TOPLINE

Among adults with overweight or obesity on continuous therapy with tirzepatide, women achieved greater total body weight loss (TBWL) than men. Sex — along with type 2 diabetes status, prior obesity medication use, and concomitant weight gain-promoting medications — emerged as a predictor of weight-loss outcomes, whereas age was not an independent predictor.

METHODOLOGY

• Obesity rates have steadily increased, leading to increased morbidity and mortality, and while tirzepatide has shown approximately 20% TBWL in clinical trials at the highest dose of 15 mg, real-world data on how sex and age affect weight-loss outcomes are still limited.
• Researchers conducted a retrospective analysis of electronic health records from the Mayo Clinic Health System (June 2022-May 2024) to evaluate how sex and age affected weight-loss outcomes among 1039 adults (90% White) with overweight (BMI ≥ 27 with adiposity-related comorbidities) or obesity (BMI ≥ 30) who used tirzepatide continuously for at least 12 months.
• Patients received either diabetes-labeled or obesity-labeled formulations on the basis of their type 2 diabetes status and were stratified by sex (594 female and 445 male) and age (198 aged ≤ 45 years, 447 aged 46-59 years, and 394 aged ≥ 60 years), with a mean age of 56 years and an average BMI of 38.
• Clinic-measured weight, laboratory assessments, and comorbidities were obtained from electronic health records. Weight measurements were noted at baseline and every 3 months for up to 15 months.
• The primary endpoint was TBWL percentage (TBWL%) at 15 months after initiating tirzepatide; secondary endpoints were TBWL% at 3, 6, 9, and 12 months and the proportion of participants achieving weight-loss thresholds of ≥ 5%, ≥ 10%, ≥ 15%, and ≥ 20% at each timepoint.

TAKEAWAY

• Women achieved greater TBWL% than men, with significant differences observed at all timepoints from 6 to 15 months (P < .001). Women were approximately twice as likely as men to achieve ≥ 15% TBWL and 2.6-fold more likely to achieve ≥ 20% TBWL at 12 and 15 months.
• In the multivariable analysis, female sex was independently associated with greater weight loss (time × sex interaction; P < .001). Age and baseline BMI were not independently associated with TBWL%.
• Type 2 diabetes, prior use of obesity medications, and concomitant use of medications promoting weight gain were independently associated with less weight loss (P < .001 for all). Exposure to a higher maximum tirzepatide dose (≥ 10 mg weekly) was associated with greater weight loss (P = .012).
• Female sex was independently associated with higher odds of achieving ≥ 5% TBWL (adjusted odds ratio [aOR], 2.01; P = .024), ≥ 10% TBWL (aOR, 13.61; P < .001), and ≥ 15% TBWL (aOR, 5.94; P = .003).

IN PRACTICE

“[The study findings] highlight the importance of considering patient-specific factors when tailoring obesity treatment strategies,” the authors of the study wrote, before they continued with, “Tirzepatide demonstrated consistent and clinically meaningful efficacy across all age groups, underscoring its utility as a powerful pharmacologic option for weight management.”

SOURCE

The study was led by Regina Castaneda, Division of General Internal Medicine, Mayo Clinic, Jacksonville, Florida. It was published online in Obesity.

LIMITATIONS

The observational study design limited causal inference and may be affected by residual confounding. Most participants were White, meaning these findings might not apply to more diverse groups. Medication commencement and discontinuation dates may lack precision. Detailed information on diet and physical activity was lacking, limiting the assessment of lifestyle behavior contributions to weight-loss outcomes. The study included only patients who completed at least 12 months of tirzepatide treatment, potentially overestimating the treatment effect by excluding individuals who discontinued therapy early due to side effects or lack of efficacy.

DISCLOSURES

The study received support from the Mayo Clinic Women’s Health Research Center. One author reported holding research technologies licensed by Gila Therapeutics and Phenomix Sciences from the University of Florida and Mayo Clinic and along with another author reported providing consulting services and receiving research funding from various sources. A third author reported serving as a consultant, delivering continuing medical education lectures for many platforms and organizations, including Medscape Medical News, and serving on the scientific advisory board for Weight Watchers. Another author reported being an advisor for Bayer Pharmaceuticals.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.