Gender differences in the management and experience of Chronic Obstructive Pulmonary Disease

Whether women receive the same medical care for COPD as men and if they are at risk of different outcomes as a result, is not known. The Confronting COPD International Survey was performed in the USA, Canada, France, Italy, Germany, The Netherlands, Spain and the UK in 2000 with 3265 COPD participants. Forty-one per cent were women; mean age in women and men was 61.2 (SD 10.5) and 64.4 (11.0) years, mean pack-years of smoking 36 (29) and 46 (35) years, respectively. After adjusting for age, pack-years, country and severe dyspnea (MRC scores 5 and 4), women were less likely to have had spirometry (OR 0.84, 95% C.I. 0.72-0.98) but more likely to get smoking cessation advice (OR 1.57, 1.33-1.86). Despite significantly lower pack-years of smoking, women were more likely to report severe dyspnea than men (OR 1.30, 1.10-1.54), with similar cough (OR 1.08, 0.92-1.27) and less sputum (OR 0.84, 0.72-0.98). There were no differences in the risk of hospitalisation or emergency room visit. This study indicates that gender differences in COPD care and outcomes exist.

Skeletal muscle weakness in patients with sarcoidosis and its relationship with exercise intolerance and reduced health status

BACKGROUND

Skeletal muscle weakness is assumed to be present in patients with sarcoidosis but has never been reported in a consecutive group of patients. Moreover, its relationship with previously observed exercise intolerance and reduced health status has never been studied in these patients.

METHODS

Pulmonary function, skeletal and respiratory muscle forces, peak and functional exercise capacity, health status, and the circulating levels of inflammatory and anabolic markers were determined in 25 patients with sarcoidosis who complained of fatigue (15 men) and in 21 healthy subjects (13 men).

RESULTS

Patients with sarcoidosis had lower respiratory and skeletal muscle forces, reduced exercise capacity and health status, higher anxiety and depression scores, and higher circulating levels of tumour necrosis factor-alpha than healthy subjects (all p< or =0.01). Its soluble receptor p75 tended to be higher (p=0.04). Circulating levels of interleukin (IL)-6, IL-8, insulin-like growth factor I and its binding protein 3 were not significantly different between the two groups. Skeletal muscle weakness was related to exercise intolerance, depression, and reduced health status in patients with sarcoidosis, irrespective of age, sex, body weight and height (p< or =0.05). Quadriceps peak torque was inversely related to fatigue but not to the circulating levels of inflammatory or anabolic markers. The mean daily dose of corticosteroids received in the 6 month period before testing was related to quadriceps peak torque only in patients who received oral corticosteroids.

CONCLUSION

Skeletal muscle weakness occurs in patients with sarcoidosis who complain of fatigue and is associated with reduced health status and exercise intolerance.

Mechanisms of Improvement in Exercise Capacity Using a Rollator in Patients With COPD

STUDY OBJECTIVE

We analyzed the effects of the use of a rollator on walking distance and physiologic variables: pulmonary gas exchange, heart rate, minute ventilation (Ve), oxygen saturation, and symptoms during the 6-min walk test (6MWT) in patients with COPD.

SETTING

Outpatient clinic at university hospital.

PATIENTS

Fourteen patients with COPD in stable clinical condition. One patient had mild COPD, five patients had moderate COPD, six patients had severe COPD, and two patients had very severe COPD.

INTERVENTIONS

Two 6MWTs were performed with a portable metabolic system (VmaxST 1.0; Viasys Healthcare; MEDA; Aartselaar, Belgium) with a rollator and without a rollator, in random order. In addition, maximal voluntary ventilation (MVV) was measured with and without a rollator, randomly.

RESULTS

The median 6MWT distance increased significantly with a rollator: 416 m without a rollator (interquartile range [IQR], 396 to 435 m), vs 462 m with a rollator (IQR, 424 to 477 m) [p = 0.04]. Significant increases were also seen in oxygen uptake (0.04 L/min [IQR, - 0.002 to 0.09 L/min]); tidal volume (0.06 L/min [IQR, - 0.001 to 0.11 L/min]); and Ve (0.95 L/min [IQR, - 0.67 to 7.1 L/min]), recorded in the last minute of the 6MWT; as well as in MVV (3 L/min [IQR, 0 to 12 L/min]) [p < 0.05 for all]. Borg dyspnea scores tended to be lower with a rollator: 6 (IQR, 4 to 7) without a rollator, vs 5 (IQR, 4 to 7) with a rollator (p = 0.10). The variation in the 6MWT was explained by individual changes in walking efficiency (partial R(2) = 0.31) and changes in Ve (partial R(2) = 0.36) [p model < 0.04].

CONCLUSION

The use of a rollator improves walking distance of patients with COPD through an increased ventilatory capacity and/or better walking efficiency.

Clinical Trial Design Considerations in Assessing Long‐Term Functional Impacts of Tiotropium in COPD: The Uplift Trial

An accelerated loss of lung function is one of the defining characteristics of chronic obstructive pulmonary disease (COPD). To date, the only successful intervention shown to conclusively attenuate the loss of lung function over time is smoking cessation. Pharmacological interventions including inhaled corticosteroids and ipratropium bromide have not altered the rate of decline of lung function. Tiotropium is an inhaled anticholinergic that provides 24-hour bronchodilation with once-daily dosing due to prolonged muscarinic M3 receptor blockade. Controlled clinical trials have suggested sustained efficacy for periods of up to one year. We therefore initiated a four-year, controlled clinical trial (UPLIFT, Understanding the Potential Long-Term Impacts on Function with Tiotropium) in patients with COPD to evaluate the long-term effects of tiotropium on the rate of decline in lung function and health status as well as the frequency of exacerbations. The design of such large, long-term clinical trials presents unique methodological challenges including the definition of endpoints, the quality and variability of spirometric measurements and premature patient discontinuations from the trial. The present manuscript outlines the rationale for the UPLIFT study, and reviews the study design and the steps taken to address methodological challenges experienced in other long term studies. Careful design and implementation of the UPLIFT trial is anticipated to yield high quality results that will help in increasing our understanding of the long term natural history of COPD in a global population as well as to elucidate the role that tiotropium can play in affecting the course of this debilitating disease.

Le réentraînement à l’effort des BPCO : bases physiologiques et résultats

INTRODUCTION

In the last decade pulmonary rehabilitation has become a well accepted treatment for patients with chronic obstructive pulmonary disease (COPD) suffering from persistent dyspnea and fatigue, despite appropriate medical treatment.

STATE OF ART

Patients with COPD frequently have muscular dysfunction that can be corrected by appropriate exercise training programmes. Muscle function as measured by strength and endurance tests exercise capacity and also the health status and quality of life are improved by exercise and endurance training. However, integration of exercise training in a multidisciplinary management programme is necessary to take account of all aspects of the illness.

PERSPECTIVES

Methods of exercise training need to be adapted for patients with severe COPD who are unable to undertake endurance training and for patients who obtain little benefit.

CONCLUSIONS

Pulmonary rehabilitation, thanks to its multidisciplinary nature, seems to be an effective modality of management for patients with COPD. However, the improvements in physical ability, quality of life and general health require an exercise training programme that is adapted for the individual patient.

Office Spirometry Significantly Improves Early Detection of COPD in General Practice

STUDY OBJECTIVES

To determine if spirometry is essential for the early detection of COPD in general practice, compared to the screening value of a short questionnaire.

METHODS

A prospective survey of the population aged 35 to 70 years visiting their general practitioner (GP) during a 12-week period, using a questionnaire on symptoms of obstructive lung disease (OLD). Spirometry was performed in all participants with positive answers and in a 10% random sample from the group without complaints. Twenty GPs were provided with a hand-held spirometer, and received training in performance and interpretation of lung function tests. All 35- to 70-year-old patients (n = 3,408) were screened for current use of bronchodilators. The subgroup receiving bronchodilators (n = 250, 7%) was assumed to have OLD, and was excluded. Airflow obstruction was defined according to the European Respiratory Society standards.

RESULTS

The positive predictive power of the questionnaire was low (sensitivity, 58%; specificity, 78%; likelihood ratio, 2.6). One hundred twenty-six cases of formerly unknown OLD were detected in the group of patients with complaints, vs an extrapolated number of 90 in the group without complaints. Despite a negative predictive value of 95% for the questionnaire used, 42% of the newly diagnosed cases of OLD would not have been detected without spirometry.

CONCLUSIONS

The use of a spirometer is mandatory if early stages of OLD are to be detected in general practice. Screening for airflow obstruction almost doubles the number of known patients with OLD.

Exercise training during rehabilitation of patients with COPD: a current perspective

Patients with chronic obstructive pulmonary disease (COPD) suffer frequently from physiologic and psychological impairments, such as dyspnea, peripheral muscle weakness, exercise intolerance, decreased health-related quality of life (HRQOL) and emotional distress. Rehabilitation programmes have shown to result in significant changes in perceived dyspnea and fatigue, utilisation of healthcare resources, exercise performance and HRQOL. Exercise training, which consists of whole-body exercise training and local resistance training, is the cornerstone of these programmes. Regrettably, the positive effects of respiratory rehabilitation deteriorate over time, especially after short programmes. Hence, attention should be given to the aftercare of these patients to prevent them to revert again to a sedentary lifestyle. On empirical basis three possibilities seem to be clinically feasible: (1) continuous outpatient exercise training; (2) exercise training in a home-based or community-based setting; or (3) exercise training sessions in a group of asthma and COPD patients.

Treatment of chronic respiratory failure: lung volume reduction surgery versus rehabilitation

Several treatment options are available for end-stage chronic obstructive pulmonary disease (COPD). Respiratory rehabilitation and lung volume reduction surgery are reviewed here. Respiratory rehabilitation can now be considered a prime treatment for COPD. Indeed, it has been clearly shown to improve exercise capacity and health status in these patients. Improvements in the former fell just below the minimal clinically important difference, whereas those in the latter exceeded it. In addition, after a respiratory rehabilitation programme, a reduction in the number of hospital admissions and duration of each admission was demonstrated. It remains, however, difficult to predict accurately which patients will improve after rehabilitation and which will not. Factors that may contribute to this prediction are: baseline peak exercise ventilation/maximal voluntary ventilation, maximal inspiratory pressure, peripheral muscle force, and 6-min walking distance. Several studies have clearly shown that training effects are as pronounced in patients with severe as in those with moderate airflow obstruction. This is the most significant insight in this area of the 1990s. Lung volume reduction surgery may also be of benefit in patients with end-stage COPD. It is clear that lung function, exercise capacity and health status improve after this procedure, although the results of only six randomised studies are currently available. It remains difficult to accurately predict which patients will benefit from the procedure. From a model analysis, the most important action mechanism appears to be resizing of the lungs. Only in patients with an increased residual volume/total lung capacity ratio are beneficial effects expected. The model analysis, however, did not fit the experimental data very well in a recent publication. Emphysema heterogeneity is also likely to be related to the response. The question remains as to whether or not lung volume reduction surgery accelerates the decline in forced expiratory volume in one second in the long run. The technique is undergoing considerable progress as numerous new surgical and endoscopic procedures are currently being developed. The results of these procedures have not yet been systematically evaluated.

Chronic Obstructive Pulmonary Disease and Chronic Heart Failure

Chronic obstructive pulmonary disease and congestive heart failure are two increasingly prevalent chronic diseases. Although care for these patients often is provided by different clinical teams, both disease conditions have much in common. In recent decades, more knowledge about the systemic impact of both diseases has become available, highlighting remarkable similarities in terms of prognostic factors and disease management. Rehabilitation programs deal with the systemic consequences of both diseases. Although clinical research also is conducted by various researchers investigating chronic obstructive pulmonary disease and chronic heart failure, it is worthwhile to compare the progress in relation to these two diseases over recent decades. Such comparison, the purpose of the current review, may help clinicians and scientists to learn about progress made in different, yet related, fields. The current review focuses on the similarities observed in the clinical impact of muscle weakness, the mechanisms of muscle dysfunction, the strategies to improve muscle function, and the effects of exercise training on chronic obstructive pulmonary disease and chronic heart failure.

Muscle force during an acute exacerbation in hospitalised patients with COPD and its relationship with CXCL8 and IGF-I

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is often associated with peripheral muscle weakness, which is caused by several factors. Acute exacerbations may contribute, but their impact on muscle force remains unclear. Correlations between peripheral muscle force and inflammatory and anabolic markers have never been studied in COPD. The effect of an acute exacerbation on quadriceps peak torque (QPT) was therefore studied in hospitalised patients, and the aforementioned correlations were examined in hospitalised and in stable patients.

METHODS

Lung function, respiratory and peripheral muscle force, and inflammatory and anabolic markers were assessed in hospitalised patients on days 3 and 8 of the hospital admission and 90 days later. The results on day 3 (n=34) were compared with those in clinically stable outpatients (n=13) and sedentary healthy elderly subjects (n=10).

RESULTS

Hospitalised patients had lowest mean (SD) QPT (66 (22)% predicted) and highest median (IQR) levels of systemic interleukin-8 (CXCL8, 6.1 (4.5 to 8.3) pg/ml). Insulin-like growth factor I (IGF-I) tended to be higher in healthy elderly subjects (p=0.09). QPT declined between days 3 and 8 in hospital (mean -5% predicted (95% CI -22 to 8)) and partially recovered 90 days after admission to hospital (mean 6% predicted (95% CI -1 to 23)). QPT was negatively correlated with CXCL8 and positively correlated with IGF-I and lung transfer factor in hospitalised and in stable patients.

CONCLUSIONS

Peripheral muscle weakness is enhanced during an acute exacerbation of COPD. CXCL8 and IGF-I may be involved in the development of peripheral muscle weakness in hospitalised and in stable patients with COPD.

[Physiological effects of lung reduction surgery: the contribution of an animal model of emphysema]

INTRODUCTION

Lung volume reduction surgery (LVRS) is a technique largely used for palliation of symptoms in selected patients with emphysema. Despite some encouraging early results, it is often still regarded as an experimental technique due to the significant associated mortality and unpredictable results.

STATE OF ART

The aim of this study was to explore the pathophysiological basis of benefit from LVRS when applied to a hamster model of emphysema induced by elastase and thus allow better selection criteria of patients being considered for this treatment.

PERSPECTIVES

Despite a positive effect on pulmonary elastic recoil pressures, LVRS did not, unlike its effects in humans, improve airway obstruction in the emphysematous hamsters. Differences in chest wall mechanics may explain these contrasting findings. Adaptation of the intrinsic and cellular properties of the diaphragm that are seen in emphysema are preserved after LVRS.

CONCLUSIONS

Despite differences with emphysema in humans, this hamster model supports the importance of the residual volume/total lung capacity ratio when selecting patients with emphysema for LVRS. The positive outcome of this intervention on the dynamics of the diaphragm is not compromised by modifications undergone by the diaphragmic myocytes.

Early changes in rat diaphragm biology with mechanical ventilation

To better characterize the effects of 24-hour mechanical ventilation on diaphragm, the expression of myogenic transcription factors, myosin heavy chains, and sarcoplasmic/endoplasmic reticulum calcium-ATPase pumps was examined in rats. In the diaphragm of mechanically ventilated animals, the mRNA of MyoD, myosin heavy chain-2a and -2b, and sarcoplasmic/endoplasmic reticulum calcium-ATPase-1a decreased, whereas myogenin mRNA increased. In the diaphragm of anesthetized and spontaneously breathing rats, only the mRNA of MyoD and myosin heavy chain-2a decreased. MyoD and myogenin protein expression followed the changes at the mRNA, whereas the myosin heavy chain isoforms did not change. Parallel experiments involving the gastrocnemius were performed to assess the relative contribution of muscle shortening versus immobilization-induced deconditioning on muscle regulatory factor expression. Passive shortening produced no additional effects compared with immobilization-induced deconditioning. The overall changes followed a remarkably similar pattern except for MyoD protein expression, which increased in the gastrocnemius and decreased in the diaphragm while its mRNA diminished in both muscles. The early alterations in the expression of muscle protein and regulatory factors may serve as underlying molecular basis for the impaired diaphragm function seen after 24 hours of mechanical ventilation. Whether immobilization-induced deconditioning and/or passive shortening play a role in these alterations could not be fully unraveled.

Detrimental effects of short-term mechanical ventilation on diaphragm function and IGF-I mRNA in rats

OBJECTIVES

Because respiratory muscle weakness appears to play an important role in weaning from mechanical ventilation, we developed an animal model of mechanical ventilation with appropriate controls in order to determine whether 24 h of mechanical ventilation already affected diaphragmatic function.

DESIGN AND INTERVENTIONS

Fifty-two male Wistar rats were randomized into three groups: a non-anesthetized control group (C, n=10), an anesthetized spontaneously breathing group (SB, n=9 out of 26), and an anesthetized and mechanically ventilated group (MV, n=12 out of 16).

RESULTS

After 24 h, in vitro diaphragmatic force was decreased in SB group but even more so in MV group (i.e., 80 Hz: -15% in SB, P<0.005 vs C and -34% in MV group, P<0.005 vs C and SB). This was associated with a significant decrease in the diaphragm type I and type IIa dimensions in the SB group, which was more pronounced in the MV group. Interestingly, diaphragm IGF-I mRNA was decreased in the SB group (-14%, P<0.05 vs C), but more so in MV group (-29%, P<0.001 vs C and P<0.01 vs SB). Moreover, there was a significant correlation between diaphragm force and IGF-I mRNA (at 80 Hz r=0.51, P=0.0056).

CONCLUSIONS

We conclude that 24 h of mechanical ventilation in rats, independently of anesthesia, already significantly reduced diaphragm force, fiber dimensions, and its IGF-I mRNA levels.