Does Covid-19 increase the risk of diabetes in children

A study published a few days ago from the United States Centers for Disease Control (CDC), suggested that Covid-19 can more than double the risk of the new development of diabetes in children.  This study adds to the information from extensive research since the start of the pandemic that Covid-19 is bad news as far as diabetes is concerned.  We already knew that in people who have pre-existing diabetes, including those who are undiagnosed, Covid-19 infection makes their diabetes worse.

These data are the ‘other side of the coin’ from the much greater body of information emphasising that pre-existing diabetes increases the risk of severe Covid-19 including death.

In this blog post I consider the evidence that Covid-19 could actually cause diabetes, especially in children.  One consequence of this being true would be to add to the case for vaccinating children 

Two types of diabetes

• I am sure most readers will be aware that in simple terms diabetes is actually 2 separate disorders: unsurprisingly called Type 1 and Type 2

• Type 2 is much more common

• The major difference between the 2 types are shown below

• As Covid-19 infection is predominantly more of a problem in the elderly, inevitably  many of the studies up to now on Covid-19 and diabetes related to Type 2 diabetes
• These studies suggested that:
  • Patients with pre-existing diabetes who became ill with Covid-19 were more likely to lose control of their blood sugar and need to be hospitalised 
  • Mild to moderate Covid-19 infection could also unmask previously silent diabetes at an earlier age, ie such patients could well be diagnosed with diabetes in the future perhaps in response to another but non-Covid-19 infection
  • A severe infection with Covid-19 could cause such major changes to our metabolism  sufficient for  the new development of Type 2 diabetes that otherwise may not have ever happened 

Can Covid-19 cause Type 1 diabetes in children?

• The stimulus behind my writing this post was the concern that Covid-19 can lead to the more serious and life changing Type 1 diabetes in children
• Prior to the data this week, there was only anecdotal data from paediatric diabetic specialists reporting they were ‘seeing more new cases of diabetes’ in children since the pandemic started in 2020
• For example, a study from London reported an 80% increase in the number of new childhood cases

• Such findings were not universal and a group of German paediatricians reported no increase in the number of cases they were seeing
• Neither of these studies was a formal epidemiological study, until the much needed CDC study reported last week.

• The CDC statisticians compared the rates of new cases of diabetes in children aged under 18 between those with (blue bars) and without (orange bars) a diagnosis of Covid-19 
• Unlike much of Europe, there is no single health care database and thus data to answer this question came from two different providers of health care data –  ‘IQVIA’ and ‘Health Verity’- and combined they cover more than 0.5 million children
• The results are shown below

• The data from IQVIA showed a more than 2.5 times increased risk of diabetes
• The data from Health-Verity showed only a 30% increased risk of diabetes
  • In interpreting these results need to note that all the children in these datasets had had a clinical contact because of their Covid-19 and would not I believe have included children who were asymptomatic 
  • The ‘non-CoVid children’ were also identified differently in these two data sets and were in the Health-Verity dataset were sicker than the non-CoVid children in the IQVIA dataset for other reasons
• If the figures are accurate then it would suggest that around 1 in 300 children becoming ill with Covid-19 could go on to have diabetes, which could be 3 times that of uninfected children

How plausible is it that infection with Covid-19 could cause diabetes in childhood?

• The causes of diabetes in children are not fully known
• Perhaps surprisingly, genes are less important in Type 1  childhood diabetes than they are in Type 2, adult obesity related diabetes
• Type 1 diabetes is thought to be an ‘auto-immune’ disease in which the body produces antibodies that attack the specific, or ‘islet’, cells in the pancreas that make insulin.
• Patients with diabetes can have high levels of such ‘anti-islet’ antibodies in their blood
• The reasons why a virus could lead to the body’s immune system producing these unwelcome antibodies that attack our own organs is neatly shown in the diagram below:

• The body responds to infection with a virus by producing antibodies, (as in red arrow on this drawing), to the green bit on the surface of the virus.  These antibodies can then knock out the virus  
• Unfortunately  –  as shown by the blue arrow  – these antibodies that were produced to attack the virus, by a sad coincidence can also attack the pancreas
• In other words, an inadvertent consequence of the body’s response to a virus is to produce an antibody that attacks the body: a case of ‘friendly fire’, perhaps

Do other viruses lead to diabetes?

• Indeed, this has been a major theory for decades as to why diabetes develops in some children 
• Supporting this theory, there are  some anecdotal reports of children who had symptoms suggestive of being unwell with ‘flu-like symptoms suggestive of a viral illness shortly before they developed their diabetes
• In fairness, however, most cases of new onset childhood diabetes cannot be tracked to a recent viral infection
• In the table below, I list some of the viruses linked to the onset of diabetes

• Some of these viruses you will have heard of eg mumps
  • Rotaviruses are RNA viruses like Covid-19, but cause gastroenteritis by infecting the bowels
  • Enteroviruses are also RNA viruses which infect via the bowels
  • Some enteroviruses, including the Coxsackie virus, have been linked not only to the development of diabetes can affect the nervous system and also cause other severe diseases such as polio

Is there anything special about Covid-19 that might explain its link with diabetes?

• This is still a topic of continuing research and data are still being collected 
• One of the current theories about ‘Long CoVid’ has been that infection leads to the development of auto-immunity, ie the continuing symptoms with long covid are related to antibodies produced in response to the virus then attacking  other body systems. 
• At the moment, though, there is little data that Covid-19 produces antibodies against the islet cells
• Another compelling research idea, based on some laboratory data,  is that the virus itself, when severe, can infect the islets directly and destroy them

Conclusions

• The recent explosion of cases from Omicron, especially in children,  has perhaps highlighted the need to consider if there are long term consequences of an otherwise mild infection
• These recent US data do suggest that Covid-19 increases the risk of diabetes in children but do require confirmation
• We also need to know how severe the infection from  Covid-19 has to be to pose a risk of diabetes?
• Nonetheless a 1/300 risk, if that is what it is, is far from negligible 
• As the debate continues about the pros and cons of vaccinating children, the potential risk of diabetes does need to be included in the discussion 

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