Diurnal Variations In The Acute Response To Exercise In Chronic Obstructive Pulmonary Disease
Bibliographic record
Abstract
Purpose: Indices of lung function and symptoms have been shown to vary throughout the day.In COPD, these variations may have clinical repercussions.The general aim of this study was to investigate the impact of time of day on the acute response to exercise in individuals with COPD.Methods: Subjects followed a counterbalanced randomized design, performing three symptom-limited incremental cycling tests -each preceded by a pulmonary function test-at 08:00, 12:00, and 16:00.COPD medications were withdrawn 6-24 hours prior to each test.Physiological response was measured breath by breath at rest and during exercise.Changes in outcomes were assessed with repeated-measures ANOVAs using the General Linear Model.Friedman tests were performed for nonparametric data.Results: Fourteen subjects (9 men, 5 women) aged 71 ± 7 years with moderate airflow obstruction (FEV 1 : 58 ± 13% predicted) completed all evaluations.No overall time effect was found for peak exercise capacity (p= 0.22) or pulmonary function.However, changes at or beyond the suggested minimal clinically important difference were observed in nine of the 14 subjects for both variables.Resting RER was higher in the morning than at other time points (p = 0.001).Trends for time effects were found for mean V T (p = 0.096) and HR (p = 0.08).VT tended to decrease throughout the day, while HR tended to increase from morning to afternoon.Conclusion: These results suggest that diurnal variations in the acute response to exercise may be heterogeneous among COPD patients and may follow more than one pattern.student and for being one of the most influential people in my life for the past three years.Teaching me, guiding me, and supporting me throughout this whole process has been incredible to me and I look forward to continuing my doctoral degree together.
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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 | 0.000 | 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".