Triglyceride-glucose index and postoperative delirium: a retrospective study exploring a lipid-related marker in neuropsychiatric risk stratification after gastric surgery

Yao et al. Lipids in Health and Disease (2025) 24:361 https://doi.org/10.1186/s12944-025-02794-1 Lipids in Health and Disease Open Access RESEARCH Triglyceride-glucose index and postoperative delirium: a retrospective study exploring a lipid-related marker in neuropsychiatric risk stratification after gastric surgery Fengwei Yao1†, Lei Liu1†, Xiaolan Chen1†, Jian Zhang1, Zhinan Hao1* and Zhijun He1* Abstract Background Delirium is a common neuropsychiatric complication following major gastrointestinal surgery and is associated with poor postoperative outcomes. Patients undergoing gastric surgery often experience significant metabolic stress and insulin resistance, which may contribute to delirium. The triglyceride-glucose (TyG) index is a simple surrogate marker of insulin resistance, but its predictive value for postoperative delirium in gastric surgery patients remains unclear. Methods This retrospective study used data from the MIMIC-IV database and included 819 ICU patients after gastric surgery. Exposure was the triglyceride–glucose (TyG) index from first available labs; outcome was ICU delirium assessed by CAM-ICU. Associations were examined with multivariable logistic regression, with standard covariate adjustment. Results Increased ICU delirium was independently linked to a higher TyG index (OR = 1.25, 95% CI: 1.01–1.56). RCS revealed a U-shaped relationship. The association remained stable after PSM and across multiple subgroups. SHAP analysis confirmed TyG as a meaningful predictor. Conclusion A greater TyG index was linked in this retrospective analysis to a higher incidence of postoperative delirium in individuals after gastric surgery. These findings support preoperative risk stratification and targeted monitoring to enhance peri-operative safety and recovery in gastric surgery patients, and prospective studies are warranted to validate its clinical utility. Keywords Delirium, Postoperative complications, General surgery, Intensive care units, Insulin resistance, Triglycerides † Fengwei Yao, Lei Liu and Xiaolan Chen contributed equally to this work. *Correspondence: Zhinan Hao Zhijun He 1 Department of Gastrointestinal Surgery, Renmin Hospital, Hubei University of Medicine, Shiyan 442000, Hubei, P. R. China © The Author(s) 2025. 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To view a copy of this licence, visit http://creati vecommons.org/licenses/by-nc-nd/4.0/. Yao et al. Lipids in Health and Disease (2025) 24:361 Introduction Acute brain malfunction known as delirium is typified by diminished awareness and focus [1–3], and it frequently occurs among patients in intensive care units (ICUs), particularly after major surgeries such as gastric operations. These procedures often trigger a biphasic metabolic stress response—from hypometabolism to hypermetabolism—marked by acute metabolic disturbances, excessive inflammatory activation, and increased insulin resistance, all of which contribute to a heightened risk of delirium [4–6]. According to studies, the prevalence of postoperative delirium in patients after stomach surgery varies between 8.2% and 54.4% [7, 8]. This condition significantly prolongs hospitalization and increases healthcare costs, and is closely associated with long-term cognitive decline and elevated mortality, severely affecting patient outcomes and quality of life [9–11]. Although various risk prediction tools for delirium exist, most focus on traditional risk factors such as age, underlying diseases, medication use, and geriatric nutritional indices [12–15]. In recent years, metabolic abnormalities—particularly insulin resistance (IR)—have gained increasing attention for their role in the development of delirium. Through a number of pathways, including as blood-brain barrier disruption, heightened neuroinflammation, and impaired cerebral glucose metabolism, IR is believed to have a role in the pathogenesis of delirium [16]. Notably, a study reported that preoperative dexamethasone administration attenuated inflammation and reduced the incidence of POCD, further highlighting the role of inflammation in perioperative neurocognitive outcomes [17]. As a straightforward and trustworthy surrogate measure for insulin resistance, the TyG index has gained widespread acceptance [18, 19]. Previous studies have confirmed the association between insulin resistance and adverse outcomes in various clinical settings, including patients undergoing gastrointestinal surgery, those with acute kidney injury, and those experiencing cardiovascular events [5, 20, 21]. Recent studies have also suggested a possible link between the TyG index and neuropsychiatric complications [22, 23]. Nevertheless, nothing is known about the possible connection between the TyG and postoperative delirium in individuals undergoing stomach surgery. Given the high metabolic stress burden and elevated risk of postoperative delirium in this population, it is clinically significant to investigate the TyG index’s association value in this context. Therefore, this study hypothesize that the TyG index, as a proxy for insulin resistance, is associated with the occurrence of postoperative delirium in gastric surgery patients and may serve as a valuable predictive biomarker. This study aims to provide a novel metabolic Page 2 of 13 perspective for identifying and managing perioperative neuropsychiatric complications. Methods Study participants and eligibility This study was based on the MIMIC-IV database (version 3.1) [24]. Research team was granted authorized access to the database upon completion of the Collaborative Institutional Training Initiative (CITI) program on human research protection and certification through PhysioNet (Certificate ID: 65083321). All patients who underwent gastric-related surgical procedures were identified using international diagnostic codes; detailed code listings are provided in Supplementary Table S1. Exclusion criteria: [1] triglyceride levels were measured more than 24 h after ICU admission; [2] patients with missing key laboratory data required for TyG calculation (i.e (...truncated)