Is Diabetes a Risk Factor for Long COVID? Possibly.

The jury is still out as to whether diabetes is a risk factor for post-acute sequelae of COVID-19 (PASC), a researcher reported.

In a scoping review of seven studies, three (43%) concluded that diabetes was indeed a "potent" risk factor for developing long COVID following infection, according to Jessica L. Harding, PhD, of Emory University School of Medicine in Atlanta.

Among these studies, diabetes was tied with more than a four times higher chance of developing long COVID symptoms, with all odds ratios settling over 4. These studies were mainly comprised of patients who were hospitalized for COVID-19 infection, she stated in a presentation at the American Diabetes Association (ADA) annual meeting.

However, in the four (57%) other included studies, the findings were inconclusive as to any significant links between diabetes and long COVID. For these studies, all ORs and relative ratios ranged between 0.5 to 2.2, and did not reach statistical significance.

"This review suggests there is some evidence that diabetes may be a potent risk factor for long COVID," Harding said, adding that results were ultimately limited by the small number of studies focusing on potential ties between diabetes and long COVID, along with the heterogeneity of the studies. In particular, there was a lack of a consistent definition of long COVID (although it generally was considered as ongoing symptoms of COVID such as fatigue, cough, dyspnea, and others); variance with regard to follow-up duration and risk adjustment; and differences in the at-risk populations included.

Harding explained that a 2022 Cell study inspired their research. That study found type 2 diabetes was one of four significant risk factors for developing long COVID, and also reported that SARS-CoV-2 RNAemia, Epstein-Barr virus viremia, and specific auto-antibodies were strong risk factors for post-acute sequelae of COVID-19.

"More high-quality studies across multiple populations and settings are needed to determine if diabetes is indeed a risk factor for long COVID," Harding's group stated. "In the meantime, while we wait for that data, careful monitoring of people with diabetes for the development of long COVID is advised."

For the review, they looked at 39 studies published from January 2020 to January 2022 that included a minimum of 4-weeks of follow-up after a COVID-19 diagnosis. All studies also compared the incidence of long COVID in people with diabetes versus patients without.

The seven studies included in the analysis had a longitudinal cohort design and had adults from high-income countries, such as Italy, Norway, U.S., U.K., and Sweden. The largest study followed 4,182 patients.

There was a mix of hospitalized and non-hospitalized patients with COVID, as well as patients with other comorbidities such as kidney transplant recipients. That study of kidney transplant recipients with COVID-19 found a 4.42-times higher odds of long COVID with diabetes (OR 4.42, 95% CI 1.16-16.8).

Comment