Covid may trigger onset of diabetes in healthy people

Diabetes puts people at a higher risk of developing severe COVID-19 because it makes the immune system weaker, scientists say.

The illness, which affects more than four million people in the UK, is caused by abnormal levels of sugar in the blood. For most people this takes the form of Type 2 diabetes, in which there is too much sugar in the blood.

This, researchers, say, thickens the blood and reduces its ability to carry substances around the body at speed.

Dr Hajira Dambha-Miller, a GP and specialist in diabetes, said a patient’s blood becomes ‘like treacle’ as a result of high sugar levels.

‘Physically, it’s harder for the immune system to get to the virus,’ she said. ‘The virus bugs do a lot of damage before the immune system even realises it’s there.’

Therefore, when someone is infected with the coronavirus, it may take longer for their body to respond and fight it off, and the response may be less effective when it does begin.

Their illness doesn’t make a diabetic person any more likely to catch the virus itself – that is indiscriminate – just less likely to be able to recover quickly.

Dr Dambha-Miller added: ‘When the body does kick in, it won’t work as it should do. The immune cells are damaged because they’ve been saturated in sugar for years and don’t work the way they should.’  

The American Diabetes Association says it’s not clear if COVID-19 will pose a difference in risk between type 1 and type 2 diabetes.

But the risk of getting very sick from COVID-19 is likely to be lower if diabetes is well-managed no matter whether it is type 1 or type 2.

The Association explains that people who have diabetes often have other health problems, such as obesity, heart disease or high blood pressure, which in turn contribute more to their risk of dying with COVID-19.

The ADA said: ‘Having heart disease or other complications in addition to diabetes could worsen the chance of getting seriously ill from COVID-19, like other viral infections, because your body’s ability to fight off an infection is compromised.

‘Viral infections can also increase inflammation, or internal swelling, in people with diabetes. This is also caused by above-target blood sugars, and both could contribute to more severe complications.’ 

People of black African or Caribbean, or south Asian, backgrounds are more likely to develop diabetes and have also been found to be at more risk of dying if they catch the coronavirus.