Longitudinal Changes in Cardiovascular-Kidney-Metabolic Syndrome Stages and Their Impact on Outcomes: A Nationwide...

Background/Objectives: The impact of longitudinal changes in cardiovascular-kidney-metabolic (CKM) stage remains unclear. This study evaluated the association between CKM stage progression and clinical outcomes. Methods: We used the Korean National Health Insurance Database to identify adults aged ≥ 20 years who underwent two health checkups between 2009 and 2012. CKM stages were assessed at both time points and categorized as decreased, maintained, or increased over a 1-2-year interval. The primary outcome was a composite of all-cause death, heart failure, stroke, and myocardial infarction, evaluated over a mean follow-up of 11.05 years. Results: Among 877,537 participants, 15.3% experienced CKM stage progression. Compared to the maintained group, the increased group had a higher risk of the composite outcome (HR: 1.071, 95% CI: 1.050-1.092). While men had a higher rate of progression, women showed greater risk of clinical events (HR: 1.124 vs. 1.040). While stage progression was more frequent in younger adults, older individuals in the increased group progressed to more advanced stages and experienced higher rates of adverse outcomes. Conclusions: CKM stage progression is independently associated with increased risk of mortality and cardiovascular events, particularly in women and older adults. Serial CKM assessment may help identify high-risk individuals for early intervention.