Bipolar disorder and metabolic syndrome: a systematic review.

Objective: Summarize data on metabolic syndrome (MS) in bipolar disorder (BD).

Methods: A systematic review of the literature was conducted using the Medline, Embase and PsycInfo databases, using the keywords "metabolic syndrome", "insulin resistance" and "metabolic X syndrome" and cross-referencing them with "bipolar disorder" or "mania". The following types of publications were candidates for review: (i) clinical trials, (ii) studies involving patients diagnosed with bipolar disorder or (iii) data about metabolic syndrome. A 5-point quality scale was used to assess the methodological weight of the studies.

Results: Thirty-nine articles were selected. None of studies reached the maximum quality score of 5 points. The prevalence of MS was significantly higher in BD individuals when compared to a control group. The analysis of MS subcomponents showed that abdominal obesity was heterogeneous. Individuals with BD had significantly higher rates of hypertriglyceridemia than healthy controls. When compared to the general population, there were no significant differences in the prevalence of low HDL-c in individuals with BD. Data on hypertension were also inconclusive. Rates of hyperglycemia were significantly greater in patients with BD compared to the general population.

Conclusions: The overall results point to the presence of an association between BD and MS, as well as between their subcomponents.