The Study
The Circadian Clock Is Sustained in the Thyroid Gland of VIP Receptor 2 Deficient Mice
This study watches two groups of mice—one normal and one with a broken internal clock signal—and checks how their thyroid genes behave over 24 hours. It can show that the patterns are different between the groups, but it can't prove that the broken signal caused the difference because the mice were born that way.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Your body has a master clock in the brain, but this study shows your thyroid has its own clock that keeps ticking even when the brain's signals are broken.
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
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.
- 1This means the thyroid clock doesn't fully rely on the brain's clock, which could matter for hormone timing in people with circadian disorders.
- 2In mice without a key brain clock signal (VPAC2), the thyroid's clock genes still cycle every 24 hours.
- 3But the ups and downs are half as big and happen 5 hours earlier than normal.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Frontiers in Endocrinology
Year
2021
Authors
B. Georg, J. Fahrenkrug, H. L. Jørgensen, J. Hannibal
Related Content
Claims (6)
Your thyroid helps control your body's daily rhythms and hormone activity by listening to your brain and telling other hormone glands what to do.
Mice that are missing a certain brain signaling system have their daily body clock in the thyroid gland running about 5 hours earlier than normal mice — this suggests that the signaling system helps set the clock in that organ.
Even when the brain's main body clock loses its rhythm, the thyroid gland in mice can still keep its own daily rhythm going — suggesting it doesn’t completely depend on signals from the brain’s clock center.
Mice that are missing a certain brain signaling system have weaker daily rhythms in their thyroid gland, which suggests this system helps keep the body's internal clock running strongly in that organ.
In mice, a clock-related protein in certain hormone cells turns on at night, and this timing shifts when a specific receptor is missing — meaning the body might fine-tune its internal clock after genes are read.
In normal mice, the hormone TSH goes up and down during the day depending on light conditions — peaking at certain times in the dark and showing two peaks when there's a regular light-dark cycle — but another hormone, T4, stays pretty steady all day long.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.