Serum adiponectin concentrations during treatment with olanzapine or risperidone: a pilot study

Adiponectin is a recently identified adipocyte-derived protein, which is associated with glucose metabolism, insulin sensitivity and adiposity. The aim of this study was to explore the alterations in serum adiponectin concentration during treatment with olanzapine or risperidone. Serum concentrations of adiponectin were investigated in body mass index (BMI, kg/m2)- and age-matched groups of non-diabetic, non-obese schizophrenic patients receiving a stable dose of olanzapine (n = 18) or risperidone (n = 15) for 4 weeks or more, and of mentally and physically healthy volunteers (n = 17). Patients undergoing treatment with olanzapine or risperidone had significantly higher adiponectin concentrations than the healthy volunteers, even after controlling for BMI. Adiponectin concentrations decreased with increasing BMI in patients taking olanzapine, while elevated levels were observed in patients taking risperidone, regardless of adiposity. This preliminary cross-sectional study indicates that adiponectin is involved in the regulation of glucose metabolism and weight in schizophrenic patients during treatment with olanzapine or risperidone, presumably showing a normalizing effect on metabolic abnormality.