Associations of Life’s Crucial 9 (LC9) with All-Cause and Cardiovascular Mortality in Adults With Cardiovascular, Kidney, and Metabolic Syndrome: A NHANES 2005–2018 Cohort Study

Background Cardiovascular, kidney, and metabolic syndrome (CKM) poses a significant threat to public health, being associated with increased mortality. Life's Crucial 9 (LC9) serves as a comprehensive and composite measure of key behavioral and clinical factors related to cardiovascular and mental health. This study aimed to investigate the association between LC9 scores and the risk of all - cause and cardiovascular mortality in US adults with CKM. Methods This prospective cohort study utilized data from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018. The study population consisted of 14,056 adults with CKM. LC9 score was calculated based on nine health metrics. Mortality follow-up data were available through linked National Death Index records until December 31, 2019. Cox proportional hazards regression models and Kaplan-Meier survival curve were used to assess associations between LC9 and all-cause mortality (primary outcome) and cardiovascular mortality (secondary outcome). Results Over a median follow-up of 91 months, 1,515 (10.8%) all-cause deaths occurred. The mean baseline age was 50.2 years (SD = 17.7). Higher LC9 scores were significantly associated with a lower risk of all-cause mortality (HR = 0.98; 95% CI: 0.97–0.98; p < 0.0001) in a fully adjusted model. Similarly, a higher LC9 score was associated with a lower risk of cardiovascular mortality (HR = 0.97; 95% CI: 0.96–0.98; p < 0.0001). A linear dose-response relationship was observed between LC9 score and both all-cause (Log-likelihood ratio test P-value 0.42) and cardiovascular mortality (Log-likelihood ratio test P-value 0.25). Conclusion In this NHANES-derived cohort of adults with cardiovascular, kidney, and metabolic syndrome characteristics, higher LC9 was linearly associated with lower risks of all-cause and cardiovascular mortality.