New light shed on who benefits most from weight-loss jabs

By Philippa Roxby

1. People who carry variations in two genes linked to appetite and digestion can lose more
2. weight when taking drugs to treat obesity, research suggests. The findings, outlined in the Nature
3. journal, could explain why some people lose far more weight than others and why some have
4. particularly bad side-effects, such as nausea and vomiting, while taking them.
5. The popular medicines remove feelings of hunger by acting like a natural gut hormone that
6. makes users feel full. While genes may play a relatively modest role in influencing how well these
7. drugs work, experts say other factors such as your sex, age and even where you come from can
8. also have an impact.
9. It is thought at least 1.6 million people in the UK have tried weight-loss drugs in the past
10. year, and that number is expected to rise. Most are being bought privately through online
11. pharmacies.
12. The percentage of body weight lost when taking weight-loss medication can vary widely.
13. In this study, based on the experiences of 15,000 people taking weight-loss medications, they
14. lost an average of 11.7% of their body weight during roughly eight months of treatment. Some
15. lost 30% of their weight, while others lost little or nothing.
16. All of those 15,000 had previously signed up for gene-testing by the company 23andMe,
17. which used that data to chart the experiences of people taking weight-loss drugs. By analysing
18. millions of their genetic variants, the researchers found a pattern suggesting a link between
19. some variants and the effectiveness of the drugs.
20. Professor Ruth Loos, from the University of Copenhagen, who wrote about the research in
21. Nature journal, said: “The study found a genetic variant associated with weight loss, which was
22. also associated with nausea”.
23. “People lose more weight if they have this variant.” And that extra lost weight amounted to
24. about 0.76 kg (1.6 lbs) on average—but those people who carry two copies of the genes can
25. double the amount they lose.
26. The variant is high in people with European ancestry—64% carry one copy, while 16% of
27. people carry two copies, she says. That compares to 7% of African Americans who carry a copy
28. of the gene. “If you carry the variant, you will lose more weight,” says Prof Loos.
29. The study found another variant that could be responsible for people experiencing
30. side-effects such as nausea and vomiting when taking tirzepatide. And that could mean up to
31. 1% of people taking the drug will have really bad vomiting—nearly 15 times worse than normal.
32. Prof Loos said the genetic effect, while modest, “is similar to other factors—and not trivial”.
33. However, she said the findings need to be reproduced in other studies and, to date, that has not
34. happened.
35. For Dr Marie Spreckley, from the University of Cambridge, “genetics is only one part of a
36. much more complex picture”. In the long term, taking genetic and other information together
37. could help guide the choice of which weight-loss drug to use, based on the potential
38. benefits—something called “precision medicine”.
39. But we are not there yet, said Professor Naveed Sattar, metabolic health expert from the
40. University of Glasgow. “Overall, these findings are scientifically interesting, but they are a long
41. way from changing clinical practice,” he said. “What we really need now is more robust trial data
42. to better define the balance of benefits and harms with these and many other emerging newer
43. therapies”.

(Available at: https://www.bbc.com/news/articles/cn5317dkqnxo – text specially adapted for this test).