Updated 7/28/25
Reading Time: 4 minutes
It doesn’t seem fair – because it’s not – but you can win the lottery you never bought a ticket for and end up with both type 1 and type 2 diabetes, which is also called “double diabetes”. This is because they are two distinct conditions with different etiologies (a fancy word for the cause of a disease).
This case is important to highlight because it has both therapeutic and genetic implications, which are different for type 1 vs type 2 diabetes. Type 2 diabetes is extremely hereditary. Even though type 1 diabetes is less genetic, if you have a close family member with type 1 or any other autoimmune condition, you should get screened for T1D autoantibodies. If you are positive, you need to learn about a medication for people with positive autoantibodies that can delay or prevent the onset of T1D.
There aren’t actual screening tests for type 2 diabetes other than testing glucose levels and A1c occasionally, but you should keep an eye out for the common metabolic syndrome abnormalities that we see in T2D, like high blood pressure, high triglycerides, and low HDL cholesterol levels. You want to be diagnosed early for the best outcomes.
So how does someone get lucky enough to end up with both type 1 and type 2? I’ll walk you through a real-life example from one of my patients.
Type 1 vs. Type 2 Diabetes: What’s the Difference?
Type 1 diabetes is an autoimmune condition that occurs when the immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas. It can happen at any stage in life, from infants to older adults. People with type 1 diabetes need daily insulin for life. According to the CDC, about 5-10% of people in the U.S. with diabetes have type 1.
In type 2 diabetes, the body still typically makes insulin, but it doesn’t really work well (this is called insulin resistance) and it’s not enough to normalize the blood sugar. T2D is most commonly diagnosed in adults over 45, but it can occur in kids too. People with type 2 diabetes can do quite well with medications and lifestyle changes. More than 38 million Americans have diabetes (about 1 in 10), and about 90% to 95% of them have type 2 diabetes.
Meet the Patient: Derek
Derek is 62 years old and was diagnosed with type 1 diabetes when he was only six. He presented with DKA (diabetic ketoacidosis) and was hospitalized in the ICU (a common occurrence way back then). He was on MDI (multiple daily injections) for decades because that was really the only treatment available, and he managed his condition as best he could for years with the help of his mom. His A1c was typically in the upper 7% range to the low 8% range. An A1c goal of 7% or under is common for most people.
In 2017, Derek transitioned from MDI to the Medtronic MiniMed 670G hybrid closed-loop system because he was tired of giving himself shots. He did well on the 670G, and after a few months his A1c was in the mid 7% range. Everything was cruising along fine until he hit middle age. Ain’t it the truth for a lot of us!
The Problem: A Strong Family History of Type 2 Diabetes
Both of Derek’s parents have type 2 diabetes. When both of your parents have type 2 diabetes, your chance of getting it at some point is huge – virtually 100%. Unfortunately the gene pool cards were stacked against Derek in this case. In his late 40s, he started to slowly develop the classic symptoms of type 2 diabetes.
Classic Signs of Type 2 Diabetes:
- Weight gain in the abdominal area
- High blood pressure
- High triglycerides
- Low HDL (the good cholesterol)
- Insulin resistance
Because Derek was becoming more insulin resistant from type 2 diabetes, he needed a lot more insulin to keep his blood sugar in range. His insulin requirements went from about 50 units per day to often more than 100 units per day – almost double!
The Game Plan: How to Tackle Double Diabetes
It’s important to note that all of these changes didn’t happen overnight – they occurred over the course of four to five years.
When it became clear that we were dealing with type 2 diabetes in addition to type 1, we started Derek on a typical type 2 diabetes treatment protocol in addition to his type 1 regimen of his MiniMed 670G hybrid closed-loop system:
- Metformin to help manage blood sugars
- Trulicity (one of the first once-weekly GLP-1 drugs) to manage blood sugar glucose values and excessive weight, in addition to protecting him against heart attacks and strokes
- An ACE inhibitor for high blood pressure and to protect his kidneys
- Gemfibrozil (Lopid) to lower his triglycerides
Later we added the SGLT2 inhibitor Farxiga because he started to develop early renal insufficiency, which is not uncommon.
When Mounjaro became available, we switched him from Trulicity to optimize his glycemic control and assist with added weight loss.
In 2023, we transitioned him to the Medtronic MiniMed 780G hybrid closed-loop system to take advantage of its advanced algorithm and improve his time in range.
If You Have Type 2 Diabetes, Can You Get Type 1 Diabetes?
Some people with type 2 diabetes who end up needing insulin will often say their type 2 diabetes “turned into” type 1. While type 2 diabetes is a progressive condition and insulin may be needed for some people at some point, that doesn’t mean that their type 2 diabetes has become type 1. It just means they now need insulin to help keep their blood sugars in a better range. The correct phrase is “insulin-requiring type 2 diabetes”.
Theoretically it is possible to have type 2 diabetes first and then also get type 1; however, those types of patients are not diagnosed and are classified as having insulin-requiring type 2 diabetes.
The Takeaway
Type 1 and type 2 diabetes are unfortunately not mutually exclusive. Just because you have one type of diabetes, it doesn’t protect you from getting the other…although it should!
If you have type 1 diabetes and you’re worried about getting type 2 diabetes due to a family history of the condition, the best thing you can do is kill two birds with one stone (why would you want to kill two birds?) and maintain an ideal bodyweight. Make sure you’re screened frequently (at a minimum once a year) so if you see signs of type 2 diabetes, you can initiate type 2 medications quickly. That will help prevent the progression.
If you are a glass-half-full kind of person, you can look at the benefit of having both type 1 and type 2 diabetes. The upside is that you can get access to all the awesome medications that are only currently approved for type 2 diabetes, and you can get coverage for a CGM. You can use the double diabetes diagnosis to your advantage, as insurance companies have to cover medications for type 2 diabetes, and technology like pumps and CGMs for type 1 diabetes.
(Side note: You can get a CGM covered by insurance if you have type 2 diabetes and you are on at least one shot of insulin per day.)
Double diabetes is actually not that uncommon, and it is important to have a level of awareness about it if you’re at risk. Living with type 1 and type 2 diabetes may be a double whammy, but it doesn’t necessarily mean double trouble. You can absolutely live well with both. But don’t seek out another diagnosis just to impress your endocrinologist!
Visit our resource library and video vault for other tips, tools, and support on how to take control of your diabetes.
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