Socioeconomic status, depressive symptoms and cardiometabolic kidney syndrome: an analysis based on national representative data

BACKGROUND: Cardiometabolic Kidney Syndrome (CKM) is a global chronic disease challenge. While links between socioeconomic status (SES) and individual CKM components exist, research often overlooks CKM's multi-system interactions and the role of psychosocial factors. Depression, prevalent in low SES groups and linked to CKM risk, may mediate the SES-CKM relationship. METHODS: Using 2005-2018 NHANES data with 11,367 participants, this study quantified SES via the family poverty-income ratio (PIR), assessed depressive symptoms with the PHQ-9 scale, and defined CKM per AHA criteria. Statistical analyses included multivariable logistic regression and structural equation modeling to examine associations and mediating effects. RESULTS: High SES was associated with 81% lower odds of advanced CKM (OR = 0.19, 95% CI: 0.10-0.36). Each unit increase in PIR was associated with 33% lower odds of depression (OR = 0.67, 95% CI: 0.63-0.72). Depression mediated 27.64% of the SES-advanced CKM link. A nonlinear threshold effect between SES and depression was found at PIR = 3.28, with subgroup analyses highlighting stronger SES-CKM associations in non-Hispanic Blacks and Whites. CONCLUSION: Socioeconomic disadvantage is significantly associated with depressive symptoms and advanced CKM in this cross-sectional study. Depressive symptoms may play a substantial mediating role based on structural equation modeling of observational data. These findings suggest that incorporating mental health interventions into CKM prevention strategies and implementing targeted policies to address health inequities could potentially enhance health equity. Future prospective studies are needed to validate these findings before refining the CKM prevention framework.