The effects of COPD progression on exercise ventilatory inefficiency
Bibliographic record
Abstract
Exercise ventilatory inefficiency (i.e., increased ventilation (V'E) to carbon dioxide output (V'CO 2 )) has become an important outcome for risk stratification and prognosis evaluation in COPD. However, it remains unknown how best express this relationship among patients with marked differences in ventilatory constraints and exercise capacity. Three hundred and two COPD patients GOLD stages I to IV and 54 age- and sex-matched controls underwent an incremental cardiopulmonary exercise test on a cycle ergometer. The V'E-to-V'CO 2 relationship was expressed as slope and intercept or as a ratio (V'E/V'CO 2 ) at its lowest point (nadir). End-inspiratory lung volume (EILV) to total lung capacity (TLC) ratio provided an index of exercise ventilatory constraints. EILV/TLC increased as disease progressed. V'E-V'CO 2 slope and intercept were both higher in GOLD I and II patients compared to normal subjects. Consequently, V'E/V'CO 2 nadir was also higher in these patients (p<0.05). Despite even greater V'E-V'CO 2 intercepts, V'E-V'CO 2 slope progressively decreased in GOLD III and IV (intercept (mean ± SD= 7.1 ± 3.1 vs. 8.5 ± 2.5 and slope= 27.6 ± 4.8 vs. 24.1 ± 5.3, respectively; p<0.05). As a result, V'E/V'CO 2 nadir did not differ across the GOLD stages. V'E-V'CO 2 intercept was associated with higher resting and exercise-related increases in end-expiratory lung volume (r= 0.56 and 0.61, respectively; p<0.05). In conclusion, estimation of exercise ventilatory inefficiency is influenced by the strategy chosen to express the V'E-to-V'CO 2 relationship in patients with COPD. V'E-V'CO 2 intercept better captures the progressive worsening in ventilatory inefficiency as the disease evolves.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.003 |
| 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".