Olanzapine-induced obesity and diabetes in Indian patients: a prospective trial comparing olanzapine with typical antipsychotics.

The association of hyperglycaemia and weight gain with the use of atypical antipsychotics has been documented. However, there is still not enough data from India. The fact that Indian patients usually have a lower body weight compared to European and American counterparts makes it difficult to extrapolate available data to the Indian context. The purpose of this study is: (a) To compare the prevalence of hyperglycaemia in schizophrenic patients taking olanzapine with those taking typical antipsychotics, and (b) to follow-up non-diabetic, non-obese schizophrenics on a stable regimen of antipsychotic monotherapy and determine the proportion of patients who develop weight gain, diabetes or impaired glucose tolerance; comparing the effects of olanzapine versus typical antipsychotics. Fifty-five schizophrenic patients attending psychiatry outpatients' department and on stable antipsychotic monotherapy for at least 6 weeks were included in the study. Those with a family or personal history of diabetes were excluded. There were 28 cases on olanzapine and 27 on either haloperidol or trifluoperazine. Fasting blood glucose estimation and body-mass Index (BMI) were recorded at baseline, at 6 weeks, and at 12 weeks. The two groups were comparable with respect to age, genderwise composition, and duration of illness. There was no significant difference in baseline glycaemic status or BMI. At the end of 12 weeks, olanzapine was not associated with any significant change in body weight, BMI or plasma fasting glucose. Duration of use of antipsychotic emerged as the only statistically significant risk factor for developing hyperglycaemia across both groups.