Abstract P3008: Plasma Proteomic Signatures Of Organ Aging Are Not Responsive To Exercise Training: HERITAGE Family Study

Introduction: A recent study utilized plasma proteins to identify organ-specific aging signatures that were related to health and disease. However, it is unknown whether exercise interventions can change predicted organ aging. Methods: We measured 4979 plasma proteins using the SomaScan assay before and after 20 weeks of endurance exercise training in 673 Black and White adults from the HERITAGE Family Study. Organ age was estimated for 11 major organs using different panels of proteins and age gap was calculated as the difference between predicted age and the LOWESS regression estimate of the population mean. Accelerated aging was defined as an age gap value ±2SD from the mean. Paired t-tests examines changes in predicted organ age with exercise training. Results: We found low-to-modest correlations between predicted organ age and chronological age for 9 of 11 traits ( Table 1 ). These correlations were almost exclusively observed in the oldest (age quartile 4: ages 47.6-65.9) and not younger participants (age quartiles 1-3: age<47.6 yrs) ( Table 1 ). A total of 37% of participants had accelerated aging in at least one organ at baseline, with 15% having 2 or more accelerated organ ages, which was balanced across chronological age quartiles. Exercise training did not significantly alter any of the predicted organ ages in the total sample or by age quartile, with wide interindividual variability in the training responsiveness of predicted organ ages. Moreover, although some participants reduced their number of accelerated organ age traits after training, the prevalence of accelerated organ aging remained 37% at post-training. Conclusions: We found that existing proteomic organ aging signatures only replicated in the oldest (middle aged) HERITAGE participants, which likely reflects the fact the signatures were derived in older populations. Importantly, organ aging signatures were not sensitive to exercise training, which likely limits their potential clinical utility.