The impact of weight loss on fat-free mass, muscle, bone and hematopoiesis health: Implications for emerging pharmacotherapies aiming at fat reduction and lean mass preservation.
Level 5 - mechanism / opinion, no new human data
Narrative review discussing mechanisms of lean mass loss and emerging pharmacotherapies without original empirical data or systematic methodology.
PubMed 39481534 · doi:10.1016/j.metabol.2024.156057
What was done
This narrative review examined the impact of profound weight loss from bariatric surgery and incretin receptor agonists on fat-free mass, skeletal muscle, bone, and hematopoiesis. The authors explored the regulatory role of the myostatin-activin-follistatin-inhibin system in body composition and evaluated the therapeutic rationale for combining incretin therapies with pipeline myostatin/activin inhibitors (such as Bimagrumab, Trevogrumab, and Garetosmab).
What was found
Incretin receptor agonists achieve 15% to 25% total weight reduction, but over 25% of the lost weight typically comes from fat-free mass, creating risks of sarcopenic obesity, bone loss, reduced metabolic rate, and anemia. In negative energy states, activin and myostatin drive muscle degradation, while follistatin opposes this effect. Inhibiting activin and myostatin signaling appears promising for sparing or increasing muscle and bone mass while maintaining fat loss, either as monotherapy or combined with incretin agonists.
Why it matters
As incretin-based anti-obesity therapies become widespread, mitigating muscle and bone loss is essential to preserve metabolic health and physical function, particularly in older or prefrail populations.
Limits
The abstract describes a narrative review without original clinical data, systematic search methods, or detailed statistical outcomes for the individual pipeline agents discussed. Long-term efficacy, functional outcomes, and safety of combination regimens remain unproven in large completed trials.
Cited by
- supports Roledumab and trevogrumab are monoclonal antibody myostatin inhibitors designed to maintain muscle mass in a caloric deficit.