Individual and area-level socioeconomic status, Life's Simple 7, and comorbid cardiovascular disease and cancer: a prospective analysis of the UK Biobank cohort.

ABSTRACT

OBJECTIVES: We aimed to investigate the associations of individual and area-level socioeconomic status (SES) with incident cardiovascular diseases (CVD) alone, cancer alone, and comorbid CVD and cancer, and the mediation role of cardiovascular health score in these associations. STUDY DESIGN: This was a population-based prospective cohort study. METHODS: We used data from the UK Biobank, a population-based prospective cohort study. Latent class analysis was used to create an individual-level SES index based on three indicators (household income, education level, and employment status), and the Townsend Index was defined as the area-level socioeconomic status. We used the American Heart Association's (AHA) Life's Simple 7 (smoking, body weight, physical activity, diet, blood pressure, blood glucose, and total cholesterol) to calculate the cardiovascular health score. We used Cox proportional hazard regression models to estimate the hazard ratio (HR) and 95% confidence interval (CI) adjusted for demographic, environmental, and genetic factors. RESULTS: Compared with high SES, the HRs in participants with low individual and area-level SES were 1.33 (95% confidence interval [CI] 1.29 to 1.38) and 1.24 (95% CI 1.20 to 1.29) for incident CVD, 0.96 (95% CI 0.93 to 0.99) and 0.95 (95%CI 0.92 to 0.98) for incident cancer, 1.32 (95%CI 1.24 to 1.40) and 1.15 (95%CI 1.08 to 1.22) for incident comorbid CVD and cancer, respectively. Additionally, the mediation proportion of CVD score for individual and area-level SES was 47.93% and 48.87% for incident CVD, 44.83% and 59.93% for incident comorbid CVD and cancer. The interactions between individual-level SES and CVD scores were significant on incident CVD, and comorbid CVD and cancer, and the protective associations were stronger in participants with high individual-level SES. CONCLUSIONS: Life's Simple 7 significantly mediated the associations between SES and comorbid CVD and cancer, while almost half of the associations remained unclear.