A recent study published in Nature on Apr. 9 found that genetic differences may help explain why some people lose more weight or experience more side effects when taking GLP-1 drugs for obesity. Researchers analyzed data from 27,885 participants to investigate how inherited variations in drug-target genes influence both the effectiveness of these medications and the risk of nausea and vomiting.
The findings are important as obesity remains a widespread public health issue linked to conditions such as type 2 diabetes and certain cancers. As government reports indicate, about 40% of adults in the United States are affected by obesity, highlighting the need for effective treatments.
The study identified a specific missense variant in the GLP1R gene associated with greater weight loss among users of GLP-1 receptor agonists. Each copy of this variant was linked to an additional average loss of 0.76 kilograms. The researchers also found that genetic variation in both GLP1R and GIPR genes was connected to increased risk of medication-induced nausea and vomiting, with the GIPR effect seen specifically among tirzepatide users.
Participants included mostly women (82.4%) with a median age of 52 years and diverse ancestry backgrounds: European (78.3%), Latino (12.9%), and African American (4.2%). Self-reported data were validated against electronic health records from a subset using Apple HealthKit, showing reasonable correlation between reported BMI changes.
Statistical analysis showed non-genetic factors such as age, sex, pre-treatment BMI, drug type, dosage, time on drug, and especially type 2 diabetes status accounted for over one-fifth of variability in weight loss outcomes; those with diabetes lost less weight on average than those without it.
According to the authors, "the present study findings strongly suggest that patient-specific variation in drug-target genes directly modulates therapeutic response." They added that while current genetic effect sizes are modest, future predictive models could help tailor treatments based on individual genetics as further validation occurs.
