Accelerated Epigenetic Age in Normal Cognitive Aging of Korean Community-Dwelling Older Adults.

Abstract

Epigenetic age acceleration has been studied as a promising biomarker of age-related conditions, including cognitive aging. This pilot study aims to explore potential cognitive aging-related biomarkers by investigating the relationship of epigenetic age acceleration and cognitive function and by examining the epigenetic age acceleration differences between successful cognitive aging (SCA) and normal cognitive aging (NCA) among Korean community-dwelling older adults (CDOAs). We used data and blood samples of Korean CDOAs from the Korean Frailty and Aging Cohort Study. The participants were classified into two groups, SCA (above the 50th percentile in all domains of cognitive function) and NCA. The genome-wide DNA methylation profiling array using Illumina Infinium MethylationEPIC BeadChip was used to calculate the following: the DNA methylation age, universal epigenetic age acceleration, intrinsic epigenetic age acceleration (IEAA), and extrinsic epigenetic age acceleration (EEAA). We also used Pearson correlation analysis and independent t-tests to analyze the data. Universal age acceleration correlated with the Frontal Assessment Battery test results (r = -0.42, p = 0.025); the EEAA correlated with the Word List Recognition test results (r = -0.41, p = 0.027). There was a significant difference between SCA and NCA groups in IEAA (p = 0.041, Cohen's d = 0.82) and EEAA (p = 0.042, Cohen's d = 0.78). Epigenetic age acceleration can be used as a biomarker for early detection of cognitive decline in Korean community-dwelling older adults. Large longitudinal studies are warranted.