Taking metformin may help overweight or obese adolescents who take antipsychotic medications avoid the weight gain commonly associated with the drugs, according to researchers in the multicenter Metformin for Overweight and Obese Children and Adolescents With Bipolar Spectrum Disorders Treated With Second-Generation Antipsychotics (MOBILITY) study. The results were recently published by the Patient-Centered Outcomes Research Institute.
Melissa P. DelBello, M.D., M.S., of the University of Cincinnati, and colleagues examined data from 1,565 youth ages 8 to 19 years who had a diagnosis of bipolar disorder and had overweight or obesity. All patients had an established history of taking a second-generation antipsychotic medication or had recently begun taking one shortly before enrollment.
The patients and their caregivers viewed a seven-minute educational video and received printed materials about healthy diet and exercise. The researchers then randomized the patients to either lifestyle alone or lifestyle plus metformin. For the metformin group, the researchers recommended starting at a dose of 500 mg daily and increasing to a maximum dose of 1,000 mg twice daily, but dosing was flexible and carried out according to clinical discretion. The researchers collected data about the patients’ height, weight, and BMI at baseline and at a maximum of 10 follow-up visits, which were recommended monthly for the first three months and every three months after that for up to two years. They also assessed the patients’ weight-related quality of life using the Sizing Me Up & Sizing Them Up scale, a 22-item self-report and parent-proxy measure of obesity-specific health-related quality of life for youth that includes subscales for emotional, physical, and school functioning as well as teasing/marginalization, positive social attributes, mealtime challenges, and social distress/avoidance.
At six months and two years, the patients in the metformin/lifestyle group had greater reductions in BMI than those in the lifestyle-only group along with greater improvements in quality of life. However, they also had more adverse events, including 12 serious adverse events necessitating or prolonging hospitalization such as abdominal pain and refractory headache. Eleven percent of patients in the metformin/lifestyle group discontinued metformin because of gastrointestinal side effects.
“Based on our assessment … of the risks and benefits of adding [metformin] to a brief healthy lifestyle intervention among youth with [bipolar disorder] who have overweight or obesity, clinicians should strongly consider prescribing [metformin] in conjunction with [second-generation antipsychotics],” the researchers wrote. “… Although most clinicians regularly assess mood symptoms in this population, the striking prevalence of [quality-of-life] impairments directly related to weight underscores the importance of discussing with patients and their caregivers how weight gain may be adversely affecting their lives.”
For related information, see the Psychiatric News articles “Metformin May Reduce Weight Gain in Youth Taking Antipsychotics” and “New Guideline Calls for Metformin to Prevent Antipsychotic-Induced Weight Gain.”
(Image: Getty Images/iStock/kimberrywood)
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