Exercise-induced bronchoconstriction and bronchodilation: investigating the effects of age, sex, airflow limitation and FEV<sub>1</sub>
Bibliographic record
Abstract
Exercise-induced bronchoconstriction (EIBc) is a recognised response to exercise in asthmatic subjects and athletes but is less well understood in an unselected broad population. Exercise-induced bronchodilation (EIBd) has received even less attention. The objective of this study was to investigate the effects of age, sex, forced expiratory volume in 1 s (FEV1) and airflow limitation (FEV1/forced vital capacity (FVC) <0.7) on the prevalence of EIBc and EIBd. This was a retrospective study based on incremental cardiopulmonary exercise testing on cycle ergometry to symptom limitation performed between 1988 and 2012. FEV1was measured before and 10 min after exercise. EIBc was defined as a percentage fall in FEV1post-exercise below the 5th percentile, while EIBd was defined as a percentage increase in FEV1above the 95th percentile. 35 258 subjects aged 6–95 years were included in the study (mean age 53 years, 60% male) and 10.3% had airflow limitation (FEV1/FVC <0.7). The lowest 5% of subjects demonstrated a ≥7.6% fall in FEV1post-exercise (EIBc), while the highest 5% demonstrated a >11% increase in FEV1post-exercise (EIBd). The probability of both EIBc and EIBd increased with age and was highest in females across all ages (OR 1.76, 95% CI 1.60–1.94; p<0.0001). The probability of EIBc increased as FEV1% pred declined (<40%: OR 4.38, 95% CI 3.04–6.31; p<0.0001), with a >2-fold increased likelihood in females (OR 2.31, 95% CI 1.71–3.11; p<0.0001), with a trend with airflow limitation (p=0.06). The probability of EIBd increased as FEV1% pred declined, in the presence of airflow limitation (OR 1.55, 95% CI 1.24–1.95; p=0.0001), but sex had no effect. EIBc and EIBd can be demonstrated at the population level, and are influenced by age, sex, FEV1% pred and airflow limitation.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 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".