Abstract
Malnutrition and insulin resistance are linked to complications like delirium, yet their impact on elderly heart failure patients remains underexplored. This study investigates how nutritional status and the triglyceride-glucose (TyG) index influence delirium in this population. We conducted a retrospective study involving patients aged 75 and older with decompensated heart failure. Delirium was assessed using the Confusion Assessment Method (CAM), and nutritional status was evaluated with the Mini Nutritional Assessment Scale-Short Form (MNA-SF). The TyG index was calculated as: TyG index = ln [triglycerides (mg/dL) × fasting glucose (mg/dL) / 2]. The study included 412 patients (mean age 84.30 ± 5.16 years; 56.31% male), with 24.03% experiencing delirium during hospitalization. After adjusting for confounders, a higher TyG index was significantly associated with increased delirium risk (OR = 1.549, 95% CI: 1.102-2.178, P = 0.012), while a higher MNA-SF score correlated with reduced risk (OR = 0.793, 95% CI: 0.662-0.949, P = 0.011). Kaplan-Meier analysis showed significant differences in cumulative survival based on nutritional status and TyG index (Log-Rank test: χ²= 65.604, P < 0.001). Mediation analysis indicated that nutritional status partially mediated the relationship between the TyG index and delirium, and vice versa. Malnutrition and elevated TyG index levels increase delirium risk in elderly heart failure patients, underscoring the need for effective nutritional management and metabolic regulation.