Cardiovascular-Kidney-Metabolic Syndrome Age Derived From Routine Health Checkup and Claims Data　- Large-Scale Epidemiological Study.

BACKGROUND: The cardiovascular-kidney-metabolic (CKM) framework emphasizes the interplay of metabolic, renal, and cardiovascular abnormalities in cardiovascular disease risk. We aimed to develop a CKM syndrome age algorithm using routinely collected health checkup and claims data in Japan. METHODS AND RESULTS: We conducted a cohort study of 376,612 men and 478,853 women aged 20-79 years in the DeSC database. Flexible parametric survival models were developed for 5 incident cardiovascular outcomes corresponding to CKM syndrome stage 4 (i.e., heart failure, myocardial infarction, atrial fibrillation, stroke, and peripheral arterial disease) and a composite outcome comprising these 5 outcomes. The models used available CKM-related variables obtained from health checkups and administrative claims data. Model performance was assessed using bootstrap internal validation. CKM syndrome age was defined as the age at which a hypothetical same-sex individual with an optimal CKM risk profile would have the same predicted 5-year risk as the participant. The developed prediction models showed acceptable discrimination across the 6 outcomes, with optimism-corrected Harrell's C-index ranging from 0.694 to 0.724 in men and from 0.653 to 0.716 in women. CKM syndrome age showed higher discrimination than chronological age alone across all outcomes and both sexes. CONCLUSIONS: CKM syndrome age may serve as an intuitive tool for communicating integrated cardiovascular risk beyond chronological age in health checkup settings.