The Study
Anti-myostatin antibody increases muscle mass and strength and improves insulin sensitivity in old mice
This study tested a special medicine on old mice and found that their muscles got bigger and stronger, and their bodies handled sugar a little better. But it didn't prove the medicine caused these changes for sure — it just showed they happened together.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Scientists gave old mice a special shot that blocks a protein that stops muscles from growing. After 4 weeks, the mice got stronger and their muscles used sugar better.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 518 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1For an older person, this could mean less frailty and better blood sugar control — but it's not clear if the same effect happens in humans.
- 2Muscle mass went up by 7%, grip strength by 20%, and muscle sugar use improved by 16%.
- 3Fat in muscles dropped by 30%.
- 4But energy use didn't go up.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Proceedings of the National Academy of Sciences
Year
2016
Authors
J. Camporez, Max C. Petersen, Abulizi Abudukadier, G. V. Moreira, M. Jurczak, Glenn C. Friedman, C. Haqq, K. Petersen, G. Shulman
Related Content
Claims (6)
Myostatin-inhibiting antibodies increase muscle mass in animals by blocking biological signals that normally restrict muscle growth.
In older male mice, a 4-week treatment with an anti-myostatin antibody lowered fat levels inside muscle tissue by about 30% but did not change fat levels in the liver.
In older male mice, a treatment that increases muscle size did not raise total energy use, even though similar genetic changes in other mice did raise energy use, showing that muscle growth alone does not always change how much energy the body burns.
In aged male mice, a 4-week injection of an anti-myostatin antibody increases lean body mass by 7% and grip strength by 20%.
In older male mice, a 4-week injection of an anti-myostatin antibody increases glucose uptake by muscles during insulin stimulation by 16%, without affecting the liver's glucose output, showing that greater muscle mass is linked to better insulin sensitivity in aging.
In young male mice on a high-fat diet, a 4-week anti-myostatin antibody treatment increased lean body mass by 7–9% and reduced fat mass by up to 35%, but did not improve insulin sensitivity.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.