Insulin resistance and adiponectin levels in drug-free patients with schizophrenia: A preliminary report

Objective: To compare the insulin sensitivity and adiponectin levels of medication-free patients suffering from schizophrenia or schizoaffective disorder with that of matched healthy volunteers. Method: We evaluated 9 nondiabetic patients aged 26.6 years (median 26 years, range 17 to 41 years) and matched volunteers, using the frequently sampled intravenous glucose tolerance test, minimal model analysis, and fasting adiponectin levels. Results: The mean insulin sensitivity index of the patients was 42% lower than that of the healthy volunteers (P = 0.026), with inadequate compensation in insulin secretion. Patients with schizophrenia tended to have reduced adiponectin levels (P = 0.055). Conclusions: By direct measurement, this study provides evidence of insulin resistance and susceptibility to type 2 diabetes in patients with schizophrenia who are free of antipsychotic drugs.