A Mitochondrial DNA Haplogroup Defines Patterns of Five-Year Cognitive Change

Area of Science:

• Neuroscience
• Genetics
• Gerontology

Background:

• Mitochondrial DNA (mtDNA) is implicated in Alzheimer's disease (AD) and cognitive decline.
• mtDNA haplogroup J is more prevalent in AD patients than in controls.

Purpose of the Study:

• To investigate the association between mtDNA haplogroups (H and J) and cognitive performance changes over five years.
• To test the hypothesis that haplogroup J carriers exhibit reduced cognitive resilience.

Main Methods:

• Analysis of data from 140 cognitively normal older adults.
• Factor analysis to derive composite scores for verbal memory, attention, and executive function.
• Latent growth curve modeling to assess cognitive trajectories, adjusting for covariates.

Main Results:

• Haplogroup J carriers showed significantly lower baseline verbal memory performance compared to haplogroup H carriers.
• Haplogroup J carriers demonstrated slower rates of improvement in verbal memory over five years.
• No significant differences were found in executive function or attention between haplogroups.

Conclusions:

• mtDNA plays a role in cognitive function changes, specifically impacting verbal memory, a domain relevant to dementia risk.
• The findings highlight the domain-specific effects of mtDNA on cognition, warranting further investigation into underlying mechanisms.