Journal: J Gerontol A Biol Sci Med Sci

Doi: 10.1093/gerona/glac190

Purva Jain et al

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Abstract
Background: Epigenetic age acceleration (EAA), a measure of accelerated biological aging, has been associated with increased risk of several age-related chronic conditions. This is the first study to prospectively examine the relationship between EAA and both multimorbidity count and a weighted multimorbidity score among long-lived postmenopausal women.

Methods: We included 1,951 women from the Women's Health Initiative who could have survived to age 90. EAA was estimated using the Horvath pan-tissue, Hannum, PhenoAge and GrimAge "clocks." Twelve chronic conditions were included in the multimorbidity count. The multimorbidity score was weighted for each morbidity's relationship with mortality in the study population. Using mixed-effects Poisson and linear regression models that included baseline covariates associated with both EAA and multimorbidity, we estimated relative risks (RRs) and 95% confidence intervals (CIs) for the relationships between each EAA measure at study baseline with both multimorbidity count and weighted multimorbidity score at age 90, respectively.

Results: For every one-standard deviation increase in AgeAccelPheno, the rate of multimorbidity accumulation increased 6% (RR=1.06; 95% CI=1.01-1.12; p=0.025) and the multimorbidity score by 7% (RR=1.07; 95% CI=1.01-1.13; p=0.014) for women who survived to age 90. The results for a one-standard deviation increase in AgeAccelHorvath, AgeAccelHannum and AgeAccelGrim with multimorbidity accumulation and score were weaker compared to AgeAccelPheno, and the latter two did not reach statistical significance.

Conclusion: AgeAccelPheno and AgeAccelHannum may predict multimorbidity count and score at age 90 in older women and, thus, may be useful as a biomarker predictor of multimorbidity burden in the last decades of life.

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