Socioeconomic status and cardiovascular mortality in over 170 000 cancer survivors

Aims Cardiovascular health is acknowledged as a crucial concern among cancer survivors. Socioeconomic status (SES) is an essential but often neglected risk factor for cardiovascular disease (CVD). We conducted this study to identify the relationship between SES and CVD mortality in cancer survivors. Methods and results Using the National Health Insurance Service-National Health Examinee database, we identified cancer survivors diagnosed and surviving beyond 5 years post-diagnosis. SES was assessed based on insurance premiums and classified into five groups. The primary outcome was overall CVD mortality. This study analysed 170 555 individuals (mean age 60.7 ± 11.9 years, 57.8% female). A gradual increase in risk was observed across SES groups: adjusted hazard ratios (95% confidence intervals) for overall CVD mortality were 1.15 (1.04-1.26), 1.28 (1.15-1.44), 1.31 (1.18-1.46), and 2.13 (1.30-3.49) for the second, third, and fourth quartile, and medical aid group (the lowest SES group) compared to the highest SES group, respectively (P for trend < 0.001). The lowest SES group with hypertension exhibited a 3.4-fold higher risk of CVD mortality compared to the highest SES group without hypertension. Interaction analyses revealed that low SES synergistically interacts with hypertension, heightening the risk of CVD mortality (synergy index 1.62). Conclusion This study demonstrates a significant correlation between low SES and increased CVD mortality among cancer survivors. Particularly, the lowest SES group, when combined with hypertension, significantly escalates CVD mortality. Our findings underscore the critical importance of recognizing SES as a significant risk factor for CVD mortality in this population of cancer survivors. Lay Summary Our population-based cohort study, involving over 170 000 cancer survivors, demonstrates a significant association between socioeconomic status (SES) and cardiovascular disease (CVD) mortality. Lower SES is correlated with an elevated risk of CVD mortality across diverse subgroups and specific CVD types. Notably, a lower SES amplifies the relationship between hypertension and CVD.