After COVID-19 diagnosis, risk for incident type 2 diabetes was elevated for up to 2 y
Given that this large study found an elevated incidence of type 2 diabetes up to two years after infection, COVID-19 could now be characterized as a possible risk factor for diabetes, an ACP Journal Club commentary said.
An English study found that COVID-19 infection was associated with increased risk of developing diabetes, particularly in unvaccinated patients. The retrospective cohort study looked at millions of patients who developed COVID-19 before and after vaccines were available. It found that hazard ratios for the incidence of type 2 diabetes were highest in the month after COVID-19 but stayed significantly elevated for years after infection. Diabetes risk with COVID-19 was higher in unvaccinated patients and those who were hospitalized with the virus. Type 1 diabetes showed a similar pattern as type 2, except that elevated risk did not persist beyond a year after COVID-19.
The study was published in the August issue of The Lancet Diabetes & Endocrinology. The following commentary by Stephanos Vassilopoulos, MD, ACP Resident/Fellow Member, and Eleftherios Mylonakis, MD, PhD, was published in the ACP Journal Club section of Annals of Internal Medicine on Dec. 3.
Taylor and colleagues conducted a retrospective study evaluating the incidence of type 1 and type 2 diabetes in 3 cohorts (prevaccination, vaccinated, and unvaccinated) after a COVID-19 diagnosis. Within 4 weeks after COVID-19 diagnosis, incidence of type 2 diabetes was higher in every cohort. In contrast to the largest previous UK study, which found that diabetes incidence after COVID-19 did not increase beyond 12 weeks, Taylor and colleagues found that the overall incidence of type 2 diabetes remained elevated during the second year after diagnosis. Of interest, an increased incidence of type 1 diabetes was observed during the first year after diagnosis but not beyond. COVID-19 was diagnosed by laboratory testing or by identifying SARS-CoV-2 infection as the primary or underlying cause of death, further supporting the potential association.
The large sample size, external generalizability, and stratification by multiple periods of follow-up are key strengths of the analysis. A large study from the U.S. Department of Veterans Affairs also suggested that patients with previous COVID-19 infection had an increased risk for diabetes and use of antihyperglycemic drugs. In addition, Taylor and colleagues concluded that the increased incidence of type 2 diabetes after COVID-19 was attenuated in vaccinated vs. unvaccinated patients. Thus, these findings will allow us to better counsel patients about the benefits of COVID-19 vaccination.
Because the incidence of type 2 diabetes remains elevated up to 2 years after infection, COVID-19 could now be characterized as a possible risk factor for diabetes, and prospective studies with extended follow-up are needed. Moreover, given the increasing number of SARS-CoV-2 variants, future studies evaluating new dominant variants are warranted. Ongoing monitoring and studies focusing on post–COVID-19 care (including nutrition and diabetes management) could enhance our understanding of prognosis and improve our approach for patients who develop diabetes after COVID-19.