The Study
Changes in serum T 3 T 4 and TSH before and after the T 3 -suppression test in patients treated for Graves' disease
This study watched how hormone levels changed in some patients after they took extra thyroid hormone. It saw patterns, like when one hormone went down, another did too—but it didn’t prove that one caused the other. It’s like noticing that ice cream sales go up when it’s hot—you can’t say ice cream causes heat.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
When you take extra thyroid hormone, your brain usually stops signaling the thyroid to work—but in some people with past Graves' disease, the thyroid ignores the signal.
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 537 / 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.
- 1Yes—this means your thyroid might still be overactive even if your blood tests show normal hormone signals, which could explain why some people relapse after treatment.
- 2After 8 days of 75 μg T3: TSH dropped from 16.5 to 0.6 μU/mL, but iodine uptake stayed at ~26.5%; T4 dropped only in those whose iodine uptake fell.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Folia Endocrinologica Japonica
Year
1977
Authors
Tamai Hajime, 一 玉井, 弘行 末松, Suematsu Hiroyuki, 正博 江崎, E. Masahiro, 順夫 黒川, Kurakawa Nobuo, 宏之 青木, Aoki Hiroyuki, 寛二 隈, Kuma Kanji, 文夫 松塚, Matsuzaka Fumio, M. Akira, 昭 宮内
Related Content
Claims (2)
In Graves' disease, blood tests show higher than normal levels of thyroid hormones T3 and T4, and very low or undetectable levels of thyroid-stimulating hormone (TSH).
In patients treated for Graves' disease, thyroid iodine uptake does not decrease as expected after T3 administration, indicating the presence of autonomous thyroid activity or non-TSH substances that stimulate the thyroid.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.