Effects Of An Aging Pulmonary System On Expiratory Flow Limitation Susceptibility During Exercise In Healthy Women
Bibliographic record
Abstract
Aging is associated with a decline in lung function, primarily because of a loss of elastic recoil which acts to reduce maximal expiratory flow rates. Aging related changes in pulmonary function might make older women more susceptible to developing expiratory flow limitation (EFL) relative to their younger counterparts, despite having lower levels of minute ventilation (VE) during exercise. PURPOSE: To determine if there are aging related differences in the susceptibility and severity of EFL during exercise in healthy women. METHODS: Healthy young (YW; n=8; 29±7 (20-39) yrs) and old (OW; n=8; 64±3 (60-68) yrs) women participated in this study and were matched for %predicted forced vital capacity (115±5 vs. 122±14 %, respectively, P>0.05) and forced expiratory volume in 1 second (104±7 vs. 108±20 %, respectively, P>0.05). EFL was calculated as the percent overlap between tidal flow-volume loops during maximal exercise and the maximal expiratory flow-volume (MEFV) curve. The MEFV curve was generated by having subjects perform several expirations from total lung capacity to residual volume at different efforts before and after exercise to account for both thoracic gas compression and exercise-induced bronchodilation. RESULTS: Maximal O2 consumption was lower in the OW (29.4±3.6 ml·kg-1·min-1) compared to the YW (49.1±8.9 ml·kg-1·min-1, P<0.05). Maximal VE during exercise was also lower in the OW (73.7±18.4 l·min-1) compared to the YW (108.7±14.1 l·min-1, P<0.05). EFL at maximal exercise was present in 2 of 8 YW (25%) and in 5 of 8 OW (63%). There were no differences in the magnitude of EFL between OW (23±24 (0-69) %EFL) and YW (9±18 (0-46) %EFL, P>0.05). The magnitude of EFL in OW appeared to be inversely related to %predicted forced vital capacity (r=-0.70, P=0.05). CONCLUSION: OW tend to be more susceptible to EFL than YW despite having lower levels of VE during exercise. Funding by: BC Lung Association and NSERC
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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) | 0.001 | 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".