Study Finds Many with Type 1 Diabetes Are Misdiagnosed with Type 2

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By : dLife Editors

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 from the University of Exeter in the U.K. reveals.

The study 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 was still diagnosed as Type 2 diabetes 13 years later.

British 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.

“For people with Type 1 diabetes, taking tablets and losing weight are not effective – they need insulin treatment, says Dr. Angus Jones, who led the research at the University of Exeter Medical School says. “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.”

Jones says their 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 having a missed Type 1 diabetes diagnosis.

“Therefore, they need a blood test to confirm what type of diabetes they have, to ensure they receive the right monitoring, education, and treatment,” he emphasizes.

How was the Study Conducted?

With support from the NIHR Exeter Clinical Research Facility, the team analyzed 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 characterized 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 (hypoglycemia) 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.

“While people with Type 2 diabetes may eventually need insulin, their treatment and education are very different from Type 1,” says Dr. Nick Thomas, first author of the study. “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.”

Thomas says this means having the right diagnosis is vitally important even if insulin treatment has already been started.

The research was funded by NIHR and the Wellcome Trust and is published in the journal Diabetologia.

The University of Exeter.


  1. The University of Exeter. A third of type one diabetes is misdiagnosed in the over 30s. (2019, April 30). EurekAlert! Retrieved: