Effects of Metformin on Weight Loss and Metabolic Control in Obese Patients With Schizophrenia and Schizoaffective Disorder: A Randomized Double-Blind Controlled Clinical Trial

Objectives: The effect of metformin on weight changes and some metabolic parameters in patients with schizophrenia and schizoaffective disorder was investigated in this study. Methods: As a randomized double-blind controlled clinical trial, this study was performed from 2018 to 2019. A total of 66 obese patients (BMI≥27) with schizophrenia and schizoaffective disorder, hospitalized in the departments of Razi Psychiatric Hospital, entered the study; then, they were randomly divided into intervention and control groups after completing the informed consent form. The patients received metformin or placebo for 12 weeks. The dose of metformin was gradually increased and in case of a patient’s tolerance, was prescribed up to 500 mg twice daily. During the study, all patients received their previous therapies. The variables included BMI, weight, waist circumference, lipid profile, and fasting blood glucose, which were studied at the beginning of the study and at weeks 4, 8, and, 12. The data were analyzed, using a post hoc test by SPSS software. Results: The results showed a significant decrease in weight (3.5 kg) and BMI (1.30) at the end of the week 12, and there was a significant reduction in waist circumference (5.9 cm) at the end of the week 8 compared to the placebo group (P