Influence of 5-HT2c receptor and leptin gene polymorphisms, smoking and drug treatment on metabolic disturbances in patients with schizophrenia

Background - Obesity and metabolic syndrome are significant problems for patients taking antipsychotic drugs. Evidence is emerging of genetic risk factors.

Aims - To investigate the influence of two candidate genes, smoking and drug treatment on obesity and metabolic syndrome in patients with schizophrenia.

Method - Patients (n=134) were assessed for measures of obesity, other factors contributing to metabolic syndrome, and two genetic polymorphisms (5-HT2C receptor –759C/T and leptin –2548A/G).

Results - Neither genotype nor smoking was significantly associated with measures of obesity. However, both leptin genotype and smoking were significantly associated with metabolic syndrome. Significant interaction occurred between the genetic polymorphisms for effects on obesity, whereby a genotype combination increased risk. Drug treatment showed significant effects on measures of obesity and triglyceride concentrations; risperidone was associated with lower values than olanzapine or clozapine.

Conclusions - The findings suggest interacting genetic risk factors and smoking influence development of metabolic syndrome in patients on antipsychotic drugs.