Telomere length and brain aging: A systematic review and meta-analysis

Area of Science:

• Neuroscience
• Genetics
• Gerontology

Background:

• Leukocyte telomere length (LTL) is a biomarker of cellular aging.
• Existing research on LTL's association with brain structure and cognition is inconsistent.
• Age-related cognitive decline and brain changes are significant public health concerns.

Purpose of the Study:

• To systematically review and meta-analyze the evidence linking LTL to brain structure and cognitive function in non-demented individuals.
• To clarify the relationship between LTL and age-related brain changes.
• To identify potential subgroup-specific effects of LTL on brain health.

Main Methods:

• Systematic review and meta-analysis adhering to PRISMA 2020 guidelines.
• Inclusion of data from 27 observational studies involving non-demented participants.
• Application of both effect size and p-value based meta-analysis methods to account for study heterogeneity.

Main Results:

• Longer LTL was significantly associated with increased brain volume and higher global cognitive function.
• P-value based meta-analysis confirmed associations with brain volume, hippocampal volume, global cognition, attention/speed, and executive functions.
• No significant link was found between LTL and brain white matter hyperintensities.
• Evidence suggests a stronger beneficial effect of LTL in older adults and females.

Conclusions:

• Meta-analytic evidence supports a beneficial role of telomere length in maintaining brain structure and cognitive function.
• A subgroup-specific effect of telomeres, particularly in older individuals and females, warrants further investigation.
• Findings highlight the potential of LTL as a biomarker for brain health across the lifespan.