Introduction & Objective: Life’s Essential 8 (LE8) is an updated metric released by the American Heart Association for assessing cardiovascular health. This study aimed to investigate the relationship between triglyceride-glucose (TyG) index and homeostasis model assessment of insulin resistance (HOMA-IR), commonly-used insulin resistance-related parameters, and LE8.
Methods: This study used data from the National Health and Nutrition Examination Survey (NHANES) 2005-2018. LE8 score was measured according to the AHA LE8 algorithm. The association between TyG index and HOMA-IR (exposure), LE8 scores (outcome) and inflammatory marker (C-reactive protein [CRP]) (mediator) was explored using weighted multivariable linear regression, restricted cubic spline (RCS) models, and mediation analysis. Multiple stratified analyses and sensitivity analyses were also performed.
Results: A total of 13,750 participants, representing 186.3 million US non-institutionalized adults, were included. After multivariable adjustments, compared with the lowest quartile, the β with 95% CIs in the highest quartile were -16.61 (-17.47, -15.75) for TyG index and LE8 (P for trend<0.001) and -15.64 (-16.37, -14.91) for HOMA-IR and LE8 (P for trend<0.001). RCS plots showed a linear negative association between TyG index and LE8 and a nonlinear negative association between HOMA-IR and LE8. Besides, this negative association was significantly stronger in women than in men (P for interaction<0.05). Mediation analysis revealed that CRP significantly mediated the relationship of TyG index and HOMA-IR to LE8 scores with mediation proportions of 13.1% and 22.5%, respectively.
Conclusion: TyG index and HOMA-IR were negatively associated with LE8 scores and cardiovascular health in US adults, especially in women, and systemic inflammation was a partial mediator of this association.
S. Wang: None. L. Wang: None.
Key Clinical Frontier Technology Project of Department of Science and Technology of Jiangsu Province (NO. BE2022806); National Natural Science Foundation of China (NO. 82070367)