A population-based study of deep learning derived organ and tissue measures for accelerated aging using repurposed abdominal CT images

PROJECT SUMMARY There has been a dramatic increase in the number of persons living with reduced physical function and with aging-related chronic conditions. If we compare chronological age (calendar-based age) with biological age (changes at the cellular, tissue, organ, and system levels), we can classify persons as aging faster (accelerated aging) or slower (successful aging) than their peers. Methods have been developed to measure biological age based on DNA methylation, telomere length, and blood biomarkers. However, such measures may not accurately reflect organ- and tissue-level changes from aging. A multi-organ/tissue approach is needed to identify comprehensive age-related structural changes before signs, symptoms, or clinical diagnoses occur. Abdominal computed tomography (CT) has widespread use in the general population (35% of adults ages 20-89 years in an 11-year period). Quantitative measures of the organs and tissues on abdominal CT may predict organ-specific diseases, or in combination, may be used to calculate biological age and predict the more global outcomes of hospitalization and mortality. Therefore, our central hypothesis is that deep learning (DL) models applied to abdominal CTs can quantify structural features of the organs and tissues to identify persons with accelerated aging at high-risk for organ-specific disease, hospitalization, and death. The Rochester Epidemiology Project record-linkage system provides access to a general population archive of images for 423,081 abdominal CTs and to comprehensive medical record data among 181,187 adults (ages 20-89 years) between 2010-2020. Our team has already developed and validated DL tools to measure liver, kidney, aorta, fat, muscle, and bone on abdominal CT images. We will leverage these resources to 1) establish percentiles of abdominal CT biomarkers from both healthy and general population samples; 2) determine the risk of organ-specific clinical disease by abdominal CT biomarkers in the general population; and 3) determine the risk of hospitalization and death associated with abdominal CT measures in the general population. If successful, application of DL tools to abdominal CT images will enrich the characterization of age-related health risks without additional testing burden. Subclinical abdominal CT biomarkers may also inform the biology of aging and early disease, improve disease classification, and provide opportunities for early intervention.