Teens and Type 2
Research is finding that type 2 diabetes hits kids harder than it does adults
As recently as the early 1990s, type 2 diabetes was considered an adult disease—so much so that it was referred to as “adult-onset diabetes” to set it apart from type 1.
Today the situation is different. In the United States, over 5,300 people under the age of 20 were diagnosed with type 2 in 2011–2012, an increase of 70 percent since 2002–2003.
To understand the emerging epidemic, the National Institutes of Health has funded a series of large-scale studies over the past 20 years. The results have given researchers a better idea of what causes type 2 diabetes in kids and how it differs from the disease in grown-ups.
The Fast and the Furious
The emerging picture is unsettling. “What we know is it’s a very aggressive disease in youth, more aggressive than in adults,” says Rose Gubitosi-Klug, MD, PhD, a pediatric endocrinologist at Case Western Reserve University School of Medicine who helped lead the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) trial, a study that looked at nearly 700 kids with type 2 ages 10 to 17. (They tested for islet cell autoantibodies to rule out children with type 1 diabetes.)
When researchers followed the TODAY participants as they aged, their health got worse. By the time they were in their 20s, many of those diagnosed as teens had developed diabetes-related complications usually seen in people 40 or 50 years older, including heart disease, tiny broken blood vessels in the retina of the eye called microaneurysms, and even more-advanced eye disease. When women in the TODAY study got pregnant, they had much higher rates of complications compared with women who developed type 2 diabetes later in life.
The TODAY study also revealed that metformin and other treatments developed for adults with type 2 diabetes don’t work nearly as well in teens, leaving researchers scrambling to find solutions to a growing problem. “So far, all of our strategies to try to preserve beta cell function in adolescents have failed,” says Tamara Hannon, MD, MS, a pediatric endocrinologist at Indiana University School of Medicine.
TODAY started out as an effort to learn whether metformin, a drug called rosiglitazone (Avandia), and lifestyle interventions could help kids with type 2 diabetes. When they looked at the data, researchers were dismayed to see study participants as young as 13 or 14 with little to no insulin production.
That was a surprise. In adults, the body’s insulin factories—called beta cells—“can typically hang in for a decade or more,” Gubitosi-Klug says. Helped along by medications such as metformin and lifestyle adjustments such as improved diet and more exercise, beta cells can usually supply the body’s insulin needs without requiring insulin injections.
In kids, the disease was moving much faster, and about three-quarters of study participants didn’t respond to metformin or rosiglitazone. “Within a year of starting therapy, half the youth in the study had to go on insulin,” Gubitosi-Klug says. “There was a very rapid decline of beta cell function.”
There’s hope on the horizon, though. Major clinical trials like the TODAY study have shed light on what’s going on in teens with type 2, an important first step in developing new strategies to cope with it. And as awareness grows, doctors are identifying and treating type 2 earlier, which may help preserve beta cell function in the long run.
Flood of Hormones
One of the big lessons researchers have learned is that time of diagnosis is everything. Puberty, a critical developmental stage when hormones signal the body to grow and develop, seems to play a major role in pushing kids who are already obese toward type 2 diabetes. It’s very rare to see type 2 diagnoses in kids under age 10, even among those who are obese or overweight, says Amy Shah, MD, MS, an endocrinologist at the Cincinnati Children’s Hospital Medical Center. As children enter their teen years, however, diabetes rates increase.
It’s no surprise that the flood of hormones that accompany the teen years is responsible for changes in how the body functions. Puberty is a time when insulin production in particular ramps up dramatically. That’s because insulin is a key growth hormone, alongside its role signaling the body to absorb glucose from the blood. “All children need insulin in order to grow normally,” Hannon says. “Even kids with type 1 need about twice as much insulin when they’re in puberty.”
As the body strains to produce more insulin, it also becomes more insulin resistant. During puberty, kids who don’t have diabetes make about twice as much insulin and are twice as insulin resistant as their adult counterparts.
For young people who are obese and at higher risk of developing type 2 diabetes, the flood of insulin produced during puberty—and the body’s toned-down response to it—seems to push the pancreas and beta cells too hard, too fast. “They’re developing this disease at a time when the demands on the body are already very high,” Hannon says.
Data on type 2 diabetes in youth contains some mysteries researchers haven’t figured out yet. “We know type 2 in young people isn’t an equal-opportunity disease,” Hannon says. “Not every kid who’s obese gets type 2.” Research shows that family history of type 2 diabetes and a mother who had diabetes during pregnancy are clear risk factors—information that can help doctors identify and treat kids with type 2 early.
Ethnicity also seems to play a role. In the TODAY study, American Indian youth had the highest risk of developing type 2 diabetes as children, followed by African American kids and Latinos.
Genetics almost certainly plays a role, but there may be other risk factors. “Children in these groups tend to be poorer, have more social disadvantage, and have a lot more stressors,” says Hannon. “Is it just a coincidence that racial minorities have [higher rates of type 2 in childhood], or is it a combination of genetics and what’s going on in their lives?”
The Matter of Medication
The TODAY study and its follow-up, TODAY2, have revealed how aggressive type 2 diabetes in kids can be. They’ve also prompted research into treatment options besides metformin.
Last year, for example, the Food and Drug Administration gave liraglutide, a drug that encourages the pancreas to release more insulin, the green light for treating young people with type 2. “Many of the type 2 drugs approved in adults are being tested and approved in pediatric populations,” says Shah. “That will provide more options for treating pediatric patients.”
In one of the most promising developments, research efforts are zeroing in on kids in the TODAY study whose response to metformin and other diabetes drugs was good. That group included about a quarter of the participants in the TODAY study. Many of these teens, dubbed “durable responders,” managed to maintain beta cell function through puberty with the help of medications and lifestyle changes.
Once the hormonal surges of puberty passed, this group’s beta cell function went back to what researchers would expect for an average adult with type 2 diabetes. “They reached adulthood and went off medication and had normal blood glucose control [for an adult with type 2] and lower rates of complications,” Gubitosi-Klug says. “They went on to have a great response.”
Understanding what’s different about the kids in the durable-responder group could help researchers develop treatments to create similar responses in others. Already, they’ve found that durable responders are easy to spot: In a study published in 2013 in the journal Diabetes Care, researchers working with data from the TODAY study showed that children who responded well to metformin within a few weeks of starting treatment were more likely to have a beneficial long-term response to metformin than those who didn’t respond to the drug in the first few weeks.
The years to come should bring more research into treatments for the problem. “We’re continuing to try to understand the triggers of type 2 to come up with solutions and ways to prevent complications,” Shah says.
The research may also help get the attention of family practitioners and endocrinologists. Raising awareness among physicians who might have misdiagnosed or dismissed early signs of type 2 diabetes in young patients in the past could make a big difference.
“Sometimes this is picked up by a family practitioner or pediatrician, and they just encourage the kid to lose weight,” Gubitosi-Klug says. “We need to make sure people are aware this is an aggressive disease, and it’s treated as such from the start.”
Treating Teens With Diabetes
One of the greatest risk factors for type 2 diabetes in youth is a family history of the disease. If your child is at risk, or has already been diagnosed, here is some expert advice.
When should I get my kids screened for type 2 diabetes?
The American Diabetes Association’s 2020 Standards of Medical Care in Diabetes recommends screening high-risk kids at age 10 or once puberty begins, whichever happens first. Children are considered at risk if they have three or more risk factors, which include:
- Body mass index (BMI, a ratio of weight to height) at or above the 85th percentile
- A family history of type 2 diabetes in a first- or second-degree relative
- A mother who had gestational diabetes when pregnant
- Race/ethnicity (American Indian, African American, Latino, Asian American, or Pacific Islander)
- Physical signs of insulin resistance, such as acanthosis nigricans, a darkening of the skin on the back of the neck and other skin-fold areas
Should children with type 2 diabetes see an endocrinologist, or can they get the treatment they need from a pediatrician?
Take them to an endocrinologist if possible, says Indiana University pediatric endocrinologist Tamara Hannon, MD, MS. “These children need comprehensive diabetes care just like kids with type 1 diabetes. Pediatric endocrinologists have training and the resources to provide the clinical care these kids need.”
What is the best treatment if my child doesn’t respond to metformin?
Though metformin is typically the first treatment doctors prescribe for type 2 diabetes, there are two options for children 10 and older who don’t respond to metformin: injecting insulin or liraglutide (Victoza).
Do children with type 2 diabetes need treatment indefinitely, or just until they’ve gone through puberty?
“Most kids with type 2 aren’t able to manage diabetes without medication,” Hannon says. “There is no way to know how long medication will be needed.” If a child is able to get off medication, there’s a high likelihood he or she will need treatment again in the near future, so follow-up by a pediatric endocrinologist is necessary.
Empower Your Kids
The American Diabetes Association is working to slow the trajectory of childhood obesity and type 2 diabetes. Its Project Power program encourages elementary and middle school–aged children in underserved communities to eat healthy and stay active, while helping the whole family adopt good-for-you habits. Learn more here.