Association Between A Body Shape Index and Depression: Evidence From NHANES 2005-2018 With Mediation Analysis of the...

PurposeGrowing evidence suggests a bidirectional relationship between depression and obesity. This study examined the association between A Body Shape Index (ABSI) and depressive symptoms among U.S. adults and explored the mediating role of the triglyceride-glucose (TyG) index.DesignCross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES, 2005-2018).SettingUnited States, utilizing NHANES data collected between 2005 and 2018.Participants15200 non-institutionalized U.S. adults aged >=20 years with complete data on ABSI, depression (assessed by PHQ-9), and TyG index.MethodsMultivariate logistic regression, smooth curve fitting, subgroup/interaction analysis, and sensitivity analyses assessed the ABSI-depression link. Mediation analysis quantified the TyG index's role.ResultsAfter adjusting for potential confounders, a significant positive association was observed between ABSI and depressive symptoms. Participants in the highest ABSI quartile (Q4) had higher odds of depression compared to those in the lowest quartile (Q1). Subgroup and sensitivity analyses confirmed the robustness and independence of this association. Mediation analysis revealed that the TyG index partially mediated the relationship between ABSI and depression, with a mediation effect accounting for 5.31% of the total association.ConclusionThis large cross-sectional study highlights a significant association between higher ABSI and depressive symptoms among U.S. adults. These findings highlight the need for further research to explore underlying mechanisms and potential clinical implications.