If type 2 diabetes runs in my family, can I prevent it?


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The following transcript has been edited for length and clarity.

Ginger Vieira: Welcome to Collab Conversations with the American Diabetes Association and Beyond Type 1. I’m Ginger Vieira and today we’re talking to Dr. Marlon Pragnell, vice pesident of research and science at the American Diabetes Association. Hi, Dr. Pragnell. Thank you. 

Dr. Marlon Pragnell: Hello. It’s great to be here. Thanks for inviting me.

Thank you. And we’re going to be really picking your brain today about the genetics of type 2 diabetes and if it runs in someone’s family. I would love to just start right off the bat with…is type 2 diabetes considered a genetic or hereditary disease? Are those the same thing?

Yeah. It’s genetic. There’s a strong inheritable component to it. That’s why, for example, when you take a diabetes risk test, one of the questions is, “Do you have family members with type 2 diabetes?” So yeah, there is a strong genetic component, but at the same time, it’s not something that because you have a genetic risk for diabetes type 2 that you’re going to get it. There are many ways in which you can avoid that. 

I often hear that from people with family members who have type 2 and they feel doomed. They say, “Well, my mom had it or my grandma had it, so I’m definitely going to get it.” And that’s not the case, right? 

We’ve been doing a lot of research on the genetic risk of type 2 diabetes, and I think there’s a lot to be learned there. We do know there’s a risk. There are genetic components that can predispose a person to type 2 diabetes. But as we know, it’s not all just genetics. Environment plays a huge part in type 2 diabetes, and so even though you may get a score saying, “Hey, you’re at risk,” and you also have family members, there’s so much you can do to really reduce that risk dramatically. 

We live in a very different environment from what we were originally intended to live in compared with many hundreds and thousands of years ago. And so our body’s not made up for that. So we’re actually being exposed to very unusual levels of sugar, processed foods and so on. You talk about genetics, genetics is really important. I think that genetics is going to help us in the future understand maybe the different types of diabetes. 

For example, in type 2, there are multiple versions. It may also help us understand ways in which you could see what a person’s trajectory might be with diabetes, like risk for kidney complications, for example, or risk for eye disease.

Maybe it might help us, too, to decide genetics may help us say, “Will a person benefit from one kind of therapy versus another?” So will this drug work better for that person? So help kind of drive clinical decisions. 

Okay. So research has pinpointed a few very specific type 2 related genes, right, that are…

Yeah, when we think of disease like cystic fibrosis is one or two mutations, for example. Diabetes is not like that. Type 2 diabetes consists of multiple different small factors, kind of influences and so. We’re still not quite there yet in fully understanding what those are. That’s why the best way to really say if you’re at risk of diabetes is looking at your family history.

It’s inherited, right?

But there are ways, there are genetic risk scores and so on you can use to get a sense of where you’re at. But many aspects around prediction of whether you’ll develop diabetes are more clinical. Weight, if you live [a sedentary lifestyle], looking at your clinical measurements, for example, are probably more informative. 

The one way you can really dramatically improve your risk of not having diabetes, not developing diabetes, is through diet and exercise. 

And all the research now that’s coming out that shows this is the case, that you can be predisposed to it, your family can have it, you could be at high risk for diabetes, but if you work towards reducing body weight, if you’re a little bit heavy, if you’re not getting that much exercise, if you start working on increasing your exercise, that will dramatically improve your risk of not developing diabetes. 

Really important. I can’t emphasize that enough. So all this concern, if you’re a person that has diabetes in the family, if you have a genetic risk score that suggests you’re heading that direction, there’s so much you can do to stop that from happening or reduce the risk of that happening.

And where does beta cell dysfunction come into play with lifestyle habits? Beta cell dysfunction, for anybody watching, is beta cells producing insulin and in type 2, they’ve pinpointed that many people with type 2, maybe a certain percentage, it’s roughly half, I think?

Yeah, a large number…if we’re talking about type 2 diabetes, what happens is that with beta cell dysfunction, you develop this kind of insulin resistance in the body. It’s different for type 1 diabetes where you don’t produce insulin. What happens is that you produce insulin in type 2 diabetes, but the body really can’t use it that well. 

So the glucose just gets stuck outside the cells, stays in circulation. The blood can accumulate the sugar, gets sort of sweet, so to speak, and that’s the main thing.

So what happens then is that, because the body tries to help the insulin go into the tissues through using insulin, the body is going to say, “Well, okay, let me try harder.” So the first thing the beta cells do is really start cranking out that insulin and cranking it out and cranking it out and just kind of pushing. Because something’s not happening, you try harder, right? So the beta cells try harder, to the point where they start to wear out.

And then they stop working. And then actually get to the point where almost you’re in a situation where instead of all this insulin that you’re putting out to try and get the body to respond because of the reduced sensitivity, now you don’t have any insulin to deliver. And then you have to start taking insulin for that. 

Okay, wow. So beta cells are more of a process than just one thing that is not working well.

Yeah. The key thing there though is this can happen very early on in the disease. So for example, you can spend many, many years not knowing you have this propensity.

And that’s where you can really have the most impact in preventing diabetes, that early stage. So that’s why it’s so important to, if you’re in a family that has increased risk for diabetes, you totally need to understand that you potentially have… these very early stages are invisible, undetectable, where your beta cells are starting to now become a little bit less effective, starting to work harder, right? 

Right. That’s not the stage that really rattles people, because it doesn’t come with this firm, alarming diagnosis. So if it does run in your family, don’t wait for the diagnosis to tell you, oh yes, you were at risk.

You know what they say, an ounce of prevention is worth a pound of cure. It’s so important. What you can do now to prevent diabetes, if you are at the very beginning stages, it’s so much easier to prevent and delay than it is later on in the stage. At every stage, you can do something to prevent progression of complications and so on. But the earliest possible stage is absolutely the best place to start. And if you have family members that have diabetes, then you’re at risk. You’re at genetic risk. And where you start, at the very earliest stage, healthy lifestyle, healthy activities.

And it doesn’t take much. As a type 1, I can tell you that I recently didn’t do any of my intense cardio jogging for almost a whole week, and my insulin needs, I needed to increase them by 5 percent just from one week of less exercise. It’s amazing how just starting to do my daily jog again, how quickly my insulin needs go back down. It doesn’t take hours and hours of exercise or intense CrossFit workouts. Even just walking. 

Totally. If you have family members that have diabetes, your priority right now should be just really getting that bit of exercise. It doesn’t have to be a super athlete, but just small changes, small changes also in diet as well, skipping those sugary drinks and so on. Maybe eating a bit healthier. 

Well, thank you for breaking that down for us and explaining some of the deeper science of genetics. You are not doomed if it runs in your family. There’s a lot you can do. Thank you.

My pleasure.

WRITTEN BY Ginger Vieira, POSTED 12/09/21, UPDATED 10/04/22

Ginger Vieira is an author and writer living with type 1 diabetes, celiac disease, fibromyalgia and hypothyroidism. She’s authored a variety of books, including “When I Go Low” (for kids), “Pregnancy with Type 1 Diabetes,” and “Dealing with Diabetes Burnout.” Before joining Beyond Type 1 as digital content manager, Ginger wrote for Diabetes Mine, Healthline, T1D Exchange, Diabetes Strong and more! In her free time, she is jumping rope, scootering with her daughters, or walking with her handsome fella and their dog.