Association of endothelial activation and stress index with cardiovascular disease prevalence and mortality risk in older adults in the United States: a population-based study

Abstract Background The association between endothelial activation and stress index (EASIX) and cardiovascular disease (CVD) risk in older adults remains largely unexplored, lacking large-scale evidence. The objective of this study was to examine the association between EASIX and CVD prevalence in the U.S. population aged ≥ 60 years, and its association with all-cause mortality (ACM) among CVD patients. Methods This study used data from the National Health and Nutrition Examination Survey (NHANES) 2005–2018 to assess the association between EASIX and CVD prevalence in older adults using a cross-sectional design. A prospective cohort study was employed to conduct follow-up analysis of mortality among CVD patients. A weighted logistic regression model was utilized to analyze the association between EASIX and CVD prevalence, while a weighted Cox model was employed to assess the relationship between EASIX and association with ACM in CVD patients. To determine the nonlinear associations, we performed restricted cubic spline (RCS) analysis. Results Totally, 12,806 participants aged ≥ 60 years were enrolled, among whom 2,451 had CVD. After full covariate adjustment, a statistically significant positive association was revealed between EASIX and CVD prevalence in older adults (odds ratio [OR] = 1.390, 95% confidence interval [CI]: 1.153–1.686, p < 0.001). After adjusting for standard risk factors for all-cause mortality, we estimated that a one-unit higher EASIX was associated with a 29.5% higher hazard of ACM. RCS analysis confirmed nonlinear associations between EASIX and both CVD prevalence in older adults and ACM in older CVD patients. Conclusions Higher EASIX levels exhibit nonlinear positive associations with CVD prevalence among older U.S. adults and ACM risk in older CVD patients. EASIX holds promise as a valuable biomarker for evaluating the clinical risk profile of older adults and for assessing long-term prognosis in patients with established CVD.