The prevalence of metabolic syndrome in drug-naïve bipolar II disorder patients before and after twelve week pharmacological intervention

Background: Accumulating evidence indicates a high prevalence rate of metabolic disturbance in bipolar disorder (BP) patients. However, the prevalence across BP subtypes has been investigated to a lesser degree. In the current study, we surveyed the prevalence of metabolic syndrome among drug-naïve bipolar II patients. Moreover, the effects of pharmacological treatment on metabolic indexes were also evaluated.

Methods: This study recruited fifty-six drug-naïve BP II patients diagnosed according to the DSM-IV criteria. Among them, forty-four patients completed a 12-week pharmacological intervention with valproic acid, fluoxetine and lorazepam. Metabolic profiles and body mass index (BMI) were measured at baseline and 2 weeks, 8 weeks, and 12 weeks after receiving medication.

Results: The mean age of the 56 patients was 30.3±11.1. Before receiving medication, 6.5% of the patients met the ATP III criterion for metabolic syndrome. Among the 44 patients who completed the 12-week pharmacological intervention, the prevalence of metabolic syndrome increased from 7% to 10%. Repeated measurements showed that the changes in metabolic indexes were not significant, with the exceptions of BMI, waist circumference, and buttock circumference. In addition, the interaction between the improvement of hypomanic symptoms and BMI change was significant.

Limitations: The study was limited by the follow-up duration and sample size.

Conclusions: In drug-naïve BP II patients, the prevalence of metabolic syndrome was significantly lower than that observed before in BP I patients. However, medications use was also associated with an increased risk of metabolic disturbance, although the impact was lesser. Clinical evidence suggests that metabolism and emotion homeostasis might share common mechanisms.