Mega Doctor News
By Johns Hopkins Bloomberg School of Public Health
Newswise — Popular prescription weight-loss drugs called GLP-1 receptor agonists are now frequently used by type 1 diabetes patients, despite limited data on the drugs’ safety and effectiveness in this patient population, according to a study led by researchers at the Johns Hopkins Bloomberg School of Public Health.
GLP-1 receptor agonists were developed more than two decades ago to treat type 2 diabetes. Some GLP-1 receptor agonists were subsequently approved for reducing cardiovascular disease risk and for treating obesity in the general patient population. Many type 1 diabetes patients began taking GLP-1 receptor agonists—despite the fact that the drugs are thought to put type 1 diabetes patients at risk for developing hypoglycemia, a potentially life-threatening low-blood sugar condition. Because of this risk, patients with type 1 diabetes have been excluded from GLP-1 receptor agonists clinical trials.
About two million Americans have type 1 diabetes, according to the Centers for Disease Control and Prevention. The autoimmune condition occurs in individuals whose bodies do not produce enough insulin and requires lifelong insulin therapy to regulate blood sugar levels.
For their study, the researchers analyzed more than 200,000 de-identified medical records of individuals with type 1 diabetes from 2008 to 2023 and found that the obesity rate among type 1 diabetes patients increased for all age groups and ethnicities during this period.
The analysis also found that the use of GLP-1 receptor agonists rose sharply as the obesity rate increased across groups. In the highest obesity category, the proportion of adult patients using these medications increased from about 4% in 2008–2011 to about 33% in 2020–2023.
The study was published online March 3 in Diabetes, Obesity and Metabolism.
“These findings highlight the urgent need for better data—including clinical trials—on the effectiveness and safety of GLP-1 receptor agonists in people with type 1 diabetes, to inform clear guidelines on their use in these patients,” says study senior author Jung-Im Shin, MD, PhD, an associate professor in the Bloomberg School’s Department of Epidemiology.
The study’s first author, Yunwen Xu, PhD, is a postdoctoral researcher in the same department.
Type 1 diabetes was not treatable until the development of insulin treatments in the 1920s. Historically, people with type 1 diabetes tended to be thin, because insulin deficiency led to the breakdown of fat and muscle for energy, causing weight loss. However, insulin treatments, combined with an environment that promotes weight gain, have contributed to an increased obesity burden in this population and created a demand for GLP-1 receptor agonists.
The new study covered 217,442 patients with type 1 diabetes from more than 30 health systems across the U.S. The data came from electronic health records in a large commercial database and covered the period from October 2008 to September 2023.
The researchers grouped the data by three-year periods, starting with October 2008 to September 2011 and ending with October 2020 to September 2023. In keeping with other recent studies, and with trends in the wider population, they found that the prevalence of obesity among type 1 diabetes patients rose significantly from the first period to the last: from 18% to 26% among youth ages 2–19 and from 30% to 38% among adults age 20 and older. This prominent upward trend was seen among whites, Blacks, Hispanics, and Asians; among men and women; and among patients covered by Medicaid, Medicare, and commercial health insurers.
The rate of GLP-1 receptor agonist use, as measured by prescriptions, rose even faster. This rapid rise occurred in every one of the five weight categories, from normal weight to severe obesity, and among youth and adults. Four percent of severely obese adults with type 1 diabetes had prescriptions for GLP-1 receptor agonists during the 2008–11 period, whereas that figure rose to 33% in 2020–23. Among severely obese youth with type 1 diabetes, fewer than 3% used GLP-1 receptor agonists in 2008–11, but 21%—a sevenfold increase—used them in 2020–23.
As part of the study, the researchers also quantified the use of different GLP-1 receptor agonists in each period.
“In the most recent periods, there were big increases in the use of semaglutide and tirzepatide—the most potent versions of these drugs for weight loss—which again underscores the need for clinical trial data on these patients,” Xu says.
The scientists currently are following up with a more targeted study in type 1 diabetes patients, quantifying the risk of serious hypoglycemia associated with the use of GLP-1 receptor agonists.
“Trends in Obesity and Glucagon-like Peptide-1 Receptor Agonist Prescriptions in Type 1 Diabetes in the United States” was co-authored by Yunwen Xu, Justin Echouffo Tcheugui, Josef Coresh, Morgan Grams, Elizabeth Selvin, Michael Fang, and Jung-Im Shin.
Funding for the research was provided by the National Institute of Diabetes and Digestive and Kidney Diseases (K01 DK138273, R01 DK115534).
