Metformin is one of the most widely used medicines for type 2 diabetes, but scientists are studying whether its benefits may go beyond controlling blood sugar.
Research suggests that people with diabetes who regularly take metformin may have a lower risk of developing delirium and may also have a better chance of survival.
The study was conducted by Takehiko Yamanashi and colleagues from Stanford University and other institutions. The findings were published in the journal Aging.
Delirium is a sudden change in a person’s ability to think clearly and understand what is happening around them. Someone with delirium may become confused, have trouble paying attention, seem unusually sleepy or restless, or experience rapid changes in awareness and behavior.
Unlike dementia, which usually develops gradually, delirium can appear within hours or days. It is especially common among older adults who are seriously ill or hospitalized, particularly after surgery or during an infection.
Many different problems can trigger delirium. These include infections, dehydration, pain, certain medicines, major surgery, changes in body chemistry, and severe illness.
People with existing health conditions can be particularly vulnerable. Diabetes is one condition associated with a greater risk of health complications that may contribute to delirium, making prevention especially important in this group.
Metformin has been used to treat type 2 diabetes for decades. It mainly helps lower blood sugar by reducing the amount of glucose released by the liver and helping the body respond better to insulin.
Scientists have also become interested in possible effects of metformin on aging and brain health. Earlier research has explored whether the drug might be associated with a lower risk of dementia and some other age-related diseases.
To examine its possible connection with delirium, the researchers analyzed information from 1,404 patients. They compared people with type 2 diabetes who used metformin with people who had diabetes but were not taking the medicine.
The researchers found that regular metformin users were less likely to experience delirium. They also found a lower risk of death among people who had been taking metformin.
These results are promising, but they do not prove that metformin itself prevented delirium or extended people’s lives. Because the research examined existing patient data rather than randomly assigning people to treatments, other differences between the groups could have influenced the results.
For example, people who take metformin may differ from other patients in their overall health, severity of diabetes, kidney function, other medications, or access to medical care. Larger and carefully controlled studies will be needed to determine whether metformin directly protects the brain.
Researchers also need to understand how such protection might work. Better blood sugar control could be one explanation, while other possible effects of metformin on inflammation, metabolism, and processes linked to aging may also play a role.
The findings do not mean people without diabetes should take metformin to prevent delirium, or that people with diabetes should change their medication on their own. Metformin is a prescription medicine and may not be suitable for everyone, particularly some people with serious kidney or other medical problems.
Preventing delirium usually requires addressing several risks at the same time, such as treating illness, preventing dehydration, reviewing medications, supporting sleep, and helping hospitalized patients remain oriented and mobile. Still, the study raises an intriguing possibility that a familiar diabetes medicine could have additional benefits that researchers are only beginning to understand.
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