Genes predict GLP‑1 response
A large 23andMe-linked analysis found common variants in GLP1R and GIPR that predict modest differences in weight loss and side effects on GLP‑1 drugs. (The study analyzed 27,885 people and reported an average additional loss of about 0.76 kg per allele, with genetics plus basic demographics explaining roughly 25% of outcome variance.) ( ) Critics noted the effects are small while some researchers called it a pharmacogenomics proof‑of‑concept. ( )
Weight-loss drugs that mimic gut hormones do not work the same way for everyone, and a new study says part of that gap is written in DNA. Researchers linked common variants in two drug-target genes to modest differences in weight loss and side effects on glucagon-like peptide 1 drugs. (nature.com) The study, published April 8 in *Nature*, analyzed 27,885 people who reported using semaglutide or tirzepatide through the 23andMe research platform. The team ran a genome-wide association study, which scans the genome for common variants tied to a trait, and found signals in the glucagon-like peptide 1 receptor gene, or GLP1R, and the glucose-dependent insulinotropic polypeptide receptor gene, or GIPR. (nature.com; 23andme.com) One GLP1R variant was associated with about 0.76 kilograms of additional weight loss per copy of the effect allele. The same analysis also linked variation in GLP1R and GIPR to nausea or vomiting, with the GIPR signal showing up in tirzepatide users and not in semaglutide users. (nature.com; news-medical.net) These drugs target hormone receptors that act like metabolic switches after eating. Semaglutide acts on the glucagon-like peptide 1 pathway, while tirzepatide hits both glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide pathways, which helps explain why the study looked separately at GLP1R and GIPR. (23andme.com; pmc.ncbi.nlm.nih.gov) The paper arrives as doctors and patients are trying to sort out why some people lose less than 5% of body weight on these medicines while others lose more than 20%. The authors said their combined model of genetics plus demographic and clinical factors explained roughly one-quarter of the variation in weight-loss response. (23andme.com; nature.com) That does not mean a gene test can tell a patient exactly what will happen on a prescription. Trade coverage of the paper and outside commentary both stressed that the genetic effects were statistically clear but small in absolute terms. (pharmexec.com; medicalxpress.com) Researchers framed the result instead as a pharmacogenomics signal, meaning evidence that inherited variation can shape drug response. Nature’s news coverage said the findings offer clues to why responses vary and who might face adverse effects, rather than a ready-made clinical test. (nature.com; nature.com) 23andMe said it has already folded the findings into a new report and interactive tool for members of its Total Health service. The science paper is broader than that product launch, but it points toward a future in which obesity drugs may be matched a little more precisely to the patient taking them. (23andme.com; nature.com)
