Abstract Body (Do not enter title and authors here): Introduction: The American Heart Association recently highlighted the linkage of cardiovascular disease (CVD) with kidney disease and the importance of promoting cardiovascular health (CVH) to prevent them. We investigated the associations of ideal CVH and its longitudinal change with cardiovascular-kidney outcomes in young adults.

Methods: From a nationwide health screening database, we identified young adults aged 20 to 39 years who underwent baseline health examinations in 2009-2010 (N=3,837,027). Participants were categorized according to ideal CVH score, calculated as the number of non-dietary ideal CVH components met (0-6). The subgroup of participants who underwent follow-up health examinations in 2011-2014 (N=2,769,557) were additionally categorized according to the combination of baseline and follow-up CVH scores. The primary outcome was cardiovascular-kidney event, defined as a composite of atherosclerotic cardiovascular disease (ASCVD) event, heart failure (HF) event, or kidney event.

Results: The median age of the participants was 31 years; 38.2% were female. During a median follow-up of 12.1 years, 173,558 incident cardiovascular-kidney events occurred. The multivariable-adjusted risk of cardiovascular-kidney event decreased stepwise with higher CVH scores; participants with a CVH score of 6 were at a 66% lower risk of the event than those with a CVH score of 0 (HR, 0.34 [95% CI, 0.32-0.37]). An increase in CVH score from the baseline (2009-2010) to follow-up (2011-2014) examination was associated with a lower risk of cardiovascular-kidney event (HR, 0.87 [95% CI, 0.87-0.88] per +1 change in CVH score). Moreover, the risk was lower in participants who maintained high CVH scores at both the baseline and follow-up examinations than in those who newly achieved high CVH scores at the follow-up examination (HR, 0.88 [95% CI, 0.87-0.89] per +1 baseline CVH score). The findings were consistent for ASCVD-kidney event, HF-kidney event, and kidney event.

Conclusions: In young adults, achieving and maintaining high CVH were each associated with a reduced risk of cardiovascular-kidney events. These findings highlight the significance of attaining ideal CVH early in young adulthood and preserving it throughout life for the primordial prevention of cardiovascular and kidney diseases.