Alzheimer’s and aging: Brain-derived neurotrophic factor may protect against cognitive decline

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Takeaway

  • Higher gene expression levels of brain-derived neurotrophic factor (BDNF) are linked to slower cognitive decline with aging and Alzheimer’s (AD) pathology.

 

Study design/methods

  • 535 older adults had annual cognitive testing until death and brain autopsy including dorsolateral prefrontal cortex measurement of BDNF gene expression.

 

Key Results

  • Before and after adjustment for age, sex, education, and neuropathology, higher brain BDNF was associated with slower cognitive decline (P< .001), with ~50% reduction in decline rate with 90th vs 10th percentile BDNF expression, and strongest association in dementia patients.
  • BDNF was lower in persons with AD pathology (P=.006) but not associated with stroke, Lewy body disease, or hippocampal sclerosis.
  • Effect of BDNF expression on cognitive decline in persons with AD pathology was strongest for high AD pathology levels (P=.015); for 90th percentile AD pathology, cognitive decline was ~40% slower with 90th vs 10th percentile BDNF expression.

 

Limitations

  • Brain tissue analysis requires biopsy or autopsy; BNDF should be studied in CSF or with imaging markers if feasible.

 

Why this matters

  • BDNF may shed light on cognitive decline in aging and AD, hinting at underlying mechanisms, predictive markers, and therapeutic targets.