Cardiovascular Health Score, Social Network Size, and All-Cause Mortality in a Korean Prospective Cohort

Abstract Aims Social network size influences survival through health behaviors and psychosocial support, while cardiovascular health (CVH) predicts all-cause mortality. However, their combined effect remains unclear. We investigated the independent and joint associations of CVH and network size with all-cause mortality in a Korean cohort. Methods and results We analyzed 11,312 participants aged 30–79 years from the Cardiovascular and Metabolic Diseases Etiology Research Center cohort (2013–2018). CVH scores based on Life’s Essential 8 were categorized into tertiles. Network size was classified as small (0–1), medium (2–3), or large (≥4 close contacts). Mortality data through 2024 were obtained from national death records. Multivariable Cox models estimated hazard ratios (HRs) after adjustment for demographic, socioeconomic, and clinical covariates. During 100,739 person-years of follow-up (mean 8.9 years), 397 deaths occurred. Compared with lower tertile CVH group, hazard of mortality was lower in middle (HR: 0.84, 95% CI: 0.66–1.06) and upper tertile CVH group (HR: 0.61, 95% CI 0.45–0.82). Medium (HR: 0.70, 95% CI: 0.55–0.90) and large (HR: 0.69, 95% CI: 0.51–0.92) network size was also associated with lower hazard of mortality compared with small network size. Participants with both upper tertile CVH and large network size had the lowest hazard of mortality (HR: 0.36, 95% CI: 0.22–0.58). No significant interaction was observed (p = 0.41). Conclusions Higher CVH and larger networks were independently associated with lower all-cause mortality in middle-aged Korean adults. Public health strategies that combine lifestyle promotion with social engagement may help reduce premature death.