Skeletal muscle atrophy in advanced interstitial lung disease

Low handgrip strength is related to elevated echogenicity in patients with chronic kidney disease: A pilot, cross-sectional and exploratory study

OBJECTIVES

Evaluate associations between triceps braqui muscle ultrasound measures (TB US) and handgrip strength (HGS), and the sensibility of TB US for low HGS in non-dialysis-dependent chronic kidney disease (nd-CKD) patients.

PARTICIPANTS AND METHODS

This pilot, cross-sectional, and exploratory study evaluated TB cross-sectional images from A-mode US and processed by FIJI-Image J to obtain muscle thickness (MT), echogenicity (EI), cross-sectional area (CSA), pennation angle (PA), and fascicle length (Lf) associating them with absolute HGS by simple and, multiple linear regression. The HGS was normalized to body mass index (BMI) and separated into low HGS (HGS/BMI≤10p according to sex and age) and adequate HGS (HGS/BMI>10p) groups. The body composition was from multifrequency bioimpedance. ROC analysis verified the TB US diagnostic accuracy to low HGS.

RESULTS

Were included 42 (21M/21F) adults with 65.5 (60-70) y median age, 47.22% in 3b CKD stage. The low HGS group (45.23%) showed a higher fat mass (FM), TB muscle medium head's PA, and EI than adequate HGS (p<0.05). In crude model, a pixels increase in EI was associated with a 0.452kgf HGS reduction (p=0.019); adjusted for sex, age, and FM, a one-unit increase in EI was associated with a 0.510kgf HGS reduction (p=0.011). The EI also showed moderate diagnostic accuracy (AUC=0.730; CI 95%=0.589; 0.919) to low HGS and a sensitivity of 86.9% (cutoff≥13.52 pixels).

CONCLUSION

In nd-CKD patients, of all measurements from US, the EI was the most associated with HGS, and the only one sensitive to low HGS diagnosis.

Characteristics of Skeletal Muscle Strength in Subjects With Interstitial Lung Disease

OBJECTIVES

To investigate muscle strength and the prevalence of muscle weakness in adults with interstitial lung diseases (ILDs) compared to healthy subjects.

DESIGN

Cross-sectional (description of clinical features).

SETTING

Public referral center (University Hospital).

PARTICIPANTS

One hundred and twelve adults with ILD (n=48, 60±10yr, 68% female) and healthy counterparts (control group, n=64, 57±10yr, 58% female) (N=112).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURE(S)

Muscle strength and prevalence of muscle weakness in adults with ILD. Muscle strength was assessed via maximal isometric voluntary contraction of dominant upper and lower limb muscle groups. Data from the control group were used to generate reference equations. Muscle weakness was defined as a muscle strength value below the lower limit of normal calculated using data from the control group. Data were expressed as mean ± SD or median [interquartile range] according to the data distribution.

RESULTS

Compared to the control group, adults with ILD had lower muscle strength for all muscle groups assessed (values presented as %predicted: pectoralis major 75[57-86]%; quadriceps 72[58-87]%; latissimus dorsi 76[57-103]%; deltoid 74[64-98]%; biceps brachii 78[64-91]%; triceps brachii 84[62-101]%; P≤.001 for all). Prevalence of muscle weakness in people with ILD was 40% for pectoralis major, 25% for latissimus dorsi, 16% for triceps brachii, 20% for biceps brachii, 27% for deltoid and 46% for quadriceps.

CONCLUSIONS

Adults with ILD present a generalised reduction in peripheral Muscle strength, ranging between 20% to 46% of people depending on the muscle group assessed. and it was more prevalent in lower limb muscles.

Extrapulmonary manifestations of pulmonary arterial hypertension

INTRODUCTION

Extrapulmonary manifestations of pulmonary arterial hypertension (PAH) may play a critical pathobiological role and a deeper understanding will advance insight into mechanisms and novel therapeutic targets. This manuscript reviews our understanding of extrapulmonary manifestations of PAH.

AREAS COVERED

A group of experts was assembled and a complimentary PubMed search performed (October 2023 - March 2024). Inflammation is observed throughout the central nervous system and attempts at manipulation are an encouraging step toward novel therapeutics. Retinal vascular imaging holds promise as a noninvasive method of detecting early disease and monitoring treatment responses. PAH patients have gut flora alterations and dysbiosis likely plays a role in systemic inflammation. Despite inconsistent observations, the roles of obesity, insulin resistance and dysregulated metabolism may be illuminated by deep phenotyping of body composition. Skeletal muscle dysfunction is perpetuated by metabolic dysfunction, inflammation, and hypoperfusion, but exercise training shows benefit. Renal, hepatic, and bone marrow abnormalities are observed in PAH and may represent both end-organ damage and disease modifiers.

EXPERT OPINION

Insights into systemic manifestations of PAH will illuminate disease mechanisms and novel therapeutic targets. Additional study is needed to understand whether extrapulmonary manifestations are a cause or effect of PAH and how manipulation may affect outcomes.

Clinical implications of frailty assessed in hospitalized patients with acute-exacerbation of interstitial lung disease

BACKGROUND

Approximately 50% of patients with interstitial lung disease (ILD) experience frailty, which remains unexplored in acute exacerbations of ILD (AE-ILD). A better understanding may help with prognostication and resource planning. We evaluated the association of frailty with clinical characteristics, physical function, hospital outcomes, and post-AE-ILD recovery.

METHODS

Retrospective cohort study of AE-ILD patients (01/2015-10/2019) with frailty (proportion ≥0.25) on a 30-item cumulative-deficits index. Frail and non-frail patients were compared for pre- and post-hospitalization clinical characteristics, adjusted for age, sex, and ILD diagnosis. One-year mortality, considering transplantation as a competing risk, was analysed adjusting for age, frailty, and Charlson Comorbidity Index (CCI).

RESULTS

89 AE-ILD patients were admitted (median: 67 years, 63% idiopathic pulmonary fibrosis). 31 were frail, which was associated with older age, greater CCI, lower 6-min walk distance, and decreased independence pre-hospitalization. Frail patients had more major complications (32% vs 10%, p = .01) and required more multidisciplinary support during hospitalization. Frailty was not associated with 1-year mortality (HR: 0.97, 95%CI: [0.45-2.10]) factoring transplantation as a competing risk.

CONCLUSIONS

Frailty was associated with reduced exercise capacity, increased comorbidities and hospital complications. Identifying frailty may highlight those requiring additional multidisciplinary support, but further study is needed to explore whether frailty is modifiable with AE-ILD.

Comparison of Physical Activity Patterns among Three Major Chronic Respiratory Diseases

Although the level of physical activity in daily life (PADL) plays a vital role concerning the health of subjects with chronic lung diseases, it remains uncertain how PADL patterns compare among different conditions. This study's objective was to compare the PADL levels of subjects with COPD, asthma and idiopathic pulmonary fibrosis (IPF); and to investigate PADL behaviour in different diseases' severity. Stable subjects who had not undergone pulmonary rehabilitation in the previous year were included. Subjects were divided into two subgroups according to disease severity: mild/moderate and severe/very severe. The primary outcome was time spent in moderate-to-vigorous physical activities (MVPA) (Actigraph GT3x) measured during one week over 12 h/day; other assessments included pulmonary function, peripheral muscle strength and exercise capacity. Comparisons among subgroups were corrected for age, BMI and sex. The analysis involved 119 subjects (47 asthma, 48 COPD and 24 IPF). Subjects with asthma had higher PADL levels than those with COPD and IPF (MVPA 18(14-22) vs. 8(4-12) vs. 7(1-12) min/day, respectively; p ancova = 0.002). Subjects with severe/very severe IPF had the lowest PADL level among all subgroups. Adult subjects with asthma have higher PADL levels than those with COPD and IPF, whereas patients with severe and very severe IPF are the most physically inactive subjects.

Comparison of high-intensity interval training versus moderate-intensity continuous training in pulmonary rehabilitation for interstitial lung disease: a randomised controlled pilot feasibility trial

OBJECTIVES

This study aimed to investigate the feasibility and efficacy of high-intensity interval training (HIIT) compared with moderate-intensity continuous training (MICT) in pulmonary rehabilitation (PR) for people with interstitial lung disease (ILD).

DESIGN

Single-centre, randomised controlled feasibility, pilot trial.

SETTING

Patients were recruited from the chest clinic of a tertiary ILD centre and attended circuit-based PR in the hospital's gym, followed by a personalised 6-month community programme.

PARTICIPANTS

58 patients, stratified per ILD type, were randomised into two groups: 33 to HIIT (18 males:15 females) (mean age (SD): 70.2 (11.4) years) and 25 to the MICT exercise mode (14 males:11 females) (mean age (SD): 69.8 (10.8) years).

INTERVENTIONS

8-week, twice weekly, circuit-based PR programme of exercise and education, followed by a personalised 6-month community exercise programme.

OUTCOME MEASURES

Feasibility outcomes included staff-to-patient ratio and dropout rates per group. Primary outcome was the 6 min walk distance (6MWD). Secondary outcomes included the sniff nasal pressure, mouth inspiratory and expiratory pressures, handgrip and quadriceps strength and health status. Random-effects models were used to evaluate average variation in outcomes through time across the two groups.

RESULTS

The 6MWD peaked earlier with HIIT compared with MICT (at 4 months vs 5 months) but values were lower at peak (mean (95% CI): 26.3 m (3.5 to 49.1) vs 51.6 m (29.2 to 73.9)) and declined faster at 6 months post-PR. Secondary outcomes showed similar faster but smaller improvements with HIIT over MICT and more consistent maintenance 6 months post-PR with MICT than HIIT.

CONCLUSIONS

HIIT is feasible in circuit-based ILD PR programmes and provides quick improvements but requires closer supervision of training and resources than MICT and benefits may be less well sustained. This would make it a less attractive option for clinical PR programmes. A definitive, multicentre randomised controlled trial is required to address the role of HIIT in ILD.

TRIAL REGISTRATION NUMBER

ISRCTN55846300.

Effects of walking with a portable oxygen concentrator on muscle oxygenation while performing normal or pursed-lip breathing in patients with interstitial lung disease: a randomized crossover trial

BACKGROUND

In patients with interstitial lung disease (ILD), decreased oxygen saturation (SpO2) reduces physical performance and causes exertional dyspnea. Portable oxygen concentrator (POC) and pursed-lip breathing (PLB) have the potential to improve these parameters in ILD patients.

OBJECTIVE

To evaluate the effects of PLB while using a POC during walking in ILD patients.

DESIGN

Prospective, randomized crossover trial.

METHODS

We compared two breathing techniques. Participants not trained in PLB received a familiarization session before the first 6-min walking test (6MWT). During the first visit, patients performed the 6MWT under natural breathing (NB1) without oxygen (O₂); during the second visit, they performed the 6MWT twice, once each with PLB (PLB1) and natural breathing (NB2) under O₂ supplementation, to compare the effectiveness of NB and PLB.

RESULTS

Twenty participants were recruited; half had exercise-induced desaturation (EID) and half normal SpO₂. In the normoxemia group (NG), the difference in the 6-min walking distance (6MWD) between NB1 and PLB1 was 28.8 ± 24.0 m, indicating reduced exercise capacity in PLB1. There were no significant differences in the quadriceps tissue saturation index (TSI), SpO₂, and 6MWD between the PLB1 and NB2 in any patient or subgroup. All participants showed a significant increase in the SpO₂ at rest, nadir SpO₂, and mean SpO₂ during the 6MWT with PLB and NB2 using a POC than with NB1. TSI showed a significant improvement at the beginning of 6MWT in ILD patients with EID in the PLB and NB2 condition.

CONCLUSION

Acute exposure to PLB did not improve symptoms, muscle oxygenation, or SpO₂; however, it decreased the walking distance in the normoxemia group. POC improved leg muscle oxygenation in ILD patients with EID. The use of PLB and POC should be prescribed according to disease characteristics and severity.

Disseminating education to solid organ transplant recipients to promote engagement in physical activity

Objective

To evaluate the dissemination of education through a workshop to promote engagement in physical activity (PA) among solid organ transplant (SOT) recipients.

Methods

The in-person workshop consisted of expert-led lectures on topics related to physical activity (day 1) and sports and fitness training with volunteer coaches (day 2). There were separate streams for children/adolescents and adults. RE-AIM (Reach, Efficacy, Adoption, Implementation, and Maintenance) framework was used to evaluate the impact of the workshop. Presenters and participants completed evaluations of the workshop using a 5-point Likert scale. A subgroup of adults completed a self-reported PA questionnaire at baseline and 4-weeks after the workshop.

Results

103 individuals (71 SOT recipients, 32 caregivers) attended the workshop (ages 4 to 71+ years). Sessions were highly rated (median = 5) for both quality and content on both days. There was no significant change (p = 0.16) in PA. However, 56% of SOT recipients reported changing their level of PA.

Conclusion

An educational-workshop with hands-on training was an efficient and well-received method for disseminating awareness about the benefits of PA in SOT recipients.

Innovation

Dissemination of evidence-based knowledge through a novel educational-workshop in a real-world setting has the potential to inform the decisions about PA behavior among SOT recipients.

Relationship between aging-related pulmonary function, cognition, motor function, and activities of daily living in older adults with dementia

BACKGROUND: The aging process is related to cerebrovascular dysfunction and physiological changes, such as reduced pulmonary function. This ultimately induces cognitive impairment or dementia. OBJECTIVE: This study aimed to determine the relationship between aging-related pulmonary function, cognition, motor function, and activities of daily living (ADLs) in older adults with dementia. METHODS: This cross-sectional study included 69 older adults diagnosed with dementia. Aging-related pulmonary function and cognition were measured using a hand-held spirometer and the Korean version of the Mini-Mental State Examination (MMSE-K), respectively. To assess motor function and ADLs, the Berg Balance Scale (BBS), 10-meter walk test (10-MWT), 6-minute walk test (6-MWT), and modified Barthel index (MBI) were used to measure balance, walking speed, physical functional capacity (or walking tolerance), and ADLs, respectively. All data were analyzed using the Pearson’s product correlation coefficient (r). RESULTS: Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) as measures of aging-related pulmonary function correlated only with the 6-MWT (FVC: r = 0.483, p = 0.002; FEV1: r = 0.512, p = 0.001). In cognitive function, MMSE-K was associated with BBS (r = 0.283, p = 0.022) and MBI (r = 0.454, p = 0.000). Additionally, there were significant correlations (r = 0.425–0.671, p = 0.000) between all motor function and ADLs measures in older adults with dementia. CONCLUSIONS: Our findings demonstrated that aging-pulmonary function was related to a lower physical functional capacity, and hence, suggested that the reduced pulmonary function were unable to walk for longer distance in older adults with dementia.

Comparison of heart rates at fixed percentages and the ventilatory thresholds in patients with interstitial lung disease

Heart rate (HR) responses to maximal exercise are commonly used for the prescription of training intensities in pulmonary rehabilitation. Those intensities are usually based on fixed percentages of peak HR (HRpeak), heart rate reserve (HRR), or peak work load (Wpeak), and rarely on HRs at the individual ventilatory thresholds (VT1 and VT2) derived from cardiopulmonary exercise testing (CPET). For patients suffering from interstitial lung disease (ILD), data on cardiorespiratory responses to CPET are scarce. Thus, the aim of this study was to record cardiorespiratory responses to CPET and to compare fixed HR percentages with HRs at VT1 and VT2 in ILD patients. A total of 120 subjects, 80 ILD patients and 40 healthy controls, underwent a symptom‐limited CPET. From the ILD patient, 32 suffered from idiopathic pulmonary fibrosis (IPF), 37 from connective tissue disease (CTD), and 11 from sarcoidosis. HRs at fixed percentages, that is, at 70%HRpeak, at 70%Wpeak, and at 60%HRR were significantly lower in the ILD patients compared with the control group (p‐values: 0.001, 0.044, and 0.011). Large percentages of HR values at 70%Wpeak and 60%HRR ranged between the HRs at VT1 and VT2 in ILD subgroups and controls as well. HRs at 70%HRpeak were lower than HRs at VT1 in 66% of the IPF patients, 54% of the CTD patients, and 55% of patients with sarcoidosis compared with 18% in the control group. Our findings demonstrate a considerable scattering of fixed HR percentages compared with HRs at the individual VTs derived from CPET in ILD patients. These findings may provide valuable information for the prescription of exercise intensity in pulmonary rehabilitation of ILD patients.

Validation of the Brazilian Portuguese version of the University of California San Diego Shortness of Breath Questionnaire in patients with interstitial lung disease

OBJECTIVE

To investigate the reliability, internal consistency and validity of the Brazilian Portuguese version of the University of California San Diego Shortness of Breath Questionnaire (UCSD SOBQ) in patients with interstitial lung disease (ILD).

METHODS

Patients with ILD completed the questionnaire at three different time points, one week apart, with the assistance of two independent assessors. Intra- and inter-rater reliability were analysed via the intraclass correlation coefficient (ICC). Internal consistency was assessed with the Cronbach's alpha coefficient. For the validity analysis, associations between variables were assessed with Spearman's or Pearson's correlation coefficient.

RESULTS

Thirty patients with ILD (idiopathic pulmonary fibrosis, connective tissue disease-associated pulmonary fibrosis, sarcoidosis, asbestosis or non-specific interstitial pneumonia) were included (15 men; mean age, 59 ± 10 years; DLCO: 46 [33-64] % predicted). UCSD SOBQ scores showed excellent agreement and internal consistency in the intra-rater analysis (ICC: 0.93 [0.85-0.97]; Cronbach alpha: 0.95) and in the inter-rater analysis (ICC: 0.95 [0.89-0.97]; Cronbach alpha: 0.95), as well as correlating significantly with dyspnoea (as assessed by the Medical Research Council scale; r = 0.56); Medical Outcomes Study 36-item Short-Form Health Survey domains bodily pain, general health, vitality and physical functioning (-0.40 ≤ r ≤ -0.74); six-minute walk distance (r = -0.38); and quadriceps muscle strength (r = -0.41).

CONCLUSIONS

The Brazilian Portuguese version of the UCSD SOBQ is valid, is reliable and has internal consistency in patients with ILD in Brazil.

Pulmonary rehabilitation for COPD: A narrative review and call for further implementation in Saudi Arabia

Chronic obstructive pulmonary disease (COPD) is a common, preventable, and treatable condition, in which outcomes can be improved with careful management. Pulmonary rehabilitation (PR) comprises exercise and education, delivered by multidisciplinary teams. PR is a cost-effective management strategy in COPD patients which improves exercise performance, reduces dyspnea, reduces the risk of exacerbation, and improves health-related quality of life. All COPD patients appear to benefit irrespective of their baseline function, and PR has also been shown to be a clinically and cost-effective management approach following an acute exacerbation. COPD patients with greater disability and those recovering postexacerbation should be specifically targeted for PR. Due to limited current capacity, the latter group may not currently be able to benefit from PR. Therefore, there is a need for the wider implementation of PR services in Saudi Arabia, requiring us to address challenges including capacity and workforce competency.

High intensity interval training versus moderate intensity continuous training for people with interstitial lung disease: protocol for a randomised controlled trial

Background

Interstitial lung disease is a debilitating condition associated with significant dyspnoea, fatigue, and poor exercise tolerance. Pulmonary rehabilitation is an effective and key intervention in people with interstitial lung disease. However, despite the best efforts of patients and clinicians, many of those who participate are not achieving clinically meaningful benefits. This assessor-blinded, multi-centre, randomised controlled trial aims to compare the clinical benefits of high intensity interval exercise training versus the standard pulmonary rehabilitation method of continuous training at moderate intensity in people with fibrotic interstitial lung disease.

Methods

Eligible participants will be randomised to either a standard pulmonary rehabilitation group using moderate intensity continuous exercise training or high intensity interval exercise training. Participants in both groups will undertake an 8-week pulmonary rehabilitation program of twice-weekly supervised exercise training including aerobic (cycling) and strengthening exercises. In addition, participants in both groups will be prescribed a home exercise program.

Outcomes will be assessed at baseline, upon completion of the intervention and at six months following the intervention by a blinded assessor. The primary outcome is endurance time on a constant work rate test. Secondary outcomes are functional capacity (6-min walk distance), health-related quality of life (Chronic Respiratory Disease Questionnaire (CRQ), St George’s Respiratory Questionnaire idiopathic pulmonary fibrosis specific version (SGRQ-I), breathlessness (Dyspnoea 12, Modified Medical Research Council Dyspnoea Scale), fatigue (fatigue severity scale), anxiety (Hospital Anxiety and Depression Scale), physical activity level (GeneActiv), skeletal muscle changes (ultrasonography) and completion and adherence to pulmonary rehabilitation.

Discussion

The standard exercise training strategies used in pulmonary rehabilitation may not provide an optimal exercise training stimulus for people with interstitial lung disease. This study will determine whether high intensity interval training can produce equivalent or even superior changes in exercise performance and symptoms. If high intensity interval training proves effective, it will provide an exercise training strategy that can readily be implemented into clinical practice for people with interstitial lung disease.

Trial registration ClinicalTrials.gov Registry (NCT03800914). Registered 11 January 2019, https://clinicaltrials.gov/ct2/show/NCT03800914

Australian New Zealand Clinical Trials Registry ACTRN12619000019101. Registered 9 January 2019, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=376050&isReview=true

Pectoralis muscle area and its association with indices of disease severity in interstitial lung disease

RATIONALE

The pathophysiology of interstitial lung disease (ILD) impacts body composition, whereby ILD severity is linked to lower lean mass.

OBJECTIVES

To determine i) if pectoralis muscle area (PMA) is a surrogate for whole-body lean mass in ILD, ii) whether PMA is associated with ILD severity, and iii) if the longitudinal change in PMA is associated with pulmonary function and mortality in ILD.

METHODS

Patients with ILD (n = 164) were analyzed retrospectively. PMA was quantified from a chest computed tomography scan. Peripheral oxygen saturation (SpO₂), 6-min walk distance (6MWD), and pulmonary function were obtained as part of routine clinical care. Dyspnea and quality of life were assessed using the UCSD Shortness of Breath Questionnaire and European Quality of Life 5 Dimensions questionnaire, respectively.

RESULTS

PMA was associated with whole-body lean mass (p < 0.001). After adjusting for age, sex, height, body mass, and prednisone status, PMA was associated with %-predicted forced vital capacity (FVC), %-predicted diffusion capacity (DL_CO), resting and exertional SpO₂, and dyspnea (all p < 0.05), but not forced expiratory volume in 1 s (FEV₁), FEV₁/FVC, 6MWD, or quality of life (all p > 0.05). The annual negative PMA slope was associated with annual negative slopes in FVC, FEV₁, and DL_CO (all p < 0.05), but not FEV₁/FVC (p = 0.46). Annual slope in PMA was associated with all-cause mortality (hazard ratio = -0.80, 95% CI:0.889-0.959; p < 0.001).

CONCLUSION

In patients with ILD, PMA is a suitable surrogate for whole-body lean mass. A lower PMA is associated with indices of ILD severity, which supports the notion that ILD progression may involve sarcopenia.

Association of lung function with functional limitation in older adults: A cross-sectional study

INTRODUCTION

Impaired lung function is independently associated with higher rates of disability, however, few studies have examined the association between lung function and functional limitation. This study aimed to assess this association and dose-response relationship in older adults.

METHODS

Data from the National Health and Nutrition Examination Survey (2007-2012) was used as a cross-sectional study. Lung function was determined by Forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC). Functional limitation in older adults was identified by six self-reported questions on physical function. 3070 adults aged 60 and over were enrolled in our study. Logistic regression models and restricted cubic spline models were applied to examine the association between lung function and the risk of functional limitation.

RESULTS

FEV1 and FVC were inversely associated with the risk of functional limitation. In the full adjusted model, compared with the lowest tertile of FEV1, the odds ratios (95% confidence intervals) of functional limitation for tertile 2 and tertile 3 were 0.5422 (0.3848-0.7639) and 0.4403 (0.2685-0.7220), and the odds ratios (95% confidence intervals) of functional limitation for tertile 2 and tertile 3 of FVC were 0.5243 (0.3503-0.7848) and 0.3726 (0.2072-0.6698). Furthermore, an inverse association persisted after stratified analysis by gender and sensitivity analysis. Dose-response analyses showed that the odds of functional limitation declined with increase in FEV1 and FVC in a nonlinear manner.

CONCLUSIONS

Lung function was inversely associated with functional limitation among older adults.

Muscle stimulation in advanced idiopathic pulmonary fibrosis: a randomised placebo-controlled feasibility study

OBJECTIVES

To assess the acceptability of neuromuscular electrical stimulation (NMES) of the quadriceps muscles in people with idiopathic pulmonary fibrosis (IPF) and to identify whether a future definitive trial is feasible.

DESIGN

A randomised, parallel, two-group, participant and assessor-blinded, placebo-controlled feasibility trial with embedded qualitative interviews.

SETTING

Outpatient department, Royal Brompton and Harefield Hospitals.

PARTICIPANTS

Twenty-two people with IPF: median (25th, 75th centiles) age 76 (74, 82) years, forced vital capacity 62 (50, 75) % predicted, 6 min walk test distance 289 (149, 360) m.

INTERVENTIONS

Usual care (home-based exercise, weekly telephone support, breathlessness management leaflet) with either placebo or active NMES for 6 weeks, with follow-up at 6 and 12 weeks.

PRIMARY OUTCOME MEASURES

Feasibility of recruitment and retention, treatment uptake and adherence, outcome assessments, participant and outcome assessor blinding and adverse events related to interventions.

SECONDARY OUTCOME MEASURES

Outcome measures with potential to be primary or secondary outcomes in a definitive clinical trial. In addition, purposively sampled participants were interviewed to capture their experiences and acceptability of the trial.

RESULTS

Out of 364 people screened, 23 were recruited: 11 were allocated to each group and one was withdrawn prior to randomisation. Compared with the control group, a greater proportion of the intervention group completed the intervention, remained in the trial blinded to group allocation and experienced intervention-related adverse events. Assessor blinding was maintained. The secondary outcome measures were feasible with most missing data associated with the accelerometer. Small participant numbers precluded identification of an outcome measure suitable for a definitive trial. Qualitative findings demonstrated that trial process and active NMES were acceptable but there were concerns about the credibility of placebo NMES.

CONCLUSIONS

Primarily owing to recruitment difficulties, a definitive trial using the current protocol to evaluate NMES in people with IPF is not feasible.

TRIAL REGISTRATION NUMBER

NCT03499275.

Functional performance tests in interstitial lung disease: Impairment and measurement properties

BACKGROUND

There is limited information regarding impairment in functional performance tests and their measurement properties in ILD. The present study aimed to verify the impairment and measurement properties of functional performance tests in ILD.

METHODS

ILD and healthy individuals underwent assessments of pulmonary function, peripheral muscle strength (handgrip force and maximum isometric contraction of quadriceps femoris - MIVCq) and exercise capacity (6-min walk test - 6MWT). Functional performance was assessed by timed-up-and-go with usual (TUGu) and fast (TUGf) gait speeds, 4-m gait speed (4MGS), sit-to-stand in 30 s (30sec-STS), 1 min (1min-STS) and with 5 repetition (5rep-STS) and Short Physical Performance Battery (SPPB). Functional performance was compared between groups, validity (correlation with 6MWT and MIVCq) and reliability of tests were checked in subjects with ILD (intra- and inter-rater agreement analysis).

RESULTS

Seventy-six participants (40 ILD [25 women, 61 ± 11 years, FVC 75 ± 17 %pred] and 36 healthy [22 women, 61 ± 9 years, FVC 97 ± 11 %pred]) were included. Functional performance in ILD was worse than in healthy individuals in all tests, except for the 30sec-STS (p = 0.13). Pre-specified validity criteria were reached for TUGu, TUGf, 4MGS and 5rep-STS (-0.69 < r < 0.55; p < 0.05 for all). Except for 4MGS and SPPB, all tests showed good to excellent inter-rater (0.85 < ICC<0.93; p < 0.05 for all) and all tests showed good to excellent intra-rater (0.83 < ICC< 0.94; p < 0.05 for all) reliability.

CONCLUSIONS

Subjects with ILD present worse functional performance than healthy individuals. According to reliability and validity results, TUGu, TUGf and 5rep-STS seem to be the most appropriate tests to evaluate functional performance in ILD.

Respiratory Impairment, Limited Activity, and Pulmonary Rehabilitation in Patients with Interstitial Lung Disease

Interstitial lung disease (ILD) is a diverse group of chronic lung conditions characterized by dyspnea, exercise-induced hypoxemia (EIH), and exercise intolerance. Since activity limitations and impaired health-related quality of life (HRQoL) in ILD are similar to those in other chronic respiratory diseases, including chronic obstructive pulmonary disease (COPD), pulmonary rehabilitation is also indicated for patients with ILD. This rehabilitation program mainly comprises exercise training and self-management education. Exercise training is the most important component of pulmonary rehabilitation. It significantly improves dyspnea and enhances exercise capacity and HRQoL in patients with ILD. The standard exercise prescription used for COPD is also effective for ILD. However, considering that disease progression and exercise-limiting factors are different in patients with COPD is necessary. Severe EIH, the adverse effects of corticosteroid administration, and comorbidities often lead to difficulty in employing a sufficient exercise intensity. Some modifications in the exercise prescription for individual patients or strategies to minimize EIH and dyspnea are required to optimize training intensity. Since EIH is common and severe in patients with ILD, supplemental oxygen should be provided. In advanced and more severe patients, who have difficulty in performing exercises, energy conservation techniques and the use of energy-saving devices to improve and maintain the patients' activities of daily living may be effective．.

Exercise capacity and its relationship with body composition and nutrition status in patients with interstitial lung disease

BACKGROUND

Patients with interstitial lung disease (ILD) are known to have diminished exercise ability. This study aimed to explore the relationship between nutrition status and body composition parameters with exercise capacity in ILD patients. A second aim focused on assessing the appropriateness of surrogate markers of nutrition status in ILD patients.

METHODS

Disease severity was determined by the percentage of predicted forced vital capacity. Exercise capacity was determined using 6-minute walk distance. Nutrition status was assessed using the subjective global assessment (SGA), standardized phase angle (SPhA), and impedance ratio z-score (z-IR). Bioelectrical impedance analysis estimated body composition parameters.

RESULTS

45 of 79 participants (57%) were malnourished according to the SGA. FFM index z-score (z-FFMI) (r = 0.42, P = .02) and SGA (r = 0.49, P < .01) were significant predictors of exercise capacity independent of disease severity. Age (odds ratio [OR] = 1.1; 95% CI, 1.01-1.25; P = .04), low body mass index (OR = 0.73; 95% CI, 0.57-0.92; P = .01), z-FFMI (OR = 0.34; 95% CI, 0.17-0.68; P < .01), and body fat mass index z-score (OR = 0.39; 95% CI, 0.17-0.91; P = .03) were significantly associated with severe malnutrition. There was no significant difference in SPhA across SGA groups; however, a higher z-IR (poorer cell health) significantly increased the odds of severe malnutrition (OR = 2.75; 95% CI, 1.27-6.03; P = .02).

CONCLUSION

In ILD patients, malnutrition and loss of FFM negatively impact the ability to perform activities of daily living.

Muscle and cerebral oxygenation during cycling in chronic obstructive pulmonary disease: A scoping review

To synthesize evidence for prefrontal cortex (PFC), quadriceps, and respiratory muscle oxygenation using near-infrared spectroscopy (NIRS) during cycling in individuals with chronic obstructive pulmonary disease (COPD). A scoping review was performed searching databases (inception-August 2020): Ovid MEDLINE, EMBASE, Cochrane Systematic Reviews, Cochrane Central Register of Controlled Clinical Trials, CINAHL, SPORTDiscus and Pedro. The search focused on COPD, cycling, and NIRS outcomes. 29 studies (541 COPD participants) were included. Compared to healthy individuals (8 studies), COPD patients at lower cycling workloads had more rapid increases in vastus lateralis (VL) deoxygenated hemoglobin (HHb); lower increases in VL total hemoglobin (tHb) and blood flow; and lower muscle tissue saturation (StO₂). Heliox and bronchodilators were associated with smaller and slower increases in VL HHb. Heliox increased VL and intercostal blood flow compared to room air and supplemental oxygen in COPD patients (1 study). PFC oxygenated hemoglobin (O₂Hb) increased in COPD individuals during cycling in 5 of 8 studies. Individuals with COPD and heart failure demonstrated worse VL and PFC NIRS outcomes compared to patients with only COPD-higher or more rapid increase in VL HHb and no change or decrease in PFC O₂Hb. Individuals with COPD present with a mismatch between muscle oxygen delivery and utilization, characterized by more rapid increase in VL HHb, lower muscle O₂Hb and lower muscle StO₂. PFC O₂Hb increases or tends to increase in individuals with COPD during exercise, but this relationship warrants further investigation. NIRS can be used to identify key deoxygenation thresholds during exercise to inform PFC and muscle oxygenation.

Nutritional status and quality of life in interstitial lung disease: a prospective cohort study

Background

Malnutrition and altered body composition are well-documented in chronic pulmonary diseases; however, investigation of nutritional status in interstitial lung disease (ILD) is limited. This study aimed to describe the nutritional status of ILD patients within three diagnostic groups and explore the relationship between nutritional status and quality of life (QoL).

Methods

Consecutive patients attending an ILD clinic within a tertiary referral hospital in Sydney, Australia were studied. Weight, body-mass-index, anthropometrics, handgrip strength (HGS), subjective global assessment and QoL questionnaires (EQ-5D-5L and King’s-Brief Interstitial-Lung-Disease ‘K-BILD’) were collected. Associations between nutritional status and QoL were analysed.

Results

Ninety participants were recruited and categorised: (1) Idiopathic Pulmonary Fibrosis (IPF) (2) Connective-Tissue Disease associated-ILD (CTD-ILD) or (3) Other (non-IPF/non-CTD ILD). Median age was 66.5 (18) years. Four-percent of patients were underweight and 50% were overweight or obese. Median HGS was 71%-(25.3) of predicted and was correlated to all measures of QoL including EQ-5D health-state index (r = 0.376, p < 0.0001), patient-reported EQ-5D-5L Visual Analogue Score (r = 0.367, p < 0.0001) and K-BILD total score (r = 0.346, p = 0.001). Twenty-three percent of the variance in K-BILD total score (F = 12.888, p < 0.0001) was explained by HGS (ß = 0.273, p = 0.006) and forced vital capacity % predicted (ß = 0.331, p = 0.001).

Conclusions

Although a small number of ILD patients were malnourished, a large proportion of the cohort were overweight or obese. Handgrip strength was compromised and correlated to QoL. Future research with a larger cohort is required to explore the role of HGS as a predictor of QoL.

Reliability of skeletal muscle ultrasound in critically ill trauma patients

Objective

To evaluate the safety and feasibility of the ultrasound assessment of quadriceps in the emergency setting. To assess the intra- and interrater reliability for the acquisition and analysis of ultrasound images of muscle thickness and echogenicity in critically ill trauma patients between health professionals with different levels of expertise.

Methods

Diagnostic accuracy study. Two examiners (expert and novice) acquired ultrasound images from ten patients; an experienced, blinded analyst quantified the images. In a separate group of ten patients, two analysts (expert and novice) quantified quadriceps muscle thickness and echogenicity (square or trace method) from images acquired by one examiner.

Results

Excellent reliability was found for image acquisition and analysis (intraclass correlation coefficients > 0.987; p < 0.001). The standard error of the measurement values ranged from 0.01 - 0.06cm for muscle thickness and from 0.75 - 2.04 arbitrary units for muscle echogenicity. The coefficients of variation were < 6% for thickness and echogenicity. The echogenicity values were higher when using the square technique than when using the tracing technique (p = 0.003).

Conclusion

Ultrasound is safe, feasible, and reliable for muscle assessment in critically ill trauma patients, regardless of the assessor's level of expertise.

Chest computed tomography is a valid measure of body composition in individuals with advanced lung disease

There is growing interest in evaluating body composition using routine clinical computed tomography (CT) scans; however, the validity of this technique in lung transplant patients has not been described. The study objectives were to determine the reliability of measuring fat compartments from thoracic CT and evaluate the validity of muscle and fat cross-sectional area (CSA) from thoracic CT by comparing to bioelectrical impedance analysis (BIA). Thoracic CT scans from lung transplant assessments were obtained for analysis. Total thoracic muscle CSA, pectoral muscle CSA, subcutaneous adipose tissue (SAT), and mediastinal adipose tissue (MAT) were manually segmented by two independent raters. Reliability was analysed using intra-class correlation coefficient (ICC). Correlations were determined between CT measures with fat-free mass index (FFMI), body fat mass index (BFMI) and per cent body fat (%BF) from BIA; and anthropometrics [body mass index (BMI) and waist circumference (WC)]. High inter- and intra-rater reliability were found for SAT and MAT (ICCs = 0.99). Pectoral and total muscle CSA were correlated with FFMI (r = .41, p = .003 and r = .57, p < .001, respectively). SAT was associated with whole-body fat from BIA and with BMI and WC (r = .61 to .80, p < .001). MAT was associated with BMI (r = .58, p < .001) and WC (r = .61, p < .001). This study supports the reliability and validity of using thoracic CT to measure muscle and fat. Future studies are needed to investigate whether these CT-based measures are predictive of clinical and post-transplant outcomes in advanced lung disease.

[Treatment of complications and nonpharmacological management of idiopathic pulmonary fibrosis]

Komplikationen der idiopathischen pulmonalen Fibrose (IPF) sind für einen relevanten Mortalitätsanteil verantwortlich. Als wichtigstes Beispiel ist diesbezüglich die akute Exazerbation anzuführen, deren Krankenhausletalität über 50 % beträgt bei einem mittleren Überleben von nur wenigen Monaten. Somit kommt der Betrachtung von Komplikationen eine große Bedeutung für Krankheitsverständnis sowie Therapieplanung zu. Des Weiteren ist in den letzten Jahren die Evidenz für pneumologische Rehabilitation bei IPF deutlich gestiegen und wird von der Amerikanischen und Europäischen Gesellschaft für Pneumologie (American Thoracic Society [ATS]/European Respiratory Society [ERS]) zur Verbesserung der körperlichen Leistungsfähigkeit, Lebensqualität und der Symptome empfohlen.

Noninvasive assessment of peripheral skeletal muscle weakness in idiopathic pulmonary fibrosis: a pilot study with multiparametric MRI of the rectus femoris muscle

Background

To investigate differences in magnetic resonance imaging (MRI) features of rectus femoris muscle between idiopathic pulmonary fibrosis (IPF) patients and healthy volunteers.

Methods

Thirteen IPF patients with GAP Index stage II disease were subjected to pulmonary function tests, 6-minute walk test (6MWT), quadriceps femoris muscle strength measurement and MRI of the thigh at rest. At MRI, muscle cross-sectional areas, T2 and T2* relaxometry, and 3-point Dixon fat fraction were measured. The results were compared to those of eight healthy sedentary volunteers.

Results

IPF patients had significantly lower %predicted FVC, FEV¹ and DL_CO (p<0.001 for the three variables) and walked significantly less in the 6MWT (p=0.008). Mean quadriceps femoris muscle strength also was significantly lower in IPF patients (p=0.041). Rectus femoris muscle T2* measurements were significantly shorter in IPF patients (p=0.027). No significant intergroup difference was found regarding average muscle cross-sectional areas (p=0.790 for quadriceps and p=0.816 for rectus femoris) or rectus femoris fat fraction (p=0.901). Rectus femoris T2 values showed a non-significant trend to be shorter in IPF patients (p=0.055).

Conclusions

Our preliminary findings suggest that, besides disuse atrophy, other factors such as hypoxia (but not inflammation) may play a role in the peripheral skeletal muscle dysfunction observed in IPF patients. This might impact the rehabilitation strategies for IPF patients and warrants further investigation.

IL-13-driven pulmonary emphysema leads to skeletal muscle dysfunction attenuated by endurance exercise

Patients with chronic obstructive pulmonary disease (COPD) usually develop skeletal muscle dysfunction, which represents a major comorbidity in these patients and is strongly associated with mortality and other poor outcomes. Although clinical data indicates that accelerated protein degradation and metabolic disruption are common associations of muscle dysfunction in COPD, there is very limited data on the mechanisms regulating the process, in part, due to the lack of research performed on a validated animal model of pulmonary emphysema. This model deficiency complicates the translational value of data generated with highly reductionist settings. Here, we use an established transgenic animal model of COPD based on inducible IL-13-driven pulmonary emphysema (IL-13TG) to interrogate the mechanisms of skeletal muscle dysfunction. Skeletal muscles from these emphysematous mice develop most features present in COPD patients, including atrophy, decreased oxygen consumption, and reduced force-generation capacity. Analysis of muscle proteome indicates downregulation of succinate dehydrogenase C (SDH-C), which correlates with reduced enzymatic activity, also consistent with previous clinical observations. Ontology terms identified with human data, such as ATP binding/bioenergetics are also downregulated in this animal's skeletal muscles. Moreover, chronic exercise can partially restore muscle mass, metabolic and force-generation capacity, and SDH activity in COPD mice. We conclude that this animal model of COPD/emphysema is an adequate platform to further investigate mechanisms of muscle dysfunction in this setting and demonstrates multiple approaches that can be used to address specific mechanisms regulating this process.NEW & NOTEWORTHY Skeletal muscle dysfunction is a relevant comorbidity in patients with chronic obstructive pulmonary disease (COPD). Mechanistic research in the area has so far been accomplished with models based on specific exposures to otherwise healthy animals, and no investigation using an established and validated animal model of COPD has been accomplished. We present an animal model of COPD that was previously shown to recapitulate pulmonary functional and histologic features present in patients with COPD, and demonstrates most of the features present in patients with pulmonary emphysema-associated muscle dysfunction, which we proposed as an adequate tool to develop mechanistic research in the area.

Practical approach to establishing pulmonary rehabilitation for people with non-COPD diagnoses

Pulmonary rehabilitation is a core aspect in the management of patients with chronic respiratory diseases. This paper describes a practical approach to establishing pulmonary rehabilitation for patients with non-COPD diagnoses using examples from the interstitial lung disease (ILD), pulmonary hypertension (PH), bronchiectasis and lung cancer patient populations. Aspects of pulmonary rehabilitation, including the rationale, patient selection, setting of programmes, patient assessment and training components (both exercise and non-exercise aspects), are discussed for these patient groups. Whilst there are many similarities in the rationale and application of pulmonary rehabilitation across these non-COPD populations, there are also many subtle differences, which are discussed in detail in this paper. With consideration of these factors, pulmonary rehabilitation programmes can be adapted to facilitate the inclusion of respiratory patients with non-COPD diagnoses.

Gait speed and prognosis in patients with idiopathic pulmonary fibrosis: a prospective cohort study

The 4-m gait speed (4MGS), a simple physical performance measure and surrogate marker of frailty, consistently predicts adverse prognosis in older adults. We hypothesised that 4MGS could predict all-cause mortality and nonelective hospitalisation in patients with idiopathic pulmonary fibrosis (IPF).4MGS and lung function were measured at baseline in 130 outpatients newly diagnosed with IPF. Survival status and nonelective hospital admissions were recorded over 1 year. We assessed the predictive value of 4MGS (as a continuous variable and as a binary variable: slow versus preserved 4MGS) by calculating hazard ratios using Cox proportional regression, adjusting for potential confounding variables. Receiver operating characteristic curves assessed discrimination between the multivariable regression models and established prognostic indices.Continuous 4MGS and slow 4MGS were independent predictors of all-cause mortality (4MGS: HR 0.03, 95% CI 0.01-0.31; p=0.004; slow 4MGS: 2.63, 95% CI 1.01-6.87; p=0.049) and hospitalisation (4MGS: HR 0.02, 95% CI 0.01-0.14; p<0.001; slow 4MGS: 2.76, 95% CI 1.16-6.58; p=0.02). Multivariable models incorporating 4MGS or slow 4MGS had better discrimination for predicting mortality than either the gender, age and lung physiology index or Composite Physiologic Index.In patients with IPF, 4MGS is an independent predictor of all-cause mortality and nonelective hospitalisation.

Quantitative assessment of erector spinae muscles in patients with Mycobacterium avium complex lung disease

BACKGROUND AND OBJECTIVE

No reports exist regarding skeletal muscle involvement in patients with Mycobacterium avium complex lung disease (MAC-LD). The cross-sectional area of the erector spinae muscles (ESM_CSA) reflects physical activity and can be assessed by computed tomography (CT). We investigated the relationship between ESM_CSA and physiological parameters and prognosis in MAC-LD patients.

MATERIAL AND METHODS

In this prospective observational study, the ESM_CSA was measured on single-slice axial CT images. MAC-LD patients and sex- and age-matched controls (non-MAC-LD participants) were evaluated. We evaluated the relationship between the ESM_CSA and physiological parameters and prognosis.

RESULTS

A total of 260 patients (209 female; median age, 69 years; 190 with nodular/bronchiectatic disease; 74 with cavitary lesions) were enrolled. The ESM_CSA was not different between MAC-LD patients and controls. In MAC-LD patients, the ESM_CSA was significantly associated with age, body mass index (BMI), pulmonary function, CT severity, and health-related quality of life (HRQL). Multivariate Cox proportional hazards analyses revealed that an ESM_CSA < -1 standard derivation (hazards ratio [HR], 2.76; P = 0.047) was significantly associated with all-cause mortality, along with BMI < 18.5 kg/m² (HR, 3.67; P = 0.02) and presence of cavitary lesions (HR, 5.84; P = 0.001). However, the ESM_CSA was not significantly associated with all-cause mortality when current treatment status, % predicted functional vital capacity, and forced expiratory volume in 1 s were added to the analyses.

CONCLUSIONS

Although the prognostic impact was limited, ESM_CSA was significantly associated with HRQL and prognostic physiological parameters, such as BMI and pulmonary function.

The Impact of Waiting List BMI Changes on the Short-term Outcomes of Lung Transplantation

BACKGROUND

Obesity and underweight are associated with a higher postlung transplantation (LTx) mortality. This study aims to assess the impact of the changes in body mass index (BMI) during the waiting period for LTx on early postoperative outcomes.

METHODS

Medical records of 502 consecutive cases of LTx performed at our institution between 1999 and 2015 were reviewed. Patients were stratified per change in BMI category between pre-LTx assessment (candidate BMI) and transplant BMI as follows: A-candidate BMI, less than 18.5 or 18.5 to 29.9 and transplant BMI, less than 18.5; B-candidate BMI, less than 18.5 and transplant BMI, 18.5 to 29.9; C-candidate BMI, 18.5 to 29.9 and transplant BMI, 18.5 to 29.9; D-candidate BMI, 30 or greater and transplant BMI, 18.5 to 29.9; and E-candidate BMI, 30 or greater or 18.5 to 29.9 and transplant BMI, 30 or greater. Our primary outcome was in-hospital mortality and secondary outcomes were length of mechanical ventilation, intensive care unit length of stay (LOS), hospital LOS and postoperative complications.

RESULTS

BMI variation during the waiting time was common, as 1/3 of patients experienced a change in BMI category. Length of mechanical ventilation (21 days vs 9 days; P = 0.018), intensive care unit LOS (26 days vs 15 days; P = 0.035), and rates of surgical complications (76% vs 44%; P = 0.018) were significantly worse in patients of group E versus group D. Obese candidates who failed to decrease BMI less than 30 by transplant exhibited an increased risk of postoperative mortality (odds ratio, 2.62; 95% confidence interval, 1.01-6.48) compared with patients in group C. Pre-LTx BMI evolution had no impact on postoperative morbidity and mortality in underweight patients.

CONCLUSIONS

Our results suggest that obese candidates with an unfavorable pretransplant BMI evolution are at greater risk of worse post-LTx outcomes.

Differential Pulmonary Rehabilitation Outcomes in Patients With and Without COPD: ROLE OF GENDER

PURPOSE

Individuals with all forms of pulmonary disease are referred for pulmonary rehabilitation. This study examines pulmonary rehabilitation outcomes between individuals with chronic obstructive lung disease (COPD) and non-COPD disease and the impact of gender.

METHODS

This is a retrospective study at a tertiary center. The primary endpoint was the difference in 6-min walk test distance. Secondary measurements included treadmill and NuStep minutes; biceps curls and front arm raises load; quality of life measured by the St George's Respiratory Questionnaire; and University of California San Diego-Shortness of Breath Questionnaire (UCSD-SOBQ) scores.

RESULTS

Eighty patients were included: 38 men (23 COPD, 15 non-COPD) and 42 women (31 COPD, 11 non-COPD). There was a statistically significant improvement in 6-min walk test distances pre- to post-pulmonary rehabilitation for all participants, P = .0003. Although both the COPD and non-COPD groups demonstrated overall improvement (P < .0004 and P = .02, respectively), subgroup analysis showed no statistically significant change in the non-COPD group when divided by gender. There was a significant statistical improvement in lower and upper extremity strength in all participants. Only women with COPD showed a statistically significant improvement with respect to overall quality of life as measured by St. George's Respiratory Questionnaire (P = .01). Women showed significant improvement in their depression score, as well as a trend toward improvement in the University of California San Diego-Shortness of Breath Questionnaire, while only men with COPD showed any improvement in their sleep quality measured by the Pittsburgh Sleep Quality Index.

CONCLUSIONS

Pulmonary rehabilitation results in different but improved outcomes regardless of gender or disease state.

Quantitative Evaluation of Denervated Muscle Atrophy with Shear Wave Ultrasound Elastography and a Comparison with the Histopathologic Parameters in an Animal Model

This study explored the efficacy of shear wave ultrasound elastography (SWUE) for quantitative evaluation of denervated muscle atrophy in a rabbit model. The elastic modulus of the triceps surae muscle was measured with SWUE and compared with histopathologic parameters at baseline and at various post-denervation times (2, 4 and 8 wk) with 10 animals in each group. Our results revealed that the elastic modulus of denervated muscle was significantly lower at 2 wk but higher at 8 wk compared with that at the baseline (p <0.05), and no significant difference was found between the elastic modulus at 4 wk and that at the baseline (p > 0.05). The wet-weight ratio and the muscle fiber cross-sectional area of the denervated muscle decreased gradually during the 8 wk post-denervation together with a gradual increase of the collagen fiber area (p <0.05). In conclusion, SWUE was useful for quantitative evaluation of muscle denervation. The decreased elastic modulus might be an early sign of denervated muscle atrophy.

Quantitative Evaluation of Muscle Function, Gait, and Postural Control in People Experiencing Critical Illness After Discharge From the Intensive Care Unit

BACKGROUND

The path to recovery of muscle strength and mobility following discharge from the intensive care unit (ICU) has not been well described.

OBJECTIVE

The study objective was to quantify muscle function, gait, and postural control at 3 and 6 months after discharge in people who were recovering from critical illness and who were ventilated for 7 days or more.

DESIGN

This was a nested longitudinal study with continuous inclusion of individuals over a 2-year period and with age- and sex-matched controls.

METHODS

Twenty-four people were tested at 3 months after ICU discharge; 16 of them (67%) were reevaluated at 6 months (post-ICU group). Healthy controls (n = 12) were tested at a single time point. Muscle function of the knee extensors (KEs), plantar flexors (PFs), and dorsiflexors (DFs) was assessed on a dynamometer. Gait was measured using an electronic walkway, and postural control was measured with 2 portable force plates.

RESULTS

Muscle weakness was observed across all muscle groups at 3 months, with the greatest strength reductions in the ankle PFs (45%) and DFs (30%). Muscle power was reduced in the PFs and DFs but was not reduced in the KEs. Gait in the post-ICU group was characterized by a narrower step, longer stride, and longer double-support time than in the controls. Improvements were found in KE strength and in stride time and double-support time during gait at 6 months. Leg muscle strength and power had moderate associations with gait velocity, step width, and stride length (r = .44–.65).

LIMITATIONS

The small heterogeneous sample of people with a high level of function was a limitation of this study.

CONCLUSIONS

Muscle strength and power were impaired at 6 months after ICU discharge and were associated with gait parameters. Future studies are needed to examine the role of muscle strength and power training in post-ICU rehabilitation programs to improve mobility.

A comparison trial of eight weeks versus twelve weeks of exercise program in interstitial lung diseases

Background: Exercise training have been shown to be the effective approach for functional outcomes in interstitial lung diseases (ILD). In many studies, the duration of exercise programs (EPs) varies between 8-12 weeks. However, the optimal duration of EPs is still unknown. Objective: In our prospective non-controlled study, we aimed to compare the results of the 8^th week with the results of the 12^th week of the PR programs applied to the patients with ILD. Methods: A total of 14 patients [Age; 63(53,70) years, body mass index: 28(25,32) kg/m², disease duration; 1.5 (1,4) years] with ILD [11 idiopathic pulmonary fibrosis, 2 sarcoidosis (stage 3 and 4) and 1 nonspecific interstitial pneumonia] were included in the study. 6-minute walk test, pulmonary function test, arterial blood gas analysis, mMRC dyspnea scale, quality of life questionnaires and hospital anxiety depression scale were performed at before and 8 and 12 weeks after the program. Results: 6-minute walk distance, dyspnea, anxiety, depression and quality of life improved both at 8^th and 12^th week after EP when compared the with the initial assessment(P<0.05). When compared with 8^th week; mMRC dyspnea score, 6-minute walk distance and quality of life scores significantly improved at 12^th weeks (P=0.046, P=0.016, P<0.05, respectively). Conclusions: Prolonging duration of the EPs results in more improvement in functional outcomes in patients with ILD. However, it has no effect on pulmonary functions and arterial blood gas results. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 299-307)

Evaluation of Skeletal Muscle Function in Lung Transplant Candidates

BACKGROUND

Lung transplantation (LTx) is offered to older and more complex patients who may be at higher risk of skeletal muscle dysfunction, but the clinical implications of this remain uncertain. The study aims were to characterize deficits in skeletal muscle mass, strength and physical performance, and examine the associations of these deficits with clinical outcomes.

METHODS

Fifty LTx candidates (58% men; age, 59 ± 9 years) were prospectively evaluated for skeletal muscle deficits: muscle mass using bioelectrical impedance, quadriceps, respiratory muscle and handgrip strength, and physical performance with the Short Physical Performance Battery. Comparisons between number of muscle deficits (low muscle mass, quadriceps strength and physical performance) and 6-minute walk distance (6MWD), London Chest Activity of Daily Living Questionnaire, and quality of life were assessed using one-way analysis of variance. Associations with pretransplant and posttransplant delisting/mortality, hospital duration, and 3-month posttransplant 6MWD were evaluated using Fisher exact test and Spearman correlation.

RESULTS

Deficits in quadriceps strength (n = 27) and physical performance (n = 24) were more common than muscle mass (n = 8). LTx candidates with 2 or 3 muscle deficits (42%) compared with those without any deficits (26%) had worse 6MWD = -109 m (95% confidence interval [CI], -175 to -43), London Chest Activity of Daily Living Questionnaire = 18 (95% CI, 7-30), and St. George's Activity Domain = 12 (95% CI, 2-21). Number of muscle deficits was associated with posttransplant hospital stay (r = 0.34, P = 0.04), but not with delisting/mortality or posttransplant 6MWD.

CONCLUSIONS

Deficits in quadriceps muscle strength and physical performance are common in LTx candidates and further research is needed to assess whether modifying muscle function pretransplant can lead to improved clinical outcomes.

Thoracic muscle cross-sectional area is associated with hospital length of stay post lung transplantation: a retrospective cohort study

Low muscle mass is common in lung transplant (LTx) candidates; however, the clinical implications have not been well described. The study aims were to compare skeletal muscle mass in LTx candidates with controls using thoracic muscle cross-sectional area (CSA) from computed tomography and assess the association with pre- and post-transplant clinical outcomes. This was a retrospective, single-center cohort study of 527 LTx candidates [median age: 55 IQR (42-62) years; 54% male]. Thoracic muscle CSA was compared to an age- and sex-matched control group. Associations between muscle CSA and pre-transplant six-minute walk distance (6MWD), health-related quality of life (HRQL), delisting/mortality, and post-transplant hospital outcomes and one-year mortality were evaluated using multivariable regression analysis. Muscle CSA for LTx candidates was about 10% lower than controls (n = 38). Muscle CSA was associated with pre-transplant 6MWD, but not HRQL, delisting or pre- or post-transplant mortality. Muscle CSA (per 10 cm² difference) was associated with shorter hospital stay [0.7 median days 95% CI (0.2-1.3)], independent of 6MWD. In conclusion, thoracic muscle CSA is a simple, readily available estimate of skeletal muscle mass predictive of hospital length of stay, but further study is needed to evaluate the relative contribution of muscle mass versus functional deficits in LTx candidates.

Cardiopulmonary exercise factors predict survival in patients with advanced interstitial lung disease referred for lung transplantation

BACKGROUND

The purpose of this work was to determine if parameters assessed during Cardiopulmonary Exercise Testing (CPET) while using supplemental oxygen can independently predict one-year transplant-free survival in patients with Interstitial Lung Disease (ILD) referred for lung transplant evaluation.

METHODS

We performed a chart review of patients with ILD who completed CPET with 30% FiO₂ and gathered spirometry, pulmonary hemodynamic, six-minute walk, and CPET data. The primary end-point was death or lung transplantation within one-year of CPET.

RESULTS

The final data set included 192 patients. 79 patients died/underwent transplant, 113 survived transplant-free. Multivariable Cox regression revealed peak workload % predicted, nadir CPET SpO₂, and FVC% predicted as independent predictors of one-year transplant-free survival. Of the independent predictors of survival, receiver operating characteristics analysis revealed peak workload %predicted cutoff of 35% to be highly discriminatory, more so than nadir CPET SpO₂ or FVC % predicted in identifying patients at risk for one-year mortality or transplant (peak workload % predicted < 35% HR = 4.71, 95% CI = 2.64-8.38 and area under the curve (AUC) = 0.740, nadir CPET SpO₂ < 86% HR = 2.27, 95%CI = 1.41-3.68, AUC = 0.645, FVC %predicted <45% HR = 1.82, 95% CI = 1.15-2.87, AUC = 0.624).

CONCLUSION

Peak workload % predicted, nadir CPET SpO₂, and FVC% predicted in ILD patients referred for lung transplant evaluation are independently predictive of one-year mortality or need for transplant.

Effects of pulmonary rehabilitation in lung transplant candidates: a systematic review

OBJECTIVES

The aim of this systematic review of randomised controlled trials (RCTs), and quasi-experimental and retrospective studies is to investigate the effects of pulmonary rehabilitation (PR) in patients with advanced chronic disease on the waiting list for lung transplantation.

SETTING

PR performed for inpatient or outpatient lung transplant candidates.

INTERVENTION

PR programme including aerobic exercise training and/or resistance exercise training.

PRIMARY AND SECONDARY OUTCOMES

Quality of life and exercise capacity (primary outcomes). Survival rate after transplant surgery; pulmonary function; respiratory muscle strength; psychological aspects; upper and lower extremity muscle strength and adverse effects (secondary outcomes). Two review authors independently selected the studies, assessed study quality and extracted data. Studies in any language were included.

RESULTS

This was a systematic review and studies were searched on the Cochrane Library, MEDLINE, EMBASE, CINAHL and PEDro. Experimental and retrospective studies evaluating the effects of PR in candidates for lung transplantation (>18 years old) with any lung diseases were included. 2 RCTs, and two quasi-experimental and two retrospectives studies, involving 1305 participants were included in the review. 5 studies included an enhancement reported in quality of life using the Short Form 36 questionnaire and showed improvements in some domains. All studies included exercise capacity evaluated through 6 min walk test and in five of them, there were improvements in this outcome after PR. Owing to the different characteristics of the studies, it was not possible to perform a meta-analysis.

CONCLUSIONS

Studies included in this review showed that PR is an effective treatment option for patients on the waiting list for lung transplantation and can improve quality of life and exercise capacity in those patients. Although individual studies reported positive effects of PR, this review shows that there is a need for more studies of a high methodological quality addressing PR effects in lung transplant candidates.

TRIAL REGISTRATION NUMBER

PROSPERO CDR42015025110.

Current best practice in rehabilitation in interstitial lung disease

Interstitial lung disease (ILD) is a group of chronic respiratory diseases characterized by dyspnoea on exertion and decline in health-related quality of life (HRQL). People with ILD experience significant exercise limitation with contributors that include ventilatory limitation, impaired gas exchange, decreased cardiac function and skeletal muscle dysfunction. Pulmonary rehabilitation (PR) is well established in patients with chronic obstructive pulmonary disease (COPD) as a means to overcome exercise limitation and improve activity-related dyspnoea. There is increasing evidence for similar effects of PR in people with ILD. This review discusses the evidence for PR in ILD, outlines the essential components of PR in this population, and highlights special considerations for exercise training in people with ILD. Possible future directions for PR research in people with ILD are explored.

Determinants of pre-transplantation pectoralis muscle area (PMA) and post-transplantation change in PMA in lung transplant recipients

BACKGROUND

This study aimed to determine predictors of pectoralis muscle area (PMA) and assess change in PMA following lung transplantation and its relationship to outcomes.

METHODS

A retrospective review of 88 lung transplant recipients at a single center was performed. PMA was determined on a single axial slice from chest computerized tomography. Pectoralis muscle index (PMI) was calculated from the PMA divided by the height squared.

RESULTS

PMI decreased post-transplantation (8.1±2.8 cm² /m² pre-transplantation, 7.5±2.9 cm² /m² at 6 months, and 7.6±2.7 cm² /m² at 12 months, P<.05). Chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) were predictors of pre-transplant PMI (β=-2.3, P=.001 for COPD; β=2.1, P<.001 for ILD) and percent change in PMI at 12 months post-transplantation relative to baseline (β=19.2, P=.04 for COPD; β=-20.1, P=.01 for ILD). Patients in the highest quartile for PMI change at 12 months had fewer ventilator days compared with patients in the other quartiles (P=.03).

CONCLUSIONS

Underlying diagnosis was a significant predictor of both pre-transplantation PMI and change in PMI post-transplantation. Further studies of PMI are needed to determine its clinical utility in predicting outcomes following lung transplantation.

Relationship of pectoralis muscle area and skeletal muscle strength with exercise tolerance and dyspnea in interstitial lung disease

Background: Pectoralis muscle area (PMA) is an easily derived computed tomography-based assessment that can provide insight into clinical features of other skeletal muscles. Respiratory and locomotor muscle dysfunction has been increasingly recognized in patients with interstitial lung disease (ILD). Its contribution to exercise performance has been controversial. Objective: We aimed to investigate if PMA is related with respiratory and locomotor skeletal muscle strength in ILD patients, and if skeletal muscle function is compromised and independently related with exercise capacity and dyspnea. Methods: Cross-sectional study where subjects performed incremental cycling cardiopulmonary exercise testing with maximal inspiratory (MIP) and expiratory (MEP) pressure measurements, and quadriceps maximal voluntary contraction (MVC) before and after exercise. Results: Thirty ILD patients (forced vital capacity [FVC] and lung diffusing capacity [DL_CO] of 60±15% and 38±10% of predicted, respectively) and 15 healthy control subjects were studied. Patients presented significantly lower MIP and qMVC compared to controls. PMA was significantly associated with qMVC only (r=0.506; p<0.01). Only expiratory muscles showed a significant strength decline after exercise, both in patients and controls. In multivariate regression analysis, only FVC remained as independent predictor of peak aerobic capacity and MEP post exercise remained as independent predictor of peak exercise dyspnea even adjusting for FVC. Conclusion: ILD patients exhibited reduced inspiratory and quadriceps strength, but PMA was associated with the later only. Muscle strength was not associated with exercise capacity while expiratory muscle fatigue might underlie exertional dyspnea. (Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 200-208)

Effects on pulmonary rehabilitation in patients with COPD or ILD: A retrospective analysis of clinical and functional predictors with particular emphasis on gender

BACKGROUND

The response of patients in a pulmonary rehabilitation (PR) is essentially good. However, not all patients benefit from PR to the same extent. In this analysis we wanted to identify the impact of gender and other factors on PR outcomes in patients with chronic obstructive pulmonary disease (COPD) or interstitial lung disease (ILD).

METHODS

Patients suffering from COPD (n = 1492) or ILD (n = 599), treated during an inpatient PR between 1997 and 2015, were analysed according to the effects of PR on exercise capacity and quality of life with regard to the impact of gender or other predictors by univariate and multivariate analyzes.

RESULTS

In the group of COPD patients, 30% did not achieve the expected physical performance during the 6-min walk test (28% of female and 32% of male patients). However, the non-responders initially have had a higher 6-min walking distance (6-MWD) (p < 0.001) and both male and female showed a significant lower BODE index (p = 0.025) in the multivariate analysis. In the ILD-group, 37% females and 43% males were classified as non-responders with regard to the 6-MWD. Also in this group, the non-responders initially have had a higher 6-MWD (p < 0.001). All other variables (age, BMI, lung function, blood gases, C-reactive Protein, Haemoglobin or rehabilitation duration) had no influence on the outcome.

CONCLUSION

Our study supports the positive effects of PR in COPD and ILD patients. In both groups, patients with the biggest limitations benefit most from PR. However, relevant gender differences or other predictors could not be found.