The side effects of GLP-1 weight loss medications can be quite varied, ranging from surprising bodily changes to, well, some pretty odd issues.
Recent findings suggest that these widely used drugs might be altering crucial medical imaging scans, which can hinder doctors from identifying serious health problems, potentially even life-threatening ones.
This interference could result in some patients facing delays in receiving diagnoses and treatments, while others might undergo unnecessary tests—not exactly ideal.
Developed initially to treat type 2 diabetes, GLP-1 medications have gained immense popularity thanks to their effectiveness for weight loss. In the US, their usage skyrocketed by an astonishing 700% from 2019 to 2023.
These medications work by imitating a natural hormone called GLP-1, which plays a role in managing blood sugar levels and curbing appetite. They also boost insulin production and slow digestion, helping users feel fuller and lose weight rapidly.
While the benefits of these biological alterations can enhance well-being, they seem to disrupt PET-CT scans, vital tools used by doctors to identify cancers and inflammatory conditions.
The science behind fear
A PET-CT scan is a combination of two advanced imaging methods that provides a comprehensive view of what’s happening inside the body.
PET scans utilize a radioactive substance known as FDG, which travels through the bloodstream and is absorbed by tissues. Abnormal cells, such as cancer cells or those associated with inflammation, have a higher metabolic rate and thus absorb more FDG.
This process allows PET scanners to detect the emitted radiation and create images that indicate where the FDG has concentrated.
Meanwhile, CT scans offer detailed visuals of organs, bones, and tissues. Together, PET-CT scans reveal both metabolic activity and physical structure, enabling doctors to make informed diagnoses and track treatment responses.
However, there have been reports of unusual FDG uptake patterns in patients using GLP-1, which can obscure cancer indicators or even make healthy tissue appear diseased.
According to Dr. Peter Stohal, medical director at Alliance Medical Ltd in the UK and the lead researcher on this topic, unusual patterns were first spotted in one patient, leading them to widen their investigation across their network.
He noted the absence of any national or international guidelines to address this increasingly common issue.
Confusing scans, costly results
Currently, about 1 in 8 adults in the US have reported using GLP-1 drugs like Ozempic, Wegovy, and Moonjaro. Given the increasing demand, it’s likely that a growing number of PET-CT scans will show these atypical patterns.
With cancer rates escalating, particularly among younger adults, early detection is crucial for effective treatment.
Medical professionals caution that misinterpreting these FDG uptake patterns could lead to unnecessary procedures, incorrect cancer staging, and harmful delays in care.
Dr. Stohal emphasized that understanding the uptake characteristics linked to GLP-1 medications can alleviate unnecessary anxiety and ensure patients receive appropriate care without confusion.
For the time being, neither Dr. Stohal nor his team suggests that patients discontinue GLP-1 medications prior to undergoing PET-CT scans.
They recommend that a patient’s medication history be meticulously recorded to facilitate better scanning interpretations while new guidelines are being formulated.
This research was presented recently at the 38th European Society of Nuclear Medicine Congress.
Looking ahead, the research team intends to collect more data from additional imaging centers to build a stronger foundation for upcoming national guidelines and hopes to collaborate internationally for consistent PET-CT interpretation worldwide.
