EPA-1389 – Predictive Values of Appetite and Early Weight Increase for Long-term Weight Variation During Psychotropic Treatment.

Abstract

Introduction

Atypical antipsychotics and some other psychotropic drugs such as valproate, lithium or mirtazapine are known to induce several metabolic complications. However there is an inter-individual variability in developing metabolic features which may be explained by clinical and genetic factors.

Objectives

To determine whether weight gain and/or appetite change after one month are predictors for a weight gain after 3 and 12 months of treatment.

Methods

A longitudinal clinical and pharmacogenetic study is presently ongoing in the Department of Psychiatry-CHUV. Several clinical data have been recorded over one year following the introduction of psychotropic treatment. 406 patients with weight at baseline, after one month and with at least a third weight measure during the first year of treatment were included in the present study.

Results

Using Receiver Operating Characteristic (ROC) analyses, an initial weight increase of 5% was found to be a good predictor for a consequent weight gain at 3 months (ROC_AUC=77) and one year (ROC_AUC=68). By using a generalized linear mixed model corrected by several confounders, this weight change of 5% was found to be significantly associated (p-value<0.0001) with an important weight change (10 to 20% increase from baseline value) over one year. Appetite was not found to be good a predictor of weight gain over one year.

Conclusion

An initial weight gain of 5% during the first month following an introduction of atypical antipsychotics, lithium, valproate and/or mirtazapine is a predictor for further weight gain and should be a warning sign to introduce weight lowering strategies.