Abstract
Background: Cognitive function measured by digital clock drawing test (dCDT) has drawn
attention for their precision, automation, and reproductivity. However, the relationship between
digital cognitive metrics and biological aging is lacking.
Methods
We conducted association analyses between cognitive function measured by dCDT
and biological aging metrics quantified by five DNA methylation (DNAm) age metrics (Horvath,
Hannum, GrimAge, PhenoAge, and DunedinPACE) in the Framingham Heart Study (FHS). We
conducted linear regression to investigate the association between cognitive functions (global
cognitive function and four sub-domain functions) and DNAm age acceleration, adjusting for
covariates. We used a false discovery rate (FDR) < 0.05 for significance.
Results
Among the 1,798 FHS participants (mean age 65±13, 53% women), we found that a
lower dCDT total score is associated with DNAm age acceleration. Larger magnitudes of
associations were observed in older participants (≥ 65 years). The dCDT total score showed the
strongest association with the DundinPACE in the pooled sample (beta = -2.1, FDR = 0.0004),
the younger (beta = -1.9, FDR = 0.02), and older age group (beta = -2.2, FDR = 0.01). The dCDT
total score was significantly associated with age acceleration estimated by Horvath (beta=-1.9,
FDR =0.01) and PhenoAge (beta=-2.5, FDR=0.01) in older participants while not in the pooled
sample or younger participants (<65 years). In sub-domain cognitive functions, we found that
simple motor function was significantly associated with DunedinPACE (FDR = 0.005) in both
age groups and associated with GrimAge (FDR = 0.05 in older age group), indicating the
deterioration in various organ systems may particularly impact this domain.
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Discussion
Our findings suggest that cognitive function measured by a digital clock drawing
test is associated with DNAm age acceleration in middle-aged and older participants in the FHS,
potentially shedding light on the epigenetic mechanisms underlying digitally measured cognitive
function.
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Introduction
Cognitive function, representing a crucial aspect of overall brain health, encompasses
various domains such as memory, reasoning, and attention1. Neuropsychological (NP) tests are
typically used to measure cognitive functions for individuals, focusing on one or several specific
cognitive domains. For example, the traditional clock drawing test evaluates spatial dysfunction
and neglect2, conducted with pen on paper. However, the assessment of the NP test is often
biased. The use of computerized devices in NP tests is gaining recognition for their efficiency,
precision, automation, and reproductivity nature3. The Digital Clock Drawing test (dCDT), an
extension of the traditional clock drawing test, evaluates the overall cognitive function and
specific sub-domains such as motor function, memory, spatial reasoning, and information
processing4. Previous research has demonstrated strong associations of dCDT performance with
mild cognitive impairment5, and with clinical indices of neurodegeneration, such as brain
volume6 and NP tests5, showing a comparable performance between dCDT and other NP tests.
Compared to traditional NP tests, dCDT can capture more subtle cognitive changes7.
Aging is an inevitable process for humans, resulting in a decline in physiological capacity
and an increasing risk of various disease conditions8, including neurodegenerative diseases9.
Biological aging, the changes at the molecular level10,11, is essential to understand the
heterogeneity in healthy aging12. Epigenetic modifications, such as DNA methylation (DNAm),
measure biological aging at the epigenetic level13-15. DNAm age16 has been associated with
general health17,18 and neurodegenerative diseases19. The first generation of epigenetic clocks use
methylation levels across varying numbers of 5'-C-phosphate-G-3'(CpG) sites with a few clinical
markers to predict chronological age16,20. Subsequent generations of epigenetic clocks have
incorporated additional clinical measurements to enhance their accuracy for age prediction21-23.
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DNAm age acceleration is assessed by regressing the estimated DNAm age on chronological
age24.
Studies have established correlations between traditional cognitive assessments and
DNAm age acceleration25, showing the possibility that DNAm age acceleration is a risk factor or
marker for cognitive function decline. However, research on the relationship between cognitive
function measured by digital devices and DNAm age acceleration is currently lacking. Our study
aimed to fill in this gap. We hypothesize that cognitive function measured by digital devices is
associated with DNAm aging. We investigated the associations of overall cognitive function and
specific sub-domains measured by DCTclock with several DNAm-based age acceleration
metrics in the Framingham Heart Study (FHS). We seek to gain additional insights into the
underlying molecular mechanism of cognitive function measured by digital devices.
Methods
Study populations
FHS, initiated in 1948, is an epidemiological prospective cohort to study risk factors for CVD26.
All FHS cohorts, including the original cohort (Gen1), offspring cohort (Gen2), and third-
generation cohort (Gen3), have undergone routine health examinations every two to six years.
Our study included 1,264 Gen2 participants at exam 8 (2005-2008) and 688 Gen3 participants at
exam 2 (2008-2011). We excluded participants whose blood samples were not collected at exam
or who did not attend dCDT (2011 -2018). After excluding participants with covariates (e.g.,
age, gender, education, cell counts) missing, we included 1,789 participants (Figure 1) in our
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statistical analyses. For participants with multiple dCDT tests, we selected dCDT data closest to
DNA methylation measurement dates for inclusion in our study.
DCTclock
DCTclock serves as an FDA-approved automated screening tool for detecting cognitive
changes4. Data collection for dCDT using DCTclock involved utilizing computerized
neuropsychological assessment devices: digital pen and digital paper. Following the standard
protocol, participants were instructed to draw clocks with the command '10 after 11' and then
replicated another clock by copying a provided model27,28. Both the drawing process and the
final drawing results were recorded, capturing spatial and temporal data, and analyzed through
the DCTclock pipeline. These data were treated as input to a trained convolutional neural
network to recognize individual symbols with classification probability (e.g., clock face, digits,
and small noise stocks). After classifying the individual symbols in drawing, these symbols were
used to derive various measurements, such as the correct placement of clock components and
pen speed. These measurements were organized into four groups representing different cognitive
aspects: Drawing Efficiency, Simple and Complex Motor, Information Processing, and Spatial
Reasoning. Drawing efficiency, for instance, evaluated the efficiency in terms of the time spent
on drawing and the size of the drawing. Similarly, Simple and Complex Motor measurements
represented motor and non-motor cognitive functions, including maximum movement speed.
Information Processing focused on cognitive functions like thinking time and latencies, while
Spatial Reasoning focused on spatial abilities through geometric property measurements. A
composite score was calculated for each cognitive aspect mentioned above using a Lasso
regularized logistic regression model4, incorporating all the measurements as parameters. Given
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the performance of two tasks (command and copy), eight sub-domain scores were generated.
Additionally, a dCDT total score was computed using a Lasso logistic regression model4. Both
sub-domain scores and the total score range from 0 to 100.
DNAm measurements
DNAm adds a methyl group onto the 5th carbon of cytosine to form 5-methylcytosine29. DNAm
measurements were conducted using whole blood samples collected during exam 8 for Gen2 and
exam 2 for Gen3. DNAm profiling was carried out through a series of procedures, including
bisulfite conversion, whole genome amplification, fragmentation, array hybridization, and
single-base pair extension30. The Illumina Human Methylation 450K Bead chips (Illumina Inc.,
San Diego, CA) were employed to analyze the DNA methylation levels across three different
laboratories. Detailed information regarding DNAm quantification and quality control
procedures in FHS had been previously documented31.
DNAm aging metrics
DNAm age is an estimator of aging based on DNAm patterns. Three generations of epigenetic
clocks were calculated. The first generation, Horvath’s age16 and Hannum’s age20, utilize a set of
CpG sites to estimate DNAm age. Horvath’s age calculated a weighted average of 353 clock
CpGs with a calibration function to estimate aging from multiple tissues. Hannum’s age
considered 71 CpG sites along with a few clinical parameters (gender, BMI, etc.) to predict aging
in whole blood samples. GrimAge22 and PhenoAge23 are the second-generation DNAm aging
metrics. Both methods calculated the DNAm age by integrating methylation levels with clinical
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markers. GrimAge first utilized DNAm data to estimate each plasma protein biomarker and
smoking pack years. Then, 7 DNAm-based plasma protein biomarkers and DNAm-based
smoking pack year were selected, which included 1,030 unique CpG sites along with gender and
chronological age to predict time to death22. PhenoAge selected 513 CpGs to predict a linear
combination of chronological age and nine clinical markers (e.g., Albumin, White blood cell
count), which predicted the time to death23. We employed the principal component version of
epigenetic clocks (PC-based clocks) to minimize unobserved technical confounders32. The
DNAm age acceleration for the first- and second-generation aging metrics were residuals
calculated by regressing each DNAm age on chronological age. Residuals larger than zero will
be considered as accelerated aging. The third generation, DunedinPACE, differed from the
previous generations by predicting the pace of aging per year rather than age in years21. The pace
of aging was calculated from 173 CpGs based on longitudinal change of 19 clinical biomarkers
(e.g., blood pressure, total cholesterol, blood urea nitrogen), representing an average rate of
biological aging per year of 1-year chronological age21. This pace of aging was used as DNAm
age acceleration for the following analysis.
Covariates
Covariates included the age at the dCDT, the time interval between the dCDT and blood sample
collection, gender, educational level, cell count information, and family relationship. The time
interval was computed as the age at the dCDT minus the age at blood sample collection.
Educational levels were categorized into four groups: less than high school completion, high
school graduate, some college, and college graduate. Cell count information was derived from
DNAm data. We included the count number of Cytotoxic T cells (CD8+T), B lymphocytes
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(CD19+ B), granulocytes (Gran), monocytes (Mono), Natural killer cells (NK), and Helper T
Cells (CD4+T) as covariates. Family relationships were included as random effects in the model.
Statistical analysis
The primary analysis explored the relationship between the dCDT total score as the outcome
variable and various DNAm aging metrics as the predictor variables. The residuals were
computed by regressing the DNAm age metrics on chronological age to obtain DNAm age
acceleration. The residuals were used as DNAm age acceleration in the following analysis. To
facilitate interpretation, we standardized the DNAm age residuals to have a mean of 0 with
a standard deviation (SD) of 1. Participants were stratified into two age groups (<65 and ≥65
years), using age at blood sample collection, to address for age modification effects in the
associations. Linear mixed models were employed to assess the association between the dCDT
total score and DNAm aging metrics. We adjusted for age at the dCDT, gender, and educational
level and used family as a random effect in both combined samples and age-stratified analyses.
To investigate the association between dCDT sub-domain scores and DNAm aging metrics,
linear mixed models were employed with the same set of covariates. The False Discovery Rate
(FDR) method33 was applied to adjust for multiple testing34.
Result
Participant characteristics
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This study included 1,789 middle-aged and older participants in FHS (mean age 65 ±13 at
dCDT, 53% women) (Table 1). On average, DNAm was measured seven years before the dCDT
measurement (Supplementary Figure 1). Education levels were significantly higher in the
younger age group (<65 years) compared to the older age group (≥65 years). On average,
participants in the younger age group exhibited higher dCDT total score and sub-domain scores
compared to those in the older age group (all p <0.001). The average estimated DNAm ages
differed between DNAm metrics (Supplemental Table 2). For instance, the mean Hannum age
was estimated at 62, while the Horvath age was estimated at 53 in pooled samples. Compared to
the mean chronological age, the mean DNAm ages calculated by Hannum, GrimAge, and
DunedinPACE showed acceleration (with DNAm age higher than chronological age) in the
pooled sample, whereas PhenoAge and Horvath showed lower mean DNAm ages than the mean
chronological age. We further observed that, except for DunedinPACE, males tended to have
advanced DNAm ages compared to females (Supplemental Table 3).
Association between dCDT total score and DNA methylation age acceleration
In the pooled sample, we observed that a higher dCDT total score was associated with lower
DNAm age estimated by all DNAm aging metrics (Figure 2). However, the association was
significant only for DunedinPACE, where a one-SD higher level in the pace of aging was
associated with a 2.1-unit lower level in the dCDT total score (FDR=0.0004) (Figure 2).
Age showed a significant effect modification of the association (p = 0.004) with DunedinPACE
but not for other epigenetic age metrics (Supplemental Table 4). Thus, we conducted stratified
analyses by age groups for all DNAm age metrics. In the younger age group (<65 years),
DunedinPACE was the only DNAm metric associated with the dCDT total score (beta = -1.9,
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FDR = 0.02). In contrast, in the older age group, three DNAm aging metrics were significantly
associated with the dCDT total score: DunedinPACE (beta=-2.2, FDR=0.01), DNAm age
acceleration estimated by Horvath (beta=-1.9, FDR=0.01) and PhenoAge (beta=-2.5,
FDR=0.01). Although the association between dCDT total score and other DNAm aging metrics
was not significant, the directionality of the associations was consistent in both older and
younger age groups (Figure 3, Supplementary Figure 3).
Association between dCDT sub-domain scores and DNA methylation age acceleration
In the pooled sample, we observed a significant association between DunedinPACE and both the
dCDT simple motor function score in the command task (FDR = 0.01) and the spatial reasoning
score from the copy task (FDR = 0.01). A one-SD higher level in the pace of aging was
associated with a 0.7-unit decrease in the dCDT simple motor function score and a 1.6-unit
decrease in the spatial reasoning score. GrimAge was also found to be significantly associated
with the dCDT simple motor function score in both the copy task (beta = -0.7, FDR = 0.005) and
command task (beta=-0.9, FDR = 0.005) in the pooled sample. No other significant association
was found between the other epigenetic age acceleration metrics and the dCDT sub-domain
score in the pooled sample (Figure 2).
Different from the result in the pooled sample, we only observed similar results for
GrimAge in the older age group (>65 years), where a one-SD increase in GrimAge is
significantly associated with a 1.1-unit decrease in dCDT simple motor function score in
command task (FDR = 0.04) (Supplementary Figure 2). In addition, PhenoAge was
significantly associated with the dCDT simple motor function score in the command task (beta
=-1.0, FDR = 0.04). While no significant association was found between dCDT sub-domain
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scores and DNAm age in the younger age group, the directionality was consistent for most
associations in both younger and older age groups (Supplementary Figure 2, 3).
Discussion
In this study, we investigated the association between cognitive function measured by the dCDT
and DNAm aging metrics in 1,789 middle-aged and older participants in the FHS. We found that
lower dCDT total scores were consistently associated with advanced biological age quantified by
DNAm aging metrics. Among all DNAm aging metrics, DunedinPACE showed significant
association with the dCDT total score in the pooled sample, younger (<65 years), and older (≥ 65
years) age groups. In contrast, several other DNAm aging metrics showed significant
associations with the dCDT total score only in the older participant group.
As the need for early diagnosis in the preclinical stage of AD grows, advanced screening
tools for cognition are desired to capture subtle cognitive changes35. The dCDT has drawn
attention for its efficiency, precision, automation, and reproductivity3. It has been demonstrated
to be effective in distinguishing cognitive impairment from normal function4,7. Additionally, it is
comparable to established NP tests, such as the Wechsler Memory Scale and Boston Naming
Test, in discriminating between participants with mild cognitive impairment (MCI)6 and those
with normal function. Unlike traditional paper and pen tests, the dCDT captures more granular
data, including visuospatial, time-base, and kinematic details, offering a more detailed
assessment. Its automated scoring system provides clinicians with objective and interpretable
results4.
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DNAm is a crucial epigenetic modification that influences gene expression without
altering the underlying DNA sequence29. By incorporating different sets of CpG sites, the three
generations of epigenetic age metrics offer varied perspectives on biological aging. Unlike the
first- and second-generation clocks, which primarily estimate DNAm aging based on
chronological age, clinical markers and time to death16,20, the third-generation clock,
DunedinPACE, focuses on a set of different clinical markers (representing the progressive
decline across multiple organ systems captured by multiple CpG sites)21. In our study,
DunedinPACE is negatively associated with overall cognitive function in both younger and older
age groups, while other age clocks only showed significant results in the older age group. These
findings indicate that global cognition function, which is an indicator of brain health, may reflect
the aging rates of multiple organ systems.
The analysis of dCDT sub-domain scores with DNAm age provides additional insights
into how epigenetic aging may influence specific cognitive domains. For instance, the simple
motor function and spatial reasoning sub-domain scores show significant associations with
DunedinPACE, indicating that the deterioration in various organ systems may particularly
impact these domains. GrimAge is based on seven plasma protein markers related to various
diseases and conditions, including cardiovascular disease (Plasma B2M) and cognitive functions
(Plasma B2M, ADM, cystatin C, and leptin)16. Our observation that simple motor function was
associated with advanced GrimAge age indicates that the decline of simple motor functions
might be related to abnormal levels of these protein markers in the plasma. Future studies are
necessary to investigate the associations of these plasma proteins with cognitive decline.
Digital cognitive measures displayed stronger associations with most DNAm aging
metrics among older (≥65 years) compared to younger (<65 years) participants, likely to reflect
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the cumulative and nonlinear age influences on both brain health and DNAm. This is consistent
with our earlier findings of stronger associations between alcohol consumption and epigenetic
age metrics38. For instance, overall cognitive function exhibited significant associations with
PhenoAge in the older age group while not in the younger age group. In contrast, the global
cognitive function score was associated with DunedinPACE in both age groups, indicating that
DunedinPACE might be more sensitive to capturing the subtle influence of variations in the pace
of aging on cognitive changes.
Several similar studies have investigated the association of cognitive function measured
by traditional methods with DNAm aging metrics. Marioni et al.39 reported that general cognitive
ability was associated with Horvath age in participants over the age of seventy. Our findings,
using the dCDT, are consistent with this, showing similar associations with total score in older
participants (65 years and above). Another study assessed how various cognitive tests (e.g.,
MMSE, ADAS-Cog-13, MoCA) associated with DNAm age acceleration in participants with
a mean age of seventy-five25. They found that the faster pace of aging measured by
DunedinPACE correlates with more severe cognitive decline25. Our results align with this,
showing that worse cognitive function was associated with DunedinPACE, with a larger
magnitude in older participants. Furthermore, our findings that higher PhenoAge and
DunedinPACE were associated with poorer performance scores in older participants were also
consistent with the previous findings, where they found that higher PhenoAge and
DunedinPACE are associated with worse cognitive performance25.
Our study has limitations, including a lack of diversity (all participants were Whites) in
our study sample. Further research with diverse groups is needed. In addition, there is an
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approximate 7-year gap between DNA methylation measurement and dCDT. This may introduce
biases due to changes in DNA methylation levels and clinical conditions. Our study has several
strengths. We employed the dCDT to measure cognitive function, which is a novel measure for
assessing cognitive function. In addition, we employed PC-based clocks, which use principal
components to reduce noise and enhance accuracy. To mitigate multiple testing, we applied FDR
adjustment, which is more appropriate than Bonferroni correction for the presence of correlated
outcome and predictor variables.
In conclusion, our study investigated how digital cognitive function assessed by dCDT relates to
biological aging, measured by DNAm. These findings highlight the potential role of DNA
methylation in cognitive function. Further research is needed to uncover the underlying
biological pathways behind this association, particularly in more diverse populations.
Fundings
This work was supported by the National Heart, Lung, and Blood Institute contract (N01-HC-
25195; HHSN268201500001I) and grants from the National Institute on Aging (AG008122,
AG062109, AG068753).
Conflict of Interest
Dr. Au is a scientific advisor to Signant Health and Novo Nordisk. The other authors have no
conflict of interest.
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Table 1. Demographic and Clinical characteristics of study participants
Total Age below
65
Age above
or equal
to 65 P-value
(n=1789) (n=804) (n=985)
Female, n (%) 955 (53 %) 407 (51 %) 548 (56 %) 0.208
Age at dCDT (years) 65 (± 13) 54 (± 8) 75 (± 7)
Age at DNAm (years) 58 (± 12) 48 (± 7) 67 (± 7)
Education levels, n (%)
Incomplete high school 30 (2 %) 6 (1 %) 24 (2 %) <0.001
High school graduate 332 (19 %) 108 (13 %) 224 (23 %)
Some college 556 (31 %) 231 (29 %) 325 (33 %)
College graduate or above 871 (49 %) 459 (57 %) 412 (42 %)
Dementia 51 (3 %) 0 (0 %) 51 (5 %) <0.001
Note: In this study, we used age at DNAm for age group stratification. Mean with standard deviation
(SD) was provided for a continuous variable, while count and proportion were provided for categorical
variables.
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Figure 1. Flow chart of study design. The participation of dCDT was solely based on consent.
In the Framingham Heart Study, we identified participants with digital clock drawing test
(dCDT) measurements and DNA methylation (DNAm). Five DNAm age metrics were
calculated. Epigenetic (DNAm) age acceleration (EAA) was calculated by regression of the
DNAm age metrics on chronological age. Primary analysis focused on the association between
dCDT total scores and EAAs, whereas secondary analysis focused on the association between
dCDT sub-domain scores and EAAs.
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Figure 2. Association between dCDT scores and DNAm age acceleration in 1789
participants of the Framingham Heart Study. The dCDT total score includes command task
composite scores and copy task composite scores. DNA methylation age acceleration was obtained by
regressing DNAm age metrics on chronological age. We conducted association analysis between
standardized DNAm age acceleration and the dCDT total score, adjusted for age, gender, and education.
The numbers inside each cell represent the P-values of the associations. The color represents the change
in dCDT scores corresponding to a one SD increase in DNAm age acceleration.
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Figure 3. Comparison of effect size in the association between DNAm age acceleration and
the dCDT total score. DNAm age acceleration was obtained by regressing DNA methylation
(DNAm) metrics on chronological aging, followed by standardization with a mean of zero and SD of one.
We conducted an association analysis between the dCDT total score and standardized DNAm age
acceleration. CI, confidence interval.
Unit change in dCDT total score in
response to one SD increase of EAA
Epigenetic age
acceleration
Effect size (95%CI)
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References
1. Fisher GG, Chacon M, Chaffee DS. Chapter 2 - Theories of Cognitive Aging and Work. In: Baltes
BB, Rudolph CW, Zacher H, eds. Work Across the Lifespan. Academic Press; 2019:17-45.
2. Agrell B, Dehlin O. The clock-drawing test. Age and Ageing. 2012;41(suppl_3):iii41-iii45.
doi:10.1093/ageing/afs149
3. Bauer RM, Iverson GL, Cernich AN, Binder LM, Ruff RM, Naugle RI. Computerized
Neuropsychological Assessment Devices: Joint Position Paper of the American Academy of Clinical
Neuropsychology and the National Academy of Neuropsychology†. Archives of Clinical Neuropsychology.
2012;27(3):362-373. doi:10.1093/arclin/acs027
4. Souillard-Mandar W, Penney D, Schaible B, Pascual-Leone A, Au R, Davis R. DCTclock: Clinically-
Interpretable and Automated Artificial Intelligence Analysis of Drawing Behavior for Capturing Cognition.
Frontiers in Digital Health. 2021;3doi:10.3389/fdgth.2021.750661
5. Yuan J, Libon DJ, Karjadi C, et al. Association Between the Digital Clock Drawing Test and
Neuropsychological Test Performance: Large Community-Based Prospective Cohort (Framingham Heart
Study). J Med Internet Res. 2021/6/8 2021;23(6):e27407. doi:10.2196/27407
6. Yuan J, Au R, Karjadi C, et al. Associations Between the Digital Clock Drawing Test and Brain
Volume: Large Community-Based Prospective Cohort (Framingham Heart Study). Journal of Medical
Internet Research. 2022;24(4):e34513. doi:10.2196/34513
7. Davoudi A, Dion C, Amini S, et al. Classifying Non-Dementia and Alzheimer’s Disease/Vascular
Dementia Patients Using Kinematic, Time-Based, and Visuospatial Parameters: The Digital Clock Drawing
Test. Journal of Alzheimer's Disease. 2021;82:47-57. doi:10.3233/JAD-201129
8. Troen BR. The biology of aging. Mt Sinai J Med. Jan 2003;70(1):3-22.
9. Hou Y, Dan X, Babbar M, et al. Ageing as a risk factor for neurodegenerative disease. Nature
Reviews Neurology. 2019/10/01 2019;15(10):565-581. doi:10.1038/s41582-019-0244-7
10. Hayflick L. Theories of biological aging. Experimental Gerontology. 1985/01/01/ 1985;20(3):145-
159. doi:https://doi.org/10.1016/0531-5565(85)90032-4
11. Baker GT, 3rd, Sprott RL. Biomarkers of aging. Exp Gerontol. 1988;23(4-5):223-39.
doi:10.1016/0531-5565(88)90025-3
12. Lowsky DJ, Olshansky SJ, Bhattacharya J, Goldman DP. Heterogeneity in healthy aging. J Gerontol
A Biol Sci Med Sci. Jun 2014;69(6):640-9. doi:10.1093/gerona/glt162
13. Han S, Brunet A. Histone methylation makes its mark on longevity. Trends Cell Biol. Jan
2012;22(1):42-9. doi:10.1016/j.tcb.2011.11.001
14. Maegawa S, Hinkal G, Kim HS, et al. Widespread and tissue specific age-related DNA methylation
changes in mice. Genome Res. Mar 2010;20(3):332-40. doi:10.1101/gr.096826.109
15. López-Otín C, Blasco MA, Partridge L, Serrano M, Kroemer G. The Hallmarks of Aging. Cell.
2013;153(6):1194-1217. doi:10.1016/j.cell.2013.05.039
16. Horvath S. DNA methylation age of human tissues and cell types. Genome Biology.
2013;14(10):R115. doi:10.1186/gb-2013-14-10-r115
17. Boks MP, Derks EM, Weisenberger DJ, et al. The Relationship of DNA Methylation with Age,
Gender and Genotype in Twins and Healthy Controls. PLOS ONE. 2009;4(8):e6767.
doi:10.1371/journal.pone.0006767
18. Ryan J, Wrigglesworth J, Loong J, Fransquet PD, Woods RL. A Systematic Review and Meta-
analysis of Environmental, Lifestyle, and Health Factors Associated With DNA Methylation Age. The
Journals of Gerontology: Series A. 2020;75(3):481-494. doi:10.1093/gerona/glz099
19. Landgrave-Gómez J, Mercado-Gómez O, Guevara-Guzmán R. Epigenetic mechanisms in
neurological and neurodegenerative diseases. Review. Frontiers in Cellular Neuroscience. 2015-
February-27 2015;9doi:10.3389/fncel.2015.00058
. CC-BY-NC-ND 4.0 International licenseIt is made available under a
is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)
The copyright holder for this preprint this version posted November 7, 2024. ; https://doi.org/10.1101/2024.11.06.24316862doi: medRxiv preprint
20. Hannum G, Guinney J, Zhao L, et al. Genome-wide Methylation Profiles Reveal Quantitative
Views of Human Aging Rates. Molecular Cell. 2013;49(2):359-367. doi:10.1016/j.molcel.2012.10.016
21. Belsky DW, Caspi A, Corcoran DL, et al. DunedinPACE, a DNA methylation biomarker of the pace
of aging. Elife. Jan 14 2022;11doi:10.7554/eLife.73420
22. Lu AT, Quach A, Wilson JG, et al. DNA methylation GrimAge strongly predicts lifespan and
healthspan. Aging. 2019;11(2):303-327. doi:10.18632/aging.101684
23. Levine ME, Lu AT, Quach A, et al. An epigenetic biomarker of aging for lifespan and healthspan.
Aging. 2018;10(4):573-591. doi:10.18632/aging.101414
24. Zavala DV, Dzikowski N, Gopalan S, et al. Epigenetic Age Acceleration and Chronological Age:
Associations With Cognitive Performance in Daily Life. The Journals of Gerontology: Series A.
2023;79(1)doi:10.1093/gerona/glad242
25. Sugden K, Caspi A, Elliott ML, et al. Association of Pace of Aging Measured by Blood-Based DNA
Methylation With Age-Related Cognitive Impairment and Dementia. Neurology. Sep 27
2022;99(13):e1402-e1413. doi:10.1212/wnl.0000000000200898
26. Dawber TR, Meadors GF, Moore FE, Jr. Epidemiological approaches to heart disease: the
Framingham Study. Am J Public Health Nations Health. Mar 1951;41(3):279-81.
doi:10.2105/ajph.41.3.279
27. Price CC, Cunningham H, Coronado N, et al. Clock Drawing in the Montreal Cognitive
Assessment: Recommendations for Dementia Assessment. Dementia and Geriatric Cognitive Disorders.
2011;31(3):179-187. doi:10.1159/000324639
28. Piers RJ, Devlin KN, Ning B, et al. Age and Graphomotor Decision Making Assessed with the
Digital Clock Drawing Test: The Framingham Heart Study. Journal of Alzheimer's Disease. 2017;60:1611-
1620. doi:10.3233/JAD-170444
29. Moore LD, Le T, Fan G. DNA Methylation and Its Basic Function. Neuropsychopharmacology.
2013/01/01 2013;38(1):23-38. doi:10.1038/npp.2012.112
30. Wang M, Li Y, Lai M, et al. Alcohol consumption and epigenetic age acceleration across human
adulthood. Aging. 2023;doi:10.18632/aging.205153
31. Liu C, Marioni RE, Hedman ÅK, et al. A DNA methylation biomarker of alcohol consumption.
Molecular Psychiatry. 2018;23(2):422-433. doi:10.1038/mp.2016.192
32. Higgins-Chen AT, Thrush KL, Wang Y, et al. A computational solution for bolstering reliability of
epigenetic clocks: Implications for clinical trials and longitudinal tracking. Nat Aging. Jul 2022;2(7):644-
661. doi:10.1038/s43587-022-00248-2
33. Benjamini Y, Hochberg Y. Controlling the False Discovery Rate: A Practical and Powerful
Approach to Multiple Testing. Journal of the Royal Statistical Society: Series B (Methodological).
1995;57(1):289-300. doi:https://doi.org/10.1111/j.2517-6161.1995.tb02031.x
34. Jafari M, Ansari-Pour N. Why, When and How to Adjust Your P Values? Cell J. Jan
2019;20(4):604-607. doi:10.22074/cellj.2019.5992
35. Laske C, Sohrabi HR, Frost SM, et al. Innovative diagnostic tools for early detection of
Alzheimer's disease. Alzheimers Dement. May 2015;11(5):561-78. doi:10.1016/j.jalz.2014.06.004
36. Salameh Y, Bejaoui Y, El Hajj N. DNA Methylation Biomarkers in Aging and Age-Related Diseases.
Review. Frontiers in Genetics. 2020-March-10 2020;11doi:10.3389/fgene.2020.00171
37. Johnson AA, Akman K, Calimport SR, Wuttke D, Stolzing A, de Magalhães JP. The role of DNA
methylation in aging, rejuvenation, and age-related disease. Rejuvenation Res. Oct 2012;15(5):483-94.
doi:10.1089/rej.2012.1324
38. Wang M, Li Y, Lai M, et al. Alcohol consumption and epigenetic age acceleration across human
adulthood. Aging (Albany NY). Oct 26 2023;15(20):10938-10971. doi:10.18632/aging.205153
. CC-BY-NC-ND 4.0 International licenseIt is made available under a
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