Discordant neurohumoral responsiveness to orthostatic stress in amenorrheic physically active premenopausal women (858.4)
Bibliographic record
Abstract
In light of the known modulatory effects of estrogen on neurohumoral control of blood pressure (BP), we tested the hypothesis that muscle sympathetic nerve activity (MSNA) and serum renin angiotensin aldosterone system (RAAS) levels would differ between estrogen deficient physically active women with functional hypothalamic amenorrhea (ExFHA) and eumenorrheic estrogen replete women. MSNA, serum RAAS components (renin, angiotensin II and aldosterone), and brachial artery BP (mmHg) were recorded at baseline and during graded lower body negative pressure (LBNP; ‐10, ‐20, and ‐40mmHg) in 17 recreationally active eumenorrheic women (ExOv; 24±1 years; body mass index 20.9±0.5kg/m 2 ; mean±SEM) and 12 ExFHA women (25±1 years; 20.7±0.7 kg/m 2 ). At baseline, heart rate (HR; b/min) and systolic BP (SBP) were lower ( p <0.05) in ExFHA (47±2 and 94±2, respectively) compared with ExOv (56±2 and 105±2) women. Baseline MSNA, RAAS components, and mean arterial BP (MAP) were similar ( p >0.05) between the groups. In response to graded LBNP, HR was increased ( p <0.05) and SBP decreased ( p <0.05) in both groups, but responses were lower ( p <0.05) in ExFHA women. MSNA (bursts/100 heart beats) increased in both groups, but responses were greater ( p <0.05) in ExFHA than ExOv women at ‐20 and ‐40 mmHg (37±4 vs. 22±4; 45±4 vs. 33±4, respectively). LBNP elicited increases ( p <0.05) in all RAAS components in ExOv, but not ExFHA, women ( p >0.05). In conclusion, these findings suggest that in hypoestrogenic ExFHA women, sympathetic nerve activity, but not the RAAS, defends arterial BP during orthostatic stress. Grant Funding Source : Supported by a Cardiovascular Independent Research Award (NRA 3840028) awarded from Pfizer
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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 | 0.001 | 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) | 0.001 | 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".