RESUMO
Objective: To investigate whether antipsychotic agent-induced type 2 diabetes was associated with leptin gene -2548G/A functional polymorphism in schizophrenia patients who had treated by antipsychotics chronically. Methods: Fasting plasma glucose, 2-hour post meal plasma glucose, fasting plasma leptin and fasting plasma insulin were measured in 110 patients with chronic schizophrenia whose natural courses of the disorder were more than 5 years. According to the level of plasma glucose, these patients were divided into three groups, diabetes mellitus group, abnormal regulating glucose group and normal glucose group. The polymorphisms in the leptin promoter region (-2548 G/A) were determined with PCR-RFLP in the patients. Results: The patients in DM group were more likely to be homozygous for the -2548AA genotype. As compared with the patients with -2548AG/GG combined genotype, the patients with -2548AA genotype had significant increase in the level of plasma leptin(P=0.019). Conclusion: The -2548G/A polymorphism in promoter region of leptin gene may be associated with type 2 diabetes in schizophrenic patients treated by antipsychotics chronically. -2548A allele of leptin gene may be a genetic risk factor for the development of type 2 diabetes during antipsychotic treatment.