Early-onset CVD at the intersection of sex, race/ethnicity, education, income, and health insurance in the US: a nationwide intersectional analysis

The burden of early-onset cardiovascular disease (CVD) is increasing, but how intersecting social determinants shape this risk in US young adults is unclear. We quantified intersectional inequities in early-onset CVD prevalence and examined their temporal changes following the COVID-19 pandemic in US. In this retrospective serial cross-sectional study of 1,030,504 US adults aged 18–44 (BRFSS 2015–2024), we employed Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (MAIHDA). Individuals were nested within 240 strata defined by sex, race/ethnicity, education, income, and insurance. The variance partition coefficient (VPC) and median odds ratio (MOR) quantified disparities. Models were stratified into pre- and post-pandemic periods. The weighted prevalence of early-onset CVD was 2.1%. The variance components model revealed substantial between-stratum heterogeneity (VPC, 23.5%; MOR, 2.60). Predicted CVD probabilities ranged over 400-fold across strata (0.04%-15.91%), with the highest risk found in uninsured, low-income, low-education Asian males. Additive main effects explained only 44.6% of this inequality (PCV). Of 235 strata, 99 (42.1%) exhibited significant intersectional effects (58 penalties, 41 protections), with Asian adults featuring prominently at both risk extremes. From the pre- to post-pandemic period, intersectional inequities widened, with the MOR increasing from 3.43 (95% CI, 3.00–3.86) to 4.19 (95% CI, 3.55–4.84), a 22.2% relative increase (95% CI, − 0.4% to 44.7%). Young US adults face vast, widening, and largely non-additive intersectional inequities in early-onset CVD. Risk is exceptionally concentrated in multiply-marginalized strata, and the post-pandemic exacerbation of these disparities demands a paradigm shift from individual risk management to structurally competent, equity-focused preventive strategies.