Brittle Diabetes, Fact or Myth?

A certified diabetes educator weighs in on this term, and what might be the underlying causes of the condition it describes.

There has been a lot of recent discussion on social media about the term “brittle diabetes.” We asked Jennifer Smith of Integrated Diabetes Services to define the term and discuss its use. Here’s what she had to say:

Brittle is sometimes used to describe a type of diabetes that’s characterized by large and sudden swings in blood glucose levels. Most clinicians working in the diabetes world would define brittle diabetes as severe instability of blood glucose levels with frequent and unpredictable episodes of hypoglycemia and/or DKA that can disrupt quality of life. “Brittle” diabetes is typically associated with Type 1 diabetes, not Type 2.

There is little agreement on the use of this term among researchers. Some experts still believe in brittle diabetes as a distinct condition, while others conclude it’s no more than a myth, and that the real reasons for the roller coaster glucose levels labeled as brittle are just being poorly documented.

The concept of brittle diabetes first showed up in the 1940s as a label for people with Type 1 who didn’t respond well to insulin treatment. “Not responding well”, however, was a lot more common back then, what with the lack of technology and the early types of insulin being used at this time. Blood sugar swings were hard to avoid with such tools.

Thanks to much improved technology and treatment options, we now have a much more detailed picture of how blood glucose levels change over the course of each day. This can help us zero in on what might be causing those fluctuations. I asked Gary Scheiner, a fellow certified diabetes educator, my boss, and clinical director of Integrated Diabetes Services, to give a modern definition of brittle diabetes, and he says it “refers to glucose variability and the extent to which a person experiences an unexplained variation in blood sugar,”

However, Scheiner doesn’t like the term. He thinks doctors may have coined it when they “threw their hands up” in frustration over cases of diabetes that seemed impossible to treat. He prefers to simply refer to the phenomenon as variability. Everyone with diabetes experiences some fluctuation in blood glucose levels – some have less variation due to more regimented daily schedules; some have more, even with planned meals and activities.

As our tools for controlling blood glucose have improved, the number of people with so-called brittle diabetes has decreased. A Brazilian study led by Dr. Freddy Eliaschewitz set out to find cases of brittle diabetes, which he defined as glucose fluctuations so severe that a person cannot have a normal life. Dr. Eliaschewitz screened 500 people with Type 1, yet found only 10 met his criteria. Even those few who meet such criteria may lack education or not be using the right insulin or the right mode of delivery. If this is the case, then even the few cases marked as “brittle” diabetes may be overdiagnosed.

The ability to make insulin may be what separates brittle diabetes from regular Type 1, according to Scheiner. People with Type 1 are unable to produce enough insulin to control blood glucose levels, but research suggests that most still make some insulin. And those who can produce a bit of insulin tend to have fewer glucose fluctuations than those who don’t make any insulin. “If the pancreas can make a little bit of insulin, it serves as a buffer” against dramatic blood glucose changes, says Scheiner.

Smoothing out the dips and surges of blood glucose depends on identifying the many possible causes of the fluctuations. If psychological issues are behind brittleness, treatment with medication or counseling may help iron out things. For example, with gastroparesis, changing one’s diet and eating patterns, alongside medications and gastric pacing devices, can improve the consistency of digestion and level out blood sugar levels. Undiagnosed or uncontrolled celiac disease can result in varied absorption of food and unexplained blood sugar swings.

Whether you call it brittle diabetes or just variability, there are options for people who have a hard time getting blood glucose to level out. After identifying what’s causing the fluctuations, doctor and patient can come up with an individualized treatment plan to smooth out the ups and downs as much as possible.

Have a Question? Insulin-Quiring Minds is a free service of the clinical team at Integrated Diabetes Services LLC. Submit your questions to All questions will be answered, and yours may be chosen to appear on Insulin Nation.
Integrated Diabetes Services provides one-on-one education and glucose regulation for people who use insulin. Diabetes “coaching” services are available in-person and remotely via phone and online for children and adults. Integrated Diabetes Services offers specialized services for insulin pump and continuous glucose monitor users, athletes, pregnancy & Type 1 diabetes, and those with Type 2 diabetes who require insulin. For more information, call 1-610-642-6055, go to or write

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Jennifer Smith holds a Bachelor’s Degree in Human Nutrition and Biology from the University of Wisconsin. She is a registered and licensed dietitian, certified diabetes educator, and certified trainer on most makes/models of insulin pumps and continuous glucose monitoring systems. She has lived with Type 1 diabetes since she was a child,and thus has first-hand knowledge of the day-to-day events that affect diabetes management.