Mild COVID-19 Infection Linked to Later Type 2 Diabetes

Miriam E. Tucker

March 21, 2022

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

People who recover from a mild case of COVID-19 appear to have an increased risk for subsequent new-onset type 2 diabetes but not other types of diabetes, new data suggest.

The findings, from a nationwide primary care database in Germany, were recently published in Diabetologia.

"If confirmed, the results of the present study indicate that diabetes screening in individuals who have recovered from even mild COVID-19 should be recommended," say Wolfgang Rathmann, MD, of the Leibniz Center for Diabetes Research at Heinrich Heine University, Düsseldorf, Germany, and colleagues.

These primary care data align with those from other studies of more seriously ill patients with COVID-19 that found increased rates of type 2 diabetes diagnoses in the subsequent months following illness, they point out.

"COVID-19 infection may lead to diabetes by upregulation of the immune system after remission, which may induce pancreatic beta-cell dysfunction and insulin resistance, or patients may have been at risk for developing diabetes due to having obesity or prediabetes, and the stress COVID-19 put on their bodies speeded it up," said Rathmann in a press release.

However, because the patients with COVID-19 in the study were only followed for about 3 months, "further follow-up is needed to understand whether type 2 diabetes after mild COVID-19 is just temporary and can be reversed after they have fully recovered, or whether it leads to a chronic condition," he noted.

Increase in Type 2 Diabetes 3 Months After Mild COVID-19

The retrospective cohort analysis was performed using data from the Disease Analyzer, a representative panel of 1171 physician practices in Germany, from March 2020 to January 2021, with follow-up through July 2021.

Individuals with a history of COVID-19 or diabetes and those taking corticosteroids within 30 days after the index dates were excluded.

A total of 35,865 patients with confirmed SARS-CoV-2 infection were propensity score-matched on a one-to-one basis for sex, age, health insurance, and comorbidities with those who had acute respiratory tract infections (controls) but were COVID-19 negative. Median follow-up was 119 days for the COVID-19 group and 161 days for controls.

There was a 28% increased risk of type 2 diabetes for those who had COVID-19 versus controls (15.8 per 1000 person-years vs 12.3 per 1000 person-years, respectively, which was significantly different, and an incidence rate ratio [IRR] of 1.28).

The incidence of other types of diabetes or unspecified diabetes for the COVID-19 and control groups did not differ significantly (4.3 per 1000 person-years vs 3.7 per 1000 person-years; IRR, 1.17).

Similar findings were seen in sensitivity analyses by glucose-lowering medication prescriptions and by ICD-10 codes.

Although type 2 diabetes is not likely to be a problem for the vast majority of people who have mild COVID-19, the authors recommend that anyone who has recovered from COVID-19 be aware of the warning signs and symptoms such as fatigue, frequent urination, and increased thirst, and seek treatment right away.

CoviDiab Registry Tracking Type 1 and Type 2 Diabetes

Over the course of the pandemic, there have been conflicting data on whether COVID-19 induces or reveals a propensity for type 1 and type 2 diabetes.

The CoviDiab global registry is tracking this and will include diabetes type for adults and children.

The aim is to have "as many as possible cases of new-onset diabetes for which we can have also a minimum set of clinical data including type of diabetes and A1c," co-principal investigator Francesco Rubino, MD, of King's College London, UK, previously told Medscape Medical News.

"By looking at this information we can infer whether a role of COVID-19 in triggering diabetes is clinically plausible — or not — and what type of diabetes is most frequently associated with COVID-19."

Rubino said that the CoviDiab team is approaching the data with the assumption that, at least in adults diagnosed with type 2 diabetes, the explanation might be that the person already had undiagnosed diabetes or the hyperglycemia may be stress-induced and temporary.

The German Diabetes Center is funded by the German Federal Ministry of Health and the Ministry of Culture and Science of the State of North Rhine-Westphalia. Rathmann has reported receiving consulting fees for attending educational sessions or advisory boards for AstraZeneca, Boehringer Ingelheim, and Novo Nordisk and institutional research grants from Novo Nordisk outside of the topic of the current work.

Diabetologia. Published online March 16, 2022. Full text

Miriam E. Tucker is a freelance journalist based in the Washington, DC, area. She is a regular contributor to Medscape, with other work appearing in The Washington Post, NPR's Shots blog, and Diabetes Forecast magazine. She is on Twitter: @MiriamETucker.

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