The first time I went to a local T1D meetup group I was amazed at how many older people were there. I thought to myself, this is great, these people have been living with diabetes for ages. Their wisdom and experience will be so helpful!
But, as we went around the room introducing ourselves and giving a brief blurb on our history with type 1 diabetes, I realized most of these people had been diagnosed within the last couple of years.
I knew the average age of diagnosis had gone up over the last few decades, but a lot of these people were in their 50’s and 60’s. I didn’t even know people of that age were ever diagnosed with type 1.
It was an experience that opened my eyes to the changing world of a disease formerly known as “juvenile diabetes.” And one that led me to do more research into why people were being diagnosed further into their prime.
Can You Get Type 1 Diabetes Later in Life?
In the US, the diagnosis of type 1 is most common in youth between the ages of 10 and 19 years old, with 14 being the “peak” age for diagnosis. But, there are still a fairly significant number of people diagnosed in every age group up to 80 years and beyond.
It is considered common for type 1 to be diagnosed anytime before the age of 40 nowadays.
Here I thought being diagnosed at 20 was late. Most of the people I shared the news with at the time seemed to think the same thing. “I thought only kids got that kind?” and “Isn’t it type 2 because your an adult?” were common responses.
Strangely enough, the average age of diagnosis in my type 1 meetup group appeared to be far above the national average. In fact, for most meetings, I am the youngest one in attendance and only a few of the older attendees were diagnosed in their youth.
I’m sure this has more to do with the collection of people likely to attend meetups and less to do with the average age of diagnosis in my city. Still, thinking about the different influences that bring certain people to the group also made me consider the influences on T1D that are causing it to be more frequently diagnosed later in life.
Reasons Behind the Shift
One common theory I’ve read to explain why more people are diagnosed with type 1 later in life has to do with viruses. There is a lot of evidence that certain viruses can trigger the immune system to start attacking the beta cells of the pancreas in people with a predisposition for the illness. I remember being sick with a bad cold just days before my first symptoms of diabetes began. So I am a big believer in this theory.
Taking that idea and expanding it to the shift in diagnosis age, some scientists argue that disinfectants and cleaner living is to blame. The idea is, if particular viruses trigger diabetes, then by delaying exposure to those viruses through the use of disinfectants and lifestyle choices, you delay the onset of the disease.
This sounds like a perfectly viable explanation for people like me and those a decade or so older. But, what about the people being diagnosed over 50. These are people who were born and grew up before a healthy fear of eating dirt was established and Lysol was used on every surface. And yet they never got the disease in childhood like their peers did.
Another theory is that type 1 diabetes in older people has historically been misdiagnosed as type 2. Only about 4% of diabetics between the ages of 31 and 60 have type 1. That means that the average doctor seeing an adult with high blood sugar is going to assume they have type 2.
Even today, many adults are misdiagnosed and given oral meds instead of insulin to treat their high blood sugar. Many aren’t accurately diagnosed until the oral meds fail to help and they end up in the hospital. It’s possible that this kind of discovery wasn’t made in decades past because people this sick rarely lived to be re-diagnosed.
Type 1 Versus LADA
To complicate things even further, there is a new player in the game of diabetes. Latent autoimmune diabetes in adults (LADA) is a newer diagnosis that is becoming more common.
While this type is sometimes referred to as type 1.5 diabetes, it does appear to be just a subgroup of type 1. Like T1D, it is an autoimmune disease that starts when the immune system attacks the beta cells in the pancreas. But, unlike traditional type 1, this disease progresses very slowly and is almost always diagnosed in people over the age of 30.
Because of the slow onset of symptoms, this disease is even more frequently misdiagnosed as type 2 than regular T1D. And, because type 2 medications to increase insulin sensitivity are often helpful in the first few months of this disease, it can take even longer to figure out a mistake has been made.
It’s also possible that people previously diagnosed with type 1 in adulthood were actually suffering from LADA. For the first few months or even years, LADA may not require insulin to treat. Often, diet changes and exercise are enough to keep blood sugars down. But once most of the beta cells have been destroyed, a process that takes much longer than in traditional type 1, the patient will need to use insulin just like someone with T1D.
If a person doesn’t see a doctor until they are no longer able to produce their own insulin, they will be diagnosed with type 1 even though they technically have LADA.
More Questions Than Answers
There are likely a number of reasons behind the shift toward an older average onset of type 1 diabetes. Many of which we may never know, which leads to a lot more questions than answers.
Is LADA a new phenomenon or just something that was previously overlooked? If it is new, what’s causing it? And is that cause at all related to why type 1 is now more common in adults?
While it may take time for scientists to find out the why behind these diseases, the fact that they can occur in adults is what’s most important to know. Over a third of people over the age of 30 with type 1 diabetes are misdiagnosed as having type 2. What’s worse, half of those people are still being treated for the wrong disease over a decade later.
If you think you have been misdiagnosed, ask your doctor for an antibody test to confirm which type of diabetes you have. You are your best advocate, and being treated for the right disease is too important not to make yourself heard.