Adults are just as likely to develop type 1 diabetes as children, a study has revealed.
The autoimmune condition is often considered a ‘disease of childhood’ and is commonly referred to as ‘juvenile diabetes’.
But experts at the University of Exeter have found 40 per cent of new cases occur after the age of 30.
The researchers warned many adults are misdiagnosed with type 2 diabetes, a completely different condition which is treated in a different way.
The Prime Minister of Britain, Theresa May, who developed type 1 diabetes in 2013 at the age of 56, is one of those who has fallen victim to the confusion.
She was initially told she had type 2 diabetes and given tablets which did not control her blood sugar.
The scientists, whose work is published in The Lancet Diabetes & Endocrinology journal, found it takes a year on average for adults with type 1 diabetes to be diagnosed correctly. Dr Richard Oram of the University of Exeter said: ‘Diabetes textbooks for doctors say that type 1 diabetes is a childhood illness.
‘But our study shows that it is prevalent throughout life.
‘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. The Prime Minister is an example of someone who was misdiagnosed in this way at first. This study should raise awareness that type 1 diabetes occurs throughout adulthood and should be considered as a diagnosis.’ Type 1 diabetes is an irreversible autoimmune disease which usually strikes in childhood, and stops the body producing insulin.
Its cause is unclear, but it is thought to be genetic.
The only treatment is insulin injections, which have to be taken several times a day for the rest of a patient’s life.
Type 2 diabetes, on the other hand, is strongly linked to lifestyle and obesity, and is usually caused when someone becomes resistant to insulin.
It is usually treated with a more balanced diet or pills such as metformin, which increase insulin response.
The new study is based on health data from 380,000 people gathered in the UK Biobank database. The researchers found 42 per cent of people with type 1 diabetes were identified at the age of 31 to 60.
But they said doctors find it very difficult to pick them out because type 2 diabetes is becoming so common, mainly because of the UK obesity crisis. The researchers wrote: ‘Our results highlight the difficulty of identifying type 1 diabetes after age 30 years because of the increasing background prevalence of type 2 diabetes.
‘Failure to diagnose late-onset type 1 diabetes can have serious consequences because these patients rapidly develop insulin dependency.’
Dr Emily Burns of Diabetes UK said: ‘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.’