Effect of intranasal insulin on perioperative cognitive function in older adults: a randomized, placebo-controlled, double-blind clinical trial

• Published in: Age and ageing Vol. 53; no. 9
• Main Authors: Sun, Miao, Ruan, Xianghan, Zhou, Zhikang, Huo, Yuting, Liu, Min, Liu, Siyuan, Cao, Jiangbei, Liu, Yan-hong, Zhang, Xiaoying, Ma, Yu-long, Mi, Weidong
• Format: Journal Article
• Language: English
• Published: England Oxford Publishing Limited (England) 01.09.2024
• Subjects: Administration, Intranasal; Aged; Aged, 80 and over; Alternative medicine; Anesthesia; Biomarkers - blood; C-reactive protein; Clinical research; Clinical trials; Cognition - drug effects; Cognitive ability; Cognitive functioning; Cognitive impairment; Complications; Delirium; Double-Blind Method; Elective surgery; Female; Health care; Humans; Hypoglycemic Agents - administration & dosage; Hypoglycemic Agents - adverse effects; Induction; Insulin; Insulin - administration & dosage; Interleukin 6; Intranasal administration; Male; Mental Status and Dementia Tests; Mini-Mental State Examination; Nasal sprays; Necrosis; Older people; Orthopedic Procedures - adverse effects; Orthopedic surgery; Patients; Postoperative; Postoperative Cognitive Complications - diagnosis; Postoperative Cognitive Complications - epidemiology; Postoperative Cognitive Complications - etiology; Postoperative Cognitive Complications - prevention & control; Serum; Serum levels; Surgery; Time Factors; Treatment Outcome; Tumor necrosis factor-TNF; Tumor necrosis factor-α; Tumors; older people; insulin resistance; intranasal insulin; older surgical patient; postoperative cognitive function; postoperative delirium (POD)
• ISSN: 0002-0729; 1468-2834; 1468-2834
• DOI: 10.1093/ageing/afae188

Postoperative cognitive impairment are common neural complications in older surgical patients and exacerbate the burden of medical care on families and society. A total of 140 older patients who were scheduled for elective orthopaedic surgery or pancreatic surgery with general anaesthesia were randomly assigned to Group S or Group I with a 1:1 allocation. Patients in Group S and Group I received intranasal administration of 400 μL of normal saline or 40 IU/400 μL of insulin, respectively, once daily from 5 minutes before anaesthesia induction until 3 days postoperatively. Perioperative cognitive function was assessed using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment-Basic (MoCA-B) at 1 day before and 3 days after surgery and postoperative delirium (POD) incidence was assessed using the 3-minute Diagnostic Interview for CAM (3D-CAM) on postoperative days 1-3. Serum levels of interleukin-6 (IL-6), tumour necrosis factor α (TNF-α), S100-β and C-reactive protein (CRP) were measured on the first day after surgery. Insulin treatment significantly increased postoperative MMSE and MoCA-B scores in group I than in group S (P < 0.001, P = 0.001, respectively), decreased the incidence of POD within the 3-day postoperative period in Group I than in Group S (10.9% vs 26.6%, P = 0.024), and inhibited postoperative IL-6 and S100-β levels in Group I compared to Group S (P = 0.034, P = 0.044, respectively). Intranasal insulin administration is thus suggested as a potential therapy to improve postoperative cognition in older patients undergoing surgery. However, a more standardized multi-centre, large-sample study is needed to further validate these results.