The potential benefit of metformin to reduce delirium risk and mortality: a retrospective cohort study

Abstract

Purpose: Metformin has been reported to improve age-related disorders, including dementia, and to lower mortality. This study was conducted to investigate whether metformin use lower delirium risk, as well as longterm mortality. Methods: In this retrospective cohort study, previously recruited 1,404 subjects were analyzed. The relationship between metformin use and delirium, and the relationship between metformin use and 3-year mortality were investigated. Main findings: 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]). Conclusions: Metformin use may lower the risk of delirium and mortality in DM patients.

Metformin use history and genome-wide DNA methylation profile: potential molecular mechanism for aging and longevity

“…Our group also confirmed that inpatients using metformin had improved three-year survival rates compared to non-metformin users [12]. In addition, our data also showed that prevalence of delirium was lower among those who were on metformin compared to those without [12].…”

“…Also, agedependent, dose-dependent, and gender-dependent variable effects on lifespan were reported in mice [27,28]. Although these previous studies' results are not consistent, our cohort mentioned above (from which the present data are an analysis of its subgroup) clearly showed a positive influence of metformin use on survival among diabetic inpatients [12].…”

“…Patients with age-related diseases such as cardiovascular diseases and cancer who take metformin also had lower rates of mortality [ 24 , 25 ]. Our recent study using a cohort of over 1,400 inpatients also revealed that diabetic patients with a history of metformin use have a significantly lower 3-year mortality than diabetic patients who have not taken metformin [ 12 ]. There are, however, conflicting reports as well.…”

“…Clinical variables were gathered through electronic medical chart review, patient interviews, and collateral information from family members [41][42][43][44]. Metformin use, insulin use, and type 2 diabetes mellitus (DM) history were obtained by using the search terms "metformin", "insulin", and "DM" or "diabetes", respectively [12]. Only type 2 diabetes mellitus (DM) was included, excluding type 1 diabetes mellitus or gestational diabetes.…”

Risk factors for hypoactive delirium in patients with non-traumatic ARDS：a prospective, observational study

“…Another theory for the development of delirium is a decreased activity of the brain insulin signaling system, mainly due to central insulin resistance and insulin de ciency. Intranasally administered insulin (INI) can restore the activity of the brain insulin system, has a wide therapeutic prospect for delirium [21].In 2022, a retrospective cohort study (include 1404 subjects) found that metformin reduced the incidence and mortality of delirium in patients with diabetes mellitus [22].…”