Association Between Metabolic Syndrome, Obesity, and Cognitive Performances in Individuals With Bipolar Disorders: Cross‐Sectional and Longitudinal Analyses in the FACE‐BD Cohort

TL;DR

This study finds that metabolic syndrome is linked to worse cognitive performance in people with bipolar disorder, but not to cognitive decline over time.

Contribution

The study provides new cross-sectional and longitudinal evidence on the cognitive impact of metabolic syndrome in bipolar disorder.

Findings

Metabolic syndrome is associated with poorer cognitive performance in individuals with bipolar disorder.

Longitudinal analysis found no significant cognitive decline linked to metabolic syndrome over two years.

Cognitive flexibility, inhibition, and verbal memory were specifically affected by metabolic syndrome.

Abstract

Metabolic syndrome (MetS) has been suggested to be associated with cognitive impairments in bipolar disorder (BD); however, studies are limited by small sample sizes or cross‐sectional design. Our objective is to evaluate the cross‐sectional and longitudinal associations between MetS and cognitive performances in a large cohort of individuals with BD.

1175 individuals with a DSM‐IV diagnosis of BD were included from the FACE‐BD cohort, assessed with a standardized battery of clinical and neuropsychological tests and followed up with a cognitive retest at 2 years for a subsample (n = 367). A global cognitive index was created by using a Principal Component Analysis. Associations between MetS and cognitive performances at baseline were explored using multiple analyses of covariance and linear mixed models were used for longitudinal data.

The prevalence of MetS was 21.5% in this sample. Multivariable analyses identified associations between MetS and poorer cognitive performance in the cross‐sectional analysis, independently of age, gender, education level, psychotropic treatments, and comorbidities. Specifically, individuals with MetS showed poorer results (global cognitive index, cognitive flexibility, inhibition, and verbal memory). After adjustment, the longitudinal analysis showed no change in the global cognitive index at year 2 and no time × metabolic syndrome interaction.

Our results suggest that MetS is cross‐sectionally, but not longitudinally, associated with poorer cognitive performances in BD. This study highlights the importance of systematically and accurately screening for metabolic abnormalities in individuals with BD, and screening for cognitive deficit especially in individuals with MetS. Our results suggest that MetS is not a risk factor for cognitive decline during the follow‐up, but further longitudinal studies are required.

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