The Study
In vivo regulation of human skeletal muscle gene expression by thyroid hormone.
This study watched what happened to the genes in 9 men’s muscles after they took a hormone pill for two weeks. It found which genes got louder or quieter, but it didn’t compare them to people who didn’t take the pill — so we can’t be sure the pill caused the changes. It’s like noticing your phone battery drains faster after you turn on Bluetooth — maybe it’s the Bluetooth, or maybe you just used the phone more.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
When you take extra thyroid hormone, your muscles start burning more fuel and breaking down more protein to make energy.
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 552 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — this explains why hyperthyroid people lose weight and feel hot: their muscles are burning energy faster and breaking down muscle protein.
- 2After 14 days of taking 75 μg of thyroid hormone daily, free T3 levels rose 1.7x, metabolism increased by 13–15%, and 381 genes related to protein breakdown and energy production were turned up.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Genome research
Year
2002
Authors
K. Clément, N. Viguerie, M. Diehn, Ash A. Alizadeh, P. Barbe, C. Thalamas, John D. Storey, P. Brown, G. Barsh, D. Langin
Related Content
Claims (6)
When thyroid hormone levels are too high, the body burns energy faster, resulting in lower body weight, more frequent bowel movements, and a higher body temperature.
Administration of triiodothyronine increases the activity of 381 genes in human skeletal muscle, specifically enhancing genes involved in breaking down proteins and producing cellular energy.
Triiodothyronine increases the production of messenger RNA for proteins involved in the mitochondrial energy-producing complexes I, III, IV, and V in human skeletal muscle.
Triiodothyronine raises the levels of specific messenger RNA molecules in human skeletal muscle that are involved in mitochondrial proton leak and uncoupled respiration.
In healthy adult men, taking 75 micrograms of triiodothyronine daily for 14 days results in a 1.7-fold increase in free T3 hormone levels, a 13–15% increase in resting metabolic rate, and increased activity of 381 genes in skeletal muscle related to protein breakdown, energy production, and gene regulation.
Triiodothyronine raises the levels of messenger RNA for proteins involved in breaking down other proteins in human skeletal muscle, resulting in a greater ability to degrade proteins using energy.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.