Triglyceride-glucose index predicts postoperative delirium in elderly patients with type 2 diabetes mellitus: a retrospective cohort study

Lipids in Health and Disease Sun et al. Lipids in Health and Disease (2024) 23:107 https://doi.org/10.1186/s12944-024-02084-2 Open Access RESEARCH Triglyceride-glucose index predicts postoperative delirium in elderly patients with type 2 diabetes mellitus: a retrospective cohort study Miao Sun1,2†, Min Liu2,3†, Faqiang Zhang2,4†, Lijuan Sang1, Yuxiang Song1, Peng Li1, Siyuan Liu1, Huikai Yang1, Libin Ma1, Jiangbei Cao1, Weidong Mi1,2* and Yulong Ma1,2* Abstract Background Postoperative delirium (POD) is more prevalent among elderly patients with type 2 diabetes mellitus (T2DM). Insulin resistance (IR) can be assessed using the triglyceride-glucose (TyG) index, a novel biomarker. This study aims to investigate the predictive potential of the TyG index for POD in elderly patients with T2DM. Materials and methods Elderly patients (≥ 65) with T2DM who underwent non-neurosurgery and non-cardiac surgery were enrolled. Univariate and multivariate logistic regression analyses were conducted to assess the association between the TyG index and POD. Additionally, subgroup analyses were performed to compare the sexspecific differences in the predictive ability of the TyG index for POD. Results A total of 4566 patients were included in this retrospective cohort. The receiver operating characteristic (ROC) curve analysis determined the optimal cut-off value for the TyG index to be 8.678. In the univariate model, a TyG index > 8.678 exhibited an odds ratio (OR) of 1.668 (95% CI: 1.210–2.324, P = 0.002) for predicting POD. In the multivariate regression models, the ORs were 1.590 (95% CI: 1.133–2.252, P < 0.008), 1.661 (95% CI: 1.199–2.325, P < 0.003), and 1.603 (95% CI: 1.137–2.283, P = 0.008) for different models. Subgroup analyses demonstrated that the predictive ability of the TyG index was more pronounced in females compared to males. Conclusion The TyG index shows promise as a novel biomarker for predicting the occurrence of POD in elderly surgical patients with T2DM. Keywords Insulin resistance, Triglyceride glucose index, Postoperative delirium, Type 2 diabetes mellitus, Elderly surgical patients † Miao Sun, Min Liu and Faqiang Zhang contributed equally to this work. *Correspondence: Weidong Mi Yulong Ma 1 Department of Anesthesiology, The First Medical Center of Chinese PLA General Hospital, Beijing 100730, China 2 Nation Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing 100730, China 3 Department of Anesthesiology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China 4 Department of Anesthesiology, Shanghai Pulmonary Hospital, School of Medicine, Tongji University, Shanghai 200433, China © The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Sun et al. Lipids in Health and Disease (2024) 23:107 Introduction Diabetes has emerged as a significant metabolic disease that poses a substantial threat to human life and health. As of 2021, the global prevalence of diabetes reached 536.6 million individuals, with diabetes-related healthcare expenditure exceeding $1 trillion [1]. It is estimated that approximately half of all diabetes patients will require surgery during their lifetime [2]. However, the long-term complications associated with diabetes, including inflammation, oxidative stress, vasculopathy, and renal insufficiency, significantly elevate the risk of postoperative complications, particularly in elderly patients [2, 3]. These complications have a considerable impact on patient prognosis and quality of life. Therefore, it is imperative to focus on prevention and treatment strategies for postoperative complications in elderly diabetic patients. Postoperative delirium (POD), which is characterized by acute disturbances in attention and awareness, is a prevalent neurological complication among elderly surgical patients [4, 5]. POD has been linked to prolonged hospital stays, increased morbidity and mortality rates, and diminished quality of life [4, 5]. Prior studies have demonstrated a higher incidence of POD in elderly patients with diabetes compared with non-diabetics, which significantly affects their prognosis [6, 7]. However, limited research has investigated the risk factors associated with POD in this specific population. Identifying independent indicators for POD in elderly diabetic surgical patients is therefore crucial, as it could serve as a basis for developing novel perioperative interventions. Type 2 diabetes mellitus (T2DM) accounts for 90–95% of all diabetes cases [4]. Insulin resistance (IR) underlies the pathogenesis of T2DM, reflecting reduced sensitivity of the body and tissues to insulin. Chronic IR can lead to central nervous system (CNS) dysfunction due to insulin’s critical role in neurosynaptic functioning, synaptic plasticity modulation, glucose uptake, and neuronal survival [8]. Previous research has established a connection between IR and Alzheimer’s disease and other neurodegenerative disorders [8]. However, the correlation between IR and POD in elderly patients with T2DM has not been extensively explored. The “gold standard” for identifying IR is the hyperinsulinemic euglycemic clamp, but its application during the perioperative period is not practical [9]. The triglyceride-glucose (TyG) index, calculated by fasting glucose and triglyceride, has emerged as a promising surrogate marker of IR due to its strong correlation with the hyperinsulinemic euglycemic clamp [10]. Previous studies have shown that the TyG index can independently predict the incidence and prognosis of cardiovascular and cerebrovascular diseases [10–12]. However, the relationship Page 2 of 11 between the TyG index and POD in elderly patients with T2DM has yet to be explored. This study hypothesizes a correlation between TYG index and the incidence of POD in elderly patients with T2DM who undergo non-neurosurgery and non-cardiac surgery. The findings of this study indicated that elderly diabet (...truncated)