Prospective Associations Between Diffusion Tensor Imaging Parameters and Frailty in Older Adults

Area of Science:

• Neuroscience
• Gerontology
• Biomedical Imaging

Background:

• Cross-sectional studies suggest a link between frailty and reduced white matter (WM) integrity.
• Prospective associations between WM integrity and frailty progression remain unclear.

Purpose of the Study:

• To investigate the prospective association between white matter integrity, measured by diffusion tensor imaging (DTI), and the worsening of frailty over five years in community-dwelling older adults.

Main Methods:

• Secondary analysis of the Multidomain Alzheimer Preventive Trial (MAPT) involving 227 participants (mean age 74.7 years).
• DTI parameters (fractional anisotropy, mean diffusivity, axial diffusivity, radial diffusivity) were measured in 10 brain regions.
• Frailty was assessed using the Fried frailty phenotype over five years; mixed-effects models analyzed associations, adjusting for covariates.

Main Results:

• Significant associations were observed between radial diffusivity (RD), axial diffusivity (AxD), and mean diffusivity (MD) in multiple WM tracts and the worsening of frailty over five years.
• Specific brain regions showing significant associations include the anterior limb of the internal capsule, external capsule, and various corona radiata and fasciculus tracts.

Conclusions:

• This study provides the first evidence of an association between white matter integrity and frailty in older adults.
• Further research is needed to elucidate the underlying mechanisms connecting white matter changes and frailty progression.