New-onset type-2 diabetes associated with atypical antipsychotic medications.

PURPOSE This study compared the one-year incidence of new-onset type-2 diabetes mellitus (DM) and changes in weight in patients with a variety of psychiatric diagnoses prescribed olanzapine, risperidone, or quetiapine, compared to a reference group receiving haloperidol and no other antipsychotic medication. RESEARCH DESIGN AND METHODS Data was abstracted from charts of subjects newly initiated and then maintained for one year on olanzapine (n=112), risperidone (n=100), quetiapine (n=100), and haloperidol (n=100). Baseline and one-year DM status, height, and weight were collected, as well as concurrent psychotropic medications, medical and psychiatric comorbidities. FINDINGS Using a multivariate model, logistic regression identified a significant association between olanzapine (but not other atypical agents) and the development of diabetes compared to haloperidol over the one-year period (odds ratio 8.4, 95% CI 1.8-38.7). Baseline obesity was independently associated with new-onset DM, but only marginally greater weight gain was found among olanzapine users. CONCLUSIONS The middle-aged American veterans in this study cohort were highly vulnerable to the diabetogenic effects of olanzapine, but a close correlation with weight change was not found. Patients administered olanzapine should receive careful laboratory monitoring for elevated plasma glucose in addition to weight measurement.