Associations Between High-Density Lipoprotein Cholesterol Efflux and Brain Grey Matter Volume.

Area of Science:

• Neuroscience
• Cardiovascular Science
• Aging Research

Background:

• High-density lipoprotein (HDL) cholesterol efflux function may protect against brain amyloid beta deposition and neurodegeneration.
• The relevance of HDL's role in brain health is not well-established in diverse middle-aged populations.

Purpose of the Study:

• To investigate the association between HDL measures and brain structure and function in a diverse middle-aged population.
• To determine if HDL cholesterol efflux capacity (HDL-CEC) and HDL particle size are related to brain imaging and cognitive outcomes.

Main Methods:

• Utilized data from 1826 adults in the Dallas Heart Study, including 47% Black adults.
• Assessed brain structure (white matter hyperintensities, grey matter volume) via MRI and neurocognitive function using the Montreal Cognitive Assessment (MoCA).
• Measured HDL-CEC and HDL particle size using established laboratory techniques (fluorescence-based cholesterol efflux and NMR spectroscopy).

Main Results:

• Higher HDL-CEC and small HDL particle (HDL-P) concentration were significantly associated with increased grey matter volume normalized to total cranial volume (GMV/TCV) (p=0.002 and p=0.012, respectively).
• No significant associations were found between HDL measures and white matter hyperintensities or MoCA scores.
• These associations were consistent across different ApoE-ε4 statuses and racial/ethnic groups.

Conclusions:

• Increased HDL cholesterol efflux and higher concentrations of small HDL particles are associated with greater grey matter volume.
• These findings suggest a potential neuroprotective role for HDL in maintaining brain structure.
• Further research is needed to fully understand the neuroprotective mechanisms of HDL.