A retrospective comparison of BMI changes and the potential risk factors among schizophrenic inpatients treated with aripiprazole, olanzapine, quetiapine or risperidone

The objective of this study was to evaluate weight gain and its potential risk factors among different second generation antipsychotics (SGAs). The study was conducted for Korean inpatients with schizophrenia in a university hospital in Seoul, between Jan 2000 and Dec 2007. Data were collected by reviewing the medical records of the patients, who were prescribed to one of the SGAs among aripiprazole, olanzapine, quetiapine or risperidone. The changes of weight and body mass index (BMI); risk of clinically significant weight gain (>7% gain to initial weight) and their associations with various clinical characteristics of such patients were analyzed. Five hundred and eighty-eight (588) and 294 subjects treated with one of the four SGAs for a duration of 1 month and 2 months were included, respectively. Olanzapine showed significantly greater weight and BMI increase at month 1 (p=0.028 for weight; p=0.019 for BMI) and month 2 (p=0.032 for weight; p=0.029 for BMI) than others. Females showed greater BMI increase change (0.70±0.91kg/m ², p=0.008) and were also more likely to experience clinically significant weight gain (odd ratio=1.846, 95% CI=1.098 to 3.105, p=0.021) at month 1.Younger patients (<45years old) had significantly greater weight and BMI increase at both months 1 and 2. Younger patients also showed greater risk for clinically significant weight gain at month 2 (odd odd ratio=2.567, 95% CI=1.196 to 5.508, p=0.016). Low baseline BMI (<25kg/m ²) was associated with greater weight gain at month 1 (1.92±2.29kg, p<0.001) and month 2 (4.07±3.56kg, p<0.001) and BMI increase at month 1 and month 2 (p<0.001 for both). Patients with low baseline BMI showed higher risk of clinically significant weight gain at both months 1 and 2 (p<0.001 for both). Olanzapine was shown to have higher metabolic risk than other SGAs in inpatients with schizophrenia. The individual's own clinical characteristics also exerted influence on weight gain effects of SGAs. Younger patients with lower baseline BMI were under greater risk of antipsychotic-induced weight gain. More studies are required to verify the role of gender on weight gain.