Medical Examiner

Type 1 Diabetes Is No Longer Just for Kids

The disease, once assumed to always start in childhood, can show up at any stage of life. And patients are having a tricky time getting the right diagnosis.

A patient’s finger is poked for a diabetes test.
A patient receives a test for diabetes during a Care Harbor L.A. free medical clinic in Los Angeles on Sept. 11, 2014.
Mario Anzuoni/Reuters

Jocelyn’s bathroom breaks were becoming a cause for concern. The first-year teacher found she was increasingly asking colleagues to cover for her as she nipped out to the restroom. Suspecting that something was up, the 22-year-old asked her mother, a nurse, to check her blood sugar.

“She thought I was crazy,” said Jocelyn, until the blood-glucose meter bleeped its reply: Her blood sugar levels were too high for the machine to even read them. (Editor’s note: We are withholding Jocelyn’s last name due to the sensitive medical information given in this article.)

There must have been a mistake. There was no history of diabetes in the family, and 22-year-old Jocelyn was lean, a former competitive gymnast. Maybe the meter was broken, or perhaps she still had traces of sugar on her fingers from something she’s eaten earlier. Jocelyn’s mom sent her home with the glucometer and told her to check again in the morning.

Before breakfast the next day, Jocelyn’s blood sugar levels were four times what they should have been for a healthy adult. “I wouldn’t let myself eat because I was so paranoid,” she said.

Later that day in the hospital, she was diagnosed with Type 2 diabetes, a condition associated with adults who are older and overweight. While the nurses at the hospital seemed unsurprised by the diagnosis, Jocelyn was upset, wondering “how this could have happened,” as she put it. After a week of rumination, Jocelyn went to see an endocrinologist who ran additional blood tests, and eventually diagnosed her with latent autoimmune diabetes in adults, a subtype of Type 1 diabetes that appears in adulthood.

Jocelyn isn’t alone. Each year, somewhere between tens of thousands and hundreds of thousands of patients are likely misdiagnosed with Type 2 diabetes when they in fact have Type 1. The consequences can be dire. Without proper treatment, Type 1 diabetes can quickly become life threatening.

People who are misdiagnosed are given the wrong treatment, which causes their blood sugar levels to drift even higher. In the short term, they can end up in the emergency room with a potentially life-threatening condition known as diabetic ketoacidosis. Over a long period of time, high blood sugars can hasten the onset of diabetes complications such as nerve damage, limb loss, blindness, kidney failure, heart attack, and stroke. And many patients wait years, even decades for a correct diagnosis.

Irl Hirsch, a professor of medicine at the University of Washington and former chairman of the Professional Practice Committee of the American Diabetes Association, has described the misdiagnosis of adult-onset Type 1 diabetes as an “epidemic.” He blames a lack of awareness and insufficient medical training about diabetes as the reason why so many patients fall through the gaps. The problem is particularly frustrating because there is a simple blood test that can check for antibodies associated with Type 1 diabetes, which could easily be used in diagnosing patients.

“I have an extremely short fuse for measuring for antibodies when I’m not sure” Hirsch said.

Exactly how many adults with Type 1 diabetes are misdiagnosed each year in the United States is hard to track. Regina Castro, an endocrinologist at the Mayo Clinic, estimates that anywhere between 10 to 30 percent of adults diagnosed with Type 2 each year may in fact have Type 1. In 2015, the year for which data is most recently available, 1.5 million adults were diagnosed with diabetes, which is how, even taking the conservative end of Castro’s estimate, you get to the possibility that tens of thousands if not hundreds of thousands go misdiagnosed each year. “It is under-recognized and more prevalent than we think,” said Castro.

Unlike Type 2 diabetes, which is linked to obesity, Type 1 diabetes is an autoimmune disease in which a person’s ability to make her own insulin is severely diminished or lost altogether. Once known as juvenile diabetes, new research suggests that it develops in adults are frequently as it does in children.

A study published in the Lancet Diabetes and Endocrinology in November found that more than 40 percent of new Type 1 diagnoses in Britain were made in adults older than 30. And yet many medical professionals, and much of the general population, may not even realize that this is possible. Professor Andrew Hattersley, one of the authors of the Lancet study, said, “I think that’s been a surprising result to many doctors including many diabetes doctors.”

Diabetes experts have taken notice, though—an organization previously known as the Juvenile Diabetes Research Foundation adjusted its name in 2012 to just go by the acronym JDRF, for example. Julia Greenstein, vice president of research strategy at JDRF, said, “We usually say the diagnosis is pretty much the same above 18 and under 18.”*

Charli Guerin was diagnosed with Type 2 diabetes at 26 years old. She was neither surprised nor skeptical. “I had seen a doctor and he gave me medicine so I thought, why not trust him,” she said. Guerin was prescribed pills commonly used to manage Type 2 diabetes, but these were largely ineffective for her. Type 1 diabetes treatment, according to the American Diabetes Association, requires insulin.

Type 2 patients are commonly advised to exercise and eat healthily. After her diagnosis, Guerin kept losing weight, and her colleagues and even her doctor commended her for her dedication. But in fact, she was starving. Without insulin, her body couldn’t utilize the energy in food. By the time her actual condition was discovered, Guerin had shed 95 pounds from her 5-foot-5-inch frame.

A tingling feeling in her hands made it painful to type. Going to the bathroom five or six times during the night, a common side effect of high blood sugar levels, left her so exhausted that during her 15-minute breaks at her call center job, she would crawl under her desk for a nap. Every time Guerin took to Google, she found that her symptoms were associated with diabetes. “I thought that there was no way around it,” she said.

In the spring of 2011, almost a year after she was diagnosed as Type 2, Guerin moved back to her hometown of Kansas City, where she registered with a new endocrinologist. The morning after her first visit, she was still in bed when she received a phone call from her endocrinologist telling her go the emergency department immediately.

“You’re lucky to be alive,” he told her when he met her at the hospital. Her blood sugar was almost 17 times the upper limit expected of a nondiabetic adult. Critically dehydrated, Guerin’s kidneys were functioning at less than 20 percent of their capacity. Doctors in the hospital considered adding her to the waiting list for a kidney transplant.

“I was scared. I thought I was going to die. I immediately did powers of attorney, I spoke to my closest friends, I spoke to my parents,” said Guerin. “I was absolutely saying my goodbyes.” Luckily, within a week of being placed on the correct treatment, Guerin’s symptoms began to subside, and over time, her kidney function gradually returned to normal.

For this article, I spoke to 10 patients who were misdiagnosed. Some quickly had their diagnosis corrected once they were referred to an endocrinologist or diabetes specialist. But for many, receiving the right diagnosis was a matter if chance—moving and registering with a new doctor who happened to be more attuned to adult-onset Type 1 diabetes. Many end up doing their own research and lobbying their doctors for further tests.

Some said they felt like doctors didn’t listen when they raised their concerns. “I felt really defeated. I didn’t want to go and see my endocrinologist because they wouldn’t listen to me,” said Kayse McCann, who was misdiagnosed for five years.

For doctors, spotting an adult with Type 1 diabetes is understandably tricky. The vast majority of adults who walk into a doctor’s office with diabetes symptoms will be Type 2. Over the past 20 years the number of Americans with diabetes has tripled as the population ages and obesity levels rise. (Weight has long been a key factor in diagnosing Type 2 diabetes, but with 70 percent of American adults now overweight, it can make it even harder to distinguish those with Type 1.) And while blood tests for antibodies will catch most patients with Type 1, it is not foolproof. “It misses some and is incorrect in some,” said Hattersley.

There is very little research into adult-onset Type 1 diabetes, which Hattersley attributes to the difficulties in identifying it in the first place. “You end up with a circular argument. A clinical problem that’s hard for doctors to diagnose means it difficult for researchers to study it,” Hattersley said.

Perhaps the growing number of patients who experienced the difficult process of misdiagnosis might persuade their doctors to change that.

Correction, March 7, 2018: This article originally misidentified Julia Greenstein as Julie Greenstein. It also misstated Greenstein’s title. She is the VP of research strategy, not of discovery research.

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