1 5747 108 SOCIAL ADVERSITY AND EPIGENETIC AGING: A MULTI-COHORT STUDY ON SOCIOECONOMIC DIFFERENCES IN PERIPHERAL BLOOD DNA METHYLATION. LOW SOCIOECONOMIC STATUS (SES) IS ASSOCIATED WITH EARLIER ONSET OF AGE-RELATED CHRONIC CONDITIONS AND REDUCED LIFE-EXPECTANCY, BUT THE UNDERLYING BIOMOLECULAR MECHANISMS REMAIN UNCLEAR. EVIDENCE OF DNA-METHYLATION DIFFERENCES BY SES SUGGESTS A POSSIBLE ASSOCIATION OF SES WITH EPIGENETIC AGE ACCELERATION (AA). WE INVESTIGATED THE ASSOCIATION OF SES WITH AA IN MORE THAN 5,000 INDIVIDUALS BELONGING TO THREE INDEPENDENT PROSPECTIVE COHORTS FROM ITALY, AUSTRALIA, AND IRELAND. LOW SES WAS ASSOCIATED WITH GREATER AA (BETA = 0.99 YEARS; 95% CI 0.39,1.59; P = 0.002; COMPARING EXTREME CATEGORIES). THE RESULTS WERE CONSISTENT ACROSS DIFFERENT SES INDICATORS. THE ASSOCIATIONS WERE ONLY PARTIALLY MODULATED BY THE UNHEALTHY LIFESTYLE HABITS OF INDIVIDUALS WITH LOWER SES. INDIVIDUALS WHO EXPERIENCED LIFE-COURSE SES IMPROVEMENT HAD INTERMEDIATE AA COMPARED TO EXTREME SES CATEGORIES, SUGGESTING REVERSIBILITY OF THE EFFECT AND SUPPORTING THE RELATIVE IMPORTANCE OF THE EARLY CHILDHOOD SOCIAL ENVIRONMENT. SOCIOECONOMIC ADVERSITY IS ASSOCIATED WITH ACCELERATED EPIGENETIC AGING, IMPLICATING BIOMOLECULAR MECHANISMS THAT MAY LINK SES TO AGE-RELATED DISEASES AND LONGEVITY. 2017 2 3579 38 IMPACT OF PATERNAL EDUCATION ON EPIGENETIC AGEING IN ADOLESCENCE AND MID-ADULTHOOD: A MULTI-COHORT STUDY IN THE USA AND MEXICO. BACKGROUND: BOTH PARENTAL AND NEIGHBOURHOOD SOCIO-ECONOMIC STATUS (SES) ARE LINKED TO POORER HEALTH INDEPENDENTLY OF PERSONAL SES MEASURES, BUT THE BIOLOGICAL MECHANISMS ARE UNCLEAR. OUR OBJECTIVE WAS TO EXAMINE THESE INFLUENCES VIA EPIGENETIC AGE ACCELERATION (EAA)-THE DISCREPANCY BETWEEN CHRONOLOGICAL AND EPIGENETIC AGES. METHODS: WE EXAMINED THREE USA-BASED [CORONARY ARTERY RISK DISEASE IN ADULTS (CARDIA) STUDY, FRAGILE FAMILIES AND CHILD WELLBEING STUDY (FFCWS) AND PROGRAMMING RESEARCH IN OBESITY, GROWTH, ENVIRONMENT AND SOCIAL STRESSORS (PROGRESS)] AND ONE MEXICO-BASED (PROJECT VIVA) COHORT. DNA METHYLATION WAS MEASURED USING ILLUMINA ARRAYS, PERSONAL/PARENTAL SES BY QUESTIONNAIRE AND NEIGHBOURHOOD DISADVANTAGE FROM GEOCODED ADDRESS. IN CARDIA, WE EXAMINED THE MOST STRONGLY ASSOCIATED PERSONAL, PARENTAL AND NEIGHBOURHOOD SES MEASURES WITH EAA (HANNUM'S METHOD) AT STUDY YEARS 15 AND 20 SEPARATELY AND COMBINED USING A GENERALIZED ESTIMATING EQUATION (GEE) AND COMPARED WITH OTHER EAA MEASURES (HORVATH'S EAA, PHENOAGE AND GRIMAGE CALCULATORS, AND DUNEDINPOAM). RESULTS: EAA WAS ASSOCIATED WITH PATERNAL EDUCATION IN CARDIA [GEES: BETASOME COLLEGE = -1.01 YEARS (-1.91, -0.11) AND BETA/=35.0 VS. 18.5-24.9, BETA = 3.15 YEARS, 95% CONFIDENCE INTERVAL (CI): 2.41, 3.90; P FOR TREND < 0.001). IN A MUTUAL-ADJUSTMENT MODEL, BOTH WERE ASSOCIATED WITH PHENOAGE AGE ACCELERATION (BMI OF >/=35.0 VS. 18.5-24.9, BETA = 2.69 YEARS, 95% CI: 1.90, 3.48; P FOR TREND < 0.001; QUARTILE 4 VS.1 WTH, BETA = 1.00 YEARS, 95% CI: 0.34, 1.65; P FOR TREND < 0.008). AFTER ADJUSTMENT, PHYSICAL ACTIVITY WAS ASSOCIATED ONLY WITH GRIMAGE (QUARTILE 4 VS. 1, BETA = -0.42 YEARS, 95% CI: -0.70, -0.14; P FOR TREND = 0.001). PHYSICAL ACTIVITY ATTENUATED THE WAIST CIRCUMFERENCE ASSOCIATIONS WITH PHENOAGE AND GRIMAGE. EXCESS ADIPOSITY WAS ASSOCIATED WITH EPIGENETIC AGE ACCELERATION; PHYSICAL ACTIVITY MIGHT ATTENUATE ASSOCIATIONS WITH WAIST CIRCUMFERENCE. 2021 13 648 27 BIRTH WEIGHT AND MATERNAL ENERGY STATUS DURING PREGNANCY AS PREDICTORS OF EPIGENETIC AGE ACCELERATION IN YOUNG ADULTS FROM METROPOLITAN CEBU, PHILIPPINES. EPIGENETIC CLOCKS QUANTIFY REGULAR CHANGES IN DNA METHYLATION THAT OCCUR WITH AGE, OR IN RELATION TO BIOMARKERS OF AGEING, AND ARE STRONG PREDICTORS OF MORBIDITY AND MORTALITY. HERE, WE ASSESS WHETHER MEASURES OF FETAL NUTRITION AND GROWTH THAT PREDICT ADULT CHRONIC DISEASE ALSO PREDICT ACCELERATED BIOLOGICAL AGEING IN YOUNG ADULTHOOD USING A SUITE OF COMMONLY USED EPIGENETIC CLOCKS. DATA COME FROM THE CEBU LONGITUDINAL HEALTH AND NUTRITION SURVEY (CLHNS), A LONG-RUNNING COHORT FOLLOWED SINCE BIRTH IN METROPOLITAN CEBU, PHILIPPINES. PAST WORK HAS SHOWN THAT BIRTH WEIGHT (BW) AND THE MOTHER'S ARM FAT DURING PREGNANCY (A MEASURE OF PREGNANCY ENERGY STATUS) RELATE INVERSELY TO HEALTH OUTCOMES IN THE CLHNS BUT PRIMARILY IN MALES. GENOME-WIDE DNA METHYLATION WAS ASSESSED IN WHOLE BLOOD USING THE INFINIUM EPIC ARRAY. PARTICIPANTS INCLUDED MALES (N=895) AND FEMALES (N=803) MEASURED IN 2005 (20.8-22.5 YEARS). CLOCKS INCLUDED THE HANNUM AND HORVATH CLOCKS TRAINED ON CHRONOLOGICAL AGE, THE DNAMPHENOAGE AND DNAMGRIMAGE CLOCKS TRAINED ON CLINICAL BIOMARKERS, THE DUNEDIN PACE OF AGEING (DUNEDINPACE) CLOCK TRAINED ON LONGITUDINAL CHANGES IN AGEING BIOMARKERS, AND THE DNAMTL CLOCK TRAINED ON LEUKOCYTE TELOMERE LENGTH. IN MALES, LOWER BW PREDICTED ADVANCED BIOLOGICAL AGEING USING THE HANNUM, DNAMPHENOAGE, DUNEDINPOAM, AND DNAMTL CLOCKS. IN CONTRAST, BW DID NOT PREDICT ANY CLOCK IN FEMALE PARTICIPANTS. PARTICIPANTS' MOTHERS' PREGNANCY ARM FAT ONLY PREDICTED DNAMTL IN MALES. THESE FINDINGS SUGGEST THAT EPIGENETIC CLOCKS ARE A USEFUL TOOL FOR GAUGING LONG-TERM OUTCOMES PREDICTED BY FETAL GROWTH, AND ADD TO EXISTING EVIDENCE IN THE CLHNS FOR SEX DIFFERENCES IN THESE RELATIONSHIPS. 2022 14 1955 36 EPIGENETIC AGE ACCELERATION PREDICTS CANCER, CARDIOVASCULAR, AND ALL-CAUSE MORTALITY IN A GERMAN CASE COHORT. BACKGROUND: PREVIOUS STUDIES HAVE DEVELOPED MODELS PREDICTING METHYLATION AGE FROM DNA METHYLATION IN BLOOD AND OTHER TISSUES (EPIGENETIC CLOCK) AND SUGGESTED THE DIFFERENCE BETWEEN DNA METHYLATION AND CHRONOLOGICAL AGES AS A MARKER OF HEALTHY AGING. THE GOAL OF THIS STUDY WAS TO CONFIRM AND EXPAND SUCH OBSERVATIONS BY INVESTIGATING WHETHER DIFFERENT CONCEPTS OF THE EPIGENETIC CLOCKS IN A POPULATION-BASED COHORT ARE ASSOCIATED WITH CANCER, CARDIOVASCULAR, AND ALL-CAUSE MORTALITY. RESULTS: DNA METHYLATION AGE WAS ESTIMATED IN A COHORT OF 1863 OLDER PEOPLE, AND THE DIFFERENCE BETWEEN AGE PREDICTED BY DNA METHYLATION AND CHRONOLOGICAL AGE (DELTAAGE) WAS CALCULATED. A CASE-COHORT DESIGN AND WEIGHTED PROPORTIONAL COX HAZARD MODELS WERE USED TO ESTIMATE ASSOCIATIONS OF DELTAAGE WITH CANCER, CARDIOVASCULAR, AND ALL-CAUSE MORTALITY. HAZARD RATIOS FOR DELTAAGE (PER 5 YEARS) CALCULATED USING THE EPIGENETIC CLOCK DEVELOPED BY HORVATH WERE 1.23 (95 % CI 1.10-1.38) FOR ALL-CAUSE MORTALITY, 1.22 (95 % CI 1.03-1.45) FOR CANCER MORTALITY, AND 1.19 (95 % CI 0.98-1.43) FOR CARDIOVASCULAR MORTALITY AFTER ADJUSTMENT FOR BATCH EFFECTS, AGE, SEX, EDUCATIONAL LEVEL, HISTORY OF CHRONIC DISEASES, HYPERTENSION, SMOKING STATUS, BODY MASS INDEX, AND LEUCOCYTE DISTRIBUTION. ASSOCIATIONS WERE SIMILAR BUT WEAKER FOR DELTAAGE CALCULATED USING THE EPIGENETIC CLOCK DEVELOPED BY HANNUM. CONCLUSIONS: THESE RESULTS SHOW THAT AGE ACCELERATION IN TERMS OF THE DIFFERENCE BETWEEN AGE PREDICTED BY DNA METHYLATION AND CHRONOLOGICAL AGE IS AN INDEPENDENT PREDICTOR OF ALL-CAUSE AND CAUSE-SPECIFIC MORTALITY AND MAY BE USEFUL AS A GENERAL MARKER OF HEALTHY AGING. 2016 15 5395 35 REDUCED EPIGENETIC AGE IN OLDER ADULTS WITH HIGH SENSE OF PURPOSE IN LIFE. PSYCHOSOCIAL RISK FACTORS HAVE BEEN LINKED WITH ACCELERATED EPIGENETIC AGING, BUT LITTLE IS KNOWN ABOUT WHETHER PSYCHOSOCIAL RESILIENCE FACTORS (EG, SENSE OF PURPOSE IN LIFE) MIGHT REDUCE EPIGENETIC AGE ACCELERATION. IN THIS STUDY, WE TESTED IF OLDER ADULTS WHO EXPERIENCE HIGH LEVELS OF PURPOSE MIGHT SHOW REDUCED EPIGENETIC AGE ACCELERATION. WE EVALUATED THE RELATIONSHIP BETWEEN PURPOSE AND EPIGENETIC AGE ACCELERATION AS MEASURED BY 13 DNA METHYLATION (DNAM) "EPIGENETIC CLOCKS" ASSESSED IN 1 572 OLDER ADULTS FROM THE HEALTH AND RETIREMENT STUDY (MEAN AGE 70 YEARS). WE QUANTIFIED THE TOTAL ASSOCIATION BETWEEN PURPOSE AND DNAM AGE ACCELERATION AS WELL AS THE EXTENT TO WHICH THAT TOTAL ASSOCIATION MIGHT BE ATTRIBUTABLE TO DEMOGRAPHIC FACTORS, CHRONIC DISEASE, OTHER PSYCHOSOCIAL VARIABLES (EG, POSITIVE AFFECT), AND HEALTH-RELATED BEHAVIORS (HEAVY DRINKING, SMOKING, PHYSICAL ACTIVITY, AND BODY MASS INDEX [BMI]). PURPOSE IN LIFE WAS ASSOCIATED WITH REDUCED EPIGENETIC AGE ACCELERATION ACROSS 4 "SECOND-GENERATION" DNAM CLOCKS OPTIMIZED FOR PREDICTING HEALTH AND LONGEVITY (FALSE DISCOVERY RATE [FDR] Q < 0.0001: PHENOAGE, GRIMAGE, ZHANG EPIGENETIC MORTALITY INDEX; FDR Q < 0.05: DUNEDINPOAM). THESE ASSOCIATIONS WERE INDEPENDENT OF DEMOGRAPHIC AND PSYCHOSOCIAL FACTORS, BUT SUBSTANTIALLY ATTENUATED AFTER ADJUSTING FOR HEALTH-RELATED BEHAVIORS (DRINKING, SMOKING, PHYSICAL ACTIVITY, AND BMI). PURPOSE SHOWED NO SIGNIFICANT ASSOCIATION WITH 9 "FIRST-GENERATION" DNAM EPIGENETIC CLOCKS TRAINED ON CHRONOLOGICAL AGE. OLDER ADULTS WITH GREATER PURPOSE IN LIFE SHOW "YOUNGER" DNAM EPIGENETIC AGE ACCELERATION. THESE RESULTS MAY BE DUE IN PART TO ASSOCIATED DIFFERENCES IN HEALTH-RELATED BEHAVIORS. RESULTS SUGGEST NEW OPPORTUNITIES TO REDUCE BIOLOGICAL AGE ACCELERATION BY ENHANCING PURPOSE AND ITS BEHAVIORAL SEQUELAE IN LATE ADULTHOOD. 2023 16 4249 36 METHYLATION-BASED BIOLOGICAL AGE AND BREAST CANCER RISK. BACKGROUND: AGE IS ONE OF THE STRONGEST PREDICTORS OF CANCER, CHRONIC DISEASE, AND MORTALITY, BUT BIOLOGICAL RESPONSES TO AGING DIFFER AMONG PEOPLE. EPIGENETIC DNA MODIFICATIONS HAVE BEEN USED TO ESTIMATE "BIOLOGICAL AGE," WHICH MAY BE A USEFUL PREDICTOR OF DISEASE RISK. WE TESTED THIS HYPOTHESIS FOR BREAST CANCER. METHODS: USING A CASE-COHORT APPROACH, WE MEASURED BASELINE BLOOD DNA METHYLATION OF 2764 WOMEN ENROLLED IN THE SISTER STUDY, 1566 OF WHOM SUBSEQUENTLY DEVELOPED BREAST CANCER AFTER AN AVERAGE OF 6 YEARS. USING THREE PREVIOUSLY ESTABLISHED METHYLATION-BASED "CLOCKS" (HANNUM, HORVATH, AND LEVINE), WE DEFINED BIOLOGICAL AGE ACCELERATION FOR EACH WOMAN BY COMPARING HER ESTIMATED BIOLOGICAL AGE WITH HER CHRONOLOGICAL AGE. HAZARD RATIOS AND 95% CONFIDENCE INTERVALS FOR BREAST CANCER RISK WERE ESTIMATED USING COX REGRESSION MODELS. ALL STATISTICAL TESTS WERE TWO-SIDED. RESULTS: EACH OF THE THREE CLOCKS SHOWED THAT BIOLOGICAL AGE ACCELERATION WAS STATISTICALLY SIGNIFICANTLY ASSOCIATED WITH INCREASED RISK OF DEVELOPING BREAST CANCER (5-YEAR AGE ACCELERATION, HANNUM'S CLOCK: HAZARD RATIO [HR] = 1.10, 95% CONFIDENCE INTERVAL [CI] = 1.00 TO 1.21, P = .04; HORVATH'S CLOCK: HR = 1.08, 95% CI = 1.00 TO 1.17, P = .04; LEVINE'S CLOCK: HR = 1.15, 95% CI = 1.07 TO 1.23, P < .001). FOR LEVINE'S CLOCK, EACH 5-YEAR ACCELERATION IN BIOLOGICAL AGE CORRESPONDED WITH A 15% INCREASE IN BREAST CANCER RISK. ALTHOUGH BIOLOGICAL AGE MAY ACCELERATE WITH MENOPAUSAL TRANSITION, AGE ACCELERATION IN PREMENOPAUSAL WOMEN INDEPENDENTLY PREDICTED BREAST CANCER. CASE-ONLY ANALYSIS SUGGESTED THAT, AMONG WOMEN WHO DEVELOP BREAST CANCER, INCREASED AGE ACCELERATION IS ASSOCIATED WITH INVASIVE CANCER (ODDS RATIO FOR INVASIVE = 1.09, 95% CI = 0.98 TO 1.22, P = .10). CONCLUSIONS: DNA METHYLATION-BASED MEASURES OF BIOLOGICAL AGE MAY BE IMPORTANT PREDICTORS OF BREAST CANCER RISK. 2019 17 6018 30 THE ASSOCIATION OF EPIGENETIC AGE ACCELERATION AND MULTIMORBIDITY AT AGE 90 IN THE WOMEN'S HEALTH INITIATIVE. 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. 2022 18 2150 26 EPIGENETIC MEASURES OF AGEING PREDICT THE PREVALENCE AND INCIDENCE OF LEADING CAUSES OF DEATH AND DISEASE BURDEN. BACKGROUND: INDIVIDUALS OF THE SAME CHRONOLOGICAL AGE DISPLAY DIFFERENT RATES OF BIOLOGICAL AGEING. A NUMBER OF MEASURES OF BIOLOGICAL AGE HAVE BEEN PROPOSED WHICH HARNESS AGE-RELATED CHANGES IN DNA METHYLATION PROFILES. THESE MEASURES INCLUDE FIVE 'EPIGENETIC CLOCKS' WHICH PROVIDE AN INDEX OF HOW MUCH AN INDIVIDUAL'S BIOLOGICAL AGE DIFFERS FROM THEIR CHRONOLOGICAL AGE AT THE TIME OF MEASUREMENT. THE FIVE CLOCKS ENCOMPASS METHYLATION-BASED PREDICTORS OF CHRONOLOGICAL AGE (HORVATHAGE, HANNUMAGE), ALL-CAUSE MORTALITY (DNAM PHENOAGE, DNAM GRIMAGE) AND TELOMERE LENGTH (DNAM TELOMERE LENGTH). A SIXTH EPIGENETIC MEASURE OF AGEING DIFFERS FROM THESE CLOCKS IN THAT IT ACTS AS A SPEEDOMETER PROVIDING A SINGLE TIME-POINT MEASUREMENT OF THE PACE OF AN INDIVIDUAL'S BIOLOGICAL AGEING. THIS MEASURE OF AGEING IS TERMED DUNEDINPOAM. IN THIS STUDY, WE TEST THE ASSOCIATION BETWEEN THESE SIX EPIGENETIC MEASURES OF AGEING AND THE PREVALENCE AND INCIDENCE OF THE LEADING CAUSES OF DISEASE BURDEN AND MORTALITY IN HIGH-INCOME COUNTRIES (N 5 YEARS FROM CANCER DIAGNOSIS). DESIGN, SETTING, AND PARTICIPANTS: STUDY PARTICIPANTS WERE FROM THE ST JUDE LIFETIME COHORT, INITIATED IN 2007 WITH ONGOING FOLLOW-UP. THE PRESENT STUDY WAS CONDUCTED FROM APRIL 17, 2022, TO MARCH 23, 2023. SURVIVORS IN THIS COHORT OF EUROPEAN ANCESTRY WITH DNA METHYLATION DATA WERE INCLUDED. CROSS-SECTIONAL ANNUAL CHANGES IN EA AND EAA WERE COMPARED ACROSS 5 DIFFERENT CHRONOLOGIC AGE GROUPS: AGE 0 TO 9 (CHILDREN), 10 TO 19 (ADOLESCENTS), 20 TO 34 (YOUNGER ADULTS), 35 TO 49 (MIDDLE-AGED ADULTS), AND GREATER THAN OR EQUAL TO 50 (OLDER ADULTS) YEARS. LOGISTIC REGRESSION EVALUATED THE ASSOCIATION BETWEEN EAA AND EARLY-ONSET OBESITY OR SEVERITY/BURDEN OF CHCS. COX PROPORTIONAL HAZARDS REGRESSION ASSESSED THE ASSOCIATION BETWEEN EAA AND LATE MORTALITY. MAIN OUTCOMES AND MEASURES: EARLY-ONSET OBESITY, SEVERITY/BURDEN OF CHCS (GRADED USING THE COMMON TERMINOLOGY CRITERIA FOR ADVERSE EVENTS (GRADE 1, MILD; 2, MODERATE; 3, SEVERE/DISABLING; 4, LIFE-THREATENING) AND WERE COMBINED INTO HIGH VS LOW SEVERITY/BURDEN BASED ON FREQUENCY AND GRADE), AND LATE MORTALITY WERE THE OUTCOMES BASED ON FOLLOW-UP UNTIL APRIL 2020. EXPANDED DNA METHYLATION PROFILING INCREASED THE NUMBER OF SURVIVORS YOUNGER THAN 20 YEARS (N = 690). EPIGENETIC AGE WAS CALCULATED PRIMARILY USING THE LEVINE CLOCK, AND EAA WAS DERIVED FROM LEAST SQUARES REGRESSION OF EA AGAINST CHRONOLOGIC AGE AND WAS STANDARDIZED TO A Z SCORE (LEVINE EEA). RESULTS: AMONG 2846 PARTICIPANTS (MEDIAN AGE, 30.3 [IQR, 9.3-41.5] YEARS; 53% MALES), THE CROSS-SECTIONAL ANNUAL CHANGE IN EA_LEVINE WAS HIGHER IN CHILDREN (1.63 YEARS) AND ADOLESCENTS (1.14 YEARS), AND THE ADJUSTED LEAST-SQUARES MEAN OF LEVINE EEA WAS LOWER IN CHILDREN (-0.22 YEARS) AND OLDER ADULTS (-1.70 YEARS). EACH 1-SD INCREASE IN LEVINE EEA WAS ASSOCIATED WITH INCREASED RISK OF DEVELOPING EARLY-ONSET OBESITY (ODDS RATIO [OR], 1.46; 95% CI, 1.19-1.78), HIGH SEVERITY/BURDEN OF CHCS (OR, 1.13; 95% CI, 1.03-1.24), AND LATE MORTALITY (HAZARD RATIO, 1.75; 95% CI, 1.35-2.26). CONCLUSIONS AND RELEVANCE: THE FINDINGS OF THIS STUDY SUGGEST THAT EAA MEASURED IN CHILDREN AND ADOLESCENT SURVIVORS OF CHILDHOOD CANCER IS ASSOCIATED WITH EARLY-ONSET OBESITY, SEVERITY/BURDEN OF ALL CHCS, AND LATE MORTALITY. EVALUATING EAA MAY HELP IDENTIFY SURVIVORS OF CHILDHOOD CANCER AT INCREASED RISK FOR EARLY-ONSET OBESITY, MORBIDITY IN GENERAL, AND MORTALITY. 2023