advertisement

Diabetes

13 November 2018

Type 1 diabetes often misdiagnosed in adults

British Prime Minister Theresa May has type 1 diabetes, but was mistakenly diagnosed with type 2 when in her 50s.

0

It's not always easy – even for doctors – to tell if someone has type 1 or type 2 diabetes when they're diagnosed as an adult.

And a new study finds mistakes are common.

'Oh no, I'm going to have to inject'

That's what happened to British Prime Minister Theresa May when she was diagnosed with type 2 diabetes in 2012. She was in her 50s at the time. Despite having all of the symptoms common to type 1 diabetes, including rapid weight loss, her doctor initially said she had type 2 diabetes.

After the prescribed medications didn't help, May's doctor ran more tests and realised she had type 1 diabetes. Her daily regimen was quickly changed from oral medications to injections of the hormone insulin.

"My very first reaction was that it's impossible because at my age you don't get it," May told Diabetes UK. "But then my reaction was: 'Oh no, I'm going to have to inject' and thinking about what that would mean in practical terms."

So, how do doctors mix up the two conditions?

It's really hard to tell the difference in adults, study author Dr Nick Thomas said.

"In childhood, almost all diabetes is as a result of type 1 diabetes. After 30 years of age [there's] a dramatic increase in type 2 diabetes, and type 1 represents less than 5% of all cases of diabetes, so trying to identify cases is like finding a needle in a haystack," Thomas said. He's a clinical academic fellow at the University of Exeter in England.

There's also a common misconception that type 1 diabetes can only occur in children. But that's not the case.

Insulin plays a key role in metabolism

"Type 1 diabetes can occur at any age. Doctors need to be alert to the possibility of type 1 diabetes in situations where patients rapidly fail oral therapies," Thomas added.

Type 1 diabetes is an autoimmune disease that leads the immune system to attack the insulin-producing cells in the pancreas, according to the US National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Insulin plays a key role in metabolism by ushering sugars into the body's cells to be used as fuel.

But the autoimmune attack leaves people unable to produce enough insulin. Without insulin injections – using shots or an insulin pump – type 1 diabetics couldn't survive.

The exact cause of type 2 diabetes is still unknown, but excess weight and genetics are known to play a role, NIDDK says.

People with type 2 diabetes don't use insulin properly. This makes the body produce more and more insulin. Eventually, the pancreas is unable to keep up, and people with type 2 may need insulin injections. However, type 2 can often be managed with lifestyle changes and oral medications.

Diabetes

The current study looked at almost 600 people diagnosed with diabetes after age 30 who needed to take insulin. They were diagnosed between 2007 and 2017. The researchers also looked at a group of 220 people diagnosed before 30.

Twenty-one percent of those diagnosed after age 30 were found to have severe insulin deficiency, which researchers said confirmed a diagnosis of type 1. In this group, nearly 40% weren't given insulin when they were first diagnosed. Almost half of the type 1 group said they had type 2 diabetes.

Diabetes classification very generic

"Managing type 1 diabetes as type 2 diabetes can result in rapid deterioration of a patient's health and development of a potentially life-threatening condition called diabetic ketoacidosis," Thomas said.

Dr Joel Zonszein, director of the clinical diabetes center at Montefiore Medical Center in New York City, wasn't surprised that some people were being diagnosed incorrectly.

"Years ago, we used to see type 1 only in the young, and now we're starting to see younger people with type 2. And type 1s are heavier than they used to be," he said.

Plus, "diabetes classification is very generic, and not very good. Even a good endocrinologist can miss a diagnosis," Zonszein said.

The number of incorrect diagnoses in the British study surprised him, however.

"They found 20%, and I thought it would be around 10%," Zonszein said, adding that it could have something to do with the population differences between the United Kingdom and the United States.

The study was presented last week at a meeting of the European Association for the Study of Diabetes, in Berlin, Germany. Studies presented at meetings are usually considered preliminary until published in a peer-reviewed journal.

Image credit: iStock

 

Ask the Expert

Diabetes expert

Dr. May currently works as a fulltime endocrinologist and has been in private practice since 2004. He has a variety of interests, predominantly obesity and diabetes, but also sees patients with osteoporosis, thyroid disorders, men's health disorders, pituitary and adrenal disorders, polycystic ovaries, and disorders of growth. He is a leading member of several obesity and diabetes societies and runs a trial centre for new drugs.

Still have a question?

Get free advice from our panel of experts

The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.

* You must accept our condition

Forum Rules