Level and Change in a Modified 7-Component Life's Essential 8 and Incident Cardiovascular Multimorbidity in Chinese Middle-Aged and Older Adults: The China Health and Retirement Longitudinal Study

Background: This study aimed to investigate the association between the level and change of a modified, diet-excluded Life's Essential 8 (LE8) score and the risk of incident cardiovascular multimorbidity (CVM) in Chinese middle-aged and older adults. Methods: A total of 4,646 cardiovascular disease-free participants aged ≥45 years from the China Health and Retirement Longitudinal Study (CHARLS), all of whom completed physical examinations in 2011, 2013, and 2015, were included. A modified 7-component LE8 score (diet excluded; not directly comparable with 8-component studies) was constructed at each wave, and latent class growth models were used to identify LE8 trajectories over 2011–2015. The primary outcome was incident CVM (hypertension with heart disease and/or stroke) during 2015–2020, ascertained at the 2020 wave. Results: Over follow-up, 330 of the 4,547 at-risk participants developed CVM (7.3%). Three trajectories were identified: persistent high (44.3%), persistent moderate (45.1%), and persistent low (10.7%). Compared with the persistent high group, the persistent moderate and persistent low groups had higher risks of CVM (multiple-adjusted OR, 1.95 [95% CI, 1.45–2.62] and 4.04 [2.77–5.89]; P for trend <0.001), with consistent results across all 25 sensitivity analyses. The association was reproduced in an independent 30% validation sample (persistent low: HR 4.20, 95% CI 2.39–7.39; C-index 0.662; calibration slope 0.92) and in NHANES for cardiovascular mortality (HR 0.67, 95% CI 0.59–0.76 per 10 points). After additional adjustment for the baseline LE8 score, the association of the persistent low group remained significant (OR, 2.23 [1.23–4.00]), but the trajectories added little discriminative value beyond a single baseline score (C-index increment 0.005), whereas within-person decline in LE8 was associated with a higher risk (HR, 0.82 [0.72–0.92] per 10 points). Conclusion: The level of the modified 7-component LE8 score showed a significant, graded, inverse association with incident CVM in this examination-compliant, cardiovascular disease-free population. Over the 4-year window, the trajectory classes mainly reflected baseline level, and within-person change, rather than class membership, carried the additional prognostic information; a single baseline measurement largely suffices for risk stratification, and repeated measurement adds value mainly for detecting within-person change.