Sex differences in default mode network connectivity in healthy aging adults

Area of Science:

• Neuroscience
• Neuroimaging
• Aging Research

Background:

• Women have a higher lifetime risk of Alzheimer's disease (AD).
• Default mode network (DMN) connectivity changes are linked to AD, but sex differences in aging DMN function are unclear.

Purpose of the Study:

• To investigate sex differences in DMN functional connectivity across the lifespan in cognitively healthy adults.
• To explore how these differences relate to aging and potential preclinical AD markers.

Main Methods:

• Utilized intrinsic connectivity distribution and seed connectivity analyses.
• Examined functional connectivity within the DMN and between the DMN and the whole brain.
• Included 595 healthy participants from the Human Connectome Project-Aging cohort.

Main Results:

• Women showed increased age-related connectivity in posterior DMN nodes and decreased connectivity in the medial prefrontal cortex compared to men.
• These sex differences were most pronounced around menopause.
• Higher posterior cingulate to angular gyrus connectivity in women correlated with better declarative memory and hippocampus function.

Conclusions:

• Significant sex differences exist in DMN connectivity patterns throughout aging.
• Observed patterns in aging women may resemble changes seen in preclinical AD, underscoring the importance of sex as a biological variable in neuroimaging studies of aging and neurodegeneration.