Rapid leptin elevation after initiation of olanzapine?

Weight gain is a common adverse effect associated with olanzapine treatment. Another side effect of olanzapine treatment is a significant increase in circulating leptin levels. This preliminary study monitored the changes in leptin levels for 2 weeks after olanzapine treatment had been initiated. The relationship between the changes in circulating leptin levels and alterations in body weight in 9 patients with schizophrenia who received olanzapine was examined. The results showed that olanzapine may cause a surge in circulating leptin levels before weight gain is manifested. Moreover, higher pretreatment circulating leptin levels predicted lower weight gains after olanzapine treatments (r = -0.93; p < 0.05) after controlling for the effect of sex.