Schafer Boeder, MD, discusses the incidence of type 1 diabetes, highlighting risk factors such as age and family history.
Steve Edelman, MD: Hello, and welcome to this Peer Exchange titled “Delaying the Onset of Type 1 Diabetes Through Early Intervention.” I’m Dr Steve Edelman, I’m the founder and director of Taking Control of Your Diabetes. I’m also a professor of medicine at the University of California San Diego in the division of endocrinology, diabetes, and metabolism, and I work at the Veterans Affairs Medical Center. Joining me are 4 esteemed colleagues: Dr Linda DiMeglio, a pediatric endocrinologist and a professor of pediatrics at Indiana University School of Medicine in Indianapolis, Indiana; Dr Egils Bogdanovics, an adult endocrinologist in Torrington, Connecticut; Dr Justin Gregory, a pediatric endocrinologist and assistant professor of pediatrics at Vanderbilt University in Nashville, Tennessee; and Dr Schafer Boeder, an adult endocrinologist and an assistant professor of medicine at my institution, the University of California San Diego. In today’s discussion we’ll explore the pathophysiology of type 1 diabetes [T1D] and delve into the screening and staging processes for T1D. We’ll also discuss strategies for delaying the onset of type 1 diabetes and look into the future of management and therapies. With that, we’re ready to start.
I’ve assigned each of my esteemed colleagues to start with my questions, and then it’s going to be a free-for-all, where everyone is going to jump in and add and help one another. For the first question, Schafer, what proportion of type 1 cases are diagnosed as adulthood vs childhood? The other question you might answer first is what are the risk factors and triggers that have been implicated—and implicated is probably the best word, because we don’t know for sure—in leading to type 1 diabetes?
Schafer Boeder, MD: Thanks, Steve. You’re right, we don’t understand all the risk factors that lead to type 1 diabetes. There’s been a lot of work in that area. We know that there are genetic components and environmental components, and some of the genetic components relate to the human leukocyte antigen, haplotypes that can increase the risk of developing type 1 diabetes. Those account for roughly 50% of the genetic part of what we understand to be the risk of type 1 diabetes, and a lot of other genes contribute the other 50% that occur at different loci. The environmental factors are various, and the evidence is mixed. Those are some things that have shown to be generally true.
For example, there’s increased risk geographically the farther you get from the equator. There seems to be risk factors that relate to exposures like to certain viruses. Think about coxsackieviruses and other enteroviruses. There is some evidence for nutritional factors: exposure to cow’s milk and early exposure to cereal has been looked at, as well as vitamin D levels. Interestingly, age is itself a risk factor. The incidence of diabetes is highest in children, and there are 2 peaks: from ages 4 to 7 and then a second peak around ages 10 to 14. I’m not a pediatric endocrinologist, so hopefully I got those right. The reality is type 1 diabetes can occur at any age. That’s still a misconception. A lot of individuals think it can occur in adulthood. Because there are more decades of adulthood than there are decades of childhood, more than half of the new diagnoses of type 1 diabetes occur in adults.
Steve Edelman, MD: Thank you, Schafer. All of us have seen parents or individuals with type 1 diabetes who are newly diagnosed who ask, “Why did I get this?” We don’t know. You mentioned all the factors that we know. Does anyone want to add anything?
Egils K. Bogdanovics, MD: That’s a good point about age of diagnosis. The oldest patient I diagnosed was age 85, and she was thrilled when I said we used to call it juvenile onset diabetes.
Linda A. DiMeglio, MD: The other thing is that family members of individuals with type 1 diabetes have a higher risk. I do a diabetes camp every summer, and I always ask our counselors in training what they think the risk is that their kids will develop diabetes. They always say 50%, which is very interesting. Fortunately, it’s a lot lower than that. About 4% of siblings develop diabetes, about 7% of children of men with diabetes, and about 3% children of women. It’s interesting that the children of women with diabetes have a lower risk of developing type 1 diabetes. I don’t think we understand what that’s about.
Schafer Boeder, MD: One other factoid is that 85% of individuals diagnosed with type 1 diabetes don’t have a family member with the disease.
Linda A. DiMeglio, MD: Correct.
Schafer Boeder, MD: That’s the majority of individuals. There’s clearly a familial risk, but it’s not nearly as strong as in type 2 diabetes.
Steve Edelman, MD: That’s important when we talk about screening. My answer to those parents is that there’s over a 90% chance that your child will not get diabetes, so try to take the silver lining to this. In the old days, they were afraid their child was going to come down with type 1 diabetes. That’s a life-changing event, and we’ll talk about it at the end, but all the new hybrid closed-loop and other strategies make managing type 1 diabetes much easier.
Transcript edited for clarity