COVID-19 and diabetes - what are the connections?

"SARS-CoV-2 and diabetes - correlations and latest data" was the title of a symposium at the DDG Congress 2021. Prof. Dr. Stefan Bornstein spoke on epidemiology and treatment options.

Much research still needed

"SARS-CoV-2 and diabetes - correlations and latest data" was the title of a symposium at the DDG Congress 2021. Prof. Dr. Stefan Bornstein, Director of the Medical Clinic and Polyclinic III of the University Hospital Dresden (Medizinische Klinik und Polyklinik III der Universitätsklinik Dresden), spoke on epidemiology and treatment options.

The unpleasant thing about the SARS-CoV-2 virus is that it hijacks a metabolic pathway, so to speak, and thus causes damage in the subsequent organs, the speaker explained at the beginning. More than other infectious diseases, it has a special connection to the metabolic pathways. In the meantime, more than 5,000 Pubmed articles have been published on the topic of COVID-19 and diabetes.

The exciting question is: Can COVID trigger diabetes in one way or another? And what are the long-term consequences in this respect? These questions are of course of interest to all diabetologists - but it is still too early to find an answer. There is still a lot of research to be done.

Some things are known about the mechanisms. It quickly became clear that hyperglycaemia upregulates ACE2 and is therefore a problem. Diabetes is not only a risk factor for severe courses of COVID-19, but the virus could also worsen the course of diabetes - or perhaps even trigger diabetes. Individual cases have been observed: In Kiel, a patient suddenly developed type 1 diabetes after a COVID-19 infection. This was very surprising, because in 90% of cases of type 1 diabetes certain autoantibodies are detectable - and that was not the case here. An interesting finding, although not proof that COVID-19 had triggered the diabetes.

In the meantime, a worldwide registry has been established with pancreas samples from deceased COVID patients. Many inflammatory infiltrations have been registered. There are ACE-2 receptors, but also DDP 4. In many samples, there is an infection of the beta cells by the virus, which can be detected electron-optically.

So if the virus enters the beta cells in islets, does that lead to diabetes? In order to better understand this, colleagues have set up an international registry since 2020, where 1,000 such cases are now collected. "They are still individual cases and we have to wait and see what information the register will provide in the next one or two years," says Prof. Bornstein.

It is known that the severity of the disease is clearly related to metabolic diseases. It can be assumed that of the 3 million people who died from COVID-19, a substantial proportion had a metabolic syndrome or disease. It is estimated between 30% and 70%. Data from several studies show that well-controlled blood glucose can improve patient outcomes. Also, many of the drugs used, whether tocilizumab, interleucin 6 or dexamethasone, work better when glucose is better controlled.

Risk stratification has shown that obesity is a particularly high risk, especially in the younger group - which contributes to the high COVID-19 mortality in the USA or even in Brazil.

The issue of gender differences in COVID trajectories remains interesting. In the relevant age group between 50 and 85, more men have certain underlying diseases. Androgens play an inflammatory role, while oestrogens are known to be anti-inflammatory. Now we will see, the speaker reflects, how the issue is possibly reversed in the case of vaccination side effects. Are women more at risk because of their somewhat more activated immune system?

Recommendations from clinical diabetologists

People kept asking: Should insulin be stopped in COVID-19 patients? Should ACE inhibitors be taken out of therapy?

It’s clear: The medication should be continued. A bit of caution in a severe course with metformin is right. SGLT 2 inhibitors are not ideal in a severe course in the ICU. But in essence, the medication should be continued.

In recent weeks and months, it has been added that certain drugs can show additional protective effects against viral uptake. DDP 4 as a functional receptor could block viral uptake and also have an anti-inflammatory effect. This was stated especially for metformin. The data do not yet support this. But the use of these drugs was not negative in any case, rather positive.

How to deal with vaccinations?

Unfortunately, Prof. Bornstein observed, the group of patients that is most at risk often takes the longest to be vaccinated. This plays a big role with diabetics. They need to be helped, with education and with practical support, to get their vaccination.

Collateral damage in the pandemic

If patients come too late, we lose valuable years of life - in terms of diabetes management, this is perhaps even more relevant than with other diseases, the speaker estimates. Studies, especially from Italy and Greece, clearly show that the lockdown has triggered a "covibesity". Blood sugar levels have risen on average. Especially among the young. There was an increase in weight - up to 35% and metabolism has worsened.  

Three groups of diabetic patients are particularly affected

Summary: Teamwork now particularly important

DDG 2021; Symposium "SARS-CoV-2 and diabetes - correlations and latest data". (Original title in German: "SARS-CoV-2 und Diabetes - Zusammenhänge und neuste Daten")