New light shed on who benefits most from weight-loss jabs
New light shed on who benefits most from weight-loss jabs
A recent study highlights that individuals with specific genetic variations tied to hunger and digestion may achieve greater weight reduction through medications like Wegovy and Mounjaro. The findings, detailed in a paper published in the Nature journal, could clarify why some patients experience more pronounced weight loss compared to others, and why certain side effects, such as nausea and vomiting, are more common in specific groups.
Genetic factors and drug mechanisms
These medications work by mimicking a natural gut hormone that suppresses appetite, helping users feel satiated. Researchers examined data from 15,000 individuals who had previously participated in gene-testing via 23andMe, analyzing millions of genetic markers to identify patterns. They discovered a connection between particular gene variations and the effectiveness of the drugs, suggesting a biological basis for differing outcomes.
“The study found a genetic variant associated with weight loss, which was also linked to nausea. ‘Those with this variant tend to lose more weight,’ she explains. The additional weight loss averages approximately 0.76kg (1.6 lbs), but individuals with two copies of the genes could see double that amount,” said Professor Ruth Loos of the University of Copenhagen.
The variant appears more frequently in people of European descent, with 64% carrying one copy and 16% having two. This contrasts with 7% of African Americans who possess a single copy. Professor Loos added, “If you carry the variant, you will lose more weight.”
Side effects and broader influences
The research also uncovered another genetic marker potentially responsible for severe side effects like vomiting when taking tirzepatide (Mounjaro). This could mean up to 1% of users experience vomiting 15 times worse than typical. While the genetic impact is modest, it’s comparable to other factors, such as age and sex, which also shape results.
Dr Marie Spreckley from the University of Cambridge noted that genetics is only one part of a broader, more intricate scenario. She emphasized that behavioral, clinical, and treatment-related elements—like exercise habits, dietary choices, and underlying health conditions—play a larger role in determining outcomes.
Future implications and challenges
Women, for instance, are more than twice as likely as men to lose 15% of their body weight on Mounjaro, according to prior studies. Other traits, such as being younger or of white or Asian ethnicity, are also associated with higher weight loss, though the reasons remain unclear. The type of medication, dosage, and duration of treatment further influence results.
Experts believe combining genetic and other data could eventually guide personalized treatment decisions, a concept known as precision medicine. However, Professor Naveed Sattar of the University of Glasgow cautioned, “Overall, these findings are scientifically interesting, but they are a long way from changing clinical practice.” He stressed the need for more comprehensive trial data to better understand the balance of benefits and risks associated with these therapies.
