Higher Myonuclei Density in Muscle Fibers Persists Among Former Users of Anabolic Androgenic Steroids
Authors' conclusion
Muscle fibers in former AAS users demonstrated persistently higher myonuclei density and DNA to cytoplasm ratio 4 years after AAS cessation suggestive of enhanced retraining capacity.
Study context
- Population
- Men aged 18–50 years engaged in recreational strength training; m. vastus lateralis biopsies
- Participants
- 25 men
- Exposure
- Current and former AAS users vs controls
- Current AAS usersn = 8
- Former AAS usersn = 7
- Controlsn = 10reference
- Outcome
- Myonuclei domains (myonuclei density) in muscle fibers
Methodological detailscommunity-based
- Community-based
Main finding
As reported in the abstract
Type II fibers: myonuclei density and DNA to cytoplasm ratio
- Former AAS users vs Controls: P = 0.013
Observational data: associations, not effects.
Further findings
Median, weeks
| Outcome | Current AAS users | Former AAS users | P value |
|---|---|---|---|
| Accumulated duration of AAS useCurrent AAS users vs Former AAS users | 174 (IQR 101–206) | 140 (IQR 24–260) | P = 0.482 |
- Satellite cells per myofiber in type I fibers, current AAS users vs controls · higher with current AAS users
- P = 0.031
Accumulated AAS use (weeks, log2) and myonuclei domain size in previous AAS users
- Longer accumulated AAS use associated with smaller myonuclei domains in previous AAS users: beta-coefficient
- −94 (−169; −18), P = .024 (95% CI)
Original publication
Higher Myonuclei Density in Muscle Fibers Persists Among Former Users of Anabolic Androgenic Steroids. J Clin Endocrinol Metab. Published 19 July 2023. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →