{"id":73849,"date":"2024-02-21T08:18:09","date_gmt":"2024-02-21T15:18:09","guid":{"rendered":"https:\/\/www.uchealth.org\/today\/?p=73849"},"modified":"2024-07-18T15:27:40","modified_gmt":"2024-07-18T21:27:40","slug":"explore-type-1-and-type-2-diabetes-and-potential-misdiagnoses","status":"publish","type":"post","link":"https:\/\/www.uchealth.org\/today\/explore-type-1-and-type-2-diabetes-and-potential-misdiagnoses\/","title":{"rendered":"Is there a gray area between Type 1 and Type 2 diabetes?"},"content":{"rendered":"
<\/div>
\"The
The often subtle differences between the two \u2013 or three \u2013 types of diabetes can affect the diagnosis and treatment of the disease. Photo: Getty Images.<\/figcaption><\/figure>\n

An old line, often repeated with variations, holds that the world is divided into two groups of people: those who divide the world into two kinds of people and those who don\u2019t. It might also be said that in the world of diabetes clinical care and research, the world is divided into two groups: those who divide diabetes into two types and those who don\u2019t.<\/p>\n

For the first group, there is Type 1 diabetes and there is Type 2 diabetes, both of which impair the body\u2019s ability to produce insulin and metabolize blood sugar. Each type has specific causes, symptoms and treatments. The second group holds that some patients with diabetes have characteristics that do not fit neatly into either group. They argue that these patients have a distinct condition they have labeled latent autoimmune diabetes of adults<\/a>, or LADA.<\/p>\n

In considering the question of categorizing diabetes, Dr. Cecilia Low Wang<\/a> divides the world in yet another way. There are \u201clumpers\u201d and \u201csplitters.\u201d Lumpers look for common characteristics between entities \u2014 like disease \u2014 while splitters look for differences and create new categories.<\/p>\n

Low Wang, professor of medicine in the Division of Endocrinology, Metabolism and Diabetes<\/a> at the University of Colorado School of Medicine<\/a> and director of the Glucose Management Team<\/a> at UCHealth University of Colorado Hospital<\/a> on the Anschutz Medical Campus<\/a>, is a self-described lumper. She spoke with UCHealth Today to explain the often subtle differences between the two \u2013 or three \u2013 types of diabetes and how those differences affect the diagnosis and treatment of the disease.<\/p>\n

Let\u2019s start with Type 1 and Type 2 diabetes. How are they different? <\/strong><\/h2>\n

\u201cThat absolutely comes up in every conversation when someone is newly diagnosed with diabetes as well as when we first see a person in clinic,\u201d Low Wang said. \u201cIt\u2019s something that we are always thinking about and reevaluating because there are a significant proportion of people who are misdiagnosed with Type 2 diabetes and actually end up having Type 1.\u201d<\/p>\n

\"Dr.
Dr. Cecilia Low Wang says patients with latent autoimmune diabetes of adults are often misdiagnosed with Type 2 diabetes. Photo by UCHealth.<\/figcaption><\/figure>\n

Type 2 diabetes, or what was once called adult-onset diabetes, is far more common than Type 1 \u2014 about 90%<\/a> of all people diagnosed with diabetes, Low Wang said.<\/p>\n

\u201cOne of the basic features of it is the body has insulin resistance, or an inability to use insulin very well or efficiently,\u201d she explained. \u201cYour body has to make more insulin to maintain good [blood sugar levels], and your pancreas has to work harder to make more insulin.\u201d<\/p>\n

In contrast, Type 1 diabetes, formerly called juvenile-onset diabetes, is an autoimmune disease in which the body produces auto-antibodies that attack the pancreas and the clusters of cells, called islets, that produce insulin, Low Wang said.<\/p>\n

\u201cMost people [with Type 1 diabetes] have profound destruction of the islets as part of the process of developing Type 1 diabetes,\u201d she said. As a result, \u201cPeople with Type 1 diabetes need insulin to survive.\u201d<\/p>\n

Another important difference is that Type 2 diabetes runs strongly in families, while the risk for Type 1 diabetes is less strongly inherited, Low Wang said.<\/p>\n

How do the treatments for Type 2 diabetes and Type 1 diabetes differ?<\/strong><\/h2>\n

As Low Wang mentioned, Type 1 diabetes destroys the insulin-producing cells that break down sugar, so patients with the disease must take insulin regularly, either through shots or pumps. People with Type 2 diabetes can often manage their insulin resistance and higher need for insulin with exercise, diet and non-insulin drug treatments, like Jardiance<\/a> and Ozempic<\/a> and many others that work in different ways to restore the body\u2019s ability to produce insulin or manage blood sugar levels.<\/p>\n

So far, these differences sound pretty straightforward. But are they? For example, can a person with Type 2 diabetes be misdiagnosed and actually have Type 1?<\/strong><\/h2>\n

Yes. \u201cI have seen patients who have been misdiagnosed with Type 2 diabetes for decades, and then they come to me and I diagnose them with Type 1 diabetes,\u201d Low Wang said. \u201cThen your entire frame of mind shifts because they need completely different treatments.\u201d<\/p>\n

According to the American Diabetes Association (ADA) and European Association for the Study of Diabetes EASD)<\/a>, more than 40% of people who develop Type 1 diabetes after they are 30 receive treatment initially for Type 2 diabetes.<\/p>\n

Why does diabetes misdiagnosis occur?<\/strong><\/h2>\n

There are several reasons, Low Wang said. To start, the lines between Type 1 and Type 2 diabetes are not clear-cut. For instance, terms like \u201cjuvenile-onset diabetes\u201d for Type 1 and \u201cadult-onset diabetes\u201d for Type 2 have been mostly discarded, and for good reason, she noted.<\/p>\n

\u201cA significant proportion of people with Type 1 diabetes are <\/em>diagnosed when they are below the age of 20,\u201d Low Wang said. \u201cBut probably half are diagnosed over the age of 20. And there is a significant second peak of Type 1 diabetes when people are around their 50s, so certainly it\u2019s something we should be thinking about.\u201d<\/p>\n

In addition, a patient may have some features of both Type 1 diabetes and Type 2 diabetes, Low Wang said. As the ADA and EASD report explains it, an older adult (on the surface a characteristic of a Type 2 diabetes patient) might at the same time have a normal or low body mass index (which is more typically characteristic of a Type 1 diabetes patient). Conversely, a young adult patient may have a higher-than-normal body mass index, a characteristic that again could point to either type of diabetes, the report notes.<\/p>\n

\u201cWe have some patients diagnosed with Type 2 diabetes who look like they are clearly insulin resistant, but their diabetes is also acting like they are not making very much insulin at all,\u201d Low Wang added.<\/p>\n

One important test to confirm a diagnosis of Type 1 diabetes measures levels of the GAD (glutamic acid decarboxylase) auto-antibody, which targets an enzyme that helps the pancreas produce insulin. But Low Wang said the GAD does not always provide the answer, particularly when the disease has gone undetected for a long time. In a large percentage of these people, the GAD auto-antibodies have become undetectable or \u201cfaded away,\u201d as she put it. The question for a clinician, then, is whether the patient has Type 1 diabetes and has lost the auto-antibodies or whether they never had them in the first place.<\/p>\n

\u201cThose antibody-negative Type 1 diabetes patients are probably the biggest conundrum that we face,\u201d Low Wang said.<\/p>\n

Are there other tests to confirm a Type 1 diabetes diagnosis?<\/strong><\/h2>\n

Yes. Low Wang said clinicians can use other autoantibody tests<\/a> to \u201cdrill down\u201d on a possible diagnosis if the GAD test is negative. These are often checked to determine whether a family member of an individual is at risk for Type 1 diabetes. In addition, the C-peptide level<\/a> test measures the body\u2019s actual production of insulin. That test should be used along with simultaneously monitoring glucose levels in the blood, she added.<\/p>\n

Low Wang said she bases decisions on whether to conduct the tests on listening to her patients describe their symptoms and histories, and on her \u201cclinical suspicion\u201d that a person might have Type 1 diabetes. The higher her suspicion, the more likely she will use one or more tests to confirm or rule out the diagnosis.<\/p>\n

What are the clues that lead to suspicion of Type 1 diabetes in these difficult-to-diagnose cases?<\/strong><\/h2>\n

Low Wang listed a number of factors that can point to Type 1 diabetes in patients who have been diagnosed with Type 2 diabetes:<\/p>\n