TThe possibility that Covid-19 could trigger diabetes (doctors suggest that Covid-19 could cause diabetes, March 19) fits the experiences of pediatricians treating diabetic children in London and the South East. After the first wave of Covid-19, we conducted a study of 178 children from 12 hospitals in south and northeast London, Kent and Sussex who developed type 1 diabetes between January and July 2020. We found that the prevalence of newly diagnosed children was high when compared to the levels of type 1 diabetes seen in the previous four years. But two hospitals in south London had an unusually high number of children with type 1 diabetes.
Children who developed diabetes in the pandemic were significantly sicker than before, with a higher level of diabetic ketoacidosis when they arrived at the hospital. This was not related to a delay in arriving at the hospital. We also know of two children in whom there was evidence that their diabetes was caused by a Covid-19 infection. We are conducting detailed studies, as we believe that there may be a 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 triggering factor.
Dr. Tony Hulse Pediatric endocrinologist consultant, children’s hospital Evelina London, and Dr. Caroline Ponmani Pediatric Emergency Medicine Consultant, Queens Hospital, Romford
Both types of diabetes are likely to develop after Covid-19 because each condition is caused by inflammation, mainly in the blood vessels. Problems in the major arteries precede type 2 diabetes by several years, with recent evidence showing that the smaller vessels are impaired. It is not yet known whether this occurs in the pancreas, leading to type 1 diabetes.
The excess of adipose tissue, through which small blood vessels pass, is also inflamed, configuring a chronic “pro-inflammatory” state that can aggravate Covid. This initial damage promotes long-term problems with both types of diabetes in the eyes and kidneys, with damage to the larger vessels underlying heart attacks and strokes.
JK Cruickshank
Professor Emeritus, Cardiovascular Medicine and Diabetes, King’s College London, and consultant physician, Guy’s and St Thomas’ hospitals