Abstract
BACKGROUND: Recent studies have identified a correlation between insulin resistance (IR) and depression. This study aims to explore the correlation between estimated glucose disposal rate (eGDR), a practical and noninvasive measure for assessing IR, and depression in the general population. METHODS: In this population-based cross-sectional study, data from 28,444 adults aged 18 years old or older in the NHANES during the period from 1999 to 2018 were analyzed. The correlation between eGDR and depression was examined through multivariate logistic regression analyses, subgroup analyses, restricted cubic spline, and interaction tests. Furthermore, a mediation analysis was conducted to elucidate the role of the atherogenic index of plasma (AIP) in mediating the effect of eGDR on depression. RESULTS: Multivariate logistic regression analysis and restricted cubic splines analysis indicated that eGDR can exhibit a linearly correlation with depression (OR = 0.913; 95% CI: 0.875, 0.953). Subjects in eGDR6-8 and eGDR > 8 groups had a decrease risk of depression as 25.4% and 41.5% than those in the eGDR < 4 group. This negative correlation was more pronounced in those with obesity. Mediation analysis indicated that AIP mediated 9.6% of the correlation between eGDR and depression. CONCLUSIONS: eGDR was linear negatively correlated with depression, with AIP playing a mediating role. This study provides a novel perspective on the mechanism connecting IR to depression. Managing IR and monitoring AIP may contribute to alleviating depression.