Aging, exceptional longevity and comparisons of the Hannum and Horvath epigenetic clocks.
Level 4 - case-series / case-control
Cross-sectional observational study across three cohorts
PubMed 28470125 · doi:10.2217/epi-2016-0179
What was done
Researchers measured blood DNA methylation (Illumina 450K array) in 275 participants aged 34 to 103 years across three adult cohorts. Epigenetic age (DNAm age) and age acceleration measures were calculated using the Hannum and Horvath epigenetic clocks to evaluate their performance across aging and in exceptional longevity (Sydney Centenarian Study, age 95+, n = 23).
What was found
DNAm age correlated with chronological age across all cohorts. In the long-lived cohort (n = 23), DNAm age was lower than chronological age for both clocks. Mean Hannum age acceleration was negative in the centenarian cohort, whereas the Horvath model showed positive age acceleration. Specific numerical values, correlation coefficients, and effect sizes were not reported in the abstract.
Why it matters
This paper demonstrates that individuals with exceptional longevity show younger biological profiles on standard epigenetic clocks, while highlighting that different clock algorithms can yield conflicting age acceleration results in the oldest-old.
Limits
The exceptional longevity subgroup was very small (n = 23). The cross-sectional design cannot determine whether slower epigenetic aging causes longevity or reflects survivor bias. No numerical statistics or confidence intervals were provided in the abstract.
Cited by
- supports The blood epigenetic age of centenarians and supercentenarians is measured to be substantially younger than their chronological age, potentially up to 15 years younger.