The mediating role of depression in the association between socioeconomic status and cardiovascular disease: A nationwide cross-sectional study from NHANES 2005–2018

Disparities in socioeconomic status (SES) are associated with an increased risk of cardiovascular disease (CVD). Depression is a highly prevalent cardiovascular risk factor among individuals with low SES. The present study aimed to gain a better understanding of the association between SES and CVD by examining the mediating effects of depression. 30,127 participants, 50.77 % female, with a mean age of 47.37 years from the National Health and Nutrition Examination Survey (NHANES) 2005–2018, were included. Weighted multivariable logistic regression analyses estimated the association between SES and CVD. Mediation analyses tested the mediating effects of depression. The multivariable-adjusted odds ratio (OR) of high SES for CVD was 0.42 (95 % confidence interval (CI): 0.36, 0.50; P < 0.001). In parallel, depression was negatively associated with SES, in which the multivariable-adjusted β was −1.42 (95 % CI: −1.62, −1.22; P < 0.001) in high SES compared to low SES. For the association between depression and CVD, the multivariable-adjusted OR per 1-point increase of PHQ-9 score for CVD was 1.08 (95 % CI: 1.07, 1.09; P < 0.001). The mediation models indicated that depression mediated 10.92 % of the total association between SES and CVD when fully adjusted. Identifying individuals with depression for appropriate treatment is promising for reducing the CVD burden among populations with low SES. • Disparities in SES assessed by family PIR are significantly associated with an increased risk of CVD. • Depression assessed by PHQ-9 is highly prevalent among individuals with low SES and increases the risk of having CVD. • Depression mediates the association between SES and CVD, suggesting that targeting depression may reduce CVD burden in low SES populations.