1 2411 117 EPIGENETIC SCORES FOR THE CIRCULATING PROTEOME AS TOOLS FOR DISEASE PREDICTION. PROTEIN BIOMARKERS HAVE BEEN IDENTIFIED ACROSS MANY AGE-RELATED MORBIDITIES. HOWEVER, CHARACTERISING EPIGENETIC INFLUENCES COULD FURTHER INFORM DISEASE PREDICTIONS. HERE, WE LEVERAGE EPIGENOME-WIDE DATA TO STUDY LINKS BETWEEN THE DNA METHYLATION (DNAM) SIGNATURES OF THE CIRCULATING PROTEOME AND INCIDENT DISEASES. USING DATA FROM FOUR COHORTS, WE TRAINED AND TESTED EPIGENETIC SCORES (EPISCORES) FOR 953 PLASMA PROTEINS, IDENTIFYING 109 SCORES THAT EXPLAINED BETWEEN 1% AND 58% OF THE VARIANCE IN PROTEIN LEVELS AFTER ADJUSTING FOR KNOWN PROTEIN QUANTITATIVE TRAIT LOCI (PQTL) GENETIC EFFECTS. BY PROJECTING THESE EPISCORES INTO AN INDEPENDENT SAMPLE (GENERATION SCOTLAND; N = 9537) AND RELATING THEM TO INCIDENT MORBIDITIES OVER A FOLLOW-UP OF 14 YEARS, WE UNCOVERED 137 EPISCORE-DISEASE ASSOCIATIONS. THESE ASSOCIATIONS WERE LARGELY INDEPENDENT OF IMMUNE CELL PROPORTIONS, COMMON LIFESTYLE AND HEALTH FACTORS, AND BIOLOGICAL AGING. NOTABLY, WE FOUND THAT OUR DIABETES-ASSOCIATED EPISCORES HIGHLIGHTED PREVIOUS TOP BIOMARKER ASSOCIATIONS FROM PROTEOME-WIDE ASSESSMENTS OF DIABETES. THESE EPISCORES FOR PROTEIN LEVELS CAN THEREFORE BE A VALUABLE RESOURCE FOR DISEASE PREDICTION AND RISK STRATIFICATION. 2022 2 5395 40 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 3 2150 43 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