Many adults with type 1 diabetes – including prime minister Theresa May – have been misdiagnosed due to misconceptions the condition is a childhood disease, claim researchers behind a new study.
The study, by the University of Exeter Medical School, found adults were as likely to develop type 1 diabetes as children, with more than 40% of cases of type 1 diabetes occurring after the age of 30.
“This misconception can lead to misdiagnosis with potentially serious consequences”
However, many over 30s who develop the condition are incorrectly diagnosed with type 2 diabetes at first and not given insulin to control their blood sugar levels.
This was the case with the prime minister who has type 1 diabetes but was initially told by doctors she had type 2 diabetes and was given tablets.
Previous research by the University of Exeter team found that on average it takes a year for those who have been misdiagnosed to be put on insulin.
The latest study used data from nearly 380,000 people registered with the UK Biobank and an innovative form of genetic analysis to identify type 1 diabetes in adults and spot cases not picked up by the patients’ doctors.
The research found one in nine of those who developed diabetes in adulthood were admitted to hospital with diabetic ketoacidosis, a potentially fatal condition that develops when type 1 patients are not given insulin.
Developing type 1 diabetes ‘as common’ in adults as children
Source: Derek Harper
Dr Richard Oram, a senior lecturer at the University of Exeter and consultant physician, said it was vital clinicians understood that type 1 diabetes occurred throughout adulthood
“Diabetes textbooks for doctors say that type 1 diabetes is a childhood illness. But our study shows that it is prevalent throughout life,” said Dr Oram.
“The assumption among many doctors is that adults presenting with the symptoms of diabetes will have type 2, but this misconception can lead to misdiagnosis with potentially serious consequences,” he said.
“The prime minister is an example of someone who was misdiagnosed in this way at first,” he said. “This study should raise awareness that type 1 diabetes occurs throughout adulthood and should be considered as a diagnosis.”
Type 1 cases are harder to recognise and correctly diagnose in adults because far more people develop type 2 diabetes in later life, noted the study authors.
However, when tablets failed to control blood glucose, it could be a vital clue that someone might actually have type 1 diabetes, they highlighted.
They added that adult-onset type 1 patients were also more likely to be slim, compared to type 2 patients who are often overweight or obese.
Andrew Hattersley, professor of molecular medicine at Exeter University and consultant diabetologist at the Royal Devon and Exeter NHS Foundation Trust, said failing to diagnose type 1 diabetes could be “dangerous”
“Type 1 diabetes should be considered for any patient who is rapidly failing to respond to increasing doses of tablets especially if they are slim,” he said.
“We’d ask healthcare professionals to have this insight in mind: don’t rule out type 1 diabetes”
The study, published in the Lancet Diabetes and Endocrinology journal, was funded by the Wellcome Trust and the charity Diabetes UK. The journal article is free to view due to funding from the Department of Health.
Emily Burns, head of research communications at Diabetes UK, urged health professionals not to rule out type 1 diabetes in patients aged over 30.
“While more research is needed to understand the realities of misdiagnosis, we’d ask healthcare professionals to have this insight in mind: don’t rule out type 1 diabetes after the age of 30,” she said.