Elevated prevalence of obesity, metabolic syndrome, and cardiovascular risk factors in bipolar disorder

Abstract

Background: Bipolar disorder is associated with excess cardiovascular mortality. We hypothesized outpatients with bipolar disorder would exhibit excess cardiovascular risk factors, particularly among prevalent users of the second-generation antipsychotics associated with weight gain and valproic acid derivatives.

Methods: This chart review of 217 patients with bipolar disorder examined cardiovascular risk factors of the metabolic syndrome. We also evaluated if certain medications were cross-sectionally associated with metabolic syndrome.

Results: Fifty-six patients were not weighed and many did not have available lipid profiles. Over three-quarters of those with available data (n = 161) were overweight or obese (body mass index >or= 25) and nearly half were obese (body mass index >or= 30). A prevalence exceeding general population estimates was also observed for hypertriglyceridemia, elevated blood pressure/hypertension, and elevated fasting glucose/diabetes. Among those with all requisite data (n = 60), over 50% met criteria for National Cholesterol Education Program-defined metabolic syndrome, nearly double the expected prevalence. A trend toward greater prevalence of metabolic syndrome among prevalent users of the second-generation antipsychotics associated with weight gain was observed.

Conclusions: Obesity and the metabolic syndrome were common in patients with bipolar disorder. These patients may be under-evaluated for cardiovascular risk and warrant screening and early intervention.

Figure 1

Graphical illustration of metabolic syndrome estimates from current study (restricted sample) contrasted with published general population data. General population data from NHANES 1999–2000 was utilized to provide an expected estimate for our sample based on observed gender proportions. The age distribution of our sample was comparable to the NHANES sample of adults at least 20 years of age. Nearly double the expected prevalence of metabolic syndrome was observed. Prevalent users of the second generation antipsychotics (SGAs) most strongly associated with weight gain (clozapine, risperidone, olanzapine, and quetiapine) had a higher observed metabolic syndrome prevalence though this trend did not reach significance.