Skip to content
DraconiticResearch
Search Sources API
210,049 studies31 sourcesUpdated 23 min ago
Peer-reviewedCC BY 4.0Critical Care and Resuscitation

Effect of intranasal insulin on postoperative delirium: A systematic review and dose–response meta-analysis

  • Omar Saeed1
  • Mohamedhen Vall Nounou2
  • Abdelrahman Saeed1
  • Bram Rochwerg3,4,5
  • Ali M. Abdelaziz6
  • Gerald L. Weinhouse7
  • Sung Ryul Shim8
  • Muhammed Elhadi9
9 affiliations
  1. 1Faculty of Medicine, Al-Azhar University, Damietta, Egypt
  2. 2Faculty of Medicine, University of Nouakchott Al Aasrya, Nouakchott, Mauritania
  3. 3Department of Medicine, McMaster University, Hamilton, Ontario, Canada
  4. 4Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, Ontario, Canada
  5. 5Knowledge Centre, Hamilton Health Sciences, Hamilton, Ontario, Canada
  6. 6Faculty of Medicine, Alexandria University, Alexandria, Egypt
  7. 7Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
  8. 8Department of Biomedical Informatics, Konyang University College of Medicine, Daejeon, South Korea
  9. 9College of Medicine, Korea University, Anam-ro, Seongbuk-gu, Seoul, 02841, South Korea
Read full textPDFDOICite

Abstract

Objective: Postoperative delirium (POD) is a common neurological complication associated with adverse clinical outcomes. Intranasal insulin may improve cognitive function, but its effectiveness and optimal dose for preventing POD remain uncertain. We evaluated the effect of intranasal insulin on POD and explored its dose–response relationship.

Review methods: PubMed, Scopus, Web of Science, and the Cochrane Library were searched through November 2025. Randomised controlled trials comparing intranasal insulin with placebo in adult surgical patients were included. Random-effect pairwise and one-stage dose–response meta-analyses were performed. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool, and certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation framework.

Results: Eight randomised controlled trials involving 892 patients were included (502 receiving intranasal insulin and 390 receiving placebo). Intranasal insulin probably reduces POD (moderate-certainty evidence) compared with placebo (risk ratio, 0.39; 95% confidence interval, 0.29–0.51). Subgroup analyses found no significant differences according to surgery type or anaesthetic technique. A dose–response analysis demonstrated a nonlinear association, with a rapid reduction in POD risk at lower doses and the greatest modelled benefit at 30 IU (risk ratio, 0.39; 95% confidence interval, 0.29–0.53). The dose–response curve plateaued above 30 IU, with no additional reduction in POD risk at higher doses. Seven trials had a low risk of bias, while one raised some concerns because of bias in measurement of the outcome.

Conclusions: Intranasal insulin probably reduces POD in adult surgical patients. The dose–response findings suggest that 30 IU may provide the greatest benefit, with no apparent additional reduction at higher doses. Larger multicentre trials are needed to confirm the optimal regimen and comprehensively evaluate safety.

Related

  1. Effects of intranasal insulin on postoperative delirium in older patients with and without type 2 diabetes mellitus: a secondary analysis of a randomized clinical trial
    Danyang Geng, Xianghan Ruan, Huikai Yang +7
    Aging Clinical and Experimental ResearchPeer-reviewedCC BY-NC-ND 4.0Full textGeneral medicinePMC
  2. Perioperative non-invasive brain stimulation for the prevention of postoperative delirium: a systematic review and meta-analysis of randomised controlled trials
    H. Wang, L. Du, D. Li +7
    medRxivPreprintCC BY-NC-NDFull textSurgery & anaesthesiamedRxiv
  3. Retrospective evaluation of predictors and clinical impact of postoperative delirium in liver transplant recipients
    Chunjiao Long, Huan Lin, Qi-Quan Wan
    MedicinePeer-reviewedCC BY-NCFull textGeneral medicineEurope PMC
  4. Beyond bone health: is vitamin D the next modifiable risk factor for pediatric postoperative delirium?
    Tom Giedsing Hansen, Thomas Engelhardt
    Translational pediatricsPeer-reviewedCC BY-NC-NDFull textGeneral medicineEurope PMCPMC
  5. Commentary: Incidence and independent risk factors for postoperative delirium in ICU patients after cardiopulmonary bypass cardiac surgery: a retrospective cohort study
    Antonio Salsano, Francesco Santini
    Frontiers in Cardiovascular MedicinePeer-reviewedCC BY 4.0Cardiovascular medicineCrossref

Cite

BibTeXRIS
BibTeX
@article{saeed2026effect,
  title = {{Effect of intranasal insulin on postoperative delirium: A systematic review and dose–response meta-analysis}},
  author = {Omar Saeed and Mohamedhen Vall Nounou and Abdelrahman Saeed and Bram Rochwerg and Ali M. Abdelaziz and Gerald L. Weinhouse and Sung Ryul Shim and Muhammed Elhadi},
  journal = {Critical Care and Resuscitation},
  year = {2026},
  month = oct,
  doi = {10.1016/j.ccrj.2026.100227},
  url = {https://doi.org/10.1016/j.ccrj.2026.100227},
  note = {CC BY 4.0},
}
RIS
TY  - JOUR
TI  - Effect of intranasal insulin on postoperative delirium: A systematic review and dose–response meta-analysis
AU  - Omar Saeed
AU  - Mohamedhen Vall Nounou
AU  - Abdelrahman Saeed
AU  - Bram Rochwerg
AU  - Ali M. Abdelaziz
AU  - Gerald L. Weinhouse
AU  - Sung Ryul Shim
AU  - Muhammed Elhadi
PY  - 2026
DA  - 2026/10/27
JO  - Critical Care and Resuscitation
DO  - 10.1016/j.ccrj.2026.100227
UR  - https://doi.org/10.1016/j.ccrj.2026.100227
AB  - Objective: Postoperative delirium (POD) is a common neurological complication associated with adverse clinical outcomes. Intranasal insulin may improve cognitive function, but its effectiveness and optimal dose for preventing POD remain uncertain. We evaluated the effect of intranasal insulin on POD and explored its dose–response relationship.  Review methods: PubMed, Scopus, Web of Science, and the Cochrane Library were searched through November 2025. Randomised controlled trials comparing intranasal insulin with placebo in adult surgical patients were included. Random-effect pairwise and one-stage dose–response meta-analyses were performed. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool, and certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation framework.  Results: Eight randomised controlled trials involving 892 patients were included (502 receiving intranasal insulin and 390 receiving placebo). Intranasal insulin probably reduces POD (moderate-certainty evidence) compared with placebo (risk ratio, 0.39; 95% confidence interval, 0.29–0.51). Subgroup analyses found no significant differences according to surgery type or anaesthetic technique. A dose–response analysis demonstrated a nonlinear association, with a rapid reduction in POD risk at lower doses and the greatest modelled benefit at 30 IU (risk ratio, 0.39; 95% confidence interval, 0.29–0.53). The dose–response curve plateaued above 30 IU, with no additional reduction in POD risk at higher doses. Seven trials had a low risk of bias, while one raised some concerns because of bias in measurement of the outcome.  Conclusions: Intranasal insulin probably reduces POD in adult surgical patients. The dose–response findings suggest that 30 IU may provide the greatest benefit, with no apparent additional reduction at higher doses. Larger multicentre trials are needed to confirm the optimal regimen and comprehensively evaluate safety.
SN  - 1441-2772
SN  - 2652-9335
ER  -