Effect of Semaglutide on Thigh Skeletal Muscle Volume, Fat Infiltration and Physical Function in People With Obesity: Secondary Analysis of STEP UP
Authors' conclusion
Semaglutide plus lifestyle intervention was associated with reductions in adipose tissue volume, skeletal muscle volume and skeletal muscle fat infiltration, with a preserved number of sit-to-stand repetitions.
Study context
- Population
- Adults with BMI ≥ 30 kg/m² in the STEP UP trial with a valid baseline MRI scan55 analysed
- Participants
- 1,407 adults
- Comparison
- Pooled semaglutide vs placebo
- Semaglutide 7.2 mgn = 43
- Semaglutide 2.4 mgn = 6
- Pooled semaglutiden = 49
- Placebon = 6reference
- Primary endpoint
- Absolute changes in MRI adipose/muscle compartment volumes
- Follow-up
- 72 weeks
Methodological detailsprespecified secondary analysis, phase 3b
- Prespecified secondary analysis
- Phase 3b
Primary result
As reported in the abstract
Absolute changes in adipose/muscle compartment volumes (MRI)
Each group vs placeboEstimate (95% CI)P value
Pooled semaglutide
estimated treatment difference, adipose body tissue −11.1 L(−16.5 to −5.7)
P < 0.0001Pooled semaglutide
estimated treatment difference, visceral adipose tissue −1.5 L(−2.9 to −0.1)
P = 0.04Pooled semaglutide
estimated treatment difference, lean body tissue −1.7 L(−4.0 to 0.7)
P = 0.16Pooled semaglutide
estimated treatment difference, thigh skeletal muscle volume −1.1 L(−2.3 to 0.1)
P = 0.07- Pooled semaglutide
- estimated treatment difference, thigh muscle fat infiltration −0.92 %-points (95% CI −1.41 to −0.42); P = 0.001
Further findings
Relative changes in adipose/muscle compartment volumes
- Similar results to absolute changes
Sensitivity analysis: semaglutide 7.2 mg vs placebo
- Similar results
Sit-to-stand repetitions in 30 s (pooled semaglutide and placebo) · baseline and Week 72
- Mean repetitions at baseline
- 13
- Mean repetitions at Week 72
- 15
Original publication
Effect of Semaglutide on Thigh Skeletal Muscle Volume, Fat Infiltration and Physical Function in People With Obesity: Secondary Analysis of STEP UP. Diabetes Obes Metab. Published 20 September 2026. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →