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 beta 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.