Association between Serotonin Transporter Polymorphism and the Effect of Atypical Antipsychotics on Serum Glucose and Lipids

The purpose of this study was to investigate the association between the genotype distribution of 5-HTTLPR and the effects of atypical antipsychotics on serum glucose and lipids in schizophrenic patients. The study subjects were 66 schizophrenic patients taking atypical antipsychotics (risperidone, olanzapine, clozapine, quetiapine, zotepine). The control group consisted of 82 schizophrenic patients taking a typical antipsychotics (haloperidol). All of the subjects were medicated for at least 12 weeks. We examined the serum fasting blood sugar (FBS), HbA1c, total cholesterol, and triglyceride levels, and the genotype distribution of 5-HTTLPR in all subjects. The presence of the 5-HTTLPR gene was determined by means of the polymerase chain reaction of genomic DNA with primers flanking the promoter regions of the 5-HTT gene. Between group comparisons of the genotype distribution and the effects of the antipsychotics on the serum glucose and lipid levels were performed using the score test form of the t-test, one way ANOVA and chi-square test. There was a significant increase in FBS level in all patients taking atypical antipsychotics, except for those treated with risperidone. However, there was no statistically significant correlation between the 5-HTTLPR genotype distribution and the effect of the atypical antipsychotics on the FBS, HbA1c, total cholesterol, or triglyceride serum levels in the schizophrenic patients. These results suggest that the 5-HTTLPR polymorphism has no significant association with the effect of atypical antipsychotics on the serum glucose and lipid levels in Korean schizophrenic patients.