# Cardiometabolic Index as a Mediator in the Association Between Estimated Glucose Disposal Rate and Depressive Symptoms: A Population‐Based Study

## TL;DR

Higher glucose disposal rates are linked to fewer depressive symptoms, with cardiometabolic index playing a mediating role in this relationship.

## Contribution

This study identifies cardiometabolic index as a mediator in the link between glucose disposal rate and depression.

## Key findings

- Higher estimated glucose disposal rate (eGDR) is associated with lower odds of depressive symptoms.
- Cardiometabolic index mediates approximately 11.2% of the effect of eGDR on depressive symptoms.
- eGDR shows better predictive power for depression than other insulin resistance markers like TyG, HOMA-IR, and HbA1c.

## Abstract

Estimated glucose disposal rate (eGDR) emerged as an innovative marker for insulin resistance, and this study was designed to investigate the connection between eGDR and depressive symptoms.

Information from the National Health and Nutrition Examination Survey (NHANES) was processed within the cross‐sectional research. Relationships between depressive symptoms and eGDR were examined using weighted logistic regression models, restricted cubic splines (RCS), sensitivity analyses, and subgroup comparisons. Receiver operating characteristic (ROC) curve analysis assessed the capacity for prediction of eGDR, relative to triglyceride‐glucose (TyG) index, Homeostasis Model Assessment of Insulin Resistance (HOMA‐IR), and glycated hemoglobin (HbA1c). Mediation analysis was also applied to assess cardiometabolic index (CMI)’s potential role in the eGDR‐depression relationship.

This analysis comprised 12,191 individuals stratified by eGDR tertiles (T1: <6.15; T2: 6.15–9.44; T3: ≥9.44 mg/kg/min). Multivariate logistic regression, adjusted for covariates, found that T3 had a significantly lower odds ratio for depressive symptoms than T1 (OR = 0.68, 95% CI: 0.48–0.97). RCS curves confirmed a linear trend (P for non‐linearity = 0.764). The negative association was particularly evident in participants under 60, non‐Hispanic Black individuals, those living alone, and those without cardiovascular disease. ROC analysis indicated that eGDR had better discriminative power for depressive symptoms than TyG, HOMA‐IR, and HbA1c (p < 0.05). Additionally, CMI mediated approximately 11.2% (95% CI: 4.2%–32.7%) of the total effect of eGDR on depressive symptoms.

Higher eGDR correlates with lower likelihood of depressive symptoms, with CMI acting as a mediator. Reducing insulin resistance and monitoring CMI could help decrease the occurrence of depression.

This cross‐sectional study included individuals who took part in the NHANES from 2003 to 2018. Our results demonstrated that higher eGDR correlates with lower likelihood of depressive symptoms, with CMI acting as a mediator. Reducing insulin resistance and monitoring CMI could help decrease the occurrence of depression.