Association between estimated glucose disposal rate and sarcopenia in U.S. adults: a cross-sectional study based on NHANES 2011–2018

BACKGROUND: The estimated glucose disposal rate (eGDR) is a novel indicator of insulin resistance that reflects the body's ability to process glucose. The association between eGDR and sarcopenia in adults remains unclear. This study investigated the relationship between eGDR and sarcopenia to support the improved clinical identification of the condition. METHODS: We analysed data from the 2011 to 2018 cycles of the National Health and Nutrition Examination Survey (NHANES). The final analytical sample comprised 7,147 participants. After applying survey weights, the population was 49.5% male and 50.5% female. We first calculated the weighted prevalence of sarcopenia among U.S. adults. Participants were then stratified into four groups based on eGDR quartiles. A weighted multivariate logistic regression model assessed the association between eGDR and sarcopenia risk, whereas a restricted cubic spline (RCS) examined their dose-response relationship. Subgroup analyses with interaction tests verified the stability of this association, and mediation analysis identified potential factors underlying the relationship. RESULTS: A total of 7147 adult participants were included in this study. The weighted prevalence of sarcopenia was 6.7%, and the proportion of sarcopenic obesity among patients with sarcopenia was 73.1%. Weighted multivariate logistic regression revealed an obvious inverse association between eGDR and sarcopenia. In the fully adjusted model, compared with the lowest eGDR quartile group, the adjusted odds ratios (95% confidence intervals) for sarcopenia in quartiles 2nd to 4th quartile groups were 0.70 (95% CI: 0.52, 0.95; p < 0.001), 0.35 (95% CI: 0.25, 0.50; p < 0.001), and 0.12 (95% CI: 0.08, 0.18; p < 0.001), respectively. Subgroup analyses and interaction tests indicated that this relationship was not affected by factors such as age, sex, race, marital status, education, smoking, or drinking. Mediation analysis confirmed the mediating roles of inflammatory indices in the association between eGDR and sarcopenia (p < 0.001). CONCLUSION: A negative relationship was observed between eGDR and sarcopenia prevalence. The inflammatory response may mediate this relationship. eGDR may serve as a potential biomarker for the early identification and diagnosis of sarcopenia.