Physical activity does not alter prolactin levels in post-menopausal women: results from a dose-response randomized controlled trial
Bibliographic record
Abstract
BACKGROUND: Increased circulating levels of prolactin have been associated with increased risk of both in situ and invasive breast cancer. We investigated whether or not physical activity had a dose-response effect in lowering plasma levels of prolactin in postmenopausal women. METHODS: Four hundred previously inactive but healthy postmenopausal women aged 50-74 years of age were randomized to 150 or 300 min per week of aerobic physical activity in a year-long intervention. Prolactin was measured from fasting samples with a custom-plex multiplex assay. RESULTS: A high compared to moderate volume of physical activity did not reduce plasma prolactin levels in intention-to-treat (Treatment Effect Ratio (TER) 1.00, 95% Confidence Interval (CI) 0.95 - 1.06) or per-protocol analyses (TER 1.02, 95% CI 0.93 - 1.13). CONCLUSIONS: It is unlikely that changes in prolactin levels mediate the reduced risk of breast cancer development in post-menopausal women associated with increased levels of physical activity. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT01435005.
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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 | 0.004 | 0.007 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.004 | 0.003 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.007 | 0.001 |
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".