DELIRIUM is a common and serious complication among hospitalised patients, particularly in older adults and those with pre-existing health conditions. It contributes substantially to healthcare costs and patient morbidity, yet its association with diabetes remains insufficiently explored. A recent study aimed to better understand the relationship between diabetes and delirium by evaluating the incidence of delirium among patients with diabetes, the relative risk compared to non-diabetic patients, and the influence of antidiabetic treatments on delirium onset. A key finding from this analysis is that nearly one in three patients with diabetes develop delirium.
A systematic search was conducted across MEDLINE, Scopus, Web of Science, and ClinicalTrials.gov up to 30 December 2024. Eligible studies included those reporting on the incidence of delirium in people with diabetes, comparisons of delirium rates between diabetic and non-diabetic groups, and the potential protective role of antidiabetic medications against delirium. Data were pooled and meta-analysed to provide a comprehensive picture of the current evidence base.
The pooled incidence of delirium in patients with diabetes was found to be 29% (95% CI: 26.0%–33.0%; I²=99.6%). Compared with non-diabetic patients, those with diabetes had significantly higher odds of developing delirium, with an odds ratio of 1.78 (95% CI: 1.59–1.99; I²=88.3%). Notably, certain treatments were associated with reduced risk. Intranasal insulin, when administered before surgery, reduced the risk of delirium compared with placebo (relative risk [RR]: 0.34; 95% CI: 0.23–0.52). Chronic use of metformin was also associated with a lower risk of delirium (RR: 0.71; 95% CI: 0.59–0.85; I²=84.8%).
These findings indicate that people with diabetes are at significantly increased risk of developing delirium, underscoring the need for targeted delirium prevention strategies in this population. The observed protective associations with intranasal insulin and metformin may offer promising directions for clinical practice. However, substantial heterogeneity across studies limits definitive conclusions and calls for caution in interpretation. Future studies should aim to clarify the mechanisms underpinning these associations and inform the development of diabetes-specific delirium screening and prevention protocols in clinical settings.
Reference
Komici K et al. The role of diabetes mellitus on delirium onset: a systematic review and meta-analysis. Cardiovasc Diabetol. 2025;24(1):216
