Individuals with diabetes who experience COVID-19 are at increased risk for long COVID compared to individuals without diabetes, according to data from a literature review of seven studies.
Diabetes remains a risk factor for severe COVID-19, but whether it is a risk factor for postacute sequelae of COVID-19 (PASC), also known as long COVID, remains unclear, Jessica L. Harding, PhD, of Emory University, said in a late-breaking poster session at the annual scientific sessions of the American Diabetes Association.
Long COVID is generally defined as “sequelae that extend beyond the 4 weeks after initial infection” and may include a range of symptoms that affect multiple organs, Dr. Harding said. A study conducted in January of 2022 suggested that type 2 diabetes was one of several strong risk factors for long COVID, she noted.
Dr. Harding and colleagues reviewed data from seven studies published from Jan. 1, 2020, to Jan. 27, 2022, on the risk of PASC in people with and without diabetes. The studies included patients with a minimum of 4 weeks’ follow-up after COVID-19 diagnosis. All seven studies had a longitudinal cohort design, and included adults from high-income countries, with study populations ranging from 104 to 4,182.
Across the studies, long COVID definitions varied, but included ongoing symptoms of fatigue, cough, and dyspnea, with follow-up periods of 4 weeks to 7 months.
Overall, three of the seven studies indicated that diabetes was a risk factor for long COVID (odds ratio [OR] greater than 4 for all) and four studies indicated that diabetes was not a risk factor for long COVID (OR, 0.5-2.2).
One of the three studies showing increased risk included 2,334 individuals hospitalized with COVID-19; of these about 5% had diabetes. The odds ratio for PASC for individuals with diabetes was 4.18. In another study of 209 persons with COVID-19, of whom 22% had diabetes, diabetes was significantly correlated with respiratory viral disease (meaning at least two respiratory symptoms). The third study showing an increased risk of long COVID in diabetes patients included 104 kidney transplant patients, of whom 20% had diabetes; the odds ratio for PASC was 4.42.
The findings were limited by several factors, including the relatively small number of studies and the heterogeneity of studies regarding definitions of long COVID, specific populations at risk, follow-up times, and risk adjustment, Dr. Harding noted.
More high-quality studies across multiple populations and settings are needed to determine if diabetes is indeed a risk factor for long COVID, she said.
In the meantime, “careful monitoring of people with diabetes for development of PASC may be advised,” Dr. Harding concluded.
Findings support need for screening
“Given the devastating impact of COVID on people with diabetes, it’s important to know what data has been accumulated on long COVID for future research and discoveries in this area,” Robert A. Gabbay, MD, chief science and medical officer for the American Diabetes Association, said in an interview. “The more information we have, the better we can understand the implications.”
Dr. Gabbay said he was surprised by the current study findings. “We know very little on this subject, so yes, I am surprised to see just how significant the risk of long COVID for people with diabetes seems to be, but clearly, more research needs to be done to understand long COVID,” he emphasized.
The take-home message for clinicians is the importance of screening patients for PASC; also “ask your patients if they had COVID, to better understand any symptoms they might have that could be related to PACS,” he noted.
“It is crucial that we confirm these results and then look at risk factors in people with diabetes that might explain who is at highest risk and ultimately understand the causes and potential cure,” Dr. Gabbay added.
The study was supported by the National Heart, Lung, and Blood Institute. Dr. Harding and Dr. Gabbay had no financial conflicts to disclose.