Covid-19 could lead to type 1 diabetes, researchers fear after witnessing a spike in cases of the disease among infected children.
Academics at Imperial College London looked at how many youngsters had been diagnosed at five paediatric units across the capital.
Around 30 children were diagnosed with type 1 diabetes between March 23 and June 4, the experts found.
They said this was roughly double the amount that are usually diagnosed with the condition, which isn’t driven by obesity like type 2 diabetes.
Five of the children had either tested positive for coronavirus or were likely to have had it in the past, leading scientists to make the link.
But they cautioned this figure may have been an underestimate because nine of the children were not tested.
The experts suggest the coronavirus – technically called SARS-CoV-2 – could directly attacks cells in the pancreas which are vital for producing insulin.
Covid-19 is feared to cause type 1 diabetes in children after data shows an increase in diagnoses during the pandemic (stock)
Type 1 diabetes, which affects around 314,000 people in the UK and 1.6million in the US, occurs when the immune system destroy the insulin-producing cells.
It is caused by a fault in the body’s immune response in which the immune system mistakenly targets and kills beta cells.
Experts remain baffled as to what triggers this fault but some of the best evidence points towards a virus as being the most likely trigger.
Viruses can lead to some autoimmune diseases by causing the immune system to go haywire.
But the Imperial team called for more trials to firm up the findings, insisting that they don’t yet have proof that Covid-19 can cause type 1 diabetes.
The disease – often diagnosed in childhood – stops the body making enough insulin to regulate blood glucose. If levels are persistently too high, it can lead to death.
Type 1 diabetes can be treated with several daily injections of insulin or using an insulin pump to keep blood glucose levels under control.
Medics in China and Italy have previously found more children developing type 1 diabetes during the pandemic but ruled it was unrelated to Covid-19.
Clinicians at Imperial College Healthcare NHS Trust wanted to see whether cases of type 1 diabetes might actually be linked to the pandemic.
Together with researchers at Imperial College London, the team is the first to find a possible link between Covid-19 and new-onset type 1 diabetes in children.
Dr Karen Logan, study co-author, said: ‘Our analysis shows during the peak of the pandemic the number of new cases of type 1 diabetes in children was unusually high in two of the hospitals in north west London compared to previous years.
‘When we investigated further, some of these children had active coronavirus or had previously been exposed to the virus.’
She added: ‘It appears that children are at low risk of developing serious cases of Covid-19.
‘However, we do need to consider potential health complications following exposure to the virus in children.’
The team analysed data from children based in five paediatric inpatient units from four north-west London Trusts.
These were Imperial College Healthcare NHS Trust, Chelsea & Westminster NHS Foundation Trust, The Hillingdon Hospitals NHS Foundation Trust and London North West University Healthcare NHS trust.
Between 23 March and 4 June, 30 cases were diagnosed in children aged 23 months to 16.8 years.
The team found an increase of children diagnosed with type 1 diabetes in two of the units. They diagnosed ten cases each versus typically two and four cases respectively for April and May combined.
However, rates in the other three units were similar to previous years.
Of the 30 children, 21 were tested for Covid-19 if they had symptoms including fever or cough. Two tested positive.
Some children were tested using antibody kits, which have not been widely available to the public.
Of the 16 other children given an antibody test, three were positive, suggesting they had previously had the coronavirus.
In total, five children tested positive, either for active Covid-19 infection or previous exposure to the virus.
A lack of antibody tests meant the other children were not tested for Covid-19, therefore it is not clear whether the true rates of Covid-19 in the children would have been lower or higher than discovered.
Rebecca Unsworth, joint first author of the study, said: ‘During the peak of the pandemic widespread access to testing wasn’t available so we may have missed further cases of Covid-19 in these children who have new-onset type 1 diabetes.’
Children are believed to be just as likely as adults to catch the coronavirus. But they may be diagnosed less often because their symptoms are so mild.
Testing for Covid-19 in the UK was limited only to adults until mid-May, several weeks after the peak of the pandemic.
Children under five years old can now get a test but they would only come forward if they had symptoms.
The study, published in Diabetes Care, also found that children in the study had high levels of diabetic ketoacidosis (DKA).
DKA is a serious condition that can happen to diabetics if their body starts to run out of insulin.
When this happens, harmful substances called ketones accumulate in the body. It can be life-threatening if it’s not found and treated quickly.
Seventy per cent of children had DKA and 52 per cent had severe DKA. Four children were treated in intensive care.
The authors cautioned this was a much higher rate than they would normally expect to see, and many children were very unwell.
This supports anecdotal stories from doctors in England, according to Julian Hamilton-Shield, a professor of diabetes and metabolic endocrinology at the University of Bristol, who was not involved in the research.
The researchers theorised that the spike protein found on the surface of the coronavirus may be able to attack and destroy insulin-making cells in the pancreas.
The spike protein of the virus binds to ACE-2 receptors which coat some cells in the body. Therefore, the receptors are seen as the ‘gateway’ for the virus.
ACE-2 is strongly expressed in pancreatic endocrine cells, the researchers said.
Scientists who were not involved in the study said the link warrants further investigation.
Professor Paul Zimmet, at Monash University, and Francesco Rubino, King’s College London, recently expressed their concerns about a potential diabetogenic effect of Covid-19 in the New England Journal of Medicine.
They commented today: ‘The findings add to our concerns on a potential link between Covid-19 and diabetes.
‘Early in the course of the pandemic we had become aware of similar reports of new cases of both type 1 and type 2 diabetes as well as other atypical diabetes manifestations in people with SARS-CoV-2 (Covid-19) infection.
‘This has a biological rationale since the new coronavirus can bind to receptors that are highly prevalent in cells of crucial metabolic organs such as the pancreas, the adipose tissue, the liver and the intestine, which may explain also the fact that both type 1 and type 2 diabetes have been reported in association with Covid-19.’
But Paul Hunter, a professor in medicine at the University of East Anglia, said the rise in paediatric type 1 diabetes could just be random.
He said: ‘It is often tempting but can be wrong to assume that whatever infection is common in the community is the cause of an increase in diagnoses that could have arisen just by chance.
‘During any epidemic like the current one, people will be looking out for any change in the incidence of disease in their own practice that could be related to the epidemic pathogen.’