The Study
Disruption of Hepatic Mitochondrial Pyruvate and Amino Acid Metabolism Impairs Gluconeogenesis and Endurance Exercise Capacity in Mice
This study shows what happens in specially engineered mice when two liver genes are turned off. It helps scientists understand how the liver makes sugar during exercise, but it doesn’t prove this is how it works in people or healthy animals.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
When mice exercise, their muscles need lots of sugar. Their liver makes new sugar using building blocks from muscles, like pyruvate and alanine. These go into the liver’s power plants (mitochondria) through special doors. If both doors are broken, the liver can’t make enough sugar, and the mice get tired faster.
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 510 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This shows that both pathways are needed when demand is high, but humans might compensate differently; still, it highlights how important liver metabolism is during long exercise.
- 2Mice missing both MPC2 and ALT2 genes lasted shorter on the treadmill and had 57% less sugar in their blood after exercise.
- 3Mice missing only one gene were normal.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
bioRxiv
Year
2023
Authors
Michael R. Martino, M. Habibi, D. Ferguson, Rita T. Brookheart, J. Thyfault, G. Meyer, L. Lantier, Curtis C. Hughey, B. Finck
Related Content
Claims (5)
Mice that had two specific liver genes turned off couldn't keep their blood sugar stable after exercise, and their sugar levels dropped a lot compared to normal mice.
When two specific genes are turned off in the livers of mice, their bodies make less blood sugar—both when resting and exercising—because the liver can't use certain fuel sources as well. This shows those genes are important for keeping blood sugar levels up when the body needs more energy.
When mice are genetically changed so their liver can't take in two key energy-related molecules at the same time, they get tired faster during exercise — but only when both are blocked, not just one.
In mice, when two specific liver genes are turned off, their liver cells don't process energy as well—even during exercise—because they can't get enough fuel, not because they're missing the tools to do the job.
In mice, turning off one of two specific liver genes doesn’t hurt their stamina or blood sugar control after exercise, because their bodies can use backup systems to keep making glucose.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.