Aging and Muscle Protein Synthesis
Author Information
Author(s): Christopher S. Fry, Micah J. Drummond, Erin L. Glynn, Jared M. Dickinson, David M. Gundermann, Kyle L. Timmerman, Dillon K. Walker, Shaheen Dhanani, Elena Volpi, Blake B. Rasmussen
Primary Institution: University of Texas Medical Branch
Hypothesis
Older adults would have impaired mTORC1 signaling and muscle protein synthesis response compared with young adults after acute resistance exercise.
Conclusion
Aging impairs contraction-induced human skeletal muscle mTORC1 signaling and protein synthesis, which may contribute to reduced muscle growth in older adults.
Supporting Evidence
- Muscle protein synthesis increased only in younger adults after exercise.
- Older adults showed no significant changes in key signaling proteins after exercise.
- Phosphorylation of mTOR and S6K1 was significantly lower in older adults compared to younger adults.
Takeaway
As people get older, their muscles don't respond as well to exercise, making it harder for them to build muscle.
Methodology
The study measured intracellular signaling and muscle protein synthesis in 16 older and 16 younger subjects using muscle biopsies and various biochemical techniques.
Potential Biases
Potential selection bias as participants were not randomly selected from the general population.
Limitations
The study only included healthy, physically active individuals, which may limit the generalizability of the findings.
Participant Demographics
16 younger adults (mean age 27) and 16 older adults (mean age 70), balanced by gender.
Statistical Information
P-Value
p<0.05
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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