British study: A corona infection increases the risk of developing diabetes - what influence the vaccination had on it

She is in her mid-30s, successful and seriously ill – Visa Vie, whose real name is Charlotte Mellahn, is a presenter and podcaster.

British study: A corona infection increases the risk of developing diabetes - what influence the vaccination had on it

She is in her mid-30s, successful and seriously ill – Visa Vie, whose real name is Charlotte Mellahn, is a presenter and podcaster. And she is one of those people who never recovered from their corona infection. Mellahn suffers from Post Covid and has been struggling with severe health problems since her illness. One of its long-term consequences is diabetes. Visa Vie is not alone in this. A number of studies have already found clear indications that an infection with SARS-CoV-2 has significantly increased the risk of developing type 2 diabetes in a large proportion of the population. A new study from Great Britain now suggests that, in return, a full corona vaccination has often prevented diabetes.

According to data from a nationwide survey by the Robert Koch Institute, around seven million people in Germany suffer from diabetes. More than 500,000 adults join each year. Up to 95 percent of diabetes cases are type 2 diabetes. In addition to obesity and lack of exercise, the most important causes of an illness are an unbalanced diet and smoking. But the corona infection can also lead to illness.

66 percent - that's the number that researchers at Penn State College of Medicine threw into the room at the end of last year. Corona infection increases the risk of developing diabetes by 66 percent. The scientists used data from eight studies - including data from 4.3 million people who were proven to have been infected with the virus and 43 million who were not infected. The researchers did not differentiate between type 1 and type 2 diabetes.

“After a SARS-CoV-2 infection, there is a higher incidence of type 2 diabetes among adult patients in general practices than in the control group,” writes the Robert Koch Institute, citing an evaluation of health data from 8.8 million adults in Germany from March 2020 to January 2021. This had shown that the risk of diabetes after a corona infection is 28 percent higher than after another infection of the upper respiratory tract.

Several studies also indicated that type 1 diabetes has also been diagnosed more frequently in recent years. Type 1 is the most common metabolic disease in children and adolescents. An analysis showed that 14 percent more children developed type 1 diabetes in the first year of the pandemic, and as much as 27 percent in the second year. It is not yet clear how the disease occurs. However, a study based on health insurance data in May came to the conclusion that children who had been infected with SARS-CoV-2 had a 57 percent increased risk of diabetes compared to non-infected children.

How can the viral infection cause diabetes? A possible explanation could be found in the pancreas. So-called beta cells in the pancreas produce insulin. An international team of researchers led by Stanford University School of Medicine found in 2021 that the coronavirus is capable of infecting and damaging these beta cells. This can lead to a lack of insulin in the body. The result: the tissue cells absorb less sugar from the blood, and the blood sugar level rises. If no insulin is supplied from the outside, this can be life-threatening.

Are people who have been vaccinated against the coronavirus affected by the long-term effects of diabetes just as often as people who have not been vaccinated? Does a vaccination even protect against such long-term damage? The researchers in Great Britain have now investigated this question. Data from 15 million Britons who had been infected with the corona virus were available to the scientists. About 2.8 million of them were unvaccinated. The researchers compared how high the diabetes risk was before the vaccine was available and how high it was after full immunization. It was shown that the vaccination reduced the risk of diabetes. It is the first time that a general population data set can be used to show "that the Covid-19 vaccination reduces the excessive incidence of diabetes after Covid-19, but does not completely eliminate it," according to the researchers.

The scientists found that in the time before vaccinations were possible, the risk increased by an average of three times after infection with SARS-CoV-2. If the course of the disease was severe and required hospitalization, the diabetes risk was still twice as high a year later and ten percent higher in patients with mild courses than in non-infected people. According to the researchers, by the end of 2021 the risk in unvaccinated people was almost five times higher on average. It was also increased in vaccinated people, but "only" 1.4 times and a year after the illness it had dropped back to the normal level of non-infected people.

The work has so far been published as a preprint and has not yet been peer-reviewed.