Type 2 diabetes mellitus modifies and mediates the association between the visceral adiposity index and depression: A cross-sectional study using NHANES 2005–2018 data

The objective of this investigation was to explore the correlation between the visceral adiposity index (VAI) and depression, and to analyze how type 2 diabetes mellitus (T2DM) may influence this relationship. This study included data of 12,378 participants sourced from the National Health and Nutrition Examination Survey (NHANES) 2005–2018. Utilizing multivariate logistic regression and restricted cubic spline (RCS) regression, we examined the correlation between VAI and depression. Additionally, we investigated the interactive and mediating effects of T2DM on the association between VAI and depression. Controlling for all potential confounders, the Ln logarithmic transformation of VAI showed a significant positive correlation with depression [odds ratio (OR) = 1.16, 95 % confidence interval (CI): 1.01–1.35, P = 0.041]. T2DM exhibited a notable interaction effect on the relationship connecting lnVAI and depression (P for interaction = 0.013). Specifically, the T2DM group exhibited a notable positive correlation between lnVAI and depression (OR = 1.46, 95 % CI: 1.17–1.82, P