Binational component-wise association between cardiovascular-kidney-metabolic syndrome and life’s essential 8 in South Korea and the US: A nationally representative comparative study

Although the American Heart Association (AHA) has emphasized the integration of cardiovascular-kidney-metabolic (CKM) syndrome and life's essential 8 (LE8) score, research on their association remains limited. To address this gap, this study analyzed the component-wise association between CKM syndrome and LE8 scores using nationally representative data from South Korea and the US. This binational study included adults aged 30 to 79 years from the Korea National Health and Nutrition Examination Surveys 2013 to 2020 and the US National Health and Nutrition Examination Surveys 2013 to 2020. CKM stages and LE8 scores were defined according to AHA criteria. LE8 scores encompass 4 health behaviors (diet, physical activity, nicotine exposure, and sleep) and 4 health factors (body mass index, blood lipids, blood glucose, and blood pressure). All analyses accounted for the complex survey design through appropriate sampling weights, stratification, and clustering methods. Associations between LE8 scores and the prevalence of CKM syndrome were assessed using weighted logistic regression adjusted for age, sex, household income, education level, and alcohol consumption. We included 8150 Koreans, the Korea National Health and Nutrition Examination Survey (61.30% female), and 5859 American participants (National Health and Nutrition Examination Survey; 44.80% female) aged 30 to 79. Higher LE8 scores were consistently associated with a lower prevalence of CKM syndrome in both Korea and the US. In Korea, component-wise association was primarily explained by health factor scores (weighted odds ratio [wOR], 0.09; 95% confidence interval, 0.06-0.14), whereas in the US, health behavior scores reported a distinct association (0.30; 0.17-0.52). Among all age groups, the protective association between LE8 scores and CKM syndrome was most pronounced in adults aged 30 to 44 years, with wORs of 0.89 (0.85-0.93) in Korea and 0.93 (0.91-0.95) in the US. This binational study highlights the importance of country-specific intervention strategies in reducing the burden of CKM syndrome. The findings of this study may provide a basis for designing targeted public health interventions aimed at CKM syndrome.