Association between estimated glucose disposal rate and the risk of MAFLD in American adults: a cross-sectional study

The estimated glucose disposal rate (eGDR), as a novel metric of insulin resistance (IR), has been demonstrated to correlate with hepatic steatosis in patients with diabetes. Although IR is considered as a factor affecting lipid metabolism, the correlation between eGDR and metabolic associated fatty liver disease (MAFLD) is still unclear. Data from the 2017–2020 National Health and Nutrition Examination Survey (NHANES) were employed in this cross-sectional study designed to examine the association between eGDR and MAFLD through the application of weighted multivariate logistic regression model. The nonlinear relationship was described utilizing restricted cubic spline (RCS) regression. Subgroup analysis was performed to assess the consistency of the results and causal mediation analysis was employed to explore potential mediators. The study included 5,805 participants, 3,253 of whom diagnosed MAFLD, with a prevalence rate of 56.1%. After adjusting for all confounding factors, the risk of MAFLD decreased by 51% with each unit increase in the eGDR (odds ratio [OR]: 0.49, 95% confidence interval [CI]: 0.40, 0.61, p < 0.0001). Analysis of eGDR in quartiles further supported this trend (P = 0.001). The smooth curve fitting also showed a negative correlation between eGDR and MAFLD. Causal mediation analysis indicated that the relationship between eGDR and MAFLD was partially mediated by Atherogenic index of plasma (AIP), with a mediation ratio of 18.6%. Our result demonstrated that eGDR has a significant nonlinear negative association with the prevalence of MAFLD, in which AIP plays a mediating role, providing new insights into the prevention and management of MAFLD.