The possibility that Covid-19 could trigger diabetes (Doctors suggest Covid-19 could cause diabetes, 19 March) fits with the experiences of paediatricians treating diabetic children in London and the south-east. Following the first Covid-19 wave, we undertook a study of 178 children from 12 hospitals in south and north-east London, Kent and Sussex who had developed type 1 diabetes between January and July 2020. We found that the prevalence of newly diagnosed children was high when compared with the levels of type 1 diabetes seen in the previous four years. But two inner south London hospitals had unusually high numbers of children with type 1 diabetes.
The children who had developed diabetes in the pandemic were significantly sicker than before, with a higher level of diabetic ketoacidosis when they arrived at hospital. This did not relate to a delay in coming to hospital. We also know of two children where there was evidence that their diabetes was triggered by a Covid-19 infection. We are undertaking detailed studies as we believe that there may be link between the two conditions; the cause of type 1 diabetes is complex, but it appears that asymptomatic or mildly symptomatic Covid-19 infections may be a trigger factor.
Dr Tony Hulse Consultant paediatric endocrinologist, Evelina London children’s hospital, and Dr Caroline Ponmani Consultant in paediatric emergency medicine, Queens hospital, Romford
• Diabetes of both types is likely to arise after Covid-19 because each condition is due to inflammation, particularly in blood vessels. Problems in larger arteries precede overt type 2 diabetes by several years, with recent evidence showing smaller vessels are impaired. Whether that occurs in the pancreas, leading to type 1 diabetes, is not yet known.
Excess fat tissue, which small blood vessels run through, is also inflamed, setting up a chronic “pro-inflammatory” state that Covid can aggravate. Such early damage promotes longer-term issues in both types of diabetes in the eyes and kidneys, with larger vessel damage underlying heart attacks and strokes.
JK Cruickshank
Emeritus professor, cardiovascular medicine and diabetes, King’s College London, and consultant physician, Guy’s & St Thomas’ hospitals
