1 1956 211 EPIGENETIC AGE IN PERIPHERAL BLOOD AMONG CHILDREN, ADOLESCENT, AND ADULT SURVIVORS OF CHILDHOOD CANCER. IMPORTANCE: CERTAIN CANCER THERAPIES ARE RISK FACTORS FOR EPIGENETIC AGE ACCELERATION (EAA) AMONG SURVIVORS OF CHILDHOOD CANCER, AND EAA IS ASSOCIATED WITH CHRONIC HEALTH CONDITIONS (CHCS). HOWEVER, SMALL NUMBERS OF YOUNGER SURVIVORS (AGED <20 YEARS) PREVIOUSLY EVALUATED HAVE LIMITED THE ABILITY TO CALCULATE EAA AMONG THIS AGE GROUP. OBJECTIVE: TO EVALUATE THE CHANGE RATE OF EPIGENETIC AGE (EA) AND EAA IN YOUNGER COMPARED WITH OLDER SURVIVORS AND THE POSSIBLE ASSOCIATION OF EAA WITH EARLY-ONSET OBESITY (AGED <20 YEARS), SEVERITY/BURDEN OF CHCS, AND LATE MORTALITY (>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 2 4249 51 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 3 403 75 ANALYSIS OF EPIGENETIC AGE ACCELERATION AND HEALTHY LONGEVITY AMONG OLDER US WOMEN. IMPORTANCE: ACCELERATED BIOLOGICAL AGING IS ASSOCIATED WITH DECREASED PHYSICAL CAPABILITY AND COGNITIVE FUNCTIONING, WHICH ARE ASSOCIATED WITH INCREASED RISK OF MORBIDITY AND MORTALITY. OBJECTIVE: WE INVESTIGATED ASSOCIATIONS BETWEEN EPIGENETIC AGE ACCELERATION (EAA), A BIOMARKER ASSOCIATED WITH AGING, AND HEALTHY LONGEVITY AMONG OLDER WOMEN. DESIGN, SETTING, AND PARTICIPANTS: THIS COHORT STUDY WAS A SECONDARY ANALYSIS OF PARTICIPANTS IN THE WOMEN'S HEALTH INITIATIVE (WHI) WHO WERE ELIGIBLE TO SURVIVE TO AGE 90 YEARS BY SEPTEMBER 30, 2020. PARTICIPANTS WERE LOCATED IN MULTIPLE CENTERS. THIS STUDY WAS RESTRICTED TO WOMEN WITH GENOME-WIDE DNA METHYLATION DATA, GENERATED FROM BASELINE BLOOD SAMPLES WITHIN 3 WHI ANCILLARY STUDIES. MEDIAN (IQR) FOLLOW-UP TIMES FROM BASELINE WERE 21.6 (19.6-22.9) YEARS AND 21.4 (19.8-22.7) YEARS FOR WOMEN WHO SURVIVED TO AGE 90 YEARS WITH AND WITHOUT INTACT MOBILITY, RESPECTIVELY, AND 13.2 (8.8-16.7) FOR WOMEN WHO DID NOT SURVIVE TO AGE 90 YEARS. DATA WERE ANALYZED FROM DECEMBER 2020 TO JULY 2021. EXPOSURES: EAA WAS ESTIMATED USING 4 ESTABLISHED "CLOCKS": HORVATH PANTISSUE, HANNUM, PHENO, AND GRIM. MAIN OUTCOMES AND MEASURES: USING MULTINOMIAL LOGISTIC REGRESSION, ODDS RATIOS (ORS) AND 95% CIS WERE ESTIMATED FOR 3 HEALTHY LONGEVITY OUTCOMES FOR EACH CLOCK: SURVIVAL TO AGE 90 YEARS WITH INTACT MOBILITY, SURVIVAL TO AGE 90 YEARS WITHOUT INTACT MOBILITY, AND NO SURVIVAL TO AGE 90 YEARS. RESULTS: AMONG 1813 WOMEN, THERE WERE 464 WOMEN (MEAN [SD] AGE AT BASELINE, 71.6 [3.5] YEARS) WHO SURVIVED TO AGE 90 YEARS WITH INTACT MOBILITY AND COGNITIVE FUNCTIONING, 420 WOMEN (MEAN [SD] AGE AT BASELINE, 71.3 [3.2] YEARS) WHO SURVIVED TO AGE 90 YEARS WITHOUT INTACT MOBILITY AND COGNITIVE FUNCTIONING, AND 929 WOMEN (MEAN [SD] AGE AT BASELINE, 70.2 [3.4] YEARS) WHO DID NOT SURVIVE TO AGE 90 YEARS. WOMEN WHO SURVIVED TO AGE 90 YEARS WITH INTACT MOBILITY AND COGNITIVE FUNCTION WERE HEALTHIER AT BASELINE COMPARED WITH WOMEN WHO SURVIVED WITHOUT THOSE OUTCOMES OR WHO DID NOT SURVIVE TO AGE 90 YEARS (EG, 143 WOMEN [30.8%] VS 101 WOMEN [24.0%] AND 202 WOMEN [21.7%] WITH 0 CHRONIC CONDITIONS). THE ODDS OF SURVIVING TO AGE 90 YEARS WITH INTACT MOBILITY WERE LOWER FOR EVERY 1 SD INCREASE IN EAA COMPARED WITH THOSE WHO DID NOT SURVIVE TO AGE 90 YEARS AS MEASURED BY AGEACCELHORVATH (OR, 0.82; 95% CI, 0.69-0.96; P = .01), AGEACCELHANNUM (OR, 0.67; 95% CI, 0.56-0.80; P < .001), AGEACCELPHENO (OR, 0.60; 95% CI, 0.51-0.72; P < .001), AND AGEACCELGRIM (OR, 0.68; 95% CI, 0.55-0.84; P < .001). ORS WERE SIMILAR FOR WOMEN WHO SURVIVED TO AGE 90 YEARS WITH INTACT MOBILITY AND COGNITIVE FUNCTION (EG, AGEACCELHORVATH: OR PER 1 SD INCREASE IN EAA, 0.83; 95% CI, 0.71-0.98; P = .03) COMPARED WITH WOMEN WHO DID NOT SURVIVE TO AGE 90 YEARS. CONCLUSIONS AND RELEVANCE: THESE FINDINGS SUGGEST THAT EAA MAY BE A VALID BIOMARKER ASSOCIATED WITH HEALTHY LONGEVITY AMONG OLDER WOMEN AND MAY BE USED FOR RISK STRATIFICATION AND RISK ESTIMATION OF FUTURE FUNCTIONAL AND COGNITIVE AGING. OUTCOMES SUGGEST THAT FUTURE STUDIES MAY FOCUS ON THE POTENTIAL FOR PUBLIC HEALTH INTERVENTIONS TO COUNTERACT EAA AND ITS ASSOCIATION WITH POOR HEALTH OUTCOMES TO LOWER DISEASE BURDEN WHILE INCREASING LONGEVITY. 2022 4 1955 49 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 5 5463 44 RESIDENTIAL PM(2.5) EXPOSURE AND THE NASAL METHYLOME IN CHILDREN. RATIONALE: PM(2.5-)INDUCED ADVERSE EFFECTS ON RESPIRATORY HEALTH MAY BE DRIVEN BY EPIGENETIC MODIFICATIONS IN AIRWAY CELLS. THE POTENTIAL IMPACT OF EXPOSURE DURATION ON EPIGENETIC ALTERATIONS IN THE AIRWAYS IS NOT YET KNOWN. OBJECTIVES: WE AIMED TO STUDY ASSOCIATIONS OF FINE PARTICULATE MATTER PM(2.5) EXPOSURE WITH DNA METHYLATION IN NASAL CELLS. METHODS: WE CONDUCTED NASAL EPIGENOME-WIDE ASSOCIATION ANALYSES WITHIN 503 CHILDREN FROM PROJECT VIVA (MEAN AGE 12.9 Y), AND EXAMINED VARIOUS EXPOSURE DURATIONS (1-DAY, 1-WEEK, 1-MONTH, 3-MONTHS AND 1-YEAR) PRIOR TO NASAL SAMPLING. WE USED RESIDENTIAL ADDRESSES TO ESTIMATE AVERAGE DAILY PM(2.5) AT 1 KM RESOLUTION. WE COLLECTED NASAL SWABS FROM THE ANTERIOR NARES AND MEASURED DNA METHYLATION (DNAM) USING THE ILLUMINA METHYLATIONEPIC BEADCHIP. WE TESTED 719,075 HIGH QUALITY AUTOSOMAL CPGS USING CPG-BY-CPG AND REGIONAL DNAM ANALYSES CONTROLLING FOR MULTIPLE COMPARISONS, AND ADJUSTED FOR MATERNAL EDUCATION, HOUSEHOLD SMOKERS, CHILD SEX, RACE/ETHNICITY, BMI Z-SCORE, AGE, SEASON AT SAMPLE COLLECTION AND CELL-TYPE HETEROGENEITY. WE FURTHER CORRECTED FOR BIAS AND GENOMIC INFLATION. WE TESTED FOR REPLICATION IN A COHORT FROM THE NETHERLANDS (PIAMA). RESULTS: IN ADJUSTED ANALYSES, WE FOUND 362 CPGS ASSOCIATED WITH 1-YEAR PM(2.5) (FDR < 0.05), 20 CPGS PASSING BONFERRONI CORRECTION (P < 7.0X10(-8)) AND 10 DIFFERENTIALLY METHYLATED REGIONS (DMRS). IN 445 PIAMA PARTICIPANTS (MEAN AGE 16.3 YEARS) 11 OF 203 AVAILABLE CPGS REPLICATED AT P < 0.05. WE OBSERVED DIFFERENTIAL DNAM AT/NEAR GENES IMPLICATED IN CELL CYCLE, IMMUNE AND INFLAMMATORY RESPONSES. THERE WERE NO CPGS OR REGIONS ASSOCIATED WITH PM(2.5) LEVELS AT 1-DAY, 1-WEEK, OR 1-MONTH PRIOR TO SAMPLE COLLECTION, ALTHOUGH 2 CPGS WERE ASSOCIATED WITH PAST 3-MONTH PM(2.5). CONCLUSION: WE OBSERVED WIDE-SPREAD DNAM VARIABILITY ASSOCIATED WITH AVERAGE PAST YEAR PM(2.5) EXPOSURE BUT WE DID NOT DETECT ASSOCIATIONS WITH SHORTER-TERM EXPOSURE. OUR RESULTS SUGGEST THAT NASAL DNAM MARKS REFLECT CHRONIC AIR POLLUTION EXPOSURE. 2021 6 173 36 ACCELERATED AGING IN BIPOLAR DISORDERS: AN EXPLORATORY STUDY OF SIX EPIGENETIC CLOCKS. BIPOLAR DISORDER (BD) IS A CHRONIC AND SEVERE PSYCHIATRIC DISORDER ASSOCIATED WITH SIGNIFICANT MEDICAL MORBIDITY AND REDUCED LIFE EXPECTANCY. IN THIS STUDY, WE ASSESSED ACCELERATED EPIGENETIC AGING IN INDIVIDUALS WITH BD USING VARIOUS DNA METHYLATION (DNAM)-BASED MARKERS. FOR THIS PURPOSE, WE USED FIVE EPIGENETIC CLOCKS (HORVATH, HANNUM, EN, PHENOAGE, AND GRIMAGE) AND A DNAM-BASED TELOMERE LENGTH CLOCK (DNAMTL). DNAM PROFILES WERE OBTAINED USING INFINIUM METHYLATIONEPIC ARRAYS FROM WHOLE-BLOOD SAMPLES OF 184 INDIVIDUALS WITH BD. WE ALSO ESTIMATED BLOOD CELL COUNTS BASED ON DNAM LEVELS FOR ADJUSTMENT. SIGNIFICANT CORRELATIONS BETWEEN CHRONOLOGICAL AGE AND EACH EPIGENETIC AGE ESTIMATED USING THE SIX DIFFERENT CLOCKS WERE OBSERVED. FOLLOWING ADJUSTMENT FOR BLOOD CELL COUNTS, WE FOUND THAT THE SIX EPIGENETIC AGEACCELS (AGE ACCELERATIONS) WERE SIGNIFICANTLY ASSOCIATED WITH THE BODY MASS INDEX. GRIMAGE AGEACCEL WAS SIGNIFICANTLY ASSOCIATED WITH MALE SEX, SMOKING STATUS AND CHILDHOOD MALTREATMENT. DNAMTL AGEACCEL WAS SIGNIFICANTLY ASSOCIATED WITH SMOKING STATUS. OVERALL, THIS STUDY SHOWED THAT DISTINCT EPIGENETIC CLOCKS ARE SENSITIVE TO DIFFERENT ASPECTS OF AGING PROCESS IN BD. FURTHER INVESTIGATIONS WITH COMPREHENSIVE EPIGENETIC CLOCK ANALYSES AND LARGE SAMPLES ARE REQUIRED TO CONFIRM OUR FINDINGS OF POTENTIAL DETERMINANTS OF AN ACCELERATED EPIGENETIC AGING IN BD. 2023 7 5746 35 SMOKING-RELATED DNA METHYLATION IS ASSOCIATED WITH DNA METHYLATION PHENOTYPIC AGE ACCELERATION: THE VETERANS AFFAIRS NORMATIVE AGING STUDY. DNA METHYLATION MAY PLAY A CRITICAL ROLE IN AGING AND AGE-RELATED DISEASES. DNA METHYLATION PHENOTYPIC AGE (DNAMPHENOAGE) IS A NEW AGING BIOMARKER AND PREDICTOR OF CHRONIC DISEASE RISK. WHILE SMOKING IS A STRONG RISK FACTOR FOR CHRONIC DISEASES AND INFLUENCES METHYLATION, ITS INFLUENCE ON DNAMPHENOAGE IS UNKNOWN. WE INVESTIGATED ASSOCIATIONS OF SELF-REPORTED AND EPIGENETIC SMOKING INDICATORS WITH DNAMPHENOAGE ACCELERATION IN A LONGITUDINAL AGING STUDY IN EASTERN MASSACHUSETTS. DNA METHYLATION WAS MEASURED IN WHOLE BLOOD SAMPLES FROM MULTIPLE VISITS FOR 692 MALE PARTICIPANTS IN THE VETERANS AFFAIRS NORMATIVE AGING STUDY DURING 1999-2013. ACCELERATION WAS DEFINED USING RESIDUALS FROM LINEAR REGRESSION OF THE DNAMPHENOAGE ON THE CHRONOLOGICAL AGE. CUMULATIVE SMOKING (PACK-YEARS) WAS SIGNIFICANTLY ASSOCIATED WITH DNAMPHENOAGE ACCELERATION, WHEREAS SELF-REPORTED SMOKING STATUS WAS NOT. WE OBSERVED SIGNIFICANT VALIDATED ASSOCIATIONS BETWEEN SMOKING-RELATED LOCI AND DNAMPHENOAGE ACCELERATION FOR 52 CPG SITES, WHERE 18 WERE HYPOMETHYLATED AND 34 WERE HYPERMETHYLATED, MAPPED TO 16 GENES. THE AHRR GENE HAD THE MOST LOCI (N = 8) AMONG THE 16 GENES. WE GENERATED A SMOKING AGING INDEX BASED ON THESE 52 LOCI, WHICH SHOWED POSITIVE SIGNIFICANT ASSOCIATIONS WITH DNAMPHENOAGE ACCELERATION. THESE EPIGENETIC BIOMARKERS MAY HELP TO PREDICT AGE-RELATED RISKS DRIVEN BY SMOKING. 2019 8 6460 40 TIME TO RELAPSE IN CHRONIC LYMPHOCYTIC LEUKEMIA AND DNA-METHYLATION-BASED BIOLOGICAL AGE. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS A MATURE B CELL NEOPLASM WITH A PREDILECTION FOR OLDER INDIVIDUALS. WHILE PREVIOUS STUDIES HAVE IDENTIFIED EPIGENETIC SIGNATURES ASSOCIATED WITH CLL, WHETHER AGE-RELATED DNA METHYLATION CHANGES MODULATE CLL RELAPSE REMAINS ELUSIVE. IN THIS STUDY, WE EXAMINED THE ASSOCIATION BETWEEN EPIGENETIC AGE ACCELERATION AND TIME TO CLL RELAPSE IN A PUBLICLY AVAILABLE DATASET. DNA METHYLATION PROFILING OF 35 CLL PATIENTS PRIOR TO INITIATING CHEMOIMMUNOTHERAPY WAS PERFORMED USING THE INFINIUM HUMANMETHYLATION450 BEADCHIP. FOUR EPIGENETIC AGE ACCELERATION METRICS (INTRINSIC EPIGENETIC AGE ACCELERATION [IEAA], EXTRINSIC EPIGENETIC AGE ACCELERATION [EEAA], PHENOAGE ACCELERATION [PHENOAA], AND GRIMAGE ACCELERATION [GRIMAA]) WERE ESTIMATED FROM BLOOD DNA METHYLATION LEVELS. LINEAR, QUANTILE, AND LOGISTIC REGRESSION AND RECEIVER OPERATING CHARACTERISTIC CURVE ANALYSES WERE CONDUCTED TO ASSESS THE ASSOCIATION BETWEEN EACH EPIGENETIC AGE METRIC AND TIME TO CLL RELAPSE. EEAA (P = 0.011) AND PHENOAA (P = 0.046) WERE NEGATIVELY AND GRIMAA (P = 0.040) WAS POSITIVELY ASSOCIATED WITH TIME TO CLL RELAPSE. SIMULTANEOUS ASSESSMENT OF EEAA AND GRIMAA IN MALE PATIENTS DISTINGUISHED PATIENTS WHO RELAPSED EARLY FROM PATIENTS WHO RELAPSED LATER (P = 0.039). NO ASSOCIATIONS WERE OBSERVED WITH IEAA. THESE FINDINGS SUGGEST EPIGENETIC AGE ACCELERATION PRIOR TO CHEMOIMMUNOTHERAPY INITIATION IS ASSOCIATED WITH TIME TO CLL RELAPSE. OUR RESULTS PROVIDE NOVEL INSIGHT INTO THE ASSOCIATION BETWEEN AGE-RELATED DNA METHYLATION CHANGES AND CLL RELAPSE AND MAY SERVE HAS BIOMARKERS FOR TREATMENT RELAPSE, AND POTENTIALLY, TREATMENT SELECTION. 2023 9 5005 39 PERIPHERAL BLOOD DNA METHYLATION-BASED MACHINE LEARNING MODELS FOR PREDICTION OF KNEE OSTEOARTHRITIS PROGRESSION: BIOLOGIC SPECIMENS AND DATA FROM THE OSTEOARTHRITIS INITIATIVE AND JOHNSTON COUNTY OSTEOARTHRITIS PROJECT. OBJECTIVE: THE LACK OF ACCURATE BIOMARKERS TO PREDICT KNEE OSTEOARTHRITIS (OA) PROGRESSION IS A KEY UNMET NEED IN OA CLINICAL RESEARCH. THE OBJECTIVE OF THIS STUDY WAS TO DEVELOP BASELINE PERIPHERAL BLOOD EPIGENETIC BIOMARKER MODELS TO PREDICT KNEE OA PROGRESSION. METHODS: GENOME-WIDE BUFFY COAT DNA METHYLATION PATTERNS FROM 554 INDIVIDUALS FROM THE OSTEOARTHRITIS BIOMARKERS CONSORTIUM (OABC) WERE DETERMINED USING ILLUMINA INFINIUM METHYLATIONEPIC 850K ARRAYS. DATA WERE DIVIDED INTO MODEL DEVELOPMENT AND VALIDATION SETS, AND MACHINE LEARNING MODELS WERE TRAINED TO CLASSIFY FUTURE OA PROGRESSION BY KNEE PAIN, RADIOGRAPHIC IMAGING, KNEE PAIN PLUS RADIOGRAPHIC IMAGING, AND ANY PROGRESSION (PAIN, RADIOGRAPHIC, OR BOTH). PARSIMONIOUS MODELS USING THE TOP 13 CPG SITES MOST FREQUENTLY SELECTED DURING DEVELOPMENT WERE TESTED ON INDEPENDENT SAMPLES FROM PARTICIPANTS IN THE JOHNSTON COUNTY OSTEOARTHRITIS (JOCO OA) PROJECT (N = 128) AND A PREVIOUSLY PUBLISHED OSTEOARTHRITIS INITIATIVE (OAI) DATA SET (N = 55). RESULTS: FULL MODELS ACCURATELY CLASSIFIED FUTURE RADIOGRAPHIC-ONLY PROGRESSION (MEAN +/- SEM ACCURACY 87 +/- 0.8%, AREA UNDER THE CURVE [AUC] 0.94 +/- 0.004), PAIN-ONLY PROGRESSION (ACCURACY 89 +/- 0.9%, AUC 0.97 +/- 0.004), PAIN PLUS RADIOGRAPHIC PROGRESSION (ACCURACY 72 +/- 0.7%, AUC 0.79 +/- 0.006), AND ANY PROGRESSION (ACCURACY 78 +/- 0.4%, AUC 0.86 +/- 0.004). PAIN-ONLY AND RADIOGRAPHIC-ONLY PROGRESSORS WERE NOT DISTINGUISHABLE (MEAN +/- SEM ACCURACY 58 +/- 1%, AUC 0.62 +/- 0.001). PARSIMONIOUS MODELS SHOWED SIMILAR PERFORMANCE AND ACCURATELY CLASSIFIED FUTURE RADIOGRAPHIC PROGRESSORS IN THE OABC COHORT AND IN BOTH VALIDATION COHORTS (MEAN +/- SEM ACCURACY 80 +/- 0.3%, AUC 0.88 +/- 0.003 [USING JOCO OA PROJECT DATA], ACCURACY 80 +/- 0.8%, AUC 0.89 +/- 0.002 [USING PREVIOUS OAI DATA]). CONCLUSION: OUR DATA SUGGEST THAT PAIN AND STRUCTURAL PROGRESSION SHARE SIMILAR EARLY SYSTEMIC IMMUNE EPIGENOTYPES. FURTHER STUDIES SHOULD FOCUS ON EVALUATING THE PATHOPHYSIOLOGIC CONSEQUENCES OF DIFFERENTIAL DNA METHYLATION AND PERIPHERAL BLOOD CELL EPIGENOTYPES IN INDIVIDUALS WITH KNEE OA. 2023 10 3637 39 INCREASED EPIGENETIC AGE ACCELERATION IN THE HIDRADENITIS SUPPURATIVA SKIN. EPIGENETIC (OR DNA METHYLATION) AGE IS CALCULATED BASED ON METHYLATION OF CERTAIN CYTOSINE-GUANINE (CPG) REPEATS, AND IT CAN ACCURATELY ESTIMATE ONE'S CHRONOLOGIC AGE. IMPORTANTLY, EPIGENETIC AGE ACCELERATION (EAA) IS HIGHLY PREDICTIVE OF AGE-ASSOCIATED MORBIDITY AND ALL-CAUSE MORTALITY. HIDRADENITIS SUPPURATIVA (HS) IS A CHRONIC INFLAMMATORY SKIN DISEASE WITH SIGNIFICANT SYSTEMIC DISEASE BURDEN. HERE, WE PERFORMED A PILOT STUDY TO CALCULATE EAA FROM FORMALIN-FIXED PARAFFIN-EMBEDDED SKIN SAMPLES USING ILLUMINA INFINIUM METHYLATIONEPIC BEADCHIP ARRAYS. OUR RESULTS DEMONSTRATED NO SIGNIFICANT DIFFERENCE IN INTRINSIC EAA AMONG HS COMPARED TO CONTROLS (- 1.00 YEARS, P-VALUE = 0.52), SIGNIFICANT INCREASES IN BOTH EXTRINSIC EAA (13.72 YEARS, P-VALUE < 0.001) AND PHENOAGE ACCELERATION (7.72 YEARS, P-VALUE = 0.003), AND A SIGNIFICANT DECREASE IN GRIMAGE ACCELERATION (- 5.14 YEARS, P-VALUE < 0.001). OUR FINDINGS SUGGEST THAT THE ACCELERATION OF EPIGENETIC AGE IN THE HS SKIN MAY BE ASSOCIATED WITH EXTRINSIC IMMUNE-RELATED CHANGES AND CAN POTENTIALLY SERVE AS A BIOMARKER OF THE PRESENT AND/OR FUTURE DISEASE BURDEN IN HS PATIENTS. 2023 11 5957 47 TELOMERE LENGTH AND EPIGENETIC AGE ACCELERATION IN ADOLESCENTS WITH ANXIETY DISORDERS. EVIDENCE ON THE RELATIONSHIP BETWEEN GENETICS AND MENTAL HEALTH ARE FLOURISHING. HOWEVER, FEW STUDIES ARE EVALUATING EARLY BIOMARKERS THAT MIGHT LINK GENES, ENVIRONMENT, AND PSYCHOPATHOLOGY. WE AIMED TO STUDY TELOMERE LENGTH (TL) AND EPIGENETIC AGE ACCELERATION (AA) IN A COHORT OF ADOLESCENTS WITH AND WITHOUT ANXIETY DISORDERS (N = 234). WE EVALUATED A REPRESENTATIVE SUBSAMPLE OF PARTICIPANTS AT BASELINE AND AFTER 5 YEARS (N = 76) AND CATEGORIZED THEM ACCORDING TO THEIR ANXIETY DISORDER DIAGNOSIS AT BOTH TIME POINTS: (1) CONTROL GROUP (NO ANXIETY DISORDER, N = 18), (2) VARIABLE GROUP (ANXIETY DISORDER IN ONE EVALUATION, N = 38), AND (3) PERSISTENT GROUP (ANXIETY DISORDER AT BOTH TIME POINTS, N = 20). WE ASSESSED RELATIVE MEAN TL BY REAL-TIME QUANTITATIVE PCR AND DNA METHYLATION BY INFINIUM HUMANMETHYLATION450 BEADCHIP. WE CALCULATED AA USING THE HORVATH AGE ESTIMATION ALGORITHM AND ANALYZED DIFFERENCES AMONG GROUPS USING GENERALIZED LINEAR MIXED MODELS. THE PERSISTENT GROUP OF ANXIETY DISORDER DID NOT CHANGE TL OVER TIME (P = 0.495). THE VARIABLE GROUP HAD HIGHER BASELINE TL (P = 0.003) BUT NO ACCELERATED TL EROSION IN COMPARISON TO THE NON-ANXIETY CONTROL GROUP (P = 0.053). FURTHERMORE, THERE WERE NO DIFFERENCES IN AA AMONG GROUPS OVER TIME. OUR FINDINGS SUGGEST THAT ADOLESCENTS WITH CHRONIC ANXIETY DID NOT CHANGE TELOMERE LENGTH OVER TIME, WHICH COULD BE RELATED TO A DELAY IN NEURONAL DEVELOPMENT IN THIS PERIOD OF LIFE. 2021 12 382 49 AN EPIGENOME-WIDE STUDY OF BODY MASS INDEX AND DNA METHYLATION IN BLOOD USING PARTICIPANTS FROM THE SISTER STUDY COHORT. BACKGROUND/OBJECTIVES: THE RELATIONSHIP BETWEEN OBESITY AND CHRONIC DISEASE RISK IS WELL-ESTABLISHED; THE UNDERLYING BIOLOGICAL MECHANISMS DRIVING THIS RISK INCREASE MAY INCLUDE OBESITY-RELATED EPIGENETIC MODIFICATIONS. TO EXPLORE THIS HYPOTHESIS, WE CONDUCTED A GENOME-WIDE ANALYSIS OF DNA METHYLATION AND BODY MASS INDEX (BMI) USING DATA FROM A SUBSET OF WOMEN IN THE SISTER STUDY. SUBJECTS/METHODS: THE SISTER STUDY IS A COHORT OF 50 884 US WOMEN WHO HAD A SISTER WITH BREAST CANCER BUT WERE FREE OF BREAST CANCER THEMSELVES AT ENROLLMENT. STUDY PARTICIPANTS COMPLETED EXAMINATIONS WHICH INCLUDED MEASUREMENTS OF HEIGHT AND WEIGHT, AND PROVIDED BLOOD SAMPLES. BLOOD DNA METHYLATION DATA GENERATED WITH THE ILLUMINA INFINIUM HUMANMETHYLATION27 BEADCHIP ARRAY COVERING 27,589 CPG SITES WAS AVAILABLE FOR 871 WOMEN FROM A PRIOR STUDY OF BREAST CANCER AND DNA METHYLATION. TO IDENTIFY DIFFERENTIALLY METHYLATED CPG SITES ASSOCIATED WITH BMI, WE ANALYZED THIS METHYLATION DATA USING ROBUST LINEAR REGRESSION WITH ADJUSTMENT FOR AGE AND CASE STATUS. FOR THOSE CPGS PASSING THE FALSE DISCOVERY RATE SIGNIFICANCE LEVEL, WE EXAMINED THE ASSOCIATION IN A REPLICATION SET COMPRISED OF A NON-OVERLAPPING GROUP OF 187 WOMEN FROM THE SISTER STUDY WHO HAD DNA METHYLATION DATA GENERATED USING THE INFINIUM HUMANMETHYLATION450 BEADCHIP ARRAY. ANALYSIS OF THIS EXPANDED 450 K ARRAY IDENTIFIED ADDITIONAL BMI-ASSOCIATED SITES WHICH WERE INVESTIGATED WITH TARGETED PYROSEQUENCING. RESULTS: FOUR CPG SITES REACHED GENOME-WIDE SIGNIFICANCE (FALSE DISCOVERY RATE (FDR) Q<0.05) IN THE DISCOVERY SET AND ASSOCIATIONS FOR ALL FOUR WERE SIGNIFICANT AT STRICT BONFERRONI CORRECTION IN THE REPLICATION SET. AN ADDITIONAL 23 SITES PASSED FDR IN THE REPLICATION SET AND FIVE WERE REPLICATED BY PYROSEQUENCING IN THE DISCOVERY SET. SEVERAL OF THE GENES IDENTIFIED INCLUDING ANGPT4, RORC, SOCS3, FSD2, XYLT1, ABCG1, STK39, ASB2 AND CRHR2 HAVE BEEN LINKED TO OBESITY AND OBESITY-RELATED CHRONIC DISEASES. CONCLUSIONS: OUR FINDINGS SUPPORT THE HYPOTHESIS THAT OBESITY-RELATED EPIGENETIC DIFFERENCES ARE DETECTABLE IN BLOOD AND MAY BE RELATED TO RISK OF CHRONIC DISEASE. 2017 13 2678 39 EVALUATION OF A PROGNOSTIC EPIGENETIC CLASSIFICATION SYSTEM IN CHRONIC LYMPHOCYTIC LEUKEMIA PATIENTS. BACKGROUND: METHYLATION AT 5 CPG SITES WAS PREVIOUSLY SHOWN TO CLASSIFY CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) INTO 3 PROGNOSTIC SUBGROUPS. HERE, WE AIMED TO VALIDATE THE MARKER SET IN AN ADDITIONAL COHORT AND TO EVALUATE ITS CLINICAL UTILITY FOR CLL PATIENT STRATIFICATION. METHODS: WE EVALUATED THIS EPIGENETIC MARKER SET IN 79 GERMAN PATIENTS USING BISULFITE TREATMENT FOLLOWED BY PYROSEQUENCING AND CLASSIFICATION USING A SUPPORT VECTOR MACHINE-LEARNING TOOL. RESULTS: THE N-CLL, I-CLL, AND M-CLL CLASSIFICATION WAS DETECTED IN 28 (35%), 10 (13%), AND 41 (51%) PATIENTS, RESPECTIVELY. EPIGENETIC GROUPING WAS ASSOCIATED WITH IGHV MUTATIONAL STATUS (P = 2 X 10(-12)), ISOLATED DEL13Q (P = 9 X 10(-6)), DEL17P (P = .015), COMPLEX KARYOTYPE (P = .005), VH-USAGE, AND CLINICAL OUTCOME AS TIME TO FIRST TREATMENT (P = 1.4 X 10(-12)) AND OVERALL SURVIVAL (P = .003). MULTIVARIATE COX REGRESSION ANALYSIS IDENTIFIED N-CLL AS A FACTOR FOR EARLIER TREATMENT HAZARD RATIO (HR), 6.3 (95% CONFIDENCE INTERVAL [CI] 2.4-16.4; P = .0002) COMPARED TO IGHV MUTATIONAL STATUS (HR 4.6, 95% CI 1.9-11.3, P = .0008). IN ADDITION, WHEN COMPARING THE PROGNOSTIC VALUE OF THE EPIGENETIC CLASSIFICATION SYSTEM WITH THE IGHV CLASSIFICATION, EPIGENETIC GROUPING PERFORMED BETTER COMPARED TO IGHV MUTATIONAL STATUS USING KAPLAN-MEIER ESTIMATION AND ALLOWED THE IDENTIFICATION OF A THIRD, INTERMEDIATE (I-CLL) GROUP. THUS, OUR STUDY CONFIRMED THE PROGNOSTIC VALUE OF THE EPIGENETIC MARKER SET FOR PATIENT STRATIFICATION IN ROUTINE CLINICAL DIAGNOSTICS. 2022 14 2777 46 EXTREMELY LOW BIRTH WEIGHT AND ACCELERATED BIOLOGICAL AGING. BACKGROUND AND OBJECTIVES: EXTREMELY LOW BIRTH WEIGHT (ELBW) (<1000 G) SURVIVORS ARE EXPOSED TO ELEVATED LEVELS OF PHYSIOLOGIC STRESS DURING THEIR LIVES AND MAY BE SUSCEPTIBLE TO ACCELERATED AGING. USING THE OLDEST KNOWN LONGITUDINALLY FOLLOWED COHORT OF ELBW SURVIVORS, WE COMPARED BIOLOGICAL AGING IN THIS GROUP USING AN EPIGENETIC CLOCK TO A SAMPLE OF MATCHED NORMAL BIRTH WEIGHT (NBW) (>2500 G) CONTROL PARTICIPANTS. METHODS: BUCCAL CELLS WERE COLLECTED FROM 45 ELBW SURVIVORS AND 49 NBW CONTROL PARTICIPANTS AT 30 TO 35 YEARS OF AGE. EPIGENETIC AGE WAS CALCULATED FROM THE WEIGHTED AVERAGE OF DNA METHYLATION AT 353 CYTOSINE-PHOSPHATE-GUANINE SEQUENCE WITHIN DNA SITES, BY USING THE ILLUMINA INFINIUM HUMAN METHYLATION EPIC 850K BEADCHIP ARRAY. RESULTS: BEFORE AND AFTER STATISTICALLY ADJUSTING FOR NEUROSENSORY IMPAIRMENT AND THE PRESENCE OF CHRONIC HEALTH CONDITIONS, A SIGNIFICANT SEX BY BIRTH WEIGHT GROUP INTERACTION WAS OBSERVED IN THE 353-SITE EPIGENETIC-CLOCK ASSAY (P = .03), WHEREBY ELBW MEN HAD A SIGNIFICANTLY OLDER EPIGENETIC AGE THAN NBW MEN (4.6 YEARS; P = .01). WOMEN BORN AT ELBW WERE NOT FOUND TO BE EPIGENETICALLY OLDER THAN THEIR NBW PEERS. CONCLUSIONS: THE RESULTS OF THIS STUDY SUGGEST THAT PRENATAL EXPOSURES MAY PLAY AN IMPORTANT ROLE IN AGING, AND THAT MEN BORN PRETERM MAY EXPERIENCE ACCELERATED AGING RELATIVE TO THEIR PEERS. WE FURTHER HIGHLIGHT THE NEED TO MONITOR AND PROMOTE THE HEALTH OF PRETERM SURVIVORS, WITH A PARTICULAR FOCUS ON HEALTHY AGING ACROSS THE LIFE SPAN. 2021 15 93 39 A PILOT STUDY OF PERIPHERAL BLOOD DNA METHYLATION MODELS AS PREDICTORS OF KNEE OSTEOARTHRITIS RADIOGRAPHIC PROGRESSION: DATA FROM THE OSTEOARTHRITIS INITIATIVE (OAI). KNEE OSTEOARTHRITIS (OA) IS A LEADING CAUSE OF CHRONIC DISABILITY WORLDWIDE, BUT NO DIAGNOSTIC OR PROGNOSTIC BIOMARKERS ARE AVAILABLE. INCREASING EVIDENCE SUPPORTS EPIGENETIC DYSREGULATION AS A CONTRIBUTOR TO OA PATHOGENESIS. IN THIS PILOT STUDY, WE INVESTIGATED EPIGENETIC PATTERNS IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) AS MODELS TO PREDICT FUTURE RADIOGRAPHIC PROGRESSION IN OA PATIENTS ENROLLED IN THE LONGITUDINAL OSTEOARTHRITIS INITIATIVE (OAI) STUDY. PBMC DNA WAS ANALYZED FROM BASELINE OAI VISITS IN 58 FUTURE RADIOGRAPHIC PROGRESSORS (JOINT SPACE NARROWING AT 24 MONTHS, SUSTAINED AT 48 MONTHS) COMPARED TO 58 NON-PROGRESSORS. DNA METHYLATION WAS QUANTIFIED VIA ILLUMINA MICROARRAYS AND BETA- AND M-VALUES WERE USED TO GENERATE LINEAR CLASSIFICATION MODELS. DATA WERE RANDOMLY SPLIT INTO A 60% DEVELOPMENT AND 40% VALIDATION SUBSETS, MODELS DEVELOPED AND TESTED, AND CROSS-VALIDATED IN A TOTAL OF 40 CYCLES. M-VALUE BASED MODELS OUTPERFORMED BETA-VALUE BASED MODELS (ROC-AUC 0.81 +/- 0.01 VS. 0.73 +/- 0.02, MEAN +/- SEM, COMPARISON P = 0.002), WITH A MEAN CLASSIFICATION ACCURACY OF 73 +/- 1% (MEAN +/- SEM) FOR M- AND 69 +/- 1% FOR BETA-BASED MODELS. ADJUSTING FOR COVARIATES DID NOT SIGNIFICANTLY ALTER MODEL PERFORMANCE. OUR FINDINGS SUGGEST THAT PBMC DNA METHYLATION-BASED MODELS MAY BE USEFUL AS BIOMARKERS OF OA PROGRESSION AND WARRANT ADDITIONAL EVALUATION IN LARGER PATIENT COHORTS. 2019 16 713 45 CADMIUM EXPOSURE AND AGE-ASSOCIATED DNA METHYLATION CHANGES IN NON-SMOKING WOMEN FROM NORTHERN THAILAND. DNA METHYLATION CHANGES WITH AGE, AND MAY SERVE AS A BIOMARKER OF AGING. CADMIUM (CD) MODIFIES CELLULAR PROCESSES THAT PROMOTE AGING AND DISRUPTS METHYLATION GLOBALLY. WHETHER CD MODIFIES AGING PROCESSES BY INFLUENCING ESTABLISHMENT OF AGE-ASSOCIATED METHYLATION MARKS IS CURRENTLY UNKNOWN. IN THIS PILOT STUDY, WE CHARACTERIZED METHYLATION PROFILES IN > 450 000 CPG SITES IN 40 NON-SMOKING WOMEN (AGE 40-80) DIFFERENTIALLY EXPOSED TO ENVIRONMENTAL CD FROM THAILAND. BASED ON SPECIFIC GRAVITY ADJUSTED URINARY CD, WE CLASSIFIED THEM AS HIGH (HE) AND LOW (LE) EXPOSED AND AGE-MATCHED WITHIN 5 YEARS. URINARY CD WAS DEFINED AS BELOW 2 MICROG/L IN THE LE GROUP. WE PREDICTED EPIGENETIC AGE (DNAM-AGE) USING TWO PUBLISHED METHODS BY HORVATH AND HANNUM AND EXAMINED THE DIFFERENCE BETWEEN EPIGENETIC AGE AND CHRONOLOGIC AGE (DELTAAGE). WE ASSESSED DIFFERENCES BY CD EXPOSURE USING LINEAR MIXED MODELS ADJUSTED FOR ESTIMATED WHITE BLOOD CELL PROPORTIONS, BMI, AND URINARY CREATININE. WE IDENTIFIED 213 AGE-ASSOCIATED CPG SITES IN OUR POPULATION (P < 10(-4)). COUNTERINTUITIVELY, THE MEAN DELTAAGE WAS SMALLER IN HE VS. LE (HANNUM: 3.6 VS. 7.6 YEARS, P = 0.0093; HORVATH: 2.4 VS. 4.5 YEARS, P = 0.1308). THE CD EXPOSED GROUP WAS ASSOCIATED WITH CHANGES IN METHYLATION (P < 0.05) AT 12, 8, AND 20 AGE-ASSOCIATED SITES IDENTIFIED IN OUR POPULATION, HANNUM, AND HORVATH. FROM THE RESULTS OF THIS PILOT STUDY, ELEVATED CD EXPOSURE IS ASSOCIATED WITH METHYLATION CHANGES AT AGE-ASSOCIATED SITES AND SMALLER DIFFERENCES BETWEEN DNAM-AGE AND CHRONOLOGIC AGE, IN CONTRAST TO EXPECTED AGE-ACCELERATING EFFECTS. CD MAY MODIFY EPIGENETIC AGING, AND BIOMARKERS OF AGING WARRANT FURTHER INVESTIGATION WHEN EXAMINING CD AND ITS RELATIONSHIP WITH CHRONIC DISEASE AND MORTALITY. 2017 17 3063 43 GENOME-WIDE DNA METHYLATION AND LONG-TERM AMBIENT AIR POLLUTION EXPOSURE IN KOREAN ADULTS. BACKGROUND: AMBIENT AIR POLLUTION IS ASSOCIATED WITH NUMEROUS ADVERSE HEALTH OUTCOMES, BUT THE UNDERLYING MECHANISMS ARE NOT WELL UNDERSTOOD; EPIGENETIC EFFECTS INCLUDING ALTERED DNA METHYLATION COULD PLAY A ROLE. TO EVALUATE ASSOCIATIONS OF LONG-TERM AIR POLLUTION EXPOSURE WITH DNA METHYLATION IN BLOOD, WE CONDUCTED AN EPIGENOME-WIDE ASSOCIATION STUDY IN A KOREAN CHRONIC OBSTRUCTIVE PULMONARY DISEASE COHORT (N = 100 INCLUDING 60 CASES) USING ILLUMINA'S INFINIUM HUMANMETHYLATION450K BEADCHIP. ANNUAL AVERAGE CONCENTRATIONS OF PARTICULATE MATTER