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There's a lot of interest in knowing your future when you're a kid. But one thing you can know with basically 100% certainty isn't one you'd expect - your risk of developing type one diabetes. So if one simple blood test can tell you if you'll get it, would you want to know?

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Do you remember that MASH game  we used to play at recess, where you’d try to predict your future  house, job, pets, and stuff like that?

While science hasn’t determined the  accuracy of that particular methodology, there actually is a test that can predict  at least one aspect of a kid’s future: whether or not they’ll develop diabetes. A positive result means you’re going to get Type 1 diabetes at some point in your life.

And while there are a lot of benefits to  knowing about it, we have no idea what that knowledge would do to a kid. So is it always worth it to know your future? [♪ INTRO] First things first, there are  a few kinds of diabetes-es. There’s diabetes mellitus, which  you’ve probably heard about, because that’s the one that’s  about your blood sugar.

And there’s also diabetes insipidus,  which has to do with your body not being able to retain water well,  but we’re not getting into that today. Diabetes mellitus is then broken down into  type 1, type 2, and gestational diabetes. And the testing we’re talking about is just  for type 1 diabetes, not the other two.

Type 1 diabetes is an autoimmune condition, meaning it’s a disease where your immune system goes rogue and attacks your own body. In the case of type 1 diabetes, the  immune system targets the pancreas, which is bad news because the pancreas plays a huge role in our digestion  and regulating our blood sugar. In a healthy pancreas, groups of  cells called islets of Langerhans release hormones in order to maintain  the right amount of blood sugar.

And it does this with a  pretty neat two-way mechanism. The islets have alpha cells that produce  glucagon, which tells your liver and fat cells when it’s time to release  some glucose and raise your blood sugar. But they also have beta  cells which produce insulin, and that insulin gives your cells  the signal to absorb glucose out of the bloodstream, giving them their energy and bringing the blood sugar levels back down.

Glucagon and insulin are essentially  in a friendly game of tug of war, maintaining your blood sugar  and energizing cells as needed. But for someone with Type 1  diabetes, their immune system is attacking the pancreas and  destroying those beta cells, and no beta cells means no insulin, which  means dysregulated blood sugar levels. Research has shown that there is  a genetic component to developing Type 1 diabetes, since having a  family history of type 1 diabetes increases your risk of developing  the disease at some point.

It seems like specific alleles of  the HLA region of the genome may also be to blame, since that part makes  antigens that are responsible for helping your immune system figure out what’s supposed to be in your body and what isn’t. But inheriting those HLA alleles  only explains some of the risk. As many as 90% of people with type 1 diabetes don’t have any family history of the disease.

And lots of the people who do/ have  those risk factors never develop Type 1 diabetes at all, which means that  environmental factors likely play a role. Basically, we think your immune  system needs to be triggered into attacking the pancreas, but we don’t know  exactly what will trigger it, or when. Which means that most people get  their diagnosis of type 1 diabetes only after the problem has  been brewing for a while, since they didn’t have any  reason to be watching out for it.

And unfortunately, the longer diabetes  goes untreated, the worse things can get. As more and more beta cells are  destroyed and insulin levels drop, the glucose in your blood isn’t able to  energize the rest of the cells in your body. Without any sugar, your body will  start to burn fats for energy instead.

And doing this produces a  byproduct called ketones. Ketones are fine in small doses, and  if you’ve ever been on a keto diet, you were actually trying to make your  body use fat instead of sugars for energy. But if ketone levels get too high,  they can make your blood acidic, which is just about as bad as it sounds.

This can put you into diabetic  ketoacidosis, which is considered a medical emergency and requires  treatment, as soon as possible. It causes symptoms like weakness,  confusion, extreme thirst, and vomiting, which can all come on pretty suddenly. And if it’s left untreated for  too long, it can even lead to brain swelling, comas, and death.

It’s usually at this point people go to the doctor or emergency room and are tested for diabetes. For anywhere from 20-70% of children,  going into diabetic ketoacidosis is what gets them diagnosed with  type 1 diabetes in the first place. That’s a lot of people, and  since it can be, you know, fatal, there’s a lot of interest in getting  people diagnosed before it gets this far.

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Which brings us to that future-predicting  test I was telling you about. It’s a simple blood test looking for evidence of your immune system starting to  pick fights with your pancreas. While your immune system is attacking  those beta cells in the pancreas, your body also starts making autoantibodies, which is the term for antibodies that  specifically attack your own body.

In this case, the disease also makes  antibodies that target things like insulin. And those autoantibodies are what  the blood tests are looking for. If you’ve got multiple autoantibodies, you’re in at least the early  stages of type one diabetes.

There are actually two stages  of presymptomatic diabetes. People with stage 1 presymptomatic  diabetes have the autoantibodies, but their blood sugar is still  within the normal levels. Stage 2 means you’ve got the autoantibodies  and also your blood sugar is a bit off, but not enough that you would notice.

The blood test is able to pick up on  both of these presymptomatic stages, meaning that you can have an early warning way before you meet the diagnostic  standard for symptomatic diabetes. And this test is super accurate. For someone who tests positive, their  lifetime risk of developing type 1 diabetes is nearly 100%, regardless of their  family history of the disease.

It’s basically inevitable,  unless you die of something else before you develop diabetes. And these tests have actually  been around for a while. It’s just that they’re most often  done on kids with known risk factors, like a family history of type 1 diabetes.

But now that we know these tests can  pick up on autoantibodies in kids without those risk factors, there’s a  growing interest in using them on all kids, not just the ones we know to keep an eye on. One massive research study called  the Fr1da Model Project Diabetes 2015 screened over 90,000 European children for these autoantibodies between 2015 and 2019. And they looked at any children  whose parents signed them up, regardless of diabetes risk factors.

Of those 90,000, they found 280 kids  with early stages of type 1 diabetes, which is about 0.3% of the kids they tested. So the test is able to pick up  on early stages of diabetes, even in kids without any known risk factors. But what the test can’t tell us is  when your type 1 diabetes will emerge.

A 2013 study in The Journal of  the American Medical Association looked at how long it took for children  who’d gotten positive test results in previous studies to officially  develop type 1 diabetes. And they found that 69.7% of  patients with multiple autoantibodies had developed type 1 diabetes within  ten years of their initial blood test, and over 84% were diagnosed within fifteen years. But there was a lot of variation in  when exactly they got that diagnosis.

Disease onset was anywhere from  a few weeks after the blood test, all the way up to 18 years later. And other studies have  demonstrated that it can take decades for a person to progress  to symptomatic type 1 diabetes. About 11% of children who  had multiple autoantibodies develop Type 1 diabetes each year.

It’s almost like a perpetual  game of hide and seek, where you know you’ll get found eventually,  you just won’t know when it’s coming. But realistically, that game is happening anyways, whether someone knows they’ve  got the antibodies or not. From an ethics perspective,  deciding who gets this test and when isn’t all that cut and dry.

We’re talking about testing  children as young as 2 or 3, and a positive test result could mean they’ll get sick right away, or not until adulthood. It’s effectively a sword of Damocles  hanging over a toddler’s head, and there’s not much in the way of research into what that does to a kid psychologically. Plus, those autoantibodies can develop at any age, so a negative result at 3 doesn’t  necessarily mean you’re in the clear, it could just be that they haven’t developed yet.

One possible solution would be  testing regularly to keep an eye out for those autoantibodies, but  that would cost a lot more, and it’s no easy feat to get  blood samples from little kids. Some doctors think the best way  around that hurdle is waiting to test the kids until just before kindergarten, or  by adding this blood test into a panel that they’re already getting, so kids don’t  need to have even more blood drawn. And if the test does come up positive,  it’s not like there’s nothing you can do.

There’s a medication called teplizumab that can delay the development of type  1 diabetes by 2 or 3 years. Which may not sound like a huge  deal if you’re at the age where you blink and suddenly six years went by,  but it can make a major difference when 2 or 3 years is like, half your current age. That can be the difference between  dealing with type 1 diabetes while potty training versus dealing  with it while learning how to read.

That said, there is no permanent  prevention or cure for type 1 diabetes, so it’s not like this test will prevent any cases. But what it can do is prevent  the major complications from type 1 diabetes, like diabetic ketoacidosis. Avoiding a diabetic ketoacidosis emergency  is huge, since many of the kids who get it end up in the pediatric intensive  care unit, and can have permanent damage.

Studies from both Germany and Colorado  found that of the children diagnosed with presymptomatic diabetes via the blood test, the rate of diabetic ketoacidosis  was between 2.5% and 4%. And like we said at the beginning, as  many as 70% of diabetic children go into ketoacidosis before getting their  diagnosis, so that’s a huge, immediate reduction in harm from  something that can be life-threatening. As far as long term implications,  right now we don’t know what psychological effects this would  have on the kids who test positive.

After all, knowing that you’re inevitably  going to get a serious diagnosis that you can’t cure or prevent is  pretty heavy even for an adult, nevermind for kids who may not fully  understand what this information means. And because of that, it’s  unclear what tools will be needed to manage the emotional  toll this kind of thing could have. But there’s another argument to be made  that knowing early means that you can prepare the child and teach them  about the diagnosis in stages, so it’s not so much of a  shock when all of a sudden they need to know about monitoring  blood sugar and insulin.

So all in all, this blood test is a major  step in possibly preventing kids from going into ketoacidosis, which would be huge. And it’s at least one way that  knowing a negative future outcome before it happens can be a good  thing, even if you can’t stop it. [♪ OUTRO]