The obese brain as a heritable phenotype: a combined morphometry and twin study

Area of Science:

• Neuroimaging
• Genetics
• Obesity Research

Background:

• Body weight and adiposity are known heritable traits.
• The genetic control of obesity-associated brain structural alterations remains unclear.

Purpose of the Study:

• To investigate the heritability of brain structural alterations associated with body mass index (BMI).
• To determine the extent to which genetic factors influence the relationship between BMI and brain gray matter volume (GMV).

Main Methods:

• Utilized magnetic resonance imaging (MRI) data from the Human Connectome Project (n=875).
• Employed voxel-based morphometry to assess associations between BMI and regional GMV.
• Analyzed twin data (86 monozygotic, 82 dizygotic pairs) using an additive genetic, common environmental, and residual effects model to estimate heritability.

Main Results:

• Observed positive associations between BMI and GMV in the ventromedial prefrontal cortex and right cerebellum.
• Found widespread negative associations between BMI and GMV in prefrontal cortex, cerebellum, temporal lobes, and subcortical structures.
• Identified varying heritability for BMI-associated brain regions, with highest estimates for cerebellar GMV and subcortical structures.

Conclusions:

• Brain regions associated with obesity are influenced by different levels of genetic control and environmental factors.
• Specific brain regions exhibiting high heritability may represent inherent vulnerability factors for obesity.
• Genetic influences play a significant role in the structural brain differences observed in relation to BMI.