Weight change in the acute treatment of bipolar I disorder: a naturalistic observational study of psychiatric inpatients

Abstract

Background: Bipolar patients have increased prevalence rates of overweight and obesity compared with the general population. Recent increases in the use of atypical antipsychotics and combination therapies have led to growing concern about obesity and metabolic disturbances. We therefore evaluated weight change and its correlates during the treatment of acute mania in a closed-ward hospital setting.

Methods: We evaluated weight change over 4 weeks in 179 consecutive patients with bipolar I disorder presenting with acute manic symptoms.

Results: Overall weight change was +2.7+/-3.0 kg (+4.6+/-5.2%). Whereas 24.6% of patients were obese at baseline, 36.3% were obese after 4 weeks. Duration of illness was correlated with weight change, but its effect was not robust. Baseline weight/BMI, sex, age of onset, and history of previous medication were not significantly correlated with weight changes. Patients prescribed olanzapine plus valproate showed the largest increase in weight (3.8+/-2.9 kg). Overall, patients on any kind of atypical antipsychotics showed greater weight gain than those on typical antipsychotics or without antipsychotics. Combination treatment with antipsychotics and mood stabilizer resulted in greater weight gain than monotherapy with an antipsychotic or mood stabilizer.

Limitations: The short-term assessment (4 weeks) of weight change and the lack of variables previously reported to be related to weight gain, such as number of depressive episodes, warrant caution in the interpretation of our results.

Conclusions: Even during short period of acute treatment, bipolar patients showed significant weight gain and became obese in a closed-ward setting. Clinicians prescribing combination therapies should pay more attention to weight gain and obesity.