Latest Diabetes News
People with type 2 diabetes stand a higher risk of developing a severe COVID 19 infection, according to several international studies. Metformin has been correlated in at least four retrospective studies with reduced risk of COVID-19 death in these patients.
This common, inexpensive drug from the 1920s "was independently associated with a significant reduction in mortality in subjects with diabetes and COVID-19" in a recent study. This data analysis looked at hospital records for over 25,000 patients from a racially diverse hospital in Alabama.
Not everyone thinks that metformin can protect against COVID-19. Metformin is a safer choice for people who have fewer serious health conditions to begin with, Kasia Lipska, MD, of Yale School of Medicine, New Haven, Connecticut, told Medscape Medical News. She said these people tend to do better than other groups in trials since they tend to be healthier overall.
"I don't think we have enough data to suggest metformin use for COVID-19 mitigation at this point," she said.
Others agree the drug needs more testing. And that testing may never happen, writes André J. Scheen, MD, PhD. In the Aug. 1 issue of Diabetes & Metabolism, he reviewed four hospital studies that show lower instances of death in COVID-19 patients taking metformin.
He concluded that while these studies tend to confirm a connection, they cannot prove that metformin is effective. That would require a randomized controlled trial (RCT).
In an RCT, scientists attempt to prove a cause-and-effect relationship by randomly assigning subjects into two groups. One group would receive metformin, and the other would not.
RCTs can take out the “noisy” data that comes from confounding variables—people who take metformin may be healthier, but an RCT will account for that.
But RCTs are expensive and take time.
"Such trials are almost impossible in the context of COVID-19," writes Dr. Scheen.
Difficult to begin with, such a trial is unlikely, given the patent for metformin has run out. This means any drug maker can sell the drug as a generic one. Because of this, such drugs are typically not profitable enough to justify the expense of an RCT, especially when the signals in research studies of its effectiveness are not strong.
How Does Metformin Work?
Metformin works by increasing your body's sensitivity to insulin, said MedicineNet pharmacy author Omudhome Ogbru, PharmD.
However, lactic acidosis may be a risk for some patients taking metformin with serious health conditions, Dr. Ogbru said. These include patients with
- reduced function of the kidneys or liver,
- congestive heart failure,
- severe acute illnesses, and
Metformin may be useful in other treatments, Dr. Scheen said. He said prior studies have found that it lowers mortality for people with a wide range of infections, including tuberculosis and sepsis. One recent RCT showed it can reduce inflammation even in people who do not have diabetes.