Our current primary interest is the metabolic side effects of antipsychotic treatment in patients with schizophrenia and schizoaffective disorder. Individuals who store excess fat as intra-abdominal or visceral adiposity are at greater risk for the development of insulin resistance, and eventual type 2 diabetes mellitus, than those who deposit fat on the hips and thighs. The purpose of our present research is to examine the extent of improvement in insulin sensitivity and visceral adiposity in nondiabetic, overweight or obese patients with schizophrenia or schizoaffective disorder taking risperidone or olanzapine, who are randomized to usual care or switch to ziprasidone and followed for 6 months. This research will address two important questions: 1) Is switching to metabolically more neutral antipsychotic therapy a reasonable means to improve insulin sensitivity in schizophrenia patients at risk for diabetes; 2) Is the extent of improvement in insulin sensitivity seen after switching to metabolically more neutral antipsychotic therapy greater than one would expect for the amount of visceral fat lost.
A second research interest revolves around the question of whether patients with schizophrenia have an inherent predisposition towards visceral adiposity in the face of weight gain related to external stresses such as diet or medication exposure. Presently, it is not clear whether the high prevalence of type 2 diabetes mellitus and metabolic syndrome in these patients is solely related to environmental factors. Future work in this area will revolve around a search for candidate genes associated with diabetes, insulin resistance and visceral adiposity in schizophrenia patients
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