Characterizing brain-cardiovascular aging using multi-organ imaging and machine learning

The structure and function of the brain and cardiovascular system change over the lifespan. In this study, we aim to establish the extent to which age-related changes in these two vital organs are linked. Utilizing normative models and data from the UK Biobank, we estimate biological ages for the brain and heart for 2904 middle-aged and older healthy adults, including both males and females. Biological ages were based on multiple structural, morphological and functional features derived from brain and cardiovascular imaging modalities. We find that cardiovascular aging, particularly aging of its functional capacity and physiology, is selectively associated with the aging of specific brain networks, including the salience, default mode and somatomotor networks as well as the subcortex. Our work provides unique insight into brain-heart relationships and may facilitate an improved understanding of the increased co-occurrence of brain and heart diseases in aging. Significance statement As individuals age, both the brain and cardiovascular systems undergo significant changes, making them susceptible to various neurodegenerative and cardiovascular conditions. Despite the physiological interplay between the brain and the cardiovascular system, brain networks and circuits that may drive this brain-heart aging axis remain largely unknown. Using multimodal multiorgan imaging and advanced analytic approaches, we elucidate age-related structural and functional brain changes that selectively associate with cardiovascular aging. Our findings may pave the way toward an improved understanding of the increased co-occurrence of brain and cardiovascular diseases in aging, thereby facilitating the development of more effective and synergistic intervention strategies in disease management, prognosis and prevention.