Association of cardiovascular health with lung function and mortality in US adults: a national cohort study

Background: cardiovascular health (CVH), as defined by the "Life's Essential 8" (LE8) metric, is crucial for overall well-being. However, the associations among CVH, lung function, and all-cause mortality remain insufficiently explored. This study aimed to examine these relationships and assess the mediating role of lung function. Methods: data were obtained from the National Health and Nutrition Examination Survey (NHANES) 2007-2012 cycles, with mortality follow-up through December 31, 2019. The LE8 score, comprising eight key components, was used to evaluate CVH. Lung function was assessed via forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and the FEV1/FVC ratio. Multiple regression analyses and mediation models were employed to explore associations and potential mediation effects. Results: among 10,819 adults, higher CVH was linked to enhanced lung function and lower all-cause mortality. Each one-point increment in the LE8 score corresponded to a 4 % reduction in mortality risk (hazard ratio [HR] = 0.96, 95 % confidence interval [CI] = 0.94-0.98, p < 0.001). Additionally, an increase of one LE8 point was associated with a 5.11 mL rise in FEV1 (β = 5.11, 95 % CI = 4.37-5.85, p < 0.001). Notably, the FEV1/FVC ratio mediated 18.03 % of the relationship between LE8 and mortality. Conclusions: better CVH, as assessed by LE8, correlates with superior lung function and reduced mortality risk. Furthermore, lung function, particularly the FEV1/FVC ratio, partially mediates this association. These findings underscore the interdependence of cardiovascular and respiratory health in shaping long-term survival outcomes.