AI Insight
This multicentre study of 2,157 elderly diabetic patients in China found a U-shaped relationship between preoperative fasting blood glucose levels and postoperative delirium risk, with both low and high glucose levels increasing risk. The optimal glucose range associated with lowest delirium risk was 5.92-9.75 mmol/L, with patients below or above this range showing 65% and 51% increased risk respectively compared to those within the optimal range.
Why it matters
These findings could help clinicians optimize preoperative blood glucose management in elderly diabetic patients undergoing surgery, potentially reducing postoperative delirium incidence by targeting a specific glucose range rather than simply avoiding hyperglycemia.
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⚠️ Preprint – Noch nicht peer-reviewed
Dieser Artikel wurde noch nicht von unabhängigen Experten begutachtet. Die Ergebnisse sind vorläufig und sollten mit Vorsicht interpretiert werden.
Abstract Objective: The heightened susceptibility of the aging brain to dysglycemia establishes blood glucose as a pivotal risk factor for postoperative delirium (POD) in elderly diabetic patients. This study investigated the association between preoperative fasting blood glucose (FBG) and POD risk in this population to define the optimal FBG range for POD. Methods: This study included 2,157 elderly diabetic patients undergoing non-cardiac surgery between April 2020 and April 2022 in 20 hospitals across China. The POD incidence was prospectively assessed using the 3-minute Diagnostic Interview for Confusion Assessment Method (3D-CAM) within 7 postoperative days. The FBG-POD relationship was retrospectively analysed using restricted cubic splines within Cox proportional hazards model. Thresholds were validated with the machine learning-guided optimal cut-point analysis. A multivariable linear regression model was plotted to compare the distribution of time to POD onset and subgroup analyses were performed based on specific populations. Results: A significant U-shaped relationship was observed between preoperative FBG and POD risk (P for nonlinearity=0.03). The hazard ratio identified the risk nadir of FBG at 8.43 mmol L-1. Optimal cut-point analysis defined three risk strata: a hypoglycemic-risk group (FBG [≤]5.92 mmol L-1; 13.3% POD), an optimal-glycemic group (FBG 5.92-9.75 mmol L-1; 9.7% POD), and a hyperglycemic-risk group (FBG >9.75 mmol L-1; 18.5% POD). Compared with the optimal-glycemic group, both the hypoglycemic-risk group (HR=1.65, P<0.001) and the hyperglycemic-risk group (HR=1.51, P=0.03) showed significantly increased risk. Interpretation: Preoperative FBG has a U-shaped association with POD risk in elderly diabetic patients with an optimal lowest-risk range as 5.92-9.75 mmol L-1. Keywords: Diabetes Mellitus; Elderly; Fasting Blood Glucose; Postoperative Delirium; Risk Stratification; Threshold Analysis.