Numerous studies have indicated a relationship between diabetes and epilepsy, with some noting a 1.5 to 2x higher risk of epilepsy prevalence for those with diabetes. While the basis for this relationship is unclear and unproven, the distinguishable conditions do have some commonalities. For example, both involve chronic inflammation, which can damage brain tissue and increase neuronal excitability, raising the risk of developing epilepsy. Insulin resistance is also known to impair brain function and can contribute to neural issues.
Now, a new study of people with diabetes suggests the use of glucose-lowering GLP-1 drugs may be linked to a lower risk of developing epilepsy. The study is preliminary and does not prove causation, but the study authors say the results are promising.
For the study, published in Neurology, researchers at Chung Shan Medical University (Taiwan) examined a U.S. health database for adults with type 2 diabetes who started taking either a GLP-1 drug or a dipeptidyl peptidase-4 inhibitor—known as DPP-4 inhibitors or gliptins. The GLP-1 drugs included in the study were dulaglutide, liraglutide and semaglutide.
The 452,766 participants had an average age of 61, and none had a previous diagnosis of epilepsy or seize. Half took the GLP-1 drugs, while the other half took the DPP-4 inhibitors.
The participants were followed for at least five years. During that time, 1,670 people taking the GLP-1 drugs developed epilepsy (2.35%) compared with 1,886 people taking the DPP-4 inhibitors (2.41%).
Once researchers adjusted for other factors that could affect the risk of epilepsy, such as age, high blood pressure and cardiovascular disease, they found that people taking the GLP-1 drugs were 16% less likely to develop epilepsy than those taking the DPP-4 inhibitors.
When researchers looked at the individual drugs, they found that association with a lower risk of epilepsy was strongest with the drug semaglutide, the active ingredient in the popular Ozempic and Wegovy.
“Additional randomized, controlled trials that follow people over time are needed to confirm these findings, but these results are promising, since people with diabetes are at increased risk for developing epilepsy later in life,” said study author Edy Kornelius, MD, of Chung Shan Medical University. “Epilepsy can have many physical, psychological and social consequences, and many people do not respond to the current medications, so finding ways to reduce this risk is critical.”
Tirzepatide, a dual GLP-1 and GIP (glucose-dependent insulinotropic polypeptide) receptor agonist, was not included in the study, as it was introduced after the study period had started. Tirzepatide is the active ingredient in the brand name drugs Mounjaro and Zepbound.