June 23, 2023
Ever since mRNA vaccines became widely available, the incidence of severe acute illness from Covid-19 has largely diminished. Indeed, the World Health Organization declared an end to the global Public Health Emergency on May 5, 2023, and the CDC followed suit six days later.
For millions of people who survive a bout of Covid, however, there can be months of excruciating symptoms which follow recovery from the acute phase of the disease. This syndrome, known as long Covid, is characterized by intense fatigue, chest pain, dizziness and cognitive issues such as brain fog, which fluctuate in intensity and duration. Now, for the first time, the results of a placebo-controlled, randomized clinical trial of 1,100 participants, published in the medical journal Lancet Infectious Diseases, offer hope for the prevention of this chronic and debilitating illness.
The study, published on June 8, found that metformin, a widely used and inexpensive diabetes drug, reduced the risk of developing long COVID by 41% among people who are overweight and obese. Metformin is primarily used to treat type 2 diabetes and helps the body lower blood sugar levels. Previous modeling studies had suggested that it could potentially suppress the coronavirus' ability to build new proteins, and thus, make copies of itself. This prompted researchers to design a clinical trial to investigate metformin's potential preventative action against long Covid.
Although this study provides significant evidence that metformin could eventually become a Covid treatment drug, it is too early for it to be recommended for treatment by the CDC. The results of the study must be replicated with larger, more diverse sample sizes before it can be approved by the CDC for the prevention of long Covid. It is also important to emphasize that the study did not examine the effectiveness of metformin for people who already have long COVID.
Nevertheless, for Americans living with long-term symptoms, limited physical mobility, and impaired cognitive function after surviving COVID, it’s a start. Moreover, this study is important for another reason - it effectively confirms the basic existence of long COVID. As Harvard’s Jeremy Faust noted, "Treatment can only be effective if there is something to treat. Even with definitions as amorphous and heterogeneous as those currently in use for diagnosing long COVID, … this study population [provided] an ample cohort of individuals with syndromes similar enough that disease incidence could be modified, and metformin appeared to achieve that." Stay tuned.