Diabetes mellitus and impaired glucose tolerance in patients with schizophrenia, before and after antipsychotic treatment

BACKGROUND: Treatment with antipsychotics increases the risk of developing diabetes in patients of schizophrenia but this diabetogenic potential of different antipsychotics seems to be different. Moreover, there may be an independent link between schizophrenia and diabetes. So we plan to study the prevalence of glucose dysregulation in patients of schizophrenia before and after treatment with various antipsychotics. MATERIALS AND METHODS: Fifty patients (32 males and 18 females) diagnosed with schizophrenia were evaluated for glucose dysregulation using oral glucose tolerance test, initially (drug naive) and after antipsychotic treatment. Age- and sex-matched healthy volunteer group of 50 subjects (35 males and 15 females) was taken for comparison. Results were interpreted using American Diabetic Association criteria. RESULTS: Though the glycemic status of the patient group was comparable with healthy controls initially but antipsychotic treatment was associated with glucose dysregulation. For first 6 weeks the antipsychotic (olanzapine, risperidone, haloperidol and aripiprazole)-induced glucose dysregulation was comparable, which was seen to be maximum with the olanzapine-treated group at the end of this study, 14 weeks. CONCLUSION: We conclude that antipsychotic treatment of nondiabetic drug naive schizophrenia patients was associated with adverse effects on glucose regulation. For initial 6 weeks the antipsychotic-induced glucose dysregulation was comparable, which was seen to be maximum with olanzapine at the end of study, i.e. 14 weeks. Keeping this at the back of mind we can stabilize a patient initially with a more effective drug, olanzapine, and later on shift to one with less metabolic side effects.