Obesity and Use of GLP-1 Drugs are Increasing in People with Type 1 Diabetes

The use of GLP-1 receptor agonists rose in patients who have type 1 diabetes as obesity rates increased for these patients, according to a new study published online in Diabetes, Obesity and Metabolism.

In the highest obesity category assessed by researchers, the proportion of adult patients using these medications increased from about 4% in the 2008 to 2011 period to about 33% in the 2020 to 2023 timeframe.

Jung-Im Shin, M.D., Ph.D.

“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,” study senior author Jung-Im Shin, M.D., Ph.D., an associate professor in the Bloomberg School’s Department of Epidemiology, said in a news release.

About 2 million Americans have type 1 diabetes, according to the CDC. Historically, people with type 1 diabetes tended to be thin, researchers said, because insulin deficiency led to the breakdown of fat and muscle for energy, causing weight loss.

But obesity rates among those with type 1 diabetes have grown over the last 20 years, which can come with the risk of complications from heart attacks and strokes, as well as leading the body to be less sensitive to insulin.

At the same time, the demand and use of GLP-1 receptor agonists such as Wegovy and Zepound for weight loss have grown.

For patients with type 1 diabetes, taking GLP-1 receptor agonists puts them at risk for developing hypoglycemia, a potentially life-threatening low-blood sugar condition, and diabetic ketoacidosis (DKA), a serious complication resulting from a lack of insulin in the body. Without enough insulin, cells are not able to use sugar for energy. The liver will begin to break down fat for fuel, which leads to a build-up of acids called ketones in the blood.

Researchers in the Diabetes, Obesity and Metabolism study wanted to assess trends in obesity and GLP-1 drugs across adults and children with type 1 diabetes.

In this study, researchers analyzed more than 200,000 de-identified medical records of people with type 1 diabetes from 2008 to 2023 from 30 different health systems. They used longitudinal de-identified data from the Optum Labs Data Warehouse. Included in the analysis were data from 217,422 patients with type 1 diabetes. The researchers grouped the data by three-year periods, starting with October 2008 to September 2011 and ending with October 2020 to September 2023.

The researchers found that the prevalence of obesity among type 1 diabetes patients rose. From the time periods 2008 to 2011 to the time of 2020 to 2023, the prevalence of obesity among youth (defined in this study as ages 2-19) with type 1 diabetes increased from 18.1% to 26.0%. Among adults (defined as 20 years of age or older) with type 1 diabetes, the prevalence of obesity rose from 30.5% in the 2008 to 2011 period to 38.1% in the 2020 to 2023 period.

Researchers said their findings are consistent with previous research showing the rise in obesity of those with type 1 diabetes, including the finding that obesity was highest in Black and Hispanic youth and adults. This new study found that racial and ethnic disparities persisted over time, and youth with Medicaid had a higher prevalence of obesity compared with those with commercial insurance.

Over the 15-year period, prescriptions for GLP-1 drugs significantly increased across all BMI categories among both youth and adults with type 1 diabetes. In the time period of 2020 to 2023, approximately 1 in 5 youth and 1 in 3 adults with type 1 diabetes and severe obesity received GLP-1 drugs.

“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,” said frst author Yunwen Xu, PhD, a postdoctoral researcher in Bloomberg School’s Department of Epidemiology.

The scientists are doing a follow-up study to quantify the risk of serious hypoglycemia associated with the use of GLP-1 receptor agonists among those with type 1 diabetes.