Differential effects of olanzapine and risperidone on plasma adiponectin levels over time: Results from a 3-month prospective open-label study

Second-generation antipsychotics (SGA), especially clozapine and olanzapine, are associated with an increased metabolic risk. Recent research showed that plasma adiponectin levels, an adipocyte-derived hormone that increases insulin sensitivity, vary in the same way in schizophrenic patients as in the general population according to gender, adiposity and metabolic syndrome (MetS). The aim of the present study was to investigate whether different SGAs differentially affect plasma adiponectin levels independent of body mass index (BMI) and MetS status. A 113 patients with schizophrenia (65.5% males, 32.3 years old) who were free of antipsychotic medication were enrolled in this open-label prospective single-center study and received either risperidone (n = 54) or olanzapine (n = 59). They were followed prospectively for 12 weeks. Average daily dose was 4.4 mg/day for risperidone and 17.4 mg/day for olanzapine. Plasma adiponectin levels as well as fasting metabolic parameters were measured at baseline, 6 weeks and 12 weeks. A The two groups had similar baseline demographic and metabolic characteristics. A significant increase in body weight was observed over time. This increase was significantly larger in the olanzapine group than in the risperidone group (+7.0 kg versus +3.1 kg, p