Body weight and the plasma levels of leptin and endogenous immune modulators during treatment with carbamazepine or lithium

To assess whether carbamazepine and lithium have effects on weight and circulating levels of cytokines we weekly measured plasma levels of TNF-a its soluble receptors sTNF-R p55 and p75, interleukin 6 (IL-6), leptin and weight in 25 inpatients receiving lithium (N=10) or carbamazepine (N=15) during the first four weeks of treatment.

Carbamazepine treatment lead to a significant increase in weight (p=0.002) across four weeks, preceded by a significant increase of TNF-a (p=0.021) plasma levels in the first week of treatment. Patients treated with carbamazepine gained a mean weight of 1.3kg within four weeks of treatment.

Lithium treatment lead to a mean increase of body weight of 1.5kg within 4 weeks, the increase of body weight was preceded by a significant increase of TNF-a (p=0.005), sTNF-R p55 (p=0.046) and leptin (p=0.018) plasma levels in the first week of treatment.

The present results support the notion that the activation of the TNF-a cytokine system is an early marker of weight gain induced by psychotropic agents.