Obesity is a significant driver of cardiometabolic dysfunction, increasing the risk of various health complications. This clinical study aimed to evaluate the real-world effectiveness (RWE) of tirzepatide, a novel peptide therapy, on body weight, body composition, and metabolic parameters in adults with obesity or overweight, particularly those with at least one obesity-associated comorbidity.
The study involved a 24-week retrospective observational analysis of 122 adults (80% women; mean age 44 ± 15 years) who were overweight or obese but did not have diabetes. Participants received tirzepatide alongside a standardized low-carbohydrate diet and tailored physical activity. The treatment began with a dose of 2.5 mg once weekly, which was increased to 5 mg after 4 weeks, with further adjustments made based on individual needs.
Anthropometric measurements, bioelectrical impedance analysis, and metabolic parameters were assessed at baseline and after 24 weeks. The results indicated a significant reduction in body weight, with the mean weight dropping from 95 ± 20 kg to 80 ± 22 kg. Other notable changes included:
- Body Mass Index (BMI) decreased from 35 ± 6 to 29 ± 7 kg/m²
- Waist circumference reduced from 109 ± 16 to 92 ± 12 cm
- Waist-to-height ratio decreased from 0.66 ± 0.1 to 0.56 ± 0.1
Fat mass (FM) was significantly reduced by 35%, while fat-free mass slightly decreased by 5%. Importantly, skeletal muscle mass was preserved, indicating a favorable body composition change. Additionally, metabolic parameters showed improvement, including:
- HbA1c levels decreased from 5.5 ± 0.4% to 5.2 ± 0.1%
- Fasting plasma glucose levels dropped from 93 ± 12 to 84 ± 9 mg/dL
- Fasting insulin levels reduced from 17 ± 15 to 12 ± 9 μIU/mL
- HOMA-IR improved from 4.2 ± 4.7 to 2.5 ± 2.1
Correlation analysis revealed that the reduction in fat mass was significantly associated with reductions in both insulin and HOMA-IR, suggesting a link between weight loss and improved insulin sensitivity.
Interestingly, the weight loss observed in this real-world cohort after 24 weeks of tirzepatide therapy (-16%) was comparable to the results from the SURMOUNT-1 trial, which reported similar weight loss after 72 weeks.
In conclusion, this RWE study indicates that 24 weeks of tirzepatide treatment led to significant improvements in body weight, BMI, and fat mass, while preserving lean skeletal muscle mass and enhancing glycemic control and insulin sensitivity. These findings suggest that a comprehensive clinical approach to obesity in real-world settings may yield more beneficial outcomes than those observed in clinical trials.
What this study does not show
This study does not establish long-term effects or safety of tirzepatide beyond the 24-week observation period.
Evidence scorecard
- Analytic validity: Established
- Clinical validity: Partial
- Clinical utility: Not established
This evidence is based on a primary research study involving human participants.