A third of type one diabetes is misdiagnosed in the over 30s

Source: EurekAlert

More than a third of people over the age of 30 who are initially diagnosed with type 2 diabetes actually have type 1, meaning they are not receiving the right treatment, new research has revealed.

The study, led by the University of Exeter, shows that 38% of patients with type 1 diabetes occurring after age 30 were initially treated as type 2 diabetes (without insulin). the team found that half of those misdiagnosed were still diagnosed as type 2 diabetes 13 years later.

Prime Minister Theresa May is a classic case of misdiagnosis in later life. She was initially misdiagnosed with type 2 diabetes and treated with lifestyle change and tablets which did not work, before being re-tested and identified as having type 1 diabetes.

Dr Angus Jones, of the University of Exeter Medical School, who led the research, said: “For people with type 1 diabetes, taking tablets and losing weight are not effective - they need insulin treatment. It is very difficult to diagnose type 1 diabetes in older adults, as most people of this age will have type 2, even if they are thin. Our research shows that if a person diagnosed as type 2 diabetes needs insulin treatment within three years of diabetes diagnosis, they have a high chance of missed type 1 diabetes.Therefore they need a blood test to confirm what type of diabetes they have, to ensure they receive the right monitoring, education and treatment.”

The research, funded by NIHR and the Wellcome Trust, is published in the journal Diabetologia. With support from the NIHR Exeter Clinical Research Facility, the team analysed 583 people who had insulin-treated diabetes that had been diagnosed after the age of 30. The characteristics of their disease were compared with other participants who still produced some insulin, as well as with 220 individuals with severe insulin deficiency that was diagnosed before the age of 30.

T1D is characterised by the rapid and severe loss of insulin production as the cells in the pancreas which produce the hormone are attacked and destroyed by the body’s own immune system. Individuals with the disease lose the ability to make their own insulin and therefore require regular doses of insulin to control their blood glucose, either in the form of injections or via a pump, and unlike many people with T2D, cannot manage their condition through diet, exercise and tablets alone. Because they have a very high risk of low blood glucose (hypoglycaemia) they usually learn to match their insulin to food (carbohydrate counting) and may use new technology such as insulin pumps and continuous glucose monitors. These treatments are not available to people diagnosed as Type 2 diabetes even if they progress to needing insulin injections, therefore the right diagnosis remains important even if a person is treated with insulin.

First author Dr Nick Thomas, of the University of Exeter Medical School, said: "While people with type 2 diabetes may eventually need insulin, their treatment and education is very different from type 1. If people with type 1 diabetes don’t receive insulin they can develop very high blood glucose, and may develop a life threatening condition called ketoacidosis. This means having the right diagnosis is vitally important even if insulin treatment has already been started. "


Carepaths should start with checking for antibodies. I have had T1 for almost 40 years and they never checked me for antibodies and/or Celiac. At least the later is common testing in newly diagnosed patients today. I am also shocked that we do not do more preventative cardiac risk testing. Checking total cholesterol and even subtraction does not capture the risk. Need to know c-reactive protein, apoproteins, etc. I would say a T1 should have a cardiac CT too.


It is a huge problem- med professionals are not being properly educated. I have had numerous docs of all ages tell me how unusual it is that I have type 1 and some even still say it is a childhood disease. The last one, an ortho doc also tried to tell me ra is a ch disease. That was a first. I said isn’t it interesting that My gf developed graves in his 50’s and then ra in his 60’s-70’s.

Yep, that was me. Misdiagnosed as Type 2 until my primary care doctor ordered the c-peptide and anti-gad labs, and determined it must be Type 1. He referred me to an endo who told treated me as a Type 2. I ended up in the ER in severe DKA. Even there, my husband said said the ER doctors were arguing over whether or not I had Type 2 or Type 1.

This also happened to me. Was misdiagnosed as type 2. It took about 4 months before the nurse at the endo office de diet to order the c-peptide test due to my extreme weight loss. Then I was finally diagnosed with type 1 and put on insulin. Lucky to be alive.

1 Like

An “initial misdiagnosis” does not mean they are receiving the wrong treatment. I was “initially misdiagnosed” as type 2 and then when my labs came back 2 days later they realized I was type 1… but I’d have still been counted in the 38% having been misdiagnosed… I find articles like this somewhat disingenuous

I think the article is spot on as I’ve run across so many type 1’s LADA’s that were diagnosed as type 2’s first. More articles are starting to come out about it.

I was misdiagnosed for over 9 years, And I even asked if I could be type 1 because my uncle had died from type 1. The pcp at the time said medications wouldn’t work at all if I was type 1, so no you’re not. The first endo just dismissed my question if I could be type 1 and said you’re not type 1 and never tested me. He wanted to put me back on the medications that had made me so sick. I refused to go back to him.

I switched to an internist, who went ahead and added a fast acting insulin. Which I did well on. But she hadn’t thought about testing me either. When the group hired a new endo she sent me to her and the new endo tested me right away.

If I hadn’t refused to go back to the first endo, if I hadn’t switched doctors I would have stayed misdiagnosed. I probably would have ended up being really sick and who knows what damage would have been caused. It turns out a lot of us are properly diagnosed when we switch doctors and the new doctor decides to test for it.

I think the more worrying statistic is that half of those misdiagnosed are still misdiagnosed over a year later. That means 19 percent of people are using the wrong treatment plan for at least a year, possibly years.

1 Like