A study involving hundreds of Veterans Affairs patients shows a link between the diabetes drug metformin and a lower risk of death from COVID-19.

Metformin, one of the most commonly prescribed medications for people with Type 2 diabetes, is a known mammalian target of rapamycin inhibitor, which has been a recent focus of potential COVID-19 treatments.

A study published in JAMDA last week examined the drug’s influence among 775 nursing home residents infected with SARS-CoV-2 at 134 Veterans Health Administration Community Living Centers (nursing homes) between March 1 and May 13.

Diabetes is a known risk factor for developing a severe case of COVID-19, and patients typically fare worse with those infections versus non-diabetics. But residents taking metformin were at significantly reduced hazard of death in the 30 days following a COVID-19 diagnosis.

Comparing medication records for the 14-days prior to diagnosis and patient outcomes 30 days after, the study found that 12.6% of SARS-CoV-2 residents taking metformin died, compared with 17.4% of those taking other diabetes medications, 23.3% of those taking insulin and 22.7% of those not taking any diabetes medications.

“These findings suggest a relative survival benefit in nursing home residents on metformin, potentially through its mTOR inhibition effects,” reported the authors, led by James Rudolph, M.D., geriatrician and health services researcher at the Providence VA Medical Center and associate professor of medicine at Brown University. “Metformin is an inexpensive and readily available therapy that could reduce mortality and hospitalization associated with SARS-CoV-2 infection in patients with T2DM for which there are no drug contraindications.”

The research team is calling for a prospective study to investigate the drug’s potential therapeutic benefits.