Tirzepatide weight loss outcomes show women achieve 15.1% TBWL, outperforming men, with age not an independent factor

The global epidemic of obesity necessitates effective and personalized treatment strategies. While GLP-1R/GIPR dual agonists like tirzepatide have demonstrated profound weight loss efficacy in clinical trials, real-world outcomes can vary significantly among individuals. Understanding demographic factors, such as sex and age, that influence treatment response is crucial for optimizing patient selection and counseling. Current standard-of-care often applies a one-size-fits-all approach, overlooking potential biological differences that could impact drug effectiveness and patient expectations, thus leaving a gap in personalized obesity management.

Researchers conducted a retrospective cohort study involving 1039 adults with overweight or obesity who initiated tirzepatide at Mayo Clinic between June 2022 and May 2024. All participants completed ≥12 months of continuous therapy. The primary outcome measured was total body weight loss percentage (TBWL%) at 15 months, which was then stratified by sex and three age groups (≤45, 46-59, ≥60 years). Multivariable analyses were performed to identify independent predictors of weight loss, accounting for confounding factors.

Among the 1039 patients (mean age 56 ± 11 years; 57% women), women achieved significantly greater TBWL% than men after 15 months of continuous tirzepatide treatment (15.1% vs. 10.7%, p<0.001). Initial analysis showed patients aged ≤45 years experienced greater weight loss than those ≥60 years (15.1% vs. 12.3%, p=0.024). However, in comprehensive multivariable analyses, age was not identified as an independent predictor of weight loss. Instead, greater weight loss was independently associated with female sex, absence of type 2 diabetes, no prior use of obesity medications, no concomitant use of weight gain-promoting medications, and a higher tirzepatide dosage. This suggests that while age might appear to influence outcomes in simpler analyses, other factors are more determinative.

Female patients consistently achieved a 4.4% higher TBWL% than men over 15 months of tirzepatide therapy, highlighting a significant sex-based difference in real-world efficacy.