Semaglutide Linked to 56% Lower Risk of Adult-Onset Seizures in Type 2 Diabetes Patients
Key Insights
A large-scale observational study found semaglutide use was associated with a 56% lower risk of adult-onset seizures (search) compared to other glucose-lowering agents in type 2 diabetes (search) patients.
The seizure risk reduction could not be explained by improvements in blood glucose or body weight alone, suggesting direct brain-protective mechanisms.
Other GLP-1 receptor (search) agonists did not show a comparable seizure-preventive effect, pointing to semaglutide's unique pharmacological properties including partial brain penetration.
A new large-scale study published in Neurology, the journal of the American Academy of Neurology, has found that semaglutide—the active ingredient in widely prescribed diabetes and obesity medications Wegovy and Ozempic—is associated with a significantly lower risk of adult-onset seizures (search) in patients with type 2 diabetes (search). The findings suggest the drug may offer brain-protective benefits beyond its established metabolic effects.
The research was conducted by a joint team from Seoul National University Hospital, Columbia University, and the Harvard T.H. Chan School of Public Health, led by Professors Jang Yoon-hyuk and Lee Soon-tae of the Department of Neurology at Seoul National University Hospital, Professor Eun Yong of Columbia University, and PhD candidate Bong Su-hwan of Harvard.
Study Design and Patient Population
The researchers utilized electronic medical record data from the U.S. National Institutes of Health's "All of Us Program," a large-scale healthcare cohort. They identified 69,228 patients with type 2 diabetes (search) and ultimately analyzed 18,243 adult patients aged 18 or older who were newly prescribed semaglutide, other glucose-lowering agents, or SGLT2 inhibitors.
To ensure robust comparisons, the team employed a "target trial emulation" methodology designed to mimic randomized clinical trial conditions. Patients were assigned to two comparison groups: a semaglutide versus other glucose-lowering agent group (10,213 patients) and a semaglutide versus SGLT2 inhibitor group (8,605 patients). Drug effects were analyzed after finely adjusting for clinical differences including age, comorbidities, and body mass index.
Key Findings
The analysis revealed that patients newly initiated on semaglutide experienced approximately a 56% lower risk of adult-onset seizures (search) compared to those receiving other glucose-lowering agents. The 4-year cumulative risk difference—representing the actual difference in the proportion of patients who experienced seizures—was 1.78 percentage points.
When compared with SGLT2 inhibitors, the semaglutide group demonstrated about a 52% lower seizure risk, with a 4-year cumulative risk difference of 1.46 percentage points.
Translating these findings into clinical impact, the researchers calculated that substituting semaglutide for other glucose-lowering agents would prevent one additional seizure for every 70 patients treated. Substituting semaglutide for SGLT2 inhibitors would prevent one additional seizure for every 131 patients treated.
Mechanism Beyond Metabolic Control
Notably, the seizure risk reduction associated with semaglutide could not be explained solely by improvements in blood glucose or body weight. The contribution of blood glucose reduction, as measured by changes in HbA1c, accounted for only 2.4% to 6.5% of the seizure prevention effect. The contribution of weight loss, as measured by changes in body mass index, was 0.7% or less.
Furthermore, other GLP-1 receptor (search) agonists did not demonstrate a clear seizure-preventive effect comparable to that of semaglutide. The research team suggested that semaglutide's unique pharmacological properties—specifically its long residence time in the body and its partial ability to penetrate the brain—may underlie the observed preventive effect.
Clinical Significance of Adult-Onset Seizures (search)
Adult-onset seizure refers to a seizure occurring for the first time after the age of 18. In middle-aged and older adults, new-onset seizures can be associated with acquired brain injuries such as stroke, neurodegenerative diseases, and traumatic brain injury, making them an important indicator of brain health. When seizures occur, patients face increased fall risk, driving and social activity restrictions, and significant impacts on functional outcomes and quality of life.
Currently, no fundamental treatment strategy exists that prevents seizures themselves. Available therapies focus on preventing recurrence with antiseizure medications after a seizure has already occurred.
Cautions and Next Steps
Professor Jang Yoon-hyuk emphasized the importance of the findings while noting their limitations. "This study takes a fresh look at adult-onset seizures (search) from the perspective of brain health in midlife," he said. "However, because this is an observational study, long-term follow-up studies and randomized clinical trials will be needed to verify the actual preventive effect and its potential for clinical application."
The study was published in the June 14 issue of Neurology.