Use of GLP-1 Receptor Agonists Scarce in Type 2 Diabetes

Access to a certain class of diabetes agents might not be equitable across all patients, a retrospective study suggested.

Among over 1 million Americans with type 2 diabetes, only 7.7% were treated with a glucagon-like peptide-1 (GLP-1) receptor agonist at some point from October 2015 to June 2019, reported Lauren Eberly, MD, MPH, of the Perelman School of Medicine at the University of Pennsylvania, and colleagues in JAMA Health Forum.

Use of GLP-1 receptor agonists was particularly low in 2015, at only 3.2%, which slowly increased to 10.7% by 2019.

Specifically looking at patients with both type 2 diabetes and comorbid atherosclerotic cardiovascular disease — i.e., those who would benefit most from this class of agents — rates of use remained even lower, at 2.8% in 2015 to 9.4% by 2019. Beyond that, patients with pre-existing coronary artery disease or cerebrovascular disease both had a significantly lower rate of GLP-1 receptor agonist use. Having more Elixhauser comorbidities was another factor predicting lower rates of use.

In addition, many ethnic and racial minority populations had a significantly lower rate of GLP-1 receptor agonist use compared with white patients, the group found:

• Asian patients: adjusted OR 0.59 (95% CI 0.56-0.62)
• Black patients: adjusted OR 0.81 (95% CI 0.79-0.83)
• Hispanic patients: adjusted OR 0.91 (95% CI 0.88-0.93)

In trying to parse out what demographic factors were associated with higher adoption of these agents, Eberly’s group found that women were 22% more likely to be prescribed a GLP-1 receptor agonist (adjusted OR 1.22, 95% CI 1.20-1.24). Not surprisingly, patients with an annual household income of $50,000-$99,999 and over $100,000 had a 7% and 13% higher rate of use, respectively, versus patients with an annual household income under $50,000.

Clinical visits with specialists were another factor tied to greater use of a GLP-1 agent. Having at least one visit with a cardiologist each year was tied to a 19% higher likelihood of use. However, the strongest factor predicting GLP-1 receptor agonist use was endocrinologist involvement. More specifically, patients who had either one visit or more than one visit with an endocrinologist over the course of a year had a more than two times and three times higher chance of being prescribed one of these agents, respectively.

Overall, patients who filled a prescription for a GLP-1 receptor agonist had a median 30-day copayment of $40.

“Despite that 100% of this population was commercially insured, this is the first study, to our knowledge, to demonstrate notable racial, ethnic, and socioeconomic inequities in GLP-1 receptor agonist use,” Eberly’s group wrote. A previous study also led by Eberly found nearly identical findings in regards to SGLT2 inhibitors, with the only difference being that women were more likely to be prescribed a GLP-1 agent.

“Patients of racial and ethnic minority groups consistently have inequitable access to guideline-based therapeutics that improve cardiovascular disease burden and outcomes, despite often experiencing a disproportionately higher rate of these conditions,” the authors noted, pointing out how these racial and ethnic disparities persisted even after adjustment for clinical actors, engagement with specialty care, and socioeconomic status.

“[T]hese results reveal biases in health care delivery that must be rectified,” they urged.

Data for the analysis were collected from the OptumInsight Clinformatics Data Mart database, which houses data on administrative private payer claims of recipients of both commercial health insurance and Medicare Advantage health plans. A total of 1,180,260 patients with type 2 diabetes were included in the analysis, about half of whom were women, with a median age of 69. Asian patients made up 4.4% of the cohort, 12.4% were Black, 15% were Hispanic, and 58% were white.

GLP-1 receptor agonist claims were collected for albiglutide (Tanzeum), dulaglutide (Trulicity), exenatide (Byetta), exenatide extended-release (Bydureon), liraglutide (Victoza), lixisenatide (Adlyxin), and semaglutide (Ozempic).

Eberly’s group noted that the study design didn’t allow for greater insights on underlying factors and clinical decision making that may have driven providers to prescribe certain therapies.

Some possible reasons driving this inequitable prescribing could be differences in healthcare providers’ preferences, knowledge of guidelines and benefits, and level of comfort with prescribing certain therapies, as well as differences in patients’ self-advocacy and awareness of different agents.