Respiratory Muscle Structure and Function and Association With Patient Reported Outcome Measures and Physical Function Post-transplant
Bibliographic record
Abstract
Abstract Background: Lung transplantation (LTx) is a life-saving procedure with beneficial effects on health-related quality of life (HRQL) and exercise capacity. Respiratory muscle changes contribute to functional limitations pre-LTx, but their association with post-LTx respiratory symptoms, HRQL, and physical function have not been well characterized. This study aims to: 1) assess differences in respiratory muscle structure and function, HRQL, and physical function in LTx recipients compared to age and sex-matched LTx candidates; 2) evaluate the relationship between respiratory muscle function and post-LTx outcomes. Methods: Prospective, single-center cross-sectional study of adult bilateral LTx recipients (≥ 3 months post-LTx) with prior diagnosis of chronic obstructive pulmonary disease (COPD) or interstitial lung disease (ILD), and pre-LTx participants matched for age, sex, and lung disease. Ultrasound of the diaphragm (M-mode, 5-12 Hz) and sternocleidomastoid (SCM), physical function (handgrip and neck flexion strength, short physical performance battery [SPPB] and six-minute walk distance [6MWD]), respiratory symptoms and HRQL (St. George's Respiratory Questionnaire [SGRQ] and Short-Form 36 [SF-36]) were evaluated. Diaphragm thickening fraction (TF) was measured during normal (TFdi-tidal) and maximal breathing (TFdi-max) with diaphragm force reserve ratio (1-[TFdi-tidal/TFdi-max]) calculated. SCM TF was also measured at maximal inspiration. Results: 30 LTx recipients (64±8 years, 67% ILD, 33% COPD, 67% male; median 9 months post-LTx) and 10 pre-LTx controls (64±5 years, 60% ILD, 40% COPD, 30% male) were evaluated. Post-LTx participants had greater diaphragm function with a lower resting diaphragm TF, greater maximal diaphragm TF, and a higher diaphragm force reserve ratio than pre-LTx participants (Table 1). Results suggest that SCM TF during maximal inspiration may be higher in post-LTx participants (0.60 ± 0.31 vs 0.46 ± 0.24, p=0.15). HRQL, respiratory symptoms, maximal inspiratory pressure (MIP), and 6MWD were better in LTx recipients compared to candidates (Table 1). In LTx recipients, diaphragm force reserve ratio had a strong correlation with lower respiratory symptom severity (SGRQ Symptoms [r=-0.62, p=0.0004]) and greater inspiratory muscle strength (MIP [r=0.38, p=0.04]). SCM TF had a stronger correlation with SGRQ Total Score (r=-0.42, p=0.03), SF-36 PCS (r=0.44, p=0.02), and SPPB (r=0.58, p=0.002), but not 6MWD (r=0.18, p=0.37). Conclusion: Preliminary findings highlight that diaphragm function is greater in LTx recipients than candidates and respiratory muscle function is associated with improved respiratory symptoms and HRQL. However, results should be interpreted with caution due to sex imbalances between groups. This study may guide the implementation of rehabilitation interventions like inspiratory muscle training to enhance outcomes post-LTx.
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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 | 0.003 |
| 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 | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".