1 1514 134 DNA METHYLATION AND THE EPIGENETIC CLOCK IN RELATION TO PHYSICAL FRAILTY IN OLDER PEOPLE: THE LOTHIAN BIRTH COHORT 1936. BACKGROUND: THE BIOLOGICAL MECHANISMS UNDERLYING FRAILTY IN OLDER PEOPLE ARE POORLY UNDERSTOOD. THERE IS SOME EVIDENCE TO SUGGEST THAT DNA METHYLATION PATTERNS MAY BE ALTERED IN FRAIL INDIVIDUALS. METHODS: PARTICIPANTS WERE 791 PEOPLE AGED 70 YEARS FROM THE LOTHIAN BIRTH COHORT 1936. DNA METHYLATION WAS MEASURED IN WHOLE BLOOD. BIOLOGICAL AGE WAS ESTIMATED USING TWO MEASURES OF DNA METHYLATION-BASED AGE ACCELERATION-EXTRINSIC AND INTRINSIC EPIGENETIC AGE ACCELERATION. WE CARRIED OUT AN EPIGENOME-WIDE ASSOCIATION STUDY OF PHYSICAL FRAILTY, AS DEFINED BY THE FRIED PHENOTYPE. MULTINOMIAL LOGISTIC REGRESSION WAS USED TO CALCULATE RELATIVE RISK RATIOS FOR BEING PHYSICALLY FRAIL OR PRE-FRAIL ACCORDING TO EPIGENETIC AGE ACCELERATION. RESULTS: THERE WAS A SINGLE SIGNIFICANT (P = 1.16 X 10-7) ASSOCIATION IN THE EPIGENOME-WIDE ASSOCIATION STUDY COMPARING FRAIL VERSUS NOT FRAIL. THE SAME CPG WAS NOT SIGNIFICANT WHEN COMPARING PRE-FRAIL VERSUS NOT FRAIL. GREATER EXTRINSIC EPIGENETIC AGE ACCELERATION WAS ASSOCIATED WITH AN INCREASED RISK OF BEING PHYSICALLY FRAIL, BUT NOT OF BEING PRE-FRAIL. FOR A YEAR INCREASE IN EXTRINSIC EPIGENETIC AGE ACCELERATION, AGE- AND SEX-ADJUSTED RELATIVE RISK RATIOS (95% CI) FOR BEING PHYSICALLY FRAIL OR PRE-FRAIL WERE 1.06 (1.02, 1.10) AND 1.02 (1.00, 1.04), RESPECTIVELY. AFTER FURTHER ADJUSTMENT FOR SMOKING AND CHRONIC DISEASE, THE ASSOCIATION WITH PHYSICAL FRAILTY REMAINED SIGNIFICANT. INTRINSIC EPIGENETIC AGE ACCELERATION WAS NOT ASSOCIATED WITH PHYSICAL FRAILTY STATUS. CONCLUSIONS: PEOPLE WHO ARE BIOLOGICALLY OLDER, AS INDEXED BY GREATER EXTRINSIC EPIGENETIC AGE ACCELERATION, ARE MORE LIKELY TO BE PHYSICALLY FRAIL. FUTURE RESEARCH WILL NEED TO INVESTIGATE WHETHER EPIGENETIC AGE ACCELERATION PLAYS A CAUSAL ROLE IN THE ONSET OF PHYSICAL FRAILTY. 2018 2 5395 43 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 6508 39 TRAJECTORIES OF INFLAMMATORY BIOMARKERS OVER THE EIGHTH DECADE AND THEIR ASSOCIATIONS WITH IMMUNE CELL PROFILES AND EPIGENETIC AGEING. BACKGROUND: EPIGENETIC AGE ACCELERATION (AN OLDER METHYLATION AGE COMPARED TO CHRONOLOGICAL AGE) CORRELATES STRONGLY WITH VARIOUS AGE-RELATED MORBIDITIES AND MORTALITY. CHRONIC SYSTEMIC INFLAMMATION IS THOUGHT TO BE A HALLMARK OF AGEING, BUT THE RELATIONSHIP BETWEEN AN INCREASED EPIGENETIC AGE AND THIS LIKELY KEY PHENOTYPE OF AGEING HAS NOT YET BEEN EXTENSIVELY INVESTIGATED. METHODS: WE MODELLED THE TRAJECTORIES OF THE INFLAMMATORY BIOMARKERS C-REACTIVE PROTEIN (CRP; MEASURED USING BOTH A HIGH- AND LOW-SENSITIVITY ASSAY) AND INTERLEUKIN-6 (IL-6) OVER THE EIGHTH DECADE IN THE LOTHIAN BIRTH COHORT 1936. USING LINEAR MIXED MODELS, WE INVESTIGATED THE ASSOCIATION BETWEEN CRP AND IMMUNE CELL PROFILES IMPUTED FROM THE METHYLATION DATA AND EXAMINED THE CROSS-SECTIONAL AND LONGITUDINAL ASSOCIATION BETWEEN THE INFLAMMATORY BIOMARKERS AND TWO MEASURES OF EPIGENETIC AGE ACCELERATION, DERIVED FROM THE HORVATH AND HANNUM EPIGENETIC CLOCKS. RESULTS: WE FOUND THAT LOW-SENSITIVITY CRP DECLINED, HIGH-SENSITIVITY CRP DID NOT CHANGE, AND IL-6 INCREASED OVER TIME WITHIN THE COHORT. CRP LEVELS INVERSELY ASSOCIATED WITH CD8+T CELLS AND CD4+T CELLS AND POSITIVELY ASSOCIATED WITH SENESCENT CD8+T CELLS, PLASMABLASTS AND GRANULOCYTES. CROSS-SECTIONALLY, THE HANNUM, BUT NOT THE HORVATH, MEASURE OF AGE ACCELERATION WAS POSITIVELY ASSOCIATED WITH EACH OF THE INFLAMMATORY BIOMARKERS, INCLUDING A RESTRICTED MEASURE OF CRP (