The age at which adults who are overweight or obese should be screened for type 2 diabetes is going down while the prevalence of both forms of the disease is going up among children and adolescents — two developments reported Tuesday that signal a growing burden of these chronic health conditions among Americans.
The U.S. Preventive Services Task Force lowered its recommended age to 35 — down from 40 in its 2015 guidance — to test people with above-normal BMIs for elevated glucose levels that could mean prediabetes or diabetes itself. The new evidence review and recommendations, published in the Journal of the American Medical Association, would make more than 40% of adults eligible for screening, and an estimated one-third will likely meet USPSTF criteria to undertake preventive steps.
Higher body-mass index (BMI) has been strongly linked to type 2 diabetes, the more common form of the disease in which people can’t make enough insulin to convert the glucose their bodies need for fuel, or they grow insensitive to the insulin they do make. In the 1.6 million people in the U.S. with type 1, the autoimmune disease destroys their insulin-producing pancreatic islet cells, meaning they can’t make insulin to process glucose into energy and the sugar accumulates in the blood.
As rates of overweight and obesity increase overall and at younger ages, it makes sense that type 2 diabetes would too, said Chien-Wen Tseng, a family physician at the University of Hawaii and a USPSTF task force member. About 13% of U.S. adults have diabetes and 35% meet the criteria for prediabetes, putting them at greater risk for later heart attacks, strokes, kidney failure, and blindness.
“We’re recommending screening in people who don’t have symptoms. It’s such a serious health problem and easily detectable early. There’s potentially a lifetime health benefit to start screening at 35 to detect it early and even to do something about it,” Tseng said. “People in their 30s generally think of themselves as really young and really healthy. People need to be aware that now is the time, starting at age 35, to just get a simple screening test for diabetes.”
Also on Tuesday, researchers from the National Institute of Diabetes and Digestive and Kidney Diseases reported rising prevalence in children up to age 19 of both type 1 and type 2 diabetes. The study analyzed health records of nearly 3.5 million children age 19 and under in six parts of the country from 2001 to 2017. The prevalence for type 1 grew by 45% over the 16 years. For type 2, the prevalence among children 10 to 19 years old went up by 95% over the 16 years. (The sample size for children 9 and younger was too small.)
“As someone who has been studying youth with type 1 and type 2 diabetes for over 20 years, the findings did not surprise me,” Jean Lawrence, program director in the Division of Diabetes, Endocrinology and Metabolic Diseases at NIDDK and a study co-author, told STAT. “However, these findings should serve as a stark reminder of the importance of diabetes prevention and, when that is not possible, the importance of early intervention strategies to mitigate the impact of having diabetes early in the course of diabetes.”
The study in children, published in JAMA, confirms what Justin Gregory, a pediatric endocrinologist at Vanderbilt University, sees in his clinic. He was not involved in the study but underscored its message on prevention.
As an example, he recalled that 20 years ago his clinic in Nashville was staffed by three pediatric endocrinologists and two nurse practitioners. Now there are 14 endocrinologists and four nurse practitioners. “As the rates of obesity among pediatric patients increase, we certainly see an increasing incidence of type 2,” he said. “The real challenge for those of us that practice pediatric endocrinology in the United States is, how are we going to take care of an increasing number of patients who have type 1 and type 2 diabetes?”
It’s both a workforce issue and a therapeutic question. The options for treating children with obesity are not as varied as they are for adults, Gregory said. Adult obesity drugs may not be approved for children and there’s a reluctance to offer bariatric surgery before a patient is ready to weigh the benefits and risks for themself. “We feel kind of helpless in that we don’t have a lot of good medications and we don’t have a lot of surgical options.”
That leaves changes in diet and physical activity, which can pose different challenges depending on the child’s — and the family’s — circumstances. NIDDK’s Lawrence and Gregory emphasize the need to treat the whole family while recognizing there may be barriers to finding healthy food or opportunities to exercise.
“These families are trying to do the best they can with the resources they have,” Gregory said. “If it’s hard for the family to get more fruits and vegetables in their diet, they’re going to tune you out pretty quickly. And so we try very hard to try to make sure we’re taking care of our patients specifically and meeting them where they’re at.”
Lawrence takes it back further, pointing out that diabetes in youth is associated with exposure to maternal diabetes and obesity during pregnancy, family history of diabetes, and genetics. “Healthy lifestyle and achieving and maintaining a healthy weight is important for everyone in the household,” she said.
The prevalence of type 2 diabetes grew faster among Black and Hispanic youth while the prevalence of type 1 increased more among Black and white young people over the study period. Disparities persist in adulthood, Tseng said, with rates higher in Native American, Black, Latino, and Asian people compared to white individuals.
“We understand that certain communities are at higher risk. So we also understand some of this is economic,” she said. “The biggest risk factor is overweight and obesity. And that means the ability to address this has to do with having access to healthy diet and exercise and having a lifestyle that lets you pursue those things. The task force is very much aware of the fact that there are socioeconomic drivers of some of the health disparities that we’ve seen.”
Edward Gregg of Imperial College London and Tannaz Moin of UCLA said more evidence is needed to support the latest USPSTF recommendations on screening.
“The potential effects of screening, detection, and intervention for diabetes and pre-diabetes simultaneously, as now recommended, has not been tested in randomized trials,” they wrote in an editorial published with the USPSTF recommendations and the article on youth prevalence. “Thus, the rationale to screen depends on the benefits of the interventions that follow diagnosis, including the long-term attention to risk factor management and the opportunity to prevent diabetes in the large population at risk.”
While the linkage between overweight and obesity to type 2 diabetes is tight in adults and children, there is no such smoking gun for type 1. Gregory, who was diagnosed with type 1 when he was 19, has been researching this for 20 years, looking for triggers that tip a person into autoimmune disease. And the increase in type 1 prevalence is baffling. “It’s happening so fast, you can’t attribute that to genetic factors alone. So the question is, what environmental factor is the one causing it?”
That leaves prevention for type 2 and more research for type 1, while advances in closed-loop systems, sometimes called artificial pancreases, to monitor glucose levels and deliver insulin have made daily life better than 20 years ago for people with type 1.
For type 2, the study findings in children and adolescents mean more of them will have diabetes as they age into adulthood. “They will need to incorporate diabetes management into their daily lives and will be at risk for experiencing diabetes-related complications,” NIDDK’s Lawrence said. “The key to stem the rising trends in diabetes prevalence is diabetes prevention.”
In the same spirit as the USPSTF lowering the screening age for adults, Gregory said prevention efforts should start early in children, too, at the primary care level.
“You want to be bringing up healthy nutrition, healthy exercise, healthy lifestyle really from the time kids start elementary school. That’s when you need to get the message here that, hey, we need to be thinking ahead,” he said. “Once you get into the puberty years, the horse is already out of the barn.”