What is Double Diabetes?

October 13, 2021

You may have heard the term “double diabetes,” but what does that mean? A recent publication in the journal BMC Endocrine Disorders looks at how obesity relates to double diabetes in adults with type 1 diabetes.1

Double diabetes is defined as having type 1 diabetes in combination with insulin resistance, which is the main feature of type 2 diabetes.2 It’s unclear exactly how prevalent this issue is for people with diabetes, so researchers in Bristol, United Kingdom reviewed the data for their patients who met the following criteria:

  1. Low C-peptide
  2. Two or more positive type 1 diabetes autoantibodies
  3. One positive t1d autoantibody + diagnosis age < 30 years
  4. History of DKA + diagnosis age < 30 years
  5. Diagnosed < 20 years of age regardless of autoantibody presence

The clinics found a total of 107 patients who met the inclusion criteria and did not meet their exclusion criteria (having MODY, steroid-induced diabetes, etc.). They then looked at how many of the people with diabetes were overweight as defined as a body mass index (BMI) of 25-29.9 kg/m2 and how many were obese as defined as a BMI > 30 kg/m2.

To determine insulin resistance, they used a method called estimated glucose disposal rate (eGDR) and used the standard calculations to determine participants’ level of insulin resistance. This method was developed to use information from the person with diabetes including waist circumference, hypertension, weight, blood pressure and more to calculate the risk of complications associated with insulin resistance.3 This also avoids the need to conduct the standard test for measuring insulin resistance, which is more invasive to the person with diabetes.

Of the 107 patients from the clinic in Bristol, 30 (28%) were overweight and 27 (25.2%) were obese. In addition, 62 of 107 (57.9%) met the definition of having double diabetes. People were more likely to have double diabetes if they were older, had microalbuminuria (secreting protein in the urine), had a longer duration of diabetes, had poor lipid profiles, and had higher HbA1c despite higher insulin doses.

Given that the prevalence of overweight and obesity continues to rise for people with and without diabetes in our modern world, this is something to which we should all be paying attention. The added layer for people with diabetes is the increased risks it causes in addition to the risks for diabetes without insulin resistance. It’s also incredibly challenging because insulin can promote weight gain, thus creating insulin resistance and a cyclical problem for people who require insulin.

Based on the data for double diabetes, effective weight management is suggested for people with diabetes and further research on broader populations. There are many ways to help promote weight loss including dietary and lifestyle modifications as well as medications, though all have their respective challenges.

It’s worth talking to your healthcare team about what can help you if you are concerned about weight management to help reduce your risks. Meeting with a certified diabetes care and education specialist (CDCES) can be incredibly helpful as well! There are many CDCES providers throughout the United States, and you can find a program near you through the Association of Diabetes Care and Education Specialists.


  1. The association between overweight/obesity and double diabetes in adults with type 1 diabetes; a cross-sectional study
  2. Double Diabetes
  3. Double diabetes: A distinct high-risk group?

Written and clinically reviewed by Marissa Town, RN, BSN, CDCES