[The FEV1/VC ratio to define bronchial obstruction: Should we use a fixed ratio or the lower limit of normal?] / La définition de l'obstruction bronchique par le rapport VEMS/CV : seuil fixe ou limite inférieure de la normale ?

INTRODUCTION: While the screening of chronic obstructive lung diseases (COPD, asthma, etc.) constitutes a major public health issue in France and worldwide, simple spirometry appears currently as the key to meeting the challenge. Since description of the forced expiratory maneuver by Robert Tiffeneau in 1947, it has been admitted that the FEV1/VC ratio permits diagnosis obstructive pulmonary diseases. However, the diagnostic criteria for this ratio remain uncertain. The long-lasting debate between advocates of a 0.7 "fixed ratio" (FR) of 0.7 and advocates of the "lower limit of normal" (LLN) remains relevant. STATE OF THE ARTS: In this general review, we describe the respective advantages of the FR and LLN criteria according to the most recently published studies, and characterize the conditions associated with discrepancies between these criteria. PERSPECTIVES AND CONCLUSIONS: FR and LLN appear not to share similar diagnosis values and the use of both criteria facilitates proposal of an up-to-date interpretation and diagnosis strategy in the context of first-line spirometry, particularly for patients with FEV1/VC ratio in the "grey zone".

Impact of a telerehabilitation programme combined with continuous positive airway pressure on symptoms and cardiometabolic risk factors in obstructive sleep apnea patients.

Background: Obstructive sleep apnea syndrome is a common sleep-breathing disorder associated with adverse health outcomes including excessive daytime sleepiness, impaired quality of life and is well-established as a cardiovascular risk factor. Continuous positive airway pressure is the reference treatment, but its cardiovascular and metabolic benefits are still debated. Combined interventions aiming at improving patient's lifestyle behaviours are recommended in guidelines management of obstructive sleep apnea syndrome but adherence decreases over time and access to rehabilitation programmes is limited. Telerehabilitation is a promising approach to address these issues, but data are scarce on obstructive sleep apnea syndrome. Methods: The aim of this study is to assess the potential benefits of a telerehabilitation programme implemented at continuous positive airway pressure initiation, compared to continuous positive airway pressure alone and usual care, on symptoms and cardiometabolic risk factors of obstructive sleep apnea syndrome. This study is a 6-months multicentre randomized, parallel controlled trial during which 180 obese patients with severe obstructive sleep apnea syndrome will be included. We will use a sequential hierarchical criterion for major endpoints including sleepiness, quality of life, nocturnal systolic blood pressure and inflammation biological parameters. Discussion: m-Rehab obstructive sleep apnea syndrome is the first multicentre randomized controlled trial to examine the effectiveness of a telerehabilitation lifestyle programme in obstructive sleep apnea syndrome. We hypothesize that a telerehabilitation lifestyle intervention associated with continuous positive airway pressure for 6 months will be more efficient than continuous positive airway pressure alone on symptoms, quality of life and cardiometabolic risk profile. Main secondary outcomes include continuous positive airway pressure adherence, usability and satisfaction with the telerehabilitation platform and medico-economic evaluation. Trial registration: Clinicaltrials.gov Identifier: NCT05049928. Registration data: 20 September 2021.

Feasibility of a nasal breathing training during pulmonary rehabilitation. A pilot randomized controlled study.

Hyperventilation syndrome (HVS) is a common source of dyspnea and disability. While pulmonary rehabilitation (PR) including breathing exercises is indicated, randomized controlled trial are warranted to recommend one type of breathing exercise than another. We aimed to compare during PR, the effect of 5 sessions of nasal ventilation exercise (NV+PR) versus voluntary hypoventilation (vHV+PR) on exercise dyspnea (primary outcome) and capacity and health-related quality of life in patients. In this open label randomized controlled trial, 19 HVS patients (age=48.3 ± 15.2 y.o, female/male=18/1, Nijmegen score=33 ± 7.7) were randomized in a NV+PR (n = 9) or vHV+PR (n = 10) group. Modified Medical Research Council (mMRC) dyspnea, 6-minute walking distance (6MWD) with nasal/oral ventilation were assessed before and after 3 months of PR, and questionnaires (Nijmegen, VQ-11). There was a significant effect of PR of but no significant difference between groups in the improvements of dyspnea@max exercise (time effect (T): p < 0.01; group (G): p = 0.63; group*time interaction (G*T): p = 0.49), mMRC dyspnea (T: p < 0.01; G: p = 0.45; G*T: p = 0.62), 6MWD (T: p < 0.05; G: p = 0.36; G*T: p = 0.31), VQ-11 (T: p < 0.001; G: p = 0.16; G*T: p = 0.09) and plasma HCO3- (T: p < 0.05; G: p = 0.93; G*T; p = 0.36), Yet, Nijmegen score (T: p < 0.01; G: p = 0.32; G*T: p < 0.05) improvement was larger in NV+PR group. The exercise oronasal breathing shift during the 6MWT was significantly delayed in all patients (T: p < 0.05; G: p = 0.30; G*T: p = 0.32) and positively correlated with plasma HCO3-(r = 0.42; p < 0.05). Nasal exercise was not superior versus voluntary hypoventilation during PR in HVS patients. Yet, nasal exercise appeared feasible, leading to acquisition of a nasal breathing pattern during walking, improvement of PR outcomes and ventilatory alkalosis. The link between nasal breathing and hyperventilation is discussed in the light of the nasal ventilation rhythm in the limbic system and its role on the limbic emotional and ventilatory functions.

[Respiratory telerehabilitation in cases of COPD]. / Mise au point sur la téléréadaptation respiratoire dans la BPCO.

Telerehabilitation brings together a set of rehabilitation practices applied remotely by means of information and communication technologies. Even though it has been taking on increasing importance in many health fields over 10 years, telerehabilitation had yet to find its place in pulmonary rehabilitation before 2020, when the pandemic situation impelled numerous teams to put it to work. Pilot studies on respiratory diseases, primarily COPD, along with recent data from randomized or non-randomized studies, have enhanced our understanding of "remote" practice. In this review of the literature, we will show that pulmonary telerehabilitation is feasible, safe and likely to yield short-term (and possibly longer term) effects generally similar to those achieved in the pulmonary rehabilitation programs of specialized centers, especially as regards some indicators of exercise tolerance, dyspnea or patient quality of life. However, the number of studies and patients included in these programs remains too limited in terms of modalities, duration, long-term effects, or adaptations in case of exacerbation to be the subject of recommendations. The potential of respiratory telerehabilitation justifies continuing clinical trials and experiments, which need to be coordinated with the interventions characterizing a conventional program.

Carnosine, oxidative and carbonyl stress, antioxidants, and muscle fiber characteristics of quadriceps muscle of patients with COPD.

Oxidative/carbonyl stress is elevated in lower-limb muscles of patients with chronic obstructive pulmonary disease (COPD). Carnosine is a skeletal muscle antioxidant particularly present in fast-twitch fibers. The aims of the present study were to compare muscle carnosine, oxidative/carbonyl stress, antioxidants, and fiber characteristics between patients with COPD and healthy controls (HCs) and between patients after stratification for airflow limitation (mild/moderate vs. severe/very severe), as well as to investigate correlates of carnosine in patients with COPD. A vastus lateralis muscle biopsy was obtained from 40 patients with stable COPD and 20 age- and sex-matched HCs. Carnosine, oxidative/carbonyl stress, antioxidants, fiber characteristics, quadriceps strength and endurance (QE), V̇o2peak (incremental cycle test), and physical activity (PA) were determined. Patients with COPD had a similar carnosine concentration [4.16 mmol/kg wet weight (WW; SD = 1.93)] to HCs [4.64 mmol/kg WW (SD = 1.71)] and significantly higher percentage of fast-twitch fibers and lower QE, V̇o2peak, and PA versus HCs. Patients with severe/very severe COPD had a 31% lower carnosine concentration [3.24 mmol/kg WW (SD = 1.79); n = 15] versus patients with mild/moderate COPD [4.71 mmol/kg WW (SD = 1.83); n = 25; P = 0.02] and significantly lower V̇o2peak and PA versus patients with mild/moderate COPD. Carnosine correlated significantly with QE (rs = 0.427), V̇o2peak (rs = 0.334), PA (rs = 0.379), and lung function parameters in patients with COPD. In conclusion, despite having the highest proportion of fast-twitch fibers, patients with severe/very severe COPD displayed a 31% lower muscle carnosine concentration compared with patients with mild/moderate COPD. As no other markers of oxidative/carbonyl stress or antioxidants were affected, the observed carnosine deficiency is thought to be a possible first sign of muscle redox balance abnormalities.NEW & NOTEWORTHY Carnosine, particularly present in fast-twitch fibers, was investigated in the quadriceps of patients with chronic obstructive pulmonary disease (COPD). Carnosine concentration was similar between patients with COPD and healthy controls but was 31% lower in patients with severe/very severe COPD, despite their high proportion of fast-twitch fibers, versus patients with mild/moderate COPD. As no other markers of oxidative/carbonyl stress or antioxidants were affected, the observed carnosine deficiency is thought to be a possible first sign of muscle redox balance abnormalities.

Skeletal muscle effects of electrostimulation after COPD exacerbation: a pilot study.

Muscle dysfunction is a major problem in chronic obstructive pulmonary disease (COPD), particularly after exacerbations. We thus asked whether neuromuscular electrostimulation (NMES) might be directly useful following an acute exacerbation and if such a therapy decreases muscular oxidative stress and/or alters muscle fibre distribution. A pilot randomised controlled study of NMES lasting 6 weeks was carried out in 15 in-patients (n=9 NMES; n=6 sham) following a COPD exacerbation. Stimulation was delivered to the quadriceps and hamstring muscles (35 Hz). Primary outcomes were quadriceps force and muscle oxidative stress. At the end of the study, quadriceps force improvement was statistically different between groups (p=0.02), with a significant increase only in the NMES group (median (interquartile range) 10 (4.7-11.5) kg; p=0.01). Changes in the 6-min walking distance were statistically different between groups (p=0.008), with a significant increase in the NMES group (165 (125-203) m; p=0.003). NMES did not lead to higher muscle oxidative stress, as indicated by the decrease in total protein carbonylation (p=0.02) and myosin heavy chain carbonylation (p=0.01) levels. Finally, we observed a significant increase in type I fibre proportion in the NMES group. Our study shows that following COPD exacerbation, NMES is effective in counteracting muscle dysfunction and decreases muscle oxidative stress.

Cost-saving effect of supervised exercise associated to COPD self-management education program.

BACKGROUND: Although the benefits of comprehensive pulmonary rehabilitation have been demonstrated in patients with COPD, the effects of exercise sessions within self-management programs remain unclear. We hypothesized that 8 supervised exercise sessions incorporated in a 1-month self-management education program in COPD patients would be effective to improve health outcomes and to reduce direct medical costs after one year, compared to usual care. METHODS: In this randomized controlled trial, 38 moderate-to-severe COPD patients were assigned either to an intervention group or to a usual care group. The hospital-based intervention program provided a combination of 8 sessions of supervised exercise with 8 self-management education sessions over a 1-month period. The primary end-point was the 6-min walking distance (6MWD), with secondary outcomes being health-related quality of life (HRQoL)--using the St. George's Respiratory Questionnaire (SGRQ) and Nottingham Health Profile (NHP), maximal exercise capacity and healthcare utilization. Data were collected before and one year after the program. RESULTS: After 12 months, we found statistically significant between-group differences in favor of the intervention group in 6MWD (+50.5 m (95%CI, 2 to 99), in two domains of NHP (energy, -19.8 (-38 to -1); emotional reaction, -10.4 (-20 to 0)); in SGRQ-symptoms (-14.0 (-23 to -5)), and in cost of COPD medication (-480.7 € (CI, -891 to -70) per patient per year). CONCLUSION: The present hospital-based intervention combining supervised exercise with self-management education provides significant improvements in patient's exercise tolerance and HRQoL, and significant decrease of COPD medication costs, compared to usual care.

[Chronic obstructive pulmonary disease (COPD) in the elderly]. / La bronchopneumopathie chronique obstructive (BPCO) du sujet âgé en huit questions/réponses.

Chronic obstructive pulmonary disease (COPD) is a chronic disease characterized by incompletely reversible airflow limitation, measured by a decrease of FEV(1)/FVC ratio. International consensus does not agree on a single threshold for this ratio, which can define airflow obstruction. Although the prevalence of COPD in the elderly population varies according to the definition used, it definitely increases with age and could reach 15% in those over 65 years of age. Therefore, ageing of the population should result in increased prevalence and socioeconomical costs of COPD during coming years. In France, diagnosis of COPD in the elderly is difficult, late and insufficient. Management, which has the same goals as in younger populations, has to be global and coordinated. Some points should be considered with particular attention considering the cumulative risks related on the one hand to COPD and on the other to ageing: pharmacological side-effects, decreased physical and social autonomy, nutritional impairment, comorbidities. Given the lack of specific data in elderly populations, pharmacological indications are generally considered to be the same as in younger populations, but some additional precautionary measures are necessary. Pulmonary rehabilitation seems to be beneficial at any age. Palliative care comes up against important difficulties: an indefinite beginning of the palliative stage in COPD; insufficient palliative care resources; insufficient communication; insufficient utilization of palliative care resources. Global COPD management in elderly requires coordination, best reached in health care network organizations involving medical and/or social professionals.

[Practical methods for controlled diaphragmatic breathing in 2009: proposals for a consensus]. / Modalités pratiques de réalisation de la ventilation dirigée abdomino-diaphragmatique en 2009: propositions pour un consensus.

BACKGROUND: This work has been completed at the request of the French Language Society of Pneumology. It is the result of collaboration between the 'Muscles and Respiration Group' and the 'Working Group in Physiotherapy', arriving at a consensus on diaphragmatic breathing. RESULTS: From the literature followed by a formalized consensus methodology, the authors specify the terminology and define the appropriate methods of this technique that should be used. CONCLUSION: Analysis of the literature to date does not allow assessment of the efficacy of this technique. The precise definition of the methods of diaphragmatic breathing as proposed in the present study will be used as a basis for forthcoming studies on this technique.

An innovative maintenance follow-up program after a first inpatient pulmonary rehabilitation.

Although the benefits of pulmonary rehabilitation (PR) have been demonstrated in patients with COPD, most studies suggest that short-term programs are insufficient to maintain the benefits beyond a post-discharge period of 6 months to 1 year. We were interested to evaluate the effects of an innovative maintenance intervention compared with a usual after-care. Forty moderate to severe COPD patients, who had just completed their first inpatient PR, were consecutively included in either a maintenance group (MG) or a standard after-care group. The maintenance program was coordinated within a health-care network including self-help associations, and offered weekly activities. We measured the 6-min walk distance (6MWD), the quality of life using the St George Respiratory Questionnaire (SGRQ), the dyspnea, the maximal workload and the health-care utilization. Data were collected at respiratory clinic admission and discharge, and at 6- and 12-month visits after the PR. After 12 months, we found statistically and clinically significant differences in favor of the MG in 6MWD (74 m; p < or = 0.01) and in the three domains of SGRQ: symptom (19%; p < or = 0.01), activity (27%; p < or = 0.01) and impact (32%; p < or = 0.01). The results showed no difference between groups in dyspnea and maximal workload. We also found that the number of days spent in hospital for respiratory disorders was significantly lower in the MG after 12 months (p < or = 0.03). The multidisciplinary management of COPD patients in the post-rehabilitation period within a health-care network including self-help associations seems to be an effective strategy for maintaining, and even improving, the benefits of a first initial structured program.

[Which definition to use when defining airflow obstruction?]. / Quelle définition faut-il choisir pour le déficit ventilatoire obstructif?

INTRODUCTION: There is no clear consensus as to what constitutes an obstructive ventilatory defect (OVD). According to the American Thoracic Society and European Respiratory Society, it is defined as being when the ratio of the forced expiratory volume (FEV1) and the slow expiratory vital capacity (VC) is below the lower limit of normal (LLN). According to the Global initiative for chronic Obstructive Lung Disease and the British Thoracic Society, it is an FEV1/forced expiratory vital capacity (FVC)<0.70 and an FEV1<80%. In addition, in daily practice, the OVD is diagnosed by a "Fixed ratio" FEV1/FVC<0.70 or

[Factors influencing pulmonary function in Tunisian women aged 45 years and more]. / Facteurs influençant les variables ventilatoires des Tunisiennes âgées de 45 ans et plus.

INTRODUCTION: The aim of this study was to analyse the factors influencing pulmonary function and inspiratory muscle strength in healthy Tunisian women aged >or=45 years and in particular to determine the effect of parity. METHODS: A medical questionnaire together with an evaluation of sporting activity score and 2 levels for schooling and socio-economic status was administered. Parity was introduced as numeric, as dichotomous (G1:or=4) and in 3 classes (C1:<2; C2:=3-4; C3: > 4). Plethysmography with measurement of airway conductance and maximal inspiratory pressure was performed. RESULTS: 108 women were included. According to the ascending multiple linear regression, and in decreasing order, the following influencing factors are noted: Age and height, parity, weight and daily activity, schooling level, and finally leisure activity, body mass index, and physical activity. With high parity, and especially in women aged >or=60 years, there was a decrease in inspiratory muscle strength and an obstructive tendency, without associated restrictive component. Parity effects are age independent. CONCLUSIONS: Factors influencing the pulmonary function of healthy Tunisian women aged >or=45 years are multiple. Lung function declines with increasing parity.

[Evaluation of pulmonary function in the elderly. Intergroupe Pneumo Gériatrie SPLF-SFGG]. / Evaluation de la fonction respiratoire chez le sujet âgé. Intergroupe Pneumo Gériatrie SPLF-SFGG.

Aging is associated with a progressive decrease in lung function. As a consequence of aging, individual's reserve is diminished, but this decrease is heterogeneous between individual subjects. Many factors are involved in the overall decline in lung function. The prevalence of asthma in the elderly is estimated between 6 and 10%. Mortality due to COPD is increasing, especially among older subjects. Older subjects are at an increased risk of developing chronic diseases such as Parkinson's disease, which can have consequences for lung function. Under-nutrition is also common in the elderly and can produce sarcopenia and skeletal muscle dysfunction. The presentation of respiratory disorders may differ in the elderly, especially because of a lack of perception of symptoms such as dyspnea. The impact of bronchodilatators or corticosteroids on respiratory function has not been studied in the elderly. Drugs usually used for the treatment of hypertension or arrhythmias, which are often observed with aging, can have pulmonary toxicity. There is no difference between functional evaluation in younger and older subjects but it is more difficult to find predicted values for older patients. Performing pulmonary function tests in older patients is often difficult because of a higher prevalence of cognitive impairment and/or poor coordination. When assessing pulmonary function in the elderly, the choice of tests will be depend on the circumstances, with the use of voluntary manoeuvres dependent on the condition of the patient.

Hypoxaemia enhances peripheral muscle oxidative stress in chronic obstructive pulmonary disease.

BACKGROUND: Because oxidative stress affects muscle function, the underlying mechanism to explain exercise induced peripheral muscle oxidative stress in patients with chronic obstructive pulmonary disease (COPD) is clinically relevant. This study investigated whether chronic hypoxaemia in COPD worsens peripheral muscle oxidative stress and whether an abnormal muscle inflammatory process is associated with it. METHODS: Nine chronically hypoxaemic and nine non-hypoxaemic patients performed repeated knee extensions until exhaustion. Biopsy specimens were taken from the vastus lateralis muscle before and 48 hours after exercise. Muscle oxidative stress was evaluated by lipid peroxidation (lipofuscin and thiobarbituric acid reactive substances (TBARs)) and oxidised proteins. Inflammation was evaluated by quantifying muscle neutrophil and tumour necrosis factor (TNF)-alpha levels. RESULTS: When both groups were taken together, arterial oxygen pressure was positively correlated with quadriceps endurance time (n = 18, r = 0.57; p < 0.05). At rest, quadriceps lipofuscin inclusions were significantly greater in hypoxaemic patients than in non-hypoxaemic patients (2.9 (0.2) v 2.0 (0.3) inclusions/fibre; p < 0.05). Exercise induced a greater increase in muscle TBARs and oxidised proteins in hypoxaemic patients than in non-hypoxaemic patients (40.6 (9.1)% v 10.1 (5.8)% and 51.2 (11.9)% v 3.7 (12.2)%, respectively, both p = 0.01). Neutrophil levels were significantly higher in hypoxaemic patients than in non-hypoxaemic patients (53.1 (11.6) v 21.5 (11.2) counts per fibre x 10(-3); p < 0.05). Exercise did not alter muscle neutrophil levels in either group. Muscle TNF-alpha was not detected at baseline or after exercise. CONCLUSION: Chronic hypoxaemia was associated with lower quadriceps endurance time and worsened muscle oxidative stress at rest and after exercise. Increased muscle neutrophil levels could be a source of the increased baseline oxidative damage. The involvement of a muscle inflammatory process in the exercise induced oxidative stress of patients with COPD remains to be shown.

Time-based gene expression programme following diaphragm injury in a rat model.

It was hypothesised that diaphragm injury activates a time-based programme of gene expression in muscle repair. Gene expression of different substances, such as proteases (calpain 94 (p94)), transcription factors (myogenin and cFos), growth factors (both basic fibroblast growth factor (bFGF) and insulin-like growth factor (IGF)-II), and structural proteins (myosin heavy chain (MHC) and titin), was quantified by RT-PCR in rat diaphragms exposed to caffeine-induced injury. Injured and noninjured (control) rat hemidiaphragms were excised at different time points (1-240 h). In injured hemidiaphragms, in comparison with control muscles, p94 expression levels peaked at 1 h post-injury (PI), cFos mRNA levels began to rise, after an initial dip, and peaked at 96 h PI, while myogenin mRNA levels started to increase as early as 12 h PI, IGF-II mRNA levels initially decreased until 48 h PI and increased thereafter, peaking at 72 h PI, bFGF mRNA levels rose to a maximum at 96 h PI, and MHC and titin mRNA levels were significantly elevated at 72 h PI. Caffeine-induced diaphragm injury is followed by a time-based expression programme of different genes tailored to meet muscle repair needs.

Skeletal muscle microbiopsy: a validation study of a minimally invasive technique.

The study of the peripheral skeletal muscle function in patients with chronic obstructive pulmonary disease (COPD) is of growing interest, but often requires biopsies, usually with the Bergström technique. The current study was designed to test the validity of a minimally invasive technique: the microbiopsy. In 17 patients with COPD and four normal subjects, two specimens of the vastus lateralis were taken percutaneously under local anaesthesia, one with a 16-gauge needle (microbiopsy) and the other with the Bergström needle. The enzymatic activity of citrate synthase (CS) and phosphofructokinase (PFK), and the myosin heavy chain (MyoHC) composition were measured for both techniques. The subjects reported no pain or much less with the microbiopsy compared with the Bergström biopsy. The microbiopsy sample weight reached 55+/-17 mg. The two techniques showed excellent agreement for CS activity and MyoHC composition. The PFK activity did not differ statistically between the techniques, but the agreement was moderate. The agreement between both biopsy techniques was stable over time. The median (range) fibre number within the microbiopsy specimens was 144 (38-286). In conclusion, the current study shows the feasibility and validity of a minimally invasive muscle biopsy technique that appears more comfortable for subjects, compared with the Bergström technique.