Diet and Gender Moderate Clozapine-Related Weight Gain

Abstract

This study examined patients with schizophrenia in two state hospitals treated with clozapine, with particular attention to factors that may affect weight gain. A retrospective chart review was performed for 40 subjects, all of whom had been treated for at least 6 months. Patients included 26 males and 14 females, 34 caucasians and 6 blacks, with an average age of 37.5 years. Twenty-nine patients were overweight prior to initiation of treatment with clozapine, and ten patients were placed on diets prior to clozapine treatment. Dosages at 1 and 6 month intervals were were recorded, with no evident group differences related to gender or diet status. Results indicate a significant (p =. 001) treatment x diet interaction, with nondieters gaining more weight. For the 30 nondieters, weight was higher by 7.2 pounds, with women particularly affected, and for the 10 dieters, weight was 10.0 pounds lower, with men showing greater weight loss. There was also a significant (p =. 01) treatment x sex interaction, with females gaining more weight. Nondieting men gained an average of 4.5 pounds, nondieting women gained 13.3 pounds, dieting men lost an average of 15.6 pounds, and dieting women gained. 8 pounds. Patients overweight prior to clozapine therapy were no more likely to gain significant amounts of weight than were patients of normal weight. No relationship was found between dosage and weight gain. We conclude that previous reports of weight gain with clozapine treatment have revealed inconsistent results based on varied gender composition of the subject pool. It also appears that dietary management is an important component of comprehensive treatment for patients taking clozapine.