A person's odds of getting a new diabetes diagnosis were 58 percent higher in the months following a COVID-19 infection compared with prior to infection, even amid the era of omicron, researchers reported Wednesday in the journal JAMA Network Open.

The study is just the latest to link the development of diabetes to COVID-19, which pandemic data suggests increases the risk of a range of cardiometabolic conditions, including blood clots, myocarditis, stroke, and diabetes. A study published early last year in Nature Medicine tapped into the medical records of more than 11 million veterans and found that people who had recovered from COVID-19 had a 63 percent higher risk of developing any of 20 cardiovascular diseases, including a 55 percent higher risk of heart attack, stroke, and death.

The data on diabetes is equally worrying. In a systemic meta-analysis published in Scientific Reports last November, researchers compiled data from eight cohort studies involving more than 47 million people and found that COVID-19 infection was linked to a 66 percent increased risk of developing diabetes.

"Given the extraordinary number of COVID-19 survivors globally, the modest increase in diabetes risk could correspond to a drastic rise in the number of people diagnosed with the disease worldwide," the authors—researchers at Penn State College—wrote.

In a commentary written last year in the journal The Lancet Diabetes & Endocrinology, diabetes researchers at Emory noted that the long-term implications of the association are "profound." Dramatic rises in diabetes cases could end up "wreaking havoc on already over-stretched and under-resourced clinical and public health systems globally, with devastating tolls in terms of deaths and suffering."

It's still unclear how COVID-19 is sparking such dramatic cardiometabolic conditions in survivors, but researchers have speculated that immune responses play a role. For instance, in the case of diabetes, researchers have hypothesized that inflammation from COVID-19 is contributing to insulin resistance.

Persistent risk

In the new study this week, researchers extended the data to look at cardiometabolic links to COVID-19 through June 2022, a period that includes the omicron coronavirus variant wave. Omicron was widely seen as being "milder" than previous variants, raising the question of whether it poses less risk of spurring concerning long-term consequences, such as cardiovascular disease and diabetes. The answer, according to the study, is no.

The authors of the new study—researchers at Cedars Sinai Medical Center Los Angeles—looked at data from a cohort of over 23,000 patients and calculated their odds of being diagnosed with diabetes in the 90 days prior to a COVID-19 infection to the 90 days after an infection. To account for fewer doctor visits at points during the pandemic, the researchers adjusted the data based on the diagnoses rates of non-COVID-linked conditions, namely urinary tract infections and acid reflux.

In the adjusted modeling, the odds of being newly diagnosed with diabetes in the post-infection window were 58 percent higher compared with the odds prior to infection. And in further analyses, the risk remained when looking at odds prior to the omicron era and afterward. Age and sex also did not seem to sway the risk.

Unvaccinated people did appear to have higher odds of developing diabetes in the post-COVID window than vaccinated people, but the link was not statistically significant due to wide confidence intervals of the odds estimates. Studies overall have been mixed on how vaccination status impacts the risk of long-term COVID-19-associated conditions—such as diabetes—given differences in definitions of long COVID and in the time since vaccination. Some studies have found no difference in risk, while others have found that vaccination reduces the risk of long-term conditions by as much as 41 percent.

Overall, the researchers of the new diabetes study concluded that their data found a link between higher risks of diabetes and COVID-19 infection, consistent with the previous data, and that "this risk persisted as the omicron variant became predominant, and the association remained even after accounting for temporal confounders."