Aging | The Potential Benefit of Metformin to Reduce Delirium Risk and Mortality: A Retrospective Cohort Study


“In this report, we showed the potential benefit of metformin in decreasing the risk of delirium and mortality in DM [diabetes mellitus] subjects.”

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BUFFALO, NY- December 7, 2022 – A new research paper was published in Aging (listed as "Aging (Albany NY)" by MEDLINE/PubMed and "Aging-US" by Web of Science) Volume 14, Issue 22, entitled, “The potential benefit of metformin to reduce delirium risk and mortality: a retrospective cohort study.”

Metformin has been reported to improve age-related disorders, including dementia, and to lower mortality. This study was conducted to investigate whether metformin use lowers delirium risk, as well as long-term mortality.

In the current retrospective cohort study, researchers Takehiko Yamanashi, Zoe-Ella EM Anderson, Manisha Modukuri, Gloria Chang, Tammy Tran, Pedro S. Marra, Nadia E. Wahba, Kaitlyn J. Crutchley, Eleanor J. Sullivan, Sydney S. Jellison, Katie R. Comp, Cade C. Akers, Alissa A. Meyer, Sangil Lee, Masaaki Iwata, Hyunkeun R. Cho, Eri Shinozaki, and Gen Shinozaki from Stanford University School of Medicine, University of Iowa Carver College of Medicine, University of Iowa College of Public Health, and Tottori University Faculty of Medicine analyzed 1,404 previously recruited subjects. The relationship between metformin use and delirium, and the relationship between metformin use and 3-year mortality were investigated.

“Thus, in this report we aimed to investigate the relationship between DM [diabetes mellitus] and delirium risk with a focus on the influence from metformin. We hypothesized that history of metformin use is associated with lower risk for delirium. We were also interested in testing if history of metformin use can alter one of the most important patient outcomes, mortality.”

242 subjects were categorized into a type 2 diabetes mellitus (DM)-without-metformin group, and 264 subjects were categorized into a DM-with-metformin group. Prevalence of delirium was 36.0% in the DM-without-metformin group, and 29.2% in the DM-with-metformin group. A history of metformin use reduced the risk of delirium in patients with DM (OR, 0.50 [95% CI, 0.32 to 0.79]) after controlling for confounding factors. 

The 3-year mortality in the DM-without-metformin group (survival rate, 0.595 [95% CI, 0.512 to 0.669]) was higher than in the DM-with-metformin group (survival rate, 0.695 [95% CI, 0.604 to 0.770]) (p=0.035). A history of metformin use decreased the risk of 3-year mortality after adjustment for confounding factors (HR, 0.69 [95% CI, 0.48 to 0.98]). The researchers concluded that metformin use may lower the risk of delirium and mortality in DM patients.

“In this report, we showed the potential benefit of metformin in decreasing the risk of delirium and mortality in DM subjects.”


Corresponding Author: Gen Shinozaki - 

Keywords: delirium, metformin, diabetes mellitus, mortality, aging

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Cancer and aging are two sides of age-related tumorigenesis.

The mission of the journal is to understand the mechanisms surrounding aging and age-related diseases, including cancer as the main cause of death in the modern aged population.

The journal aims to promote 1) treatment of age-related diseases by slowing down aging, 2) validation of anti-aging drugs by treating age-related diseases, and 3) prevention of cancer by inhibiting aging. (Cancer and COVID-19 are age-related diseases.)

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