What We Now Know About the Cause of Type 1 Diabetes
Everyone with type 1 diabetes has a diagnosis story – some more harrowing than others – but most people are diagnosed in an emergency situation while in diabetic ketoacidosis. They immediately have to adapt to a new way of living that involves learning how to administer insulin, how to treat high and low blood sugars, how to count carbs, how to time insulin dosing for exercise, how to use unfamiliar medical devices…and they have learn it all quickly while processing a life-changing medical diagnosis.
We used to think type 1 diabetes was a condition that came on suddenly, but we now know that it happens in stages and starts long before insulin is ever needed.
The Difference Between Type 1 and Type 2 Diabetes
Even though more than 37 million Americans have diabetes, many people don’t know the difference between type 1 and type 2. People with type 2 diabetes are insulin resistant, meaning their body doesn’t respond to insulin as well as it should. Many people with type 2 can control their blood sugar with lifestyle changes (such as nutrition and exercise) and medications.
Unlike type 2 diabetes which is a metabolic condition, type 1 diabetes is an autoimmune disease where the body’s immune system is triggered to think healthy beta cells are the enemy, and it attacks them. People with type 1 ultimately don’t produce insulin themselves and must have it injected or administered by a pump to survive. Type 1 diabetes is often diagnosed in children and young adults, but it can occur at any age.
The 3 Stages of Type 1 Diabetes
Thanks to years of research, blood tests are available now that can determine if someone is at risk for developing type 1 diabetes long before they become insulin dependent. This is done by looking at proteins in the blood called autoantibodies. For anyone wanting to geek out on medical terminology, here are the autoantibodies we look for:
- Glutamic acid decarboxylase (GADAs)
- Insulinoma-associated-2 autoantibodies (IA-2A)
- Insulin autoantibodies (IAAs)
- Islet cell antibodies (ICAs)
- Zinc transporter 8 autoantibodies (ZnT8A)
The presence of one or more autoantibodies can help determine which stage of type 1 diabetes someone is in, including its earliest stages, before any symptoms are present.
We now know there are three stages of type 1 diabetes:
Stage 1:
Two or more autoantibodies can be identified, blood sugar levels are still normal, and the person has no symptoms.
Stage 2:
Two or more autoantibodies can be identified, and blood sugar levels are not normal, but most people still have no symptoms. The medical phrase is called dysglycemia.
Stage 3:
Two or more autoantibodies can be identified, blood sugar levels are high, and the person typically has symptoms like excessive thirst, frequent urination, unintended weight loss, and blurred vision. This is historically when most people are diagnosed.
Once at least two specific antibodies are detected, the risk of developing stage 3 T1D in the next five years becomes roughly 25% to 50%.
Who Should Get Screened for Type 1 Diabetes
Anyone can get screened for type 1 diabetes, but those most at risk are people who have a first-degree relative (parent, sibling, or child) with type 1. The majority of people (about 85%) who are diagnosed with stage 3 onset of type 1 have no family history of the disease, but those who have a family member with type 1 have an increased risk (up to 15x) of developing it.
Why You Should Get Screened for Type 1 Diabetes
Most people diagnosed with type 1 are thrown into the T1D fire without knowing the first thing about how to manage it. This is especially daunting for parents of newly diagnosed children. Screening can help identify early-stage type 1 long before symptoms occur, offering the following benefits:
- Time to recognize symptoms when they do appear
- The ability to create a monitoring plan with your healthcare provider so you can be aware of changing blood sugar numbers and other symptoms as they develop
- Time to become educated about type 1 diabetes and how to manage it
- The ability to reduce the risk of diabetic ketoacidosis, which typically occurs when people enter stage 3 type 1 diabetes
- The opportunity to learn about type 1 diabetes treatment options
How to Get Screened for Type 1 Diabetes
There are a few different ways you can get screened for type 1 diabetes (all are blood tests):
- Ask your healthcare provider for a test at their clinic, or for a referral to a participating lab (such as Quest or Labcorp). Most commercial insurance plans in the U.S. cover the cost of AAb screening in whole or in part.
- Visit trialnet.org. TrialNet is a free screening program for family members of people with type 1, or those between the ages of 2.5 to 45 years who’ve tested positive for at least one T1D-related autoantibody outside of TrialNet.
- Visit askhealth.org. ASK (Autoimmunity Screening for Kids) provides screening for T1D for U.S. kids ages 1-17 years. No family connection to T1D is required.
- Get an at-home test through a provider like Enable Biosciences: Get a test kit shipped directly to your home. The kit includes detailed instructions for drawing a blood sample from your fingertip.
This may not be an exhaustive list of available screening options. The appropriateness of any AAb screening test and the validity of the test results are up to the requesting physician to determine. Inclusion in this list does not imply the endorsement of Sanofi.
You can find additional screening information at ScreenForType1.com
What to Do If You Test Positive for Type 1 Diabetes Autoantibodies
According to JDRF, 97% of family members of those with type 1 and 99.7% of people in the general population will have a negative result, but if your test results come back positive, talk to your doctor about confirmatory testing (TrialNet can confirm the results), getting a blood sugar monitoring plan in place, knowing the symptoms to be aware of, and what to do if/when they do appear. If your test comes back negative but you have a family history of T1D, still speak with your doctor because getting rescreened every year is currently recommended.
In Conclusion
Anyone can be diagnosed with type 1 diabetes at any time and at any age, even without a family history of the disease. We hope in the not-too-distant future there will be age-based T1D screening for everyone, because having time to be prepared and become educated about life with type 1 (either for yourself or for a loved one) is priceless. Lastly, who knows what advances they will have for people with type 1 diabetes in those extra diabetes-free years?
Sanofi does not provide medical advice, diagnosis, or treatment. The health information contained herein is provided for general educational purposes only. Your healthcare professional is the best source of information regarding your health. Please consult your healthcare professional if you have any questions about your health or treatment.
If screening is the only way to get Tzield, then T1 screenings should be done before kids go to school so parents know the chances of developing complete Cpeptide failure and no functioning beta cells. Considering how many people are developing T1 LADA, all ages should consider it if A1C levels elevate or that famous crying for water starts.
I was diagnosed with T1 at the age 54! Six months after I had lung surgery. Prior to this surgery, my A1C was 5.
It was shocking to say the least. My pancreas does not produce any insulin at all. Now how does that happen??
There really is not a link between lung surgery and coming down with diabetes, unless you were put on high-dose steroids for a long time (which you may have been). Typically steroids do not cause diabetes, but they may bring it out in someone who has a genetic tendency. In any case, diabetes is controllable.
Why are the stages of diabetes categorized using two antibodies? What if a person tests for one autoantibody?
That’s an excellent question. To be honest, I’m not sure why one isn’t good enough. Some people would repeat the test and get the whole panel done if they test positive for one antibody. When you measure these antibodies, the result comes back in a specific number or titer, and sometimes if the titer is really high, or if the number is way off the charts, then one antibody is enough to be convinced that person has type 1. But you have to look at the actual value. If it’s just mildly positive, you probably need to repeat the test.
What if you’ve been mildly positive for GAD65 (TrialNet), then mildly positive via Quest, then negative (also via Quest/ACL)?
Fasting BG is ~110 without basal insulin, but there’s never been a second positive antibody (only GAD65) and the positives have always been just over that threshold. Is that LADA? Type 2? No other bio markers for type 2.
Thanks for any insight you can share! It’s very confusing when you get into the weeds like this.
I understand your frustration but if you have GAD that’s only mildly positive, it doesn’t really mean too much. At this stage, you are without a diagnosis and I’d call yourself normal at this stage. You could always wear a CGM and that would pick up any abnormalities. We do look at how the titres are. You had one that was negative and two mildly positive…it doesn’t really tell us too much. In short, it’s not a bad thing at all and I wouldn’t worry about it.
Question: were any of these tests available 50 years ago, or only recently? I don’t recall how I was diagnosed in 1974, other than having the symptoms of thirst, extreme weight loss, very high BG, etc. Thank you.
These tests have been around for 10-20 years, however we never had a therapy to address anyone who had positive results. Now they’re much more prevalent, so in a way they really were not around back then.
As a 58 year old LADA, I tested positive on all four autoantibody tests and the ZnT8A test wasn’t used at the time. I’m a bit concerned about my GAD result. The lab test only went up to “over 250”. Is there another “more sensitive” GAD test I can ask for so I know my exact number? I have some vague symptoms of Stiff Person Syndrome (SPS) and want to ask my PCP for a referral to a Neurologist. Do you see many T1D with SPS? Thank you so very much!
There are labs that will give you a specific number for GAD. You just need to call around and see if they’re available. You can try Labcorp, Quest, or Athena. And yes, I have seen several patients with SPS with varying degrees of severity. There are specific ways to treat it. Ask your endocrinologist if he/she has experience in this area, or ask him/her who they would refer you to. It may not be a neurologist (but it could be).