@article {9001, title = {Epigenetic Age and the Risk of Incident Atrial Fibrillation.}, journal = {Circulation}, volume = {144}, year = {2021}, month = {2021 12 14}, pages = {1899-1911}, abstract = {

BACKGROUND: The most prominent risk factor for atrial fibrillation (AF) is chronological age; however, underlying mechanisms are unexplained. Algorithms using epigenetic modifications to the human genome effectively predict chronological age. Chronological and epigenetic predicted ages may diverge in a phenomenon referred to as epigenetic age acceleration (EAA), which may reflect accelerated biological aging. We sought to evaluate for associations between epigenetic age measures and incident AF.

METHODS: Measures for 4 epigenetic clocks (Horvath, Hannum, DNA methylation [DNAm] PhenoAge, and DNAm GrimAge) and an epigenetic predictor of PAI-1 (plasminogen activator inhibitor-1) levels (ie, DNAm PAI-1) were determined for study participants from 3 population-based cohort studies. Cox models evaluated for associations with incident AF and results were combined via random-effects meta-analyses. Two-sample summary-level Mendelian randomization analyses evaluated for associations between genetic instruments of the EAA measures and AF.

RESULTS: Among 5600 participants (mean age, 65.5 years; female, 60.1\%; Black, 50.7\%), there were 905 incident AF cases during a mean follow-up of 12.9 years. Unadjusted analyses revealed all 4 epigenetic clocks and the DNAm PAI-1 predictor were associated with statistically significant higher hazards of incident AF, though the magnitudes of their point estimates were smaller relative to the associations observed for chronological age. The pooled EAA estimates for each epigenetic measure, with the exception of Horvath EAA, were associated with incident AF in models adjusted for chronological age, race, sex, and smoking variables. After multivariable adjustment for additional known AF risk factors that could also potentially function as mediators, pooled EAA measures for 2 clocks remained statistically significant. Five-year increases in EAA measures for DNAm GrimAge and DNAm PhenoAge were associated with 19\% (adjusted hazard ratio [HR], 1.19 [95\% CI, 1.09-1.31]; <0.01) and 15\% (adjusted HR, 1.15 [95\% CI, 1.05-1.25]; <0.01) higher hazards of incident AF, respectively. Mendelian randomization analyses for the 5 EAA measures did not reveal statistically significant associations with AF.

CONCLUSIONS: Our study identified adjusted associations between EAA measures and incident AF, suggesting that biological aging plays an important role independent of chronological age, though a potential underlying causal relationship remains unclear. These aging processes may be modifiable and not constrained by the immutable factor of time.

}, keywords = {Aged, Aging, Atrial Fibrillation, DNA Methylation, Epigenesis, Genetic, Epigenomics, Female, Follow-Up Studies, Humans, Incidence, Male, Mendelian Randomization Analysis, Middle Aged, Models, Cardiovascular, Models, Genetic}, issn = {1524-4539}, doi = {10.1161/CIRCULATIONAHA.121.056456}, author = {Roberts, Jason D and Vittinghoff, Eric and Lu, Ake T and Alonso, Alvaro and Wang, Biqi and Sitlani, Colleen M and Mohammadi-Shemirani, Pedrum and Fornage, Myriam and Kornej, Jelena and Brody, Jennifer A and Arking, Dan E and Lin, Honghuang and Heckbert, Susan R and Prokic, Ivana and Ghanbari, Mohsen and Skanes, Allan C and Bartz, Traci M and Perez, Marco V and Taylor, Kent D and Lubitz, Steven A and Ellinor, Patrick T and Lunetta, Kathryn L and Pankow, James S and Par{\'e}, Guillaume and Sotoodehnia, Nona and Benjamin, Emelia J and Horvath, Steve and Marcus, Gregory M} } @article {9094, title = {Integrative analysis of clinical and epigenetic biomarkers of mortality.}, journal = {Aging Cell}, volume = {21}, year = {2022}, month = {2022 Jun}, pages = {e13608}, abstract = {

DNA methylation (DNAm) has been reported to be associated with many diseases and with mortality. We hypothesized that the integration of DNAm with clinical risk factors would improve mortality prediction. We performed an epigenome-wide association study of whole blood DNAm in relation to mortality in 15 cohorts (n~=~15,013). During a mean follow-up of 10~years, there were 4314 deaths from all causes including 1235 cardiovascular disease (CVD) deaths and 868 cancer deaths. Ancestry-stratified meta-analysis of all-cause mortality identified 163 CpGs in European ancestry (EA) and 17 in African ancestry (AA) participants at p~<~1~{\texttimes}~10 , of which 41 (EA) and 16 (AA) were also associated with CVD death, and 15 (EA) and 9 (AA) with cancer death. We built DNAm-based prediction models for all-cause mortality that predicted mortality risk after adjusting for clinical risk factors. The mortality prediction model trained by integrating DNAm with clinical risk factors showed an improvement in prediction of cancer death with 5\% increase in the C-index in a replication cohort, compared with the model including clinical risk factors alone. Mendelian randomization identified 15 putatively causal CpGs in relation to longevity, CVD, or cancer risk. For example, cg06885782 (in KCNQ4) was positively associated with risk for prostate cancer (Beta~=~1.2, P ~=~4.1~{\texttimes}~10 ) and negatively associated with longevity (Beta~=~-1.9, P ~=~0.02). Pathway analysis revealed that genes associated with mortality-related CpGs are enriched for immune- and cancer-related pathways. We identified replicable DNAm signatures of mortality and demonstrated the potential utility of CpGs as informative biomarkers for prediction of mortality risk.

}, keywords = {Biomarkers, Cardiovascular Diseases, DNA Methylation, Epigenesis, Genetic, Epigenomics, Humans, Male, Neoplasms}, issn = {1474-9726}, doi = {10.1111/acel.13608}, author = {Huan, Tianxiao and Nguyen, Steve and Colicino, Elena and Ochoa-Rosales, Carolina and Hill, W David and Brody, Jennifer A and Soerensen, Mette and Zhang, Yan and Baldassari, Antoine and Elhadad, Mohamed Ahmed and Toshiko, Tanaka and Zheng, Yinan and Domingo-Relloso, Arce and Lee, Dong Heon and Ma, Jiantao and Yao, Chen and Liu, Chunyu and Hwang, Shih-Jen and Joehanes, Roby and Fornage, Myriam and Bressler, Jan and van Meurs, Joyce B J and Debrabant, Birgit and Mengel-From, Jonas and Hjelmborg, Jacob and Christensen, Kaare and Vokonas, Pantel and Schwartz, Joel and Gahrib, Sina A and Sotoodehnia, Nona and Sitlani, Colleen M and Kunze, Sonja and Gieger, Christian and Peters, Annette and Waldenberger, Melanie and Deary, Ian J and Ferrucci, Luigi and Qu, Yishu and Greenland, Philip and Lloyd-Jones, Donald M and Hou, Lifang and Bandinelli, Stefania and Voortman, Trudy and Hermann, Brenner and Baccarelli, Andrea and Whitsel, Eric and Pankow, James S and Levy, Daniel} }