Schizophrenia; body mass index; second generation antipsychotics; monotherapy; polytherapy

Objective: To investigate the differences in body mass index (BMI) changes between men and women during hospitalization. Methods: The retrospective study monitored demographic and clinical data of 462 schizophrenic patients hospitalized 737 times between 2006 and 2011. BMI analysis was performed on patients on antipsychotic medication hospitalized longer than four days. Results: Patients with an initial BMI < 25 gained more weight than patients with a BMI > 25 (3.94% vs. 0.23%, men 4.02% vs. 0.69%, women 3.79% vs. -0.52%, always p < 0.001). Greater BMI gains were reported during the first hospitalization than during subsequent ones (3.94% vs. 1.66%, men 3.97% vs. 1.98%, women 3.88% vs. 1.18%, always p < 0.001). The comparison between men and women showed a higher increase in BMI in men 2.36% vs. 1.54%, p = 0.022. Men also gained significantly more weight than women on polytherapy (+2.55% vs. +1.37%) and during subsequent hospitalizations (1.98% vs. 1.18%). For treatment with various atypical antipsychotics (AP), no significant differences were found in weight changes between men and women; during treatment using a combination of multi-receptor AP and metabolically neutral aripiprazole, a significant increase of BMI occurred in men, but not in women (p = 0.018). Conclusions: Men appear to be more prone to weight gain than women.