Atherogenic Index of Plasma as a Mediator in the association between Body Roundness Index and Depression: insights from NHANES 2005-2018.

ABSTRACT

BACKGROUND: Previous studies have shown a correlation between depression and obesity, as well as between depression and the Atherogenic Index of Plasma (AIP). However, there is limited research on the association between visceral obesity and depression, as well as the potential mediating role of AIP in this relationship. METHODS: This study included 13,123 participants from the 2005-2018 National Health and Nutrition Examination Survey. Visceral obesity was measured with the Body Roundness Index (BRI), while depression was evaluated with the Patient Health Questionnaire-9. The AIP served as a marker for lipid disorders. To investigate the association between the BRI and depression, multivariate logistic regressions, restricted cubic spline models, subgroup analyses, and interaction tests were used. Additionally, a mediation analysis was conducted to explore the role of AIP in mediating the effect of BRI on depression. RESULTS: There was a positive linear correlation between the BRI and depression. After controlling for all covariates, individuals in the highest BRI (Q4) group had an OR of 1.42 for depression (95% CI 1.12-1.82) in comparison with individuals in the lowest BRI (Q1) group. Moreover, the AIP partially mediated the association between the BRI and depression, accounting for approximately 8.64% (95% CI 2.04-16.00%) of the total effect. CONCLUSION: The BRI was positively associated with depression, with the AIP playing a mediating role. This study provides a novel perspective on the mechanism that connects visceral obesity to depression. Managing visceral fat and monitoring AIP levels may contribute to alleviating depression.