weeks' risperidone treatment, patients' waistline and BMI increased significantly (P=0.000, 0.002). There was an average increase of (1.52±1.28)kg/m² in BMI and (4.08±4.32)cm in waistline. In addition, leptin was increased during treatment without significance (P=0.102). The change in index of the body weight was associated with the baseline index of the body weight. The index of the body weight was also associated with the plasma leptin level and the change in plasma leptin level. Plasma leptin level and the changed leptin level were not associated with the genotypes, allele frequencies or the response to risperidone treatment in the patients (P>0.05). Conclusion: The -2548G/A polymorphism in promoter region of leptin gene is unlikely to play an important role in risperidone-induced weight gain. Increase in body weight is unlikely to be an indicator of response to risperidone treatment in schizophrenia or schizophrenia-like psychosis.