Glucose-lipid metabolic index reflects cognitive impairment of non-diabetic elderly individuals

Background Glucose and lipid metabolic disorders are involved in the impairment of cognitive function. However, it remains unclear the link between a new indicator of glucose-lipid metabolism index (GLMI) and cognitive impairment. Objective This study investigates the relationship between GLMI and multidimensional cognitive function in adults aged ≥ 60 years. Methods GLMI was derived from glucose and lipid metabolism parameters. Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word Learning test, Animal Fluency Test (AFT) and Digit Symbol Substitution Test (DSST) were used to evaluate the cognitive abilities of participants. Linear regression, subgroup analyses, multivariable adjustments, and restricted cubic spline (RCS) models were employed to evaluate GLMI-cognition associations. Results Among 787 participants from NHANES 2011–2014, diabetic individuals exhibited higher GLMI levels and more severe cognitive impairment than non-diabetic counterparts. In non-diabetic adults, GLMI showed linear correlations with CERAD and DSST assessed cognitive deficits. Subgroup analyses confirmed high GLMI as an independent risk factor for cognitive dysfunction in CERAD and DSST assessment. Multivariable regression revealed increased GLMI significantly elevated cognitive decline risk. ROC analysis identified 581.41 as the optimal GLMI cutoff (specificity: 86.0%) for predicting DSST impairment, outperforming traditional indices (TyG/HOMA-IR). RCS models demonstrated nonlinear GLMI-cognition associations, with a dose-dependent risk curve (200–800 range) and critical threshold at 545. Conclusions This study establishes that a high score of GLMI is associated with great severity of cognitive impairment in non-diabetic population.