Gender differences and age-related white matter changes of the human brain: a diffusion tensor imaging study

Area of Science:

• Neuroimaging
• Neuroscience
• Radiology

Background:

• Cerebral white matter integrity changes naturally with aging.
• Understanding age- and gender-related white matter alterations is crucial for neurodegenerative disease research.

Purpose of the Study:

• To investigate the association between age, gender, and white matter microstructure using fractional anisotropy (FA) and mean diffusivity (MD).
• To identify specific brain regions exhibiting age- and gender-related changes in white matter organization.

Main Methods:

• Diffusion tensor magnetic resonance imaging (DT-MRI) was performed on 145 healthy adults aged 30-80 years.
• Analysis included sixteen regions of interest (ROIs) in both brain hemispheres and a complementary voxel-based analysis.
• Global and regional FA and MD values were correlated with age and gender.

Main Results:

• Global fractional anisotropy (FA) showed a significant negative correlation with age across all participants.
• Significant age-related FA decreases were observed in the anterior corpus callosum, bilateral internal capsules, and posterior periventricular regions.
• Females exhibited lower FA than males in right deep temporal regions, with additional gender differences noted in precentral, cingulate, and anterior temporal white matter.

Conclusions:

• White matter microstructure, particularly FA, declines with age, with regional variations in susceptibility.
• Sexual dimorphism in white matter organization exists in specific brain regions, potentially linked to altered diffusion perpendicular to fiber tracts.
• These findings highlight the impact of both aging and gender on brain white matter integrity.