Socioeconomic Disparities in Cardiovascular Health: A Cross-Sectional Analysis Unpacking the Sequential Mediation Roles of Protein Intake and Handgrip Strength

Objectives: This study investigated the sequential mediating roles of protein intake and handgrip strength (HGS) in the association between socioeconomic status (SES) and 10-year atherosclerotic cardiovascular disease (ASCVD) risk within the social determinants of health (SDOH) framework. Methods: We conducted a complex survey analysis using data from 6281 adults without baseline ASCVD from the Korea National Health and Nutrition Examination Survey (2016–2018), accounting for stratification, clustering, and weighting. The 10-year ASCVD risk was estimated using the pooled cohort risk equations. SES was classified into three groups based on educational attainment and household income. Relative HGS was calculated as the sum of maximal grip strength in both hands divided by body mass index. Indirect effects were assessed using bootstrap-based confidence intervals (CIs). Results: Compared with the low-SES group, the high-SES group showed a lower 10-year ASCVD risk in both the total effect model (B = −1.630, 95% CI: −2.250 to −1.010) and the direct effect model (B = −1.550, 95% CI: −2.170 to −0.927). The total indirect effect was also significant in both the high-versus-low and middle-versus-low SES comparisons. Protein intake and relative HGS partially mediated the association between SES and 10-year ASCVD risk, and the sequential mediation pathway was also significant. Conclusions: Within the SDOH framework, these findings suggest that nutritional and muscle-strength-related pathways may link socioeconomic disadvantage to ASCVD risk and support integrated interventions targeting nutritional support and muscle-strength improvement for life-course prevention.