BACKGROUND: Antipsychotics are indicated for symptom relief and relapse prevention in bipolar disorder I (BD-1). Many second-generation antipsychotics (SGAs) are associated with weight gain. Systematic reviews of clinical trial data report that younger patients are more susceptible to SGA-induced weight gain, but additional real-world evidence is needed.
OBJECTIVES: To describe changes in weight across the life span in a US real-world cohort of patients with BD-1 treated with SGAs.
METHODS: This retrospective observational cohort study was conducted using the OM1 Real World Data Cloud (RWDC, OM1, Inc., Boston, MA). The RWDC is a US data network with linked healthcare claims and electronic medical records (EMR) data from multiple specialty providers, including OM1’s Mental Health Network of 2.5+ million patients seen in 2,000+ community-based practices. Initiators of SGAs aged ≥ 12 years with a BD-1 diagnosis and no diagnosis of schizophrenia were identified from January 2013 - November 2020. Patients using first generation antipsychotics in the prior 12 months were excluded. Mean annual percent (%) changes in body mass index (BMI) and body weight from baseline (within 3 months prior to SGA initiation) to follow-up (measurement closest to the 12 months after SGA initiation) were calculated by sex and age group.
RESULTS: The cohort included 32,728 patients (mean age: 46.4 years [standard deviation [SD]: 15.8]; 71.6% women). The mean % change in BMI was 1.7% (SD: 10.3) in women and 1.2% (SD: 9.1) in men. The mean % change in body weight was 1.7% (SD: 10.4) in women and 1.3% (SD: 8.8) in men. In women, the mean % change in BMI (SD) during adolescence was 7.6% (12.4) at 12-14 years and 4.4% (10.7) at 15-17 years. The mean % change in BMI steadily decreased through adulthood (18-24 years: 3.6% [11.0], 25-34 years: 2.3% [10.7], 35-44 years: 1.8% [10.1], 45-54 years: 1.6% [10.2], 55-64 years: 1.0% [10.0], 65+ years: 0.7% [9.8]). In men, the mean % change in BMI (SD) during adolescence was 5.2% (10.1) at 12-14 years and 3.7% (10.6) at 15-17 years. The mean % change in BMI similarly decreased through adulthood (18-24 years: 2.7% [9.6], 25-34 years: 1.7% [9.6], 35-44 years: 1.2% [8.9], 45-54 years: 0.9% [8.8], 55-64 years: 0.6% [8.6], 65+ years: 0.2% [8.8]). Similar trends were observed for mean % change in body weight for both sexes.
CONCLUSIONS: The magnitude of weight gain in this population of SGA initiators with BD-1 was highest in younger patients in both women and men. The % weight gain observed in adults is consistent with the average yearly weight gain reported in the general adult US population. Identification of patient subgroups at higher risk for SGA-induced weight gain may allow for implementation of strategies to prevent or ameliorate weight gain to improve medication adherence and quality of life.
