Five-Year Lower Extremity Function is Associated with White Matter Abnormality in Older Adults

Area of Science:

• Neuroimaging
• Gerontology
• Biomedical Engineering

Background:

• Lower extremity function (LEF) decline is a significant issue in aging populations.
• Understanding the underlying mechanisms of LEF changes is crucial for developing interventions.
• Diffusion tensor imaging (DTI) offers insights into white matter tract (WMT) integrity.

Purpose of the Study:

• To investigate the association between DTI parameters of WMTs and changes in LEF over a 5-year period in community-dwelling older adults.
• To explore whether baseline WMT integrity predicts the progression of physical function decline.

Main Methods:

• Secondary analysis of data from the Multidomain Alzheimer's Preventive Trial (MAPT) ancillary MRI study.
• Assessed 48 WMTs using DTI parameters in 208 older adults.
• Measured LEF via Short Physical Performance Battery (SPPB) score, gait speed, and chair stands time over 5 years.
• Utilized mixed-effects models and Bonferroni correction to analyze associations.

Main Results:

• Significant associations were found between 35 baseline DTI parameters from 24 WMTs and LEF progression.
• Higher DTI values correlated with decreased SPPB scores and gait speed, and increased chair stands time.
• The bilateral uncinate fasciculus showed associations with all LEF parameters, alongside other key WMTs.

Conclusions:

• Baseline DTI parameters of specific WMTs are associated with a 5-year decline in LEF.
• Alterations in WMT integrity, as measured by DTI, may serve as indicators for impaired mobility in older adults.
• This research highlights the potential of neuroimaging to elucidate the pathophysiology of mobility loss in aging.