Diurnal Thyrotropin Secretion in Short-Term Profound Primary Hypothyroidism: Does It Ever Persist?
Bibliographic record
Abstract
Circulating serum thyrotropin (TSH) levels in euthyroid humans show a definite circadian variation, which is maintained in both mild hyperthyroidism and mild hypothyroidism. Yet conflicting data exist with regard to whether this variation persists in at least some patients with severe primary hypothyroidism. We, therefore, studied the diurnal variation in serum TSH in 10 patients (age range 20 to 84 years) with a history of thyroid failure due to prior total thyroidectomy and radioiodine (RAI) ablative treatment performed for thyroid cancer after short-term discontinuation of thyroid hormone (TH) therapy. Serum TSH was measured hourly for a 24-hour period. All data were normalized by converting the TSH values to a percentage (%), designating the 11:00 hour value as 100% (baseline). The average serum TSH levels were markedly elevated in all patients. There was no statistically significant difference between the TSH % values at any time during the 24-hour period when compared with baseline. Further, cosine regression analysis showed absence of rhythmicity in TSH % values over time; notably, no patient showed a variation in TSH % values > or = 15% of baseline. In conclusion, diurnal rhythmicity in serum TSH levels was abolished in a uniform cohort of patients with short-term severe primary hypothyroidism. We speculate that the complete lack of peripheral negative feedback input to the hypothalamus or pituitary or both may override the central rhythm-sustaining influences on TSH secretion.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".