Estimated Glucose Disposal Rate and Cognitive Function Among Middle-Aged and Older Adults: Guangzhou Biobank Cohort Study

Abstract Background: Insulin resistance has been implicated in cognitive aging, but its direct assessment is impractical in large population studies. Estimated glucose disposal rate (eGDR) is an accessible surrogate of insulin sensitivity, yet its associations with immediate and delayed memory, and global cognition remain unclear. We examined these associations among older Chinese adults. Aims & methods: In this cross-sectional analysis, we included community-dwelling adults aged ≥50 years from 2008 to 2012. Cognitive function was assessed using the Delayed Word Recall Test (DWRT), Immediate Word Recall Test (IWRT), and Mini-Mental State Examination (MMSE). Multivariable regression and restricted cubic splines were used to examine associations of eGDR with cognitive function. Results: Among 5909 participants (mean age=59.8 years [SD=7.0]; 4379 [74.1%] women), each 1 mg/kg/min higher eGDR was associated with higher DWRT (adjusted β=0.03, 95% CI 0.01 to 0.05) and MMSE scores (0.04, 0.01 to 0.08), but not IWRT scores (0.04, −0.02 to 0.09). In age-stratified analyses, higher eGDR was associated with higher IWRT scores among participants aged <60 years (0.08, 0.01 to 0.14), but not with DWRT or MMSE scores. Among participants aged ≥60 years, higher eGDR was associated with higher DWRT (0.05, 0.01 to 0.08) and MMSE scores (0.10, 0.04 to 0.16), but not with IWRT scores. Discussion & conclusions: Higher eGDR was associated with better delayed memory and global cognitive performance, particularly among adults aged ≥60 years. These findings warrant prospective evaluation of eGDR as a scalable marker for identifying older adults at risk of cognitive decline.