Possíveis conseqüências de não se atingir a mínima atividade física diária recomendada em pacientes com doença pulmonar obstrutiva cronica estável

OBJETIVO: O presente estudo investigou se pacientes com Doença Pulmonar Obstrutiva Crônica (DPOC) atingem a mínima atividade física recomendada pelos guidelines do American College of Sports Medicine (ACSM), assim como as consequências da não-aderência a esses guidelines. MÉTODOS: Atividade física na vida diária (DynaPort activity monitor), função pulmonar, força muscular, capacidade de exercício, qualidade de vida, estado funcional e diferentes índices de severidade (GOLD, BODE, MRC) foram avaliados em 23 pacientes (61[59-69] anos; VEF1 39[34-53]%predito; IMC 24[21-27]kg/m²; mediana [intervalo interquartílico 25-75%]). RESULTADOS: De acordo com a aderência aos guidelines (andar no mínimo 30 minutos todo dia), 12 pacientes foram considerados "fisicamente ativos", e 11 "fisicamente inativos". Não foram observadas diferenças significativas entre os dois grupos em termos de idade, sexo, composição corporal, força muscular, reserva ventilatória, hiperinsuflação e qualidade de vida. O grupo inativo tinha pior função pulmonar, capacidade de exercício, MRC e BODE (p<0.05). Além disso, na vida diária, o grupo inativo andou menos tempo e numa velocidade menor (p<0.05). O BODE e a MRC foram superiores ao GOLD na predição de aderência aos guidelines (especificidade 0.83 para BODE e MRC e 0.50 para o GOLD). O BODE aumentou significativamente para cada dia de inatividade física. CONCLUSÃO: Grande parte dos pacientes com doença pulmonar obstrutiva crônica não andam mais de 30 minutos por dia, e portanto não atingem a mínima atividade física recomendada pelos guidelines do American College of Sports Medicine. Inatividade está relacionada com maior taxa de mortalidade. O BODE e a MRC mostraram-se superiores ao GOLD para predizer pacientes fisicamente inativos na vida diária.

Potential consequences for stable chronic obstructive pulmonary disease patients who do not get the recommended minimum daily amount of physical activity]]>

OBJECTIVE

The present study attempted to determine whether patients with chronic obstructive pulmonary disease (COPD) get the minimum daily amount of physical activity recommended in the guidelines established by the American College of Sports Medicine (ACSM), as well as to characterize the consequences of noncompliance with those guidelines.

METHODS

This study involved 23 patients (median age: 61--range, 59-69 years; FEV1: 39% of predicted--range, 34-53%; BMI: 24 kg/m(2)--range, 21-27 kg/m(2)). The following parameters were evaluated: daily physical activity (DynaPort activity monitor); pulmonary function; muscle force; exercise tolerance; quality of life; functional status; and various indices of disease severity (GOLD, BODE and MRC).

RESULTS

Based on compliance with the guidelines (minimum of 30 minutes of walking per day), 12 patients were considered "physically active", and 11 were considered "physically inactive". No significant differences were observed between the two groups in terms of age, gender, BMI, muscle force, ventilatory reserve, hyperinflation or quality of life. The inactive group presented more impaired pulmonary function and lower exercise tolerance, as well as lower MRC and BODE scores (p < 0.05). In their daily life, patients in the inactive group also walked for less time and more slowly than did those in the active group (p < 0.05). The MRC and BODE indices were superior to the GOLD index in predicting compliance with the guidelines, both presenting a specificity of 0.83, compared with 0.50 for the GOLD index. The BODE index score increased significantly with each day of inactivity.

CONCLUSION

A large number of COPD patients do not walk more than 30 minutes per day and are therefore not getting the minimum daily amount of physical activity recommended by the ACSM. Inactivity correlates with a higher mortality rate. The MRC and BODE indices proved superior to the GOLD index in predicting whether patients are physically inactive in their daily lives.

Cardiopulmonary stress during exercise training in patients with COPD

Exercise training is an essential component of pulmonary rehabilitation. However, the cardiopulmonary stress imposed during different modalities of exercise training is not yet known. In the present study, the cardiopulmonary stress of a 12-week exercise training programme in 11 chronic obstructive pulmonary disease (COPD) patients (forced expiratory volume in one second 42+/-12%pred, age 69+/-6 yrs) was measured. Pulmonary gas exchange and cardiac frequency (f(C)) of three training sessions were measured with a portable metabolic system at the beginning, mid-term and end of the programme. Symptoms were assessed with Borg scores. The exercise intensity was compared with the recommendations for exercise training by the American College of Sports Medicine (ACSM). Training effects were significant (maximum change in work: 14+/-11 Watts, 6-min walk test: 44+/-36 m). Whole body exercises (cycling, walking and stair climbing) consistently resulted in higher cardiopulmonary stress (oxygen uptake (V'(O(2))), minute ventilation and f(C)) than arm cranking and resistance training. Dyspnoea was higher during cycling than resistance training. Patients exercised for >70% (>20 min) of the total exercise time at >40% of the V'(O(2)) reserve and f(C) reserve ("moderate" intensity according to the ACSM) throughout the programme. The cardiopulmonary stress resistance training is lower than during whole-body exercise and results in fewer symptoms. In addition, exercise testing based on guidelines using a fixed percentage of baseline peak performance and symptom scores achieves and sustains training intensities recommended according to the American College of Sports Medicine.

Quantifying physical activity in daily life with questionnaires and motion sensors in COPD

Accurate assessment of the amount and intensity of physical activity in daily life is considered very important due to the close relationship between physical activity level, health, disability and mortality. For this reason, assessment of physical activity in daily life has gained interest in recent years, especially in sedentary populations, such as patients with chronic obstructive pulmonary disease (COPD). The present article aims to compare and discuss the two kinds of instruments more commonly used to quantify the amount of physical activity performed by COPD patients in daily life: subjective methods (questionnaires, diaries) and motion sensors (electronic or mechanical methods). Their characteristics are summarised and evidence of their validity, reliability and sensitivity is discussed, when available. Subjective methods have practical value mainly in providing the patients' view on their performance in activities of daily living and functional status. However, care must be taken when using subjective methods to accurately quantify the amount of daily physical activity performed. More accurate information is likely to be available with motion sensors rather than questionnaires. The selection of which motion sensor to use for quantification of physical activity in daily life should depend mainly on the purpose of its use.

Integrated care prevents hospitalisations for exacerbations in COPD patients

Hospital admissions due to chronic obstructive pulmonary disease (COPD) exacerbations have a major impact on the disease evolution and costs. The current authors postulated that a simple and well-standardised, low-intensity integrated care intervention can be effective to prevent such hospitalisations. Therefore, 155 exacerbated COPD patients (17% females) were recruited after hospital discharge from centres in Barcelona (Spain) and Leuven (Belgium). They were randomly assigned to either integrated care (IC; n = 65; age mean+/-sd 70+/-9 yrs; forced expiratory volume in one second (FEV(1)) 1.1+/-0.5 L, 43% predicted) or usual care (UC; n = 90; age 72+/-9 yrs; FEV(1) 1.1+/-0.05 L, 41% pred). The IC intervention consisted of an individually tailored care plan upon discharge shared with the primary care team, as well as accessibility to a specialised nurse case manager through a web-based call centre. After 12 months' follow-up, IC showed a lower hospitalisation rate (1.5+/-2.6 versus 2.1+/-3.1) and a higher percentage of patients without re-admissions (49 versus 31%) than UC without differences in mortality (19 versus 16%, respectively). In conclusion, this trial demonstrates that a standardised integrated care intervention, based on shared care arrangements among different levels of the system with support of information technologies, effectively prevents hospitalisations for exacerbations in chronic obstructive pulmonary disease patients.

Physical Activity and Hospitalization for Exacerbation of COPD

BACKGROUND

Acute exacerbations (AEs) have a negative impact on various aspects of the progression of COPD, but objective and detailed data on the impact of hospitalizations for an AE on physical activity are not available. Objective and measurements: We aimed to investigate physical activity using an activity monitor (DynaPort; McRoberts; the Hague, the Netherlands), pulmonary function, muscle force, 6-min walking distance, and arterial blood gas levels in 17 patients (mean age, 69 +/- 9 years [+/- SD]; body mass index, 24 +/- 5 kg/m(2)) at the beginning and end of a hospitalization period for an AE and 1 month after discharge.

RESULTS

Time spent on weight-bearing activities (walking and standing) was markedly low both at day 2 and day 7 of hospitalization (median, 7%; interquartile range [IQR], 3 to 18% of the time during the day; and median, 9%; IQR, 7 to 21%, respectively) and 1 month after discharge (median, 19% [IQR, 10 to 34%]; Friedman test, p = 0.13). Time spent on weight-bearing activities was positively correlated to quadriceps force at the end of the hospitalization period (r = 0.47; p = 0.048). Patients with hospitalization for an AE in the previous year had an even lower activity level when compared to those without a recent hospitalization. In addition, patients with a lower activity level at 1 month after discharge were more likely to be readmitted in the following year.

CONCLUSIONS

Patients with COPD are markedly inactive during and after hospitalization for an AE. Efforts to enhance physical activity should be among the aims of the disease management during and following the AE periods.

Intermittent spontaneous breathing protects the rat diaphragm from mechanical ventilation effects

OBJECTIVE

Short-term mechanical ventilation has been proven to reduce diaphragm force and fiber dimensions. We hypothesized that intermittent spontaneous breathing during the course of mechanical ventilation would minimize the effects of mechanical ventilation on diaphragm force and expression levels of transcription factors (MyoD and myogenin).

DESIGN

Randomized, controlled experiment.

SETTING

Animal basic science laboratory.

SUBJECTS

Male Wistar rats, weighing 350-500 g.

INTERVENTIONS

Anesthetized and tracheotomized rats were submitted to either 24 hrs of spontaneous breathing (SB, n = 5), 24 hrs of continuous controlled mechanical ventilation (CMV, n = 7), or controlled mechanical ventilation with intermittent spontaneous breathing: 60 mins every 5 hrs of mechanical ventilation repeated four times (ISB60, n = 8) or 5 mins every 5 hrs 55 mins of mechanical ventilation repeated four times (SB5, n = 9). They were compared with control animals free from intervention (C, n = 5).

MEASUREMENTS AND MAIN RESULTS

The profile of the diaphragm force-frequency curve of the controls and SB group was significantly different from that of the ISB and CMV groups; especially, the mean asymptotic force was less in the ISB and CMV compared with controls and SB. CMV resulted in a significant decrease in the diaphragm type I (-26%, p < .05 vs. C) and type IIx/b (-39%, p < .005 vs. C and SB) cross-sectional area, whereas this was not observed in the ISB groups. Diaphragm MyoD protein expression was significantly decreased after ISB60 (-35%, p < .0001 vs. C and SB) and even more after CMV (-73%, p < .0001 vs. others). The same pattern was observed with myogenin protein levels. Positive relationships between diaphragm MyoD and myogenin protein levels and diaphragm force were observed.

CONCLUSIONS

The data demonstrated that intermittent spontaneous breathing during the course of mechanical ventilation may minimize the deleterious effect of controlled mechanical ventilation on diaphragm force, fiber dimensions, and expression of transcription factors.

Systemic effects of COPD

Chronic obstructive pulmonary disease (COPD) is characterised by a range of pathological changes of the respiratory system, including airflow limitation secondary to structural changes of the small airways and loss of alveolar attachments, inflammation, ciliary dysfunction, and increased mucous production. COPD also has significant systemic consequences. The relationships between these pulmonary and nonpulmonary morbidities are not fully understood, and this further complicates the assessment of disease severity and prognosis. Although improving lung function and disease symptoms have been the main focus of COPD management, these parameters alone do not reflect the full burden of disease. More recent endeavours have highlighted the potential role of addressing physical limitations imposed by systemic alterations. It is evident that systemic manifestations are common in COPD. Indeed, many patients demonstrate a gradual and significant weight loss that exacerbates the course and prognosis of disease. This weight loss is often accompanied by peripheral muscle dysfunction and weakness, which markedly contribute to exercise limitation and impaired quality of life. Weight loss has been postulated to be the result of a high metabolic rate that is not compensated for by increased dietary intake. The cause of this elevated metabolism is a matter of much debate, and several factors have been implicated. Similarly, the processes underlying depletion of muscle mass and function have not been fully delineated. The impact of the systemic manifestations of COPD is substantial, and although many attempts have been made to elucidate the mechanisms underlying these manifestations, there are important questions, which remain to be answered. An increase in our understanding in this field will doubtless highlight potential therapeutic targets, and assist in guiding future therapeutic development.

Quality control of spirometry: a lesson from the BRONCUS trial

This report describes the quality control programme used within the Bronchitis Randomized on N-acetylcysteine (NAC) Cost-Utility Study, a trial designed to assess the decline in lung function, exacerbation rate, health status, and cost-effectiveness with NAC or a placebo in 523 patients with chronic obstructive pulmonary disease over a 3-yr period. Spirometry was scored from 0 (worst quality) to 6 (best quality). The mean score of 314 spirometries from 243 patients evaluated during the trial was 5.63+/-0.83. Linear regression analysis of the scores of 47 participating centres plotted against the time at which spirometries were performed yielded an intercept of 5.7+/-0.5 and a slope of -0.0001+/-0.001, which suggests that the initial high quality was maintained over time. Retrospective examination of a further 345 postbronchodilator spirometries from 208 patients with a forced expiratory volume at one second exceeding the mean individual value recorded over the study in excess of 20% revealed a slightly lower quality of the start-of-test manoeuvre compared with the 314 spirometries. In conclusion, these findings would suggest that the quality control programme is likely to have helped achieve and maintain long-term spirometry performance in the Bronchitis Randomized on N-acetylcysteine (NAC) Cost-Utility Study trial. Special care should be paid to the spirometries whose forced expiratory volume in one second values exceed the mean value.

Activity monitoring for assessment of physical activities in daily life in patients with chronic obstructive pulmonary disease

OBJECTIVE

To investigate the degree of agreement between different methods of assessing physical activities in daily life in patients with chronic obstructive pulmonary disease (COPD): video recordings (criterion standard), the DynaPort Activity Monitor (DAM), and patient self-report.

DESIGN

Study A: outcomes from video recordings were compared with DAM outcomes and with patient estimation of time spent on each activity after a 1-hour protocol including walking, cycling, standing, sitting, and lying. Study B: DAM outcomes and patient self-report were compared during 1 day in real life.

SETTING

Outpatient clinic in a university hospital.

PARTICIPANTS

Study A: 10 patients with COPD (mean age, 62+/-6 y; forced expiratory volume in the first second [FEV1]=40%+/-16% of predicted). Study B: 13 patients with COPD (mean age, 61+/-8 y; FEV1=33%+/-10% of predicted).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Time spent on different activities and movement intensity during walking and cycling.

RESULTS

Study A: time estimated by the patients in the sitting position was significantly lower than the time showed by the video recordings and the DAM (both P<.001). For the other variables, there were no statistically significant differences (all P>.05). However, Bland and Altman plots and intraclass correlation coefficients showed large disagreement between video recordings and patients' estimations, in contrast to the high degree of agreement between video recordings and DAM. Changes in walking speed correlated highly to changes in DAM movement intensity (r=.81, P<.01). Study B: patients significantly overestimated walking time (22+/-47 min, P=.04) and underestimated standing time (-45+/-71 min, P=.04).

CONCLUSIONS

The DAM showed high accuracy in objectively assessing time spent on different activities and changes in walking speed in patients with COPD. Patients' estimations of time spent on physical activities in daily life disagreed with objective assessment.

Low-Grade Systemic Inflammation and the Response to Exercise Training in Patients With Advanced COPD

STUDY OBJECTIVE

Low-grade systemic inflammation may cause a chronic catabolic state that may affect trainability in patients with COPD as has been seen previously in healthy elderly. Therefore, the aim of the present study was to study the relationship between baseline circulating levels of inflammatory markers and the response to exercise training in clinically stable patients with COPD.

DESIGN

An open prospective intervention study.

SETTING

Tertiary care setting, University Hospital Gasthuisberg, Leuven, Belgium.

PATIENTS

Seventy-eight clinically stable outpatients with COPD.

INTERVENTION

A 12-week outpatient exercise-training program consisting of strengthening and endurance types of exercises.

MEASUREMENTS AND RESULTS

Circulating levels of inflammatory markers were assessed at baseline. Moreover, lung function, quadriceps force (QF), peak and functional exercise capacity, and health-related quality of life were determined at baseline and after the intervention. Sixty-five of the 78 consecutive outpatients completed the study protocol. QF, peak and functional exercise capacity and health-related quality of life improved significantly compared to baseline. The absolute changes in health-related quality of life showed weak relationships with baseline circulating levels of interleukin-8 (CXCL8) in the whole group (n = 65; r= -0.26; p = 0.04). In addition, soluble tumor necrosis factor receptor p55 was strongly and positively related to the absolute changes in QF in the female patients only (n = 18; r = 0.81; p = 0.0001), while CXCL8 was inversely related to the absolute change in the total score of the Chronic Respiratory Disease Questionnaire (r= -0.65; p = 0.004).

CONCLUSION

Baseline markers of low-grade systemic inflammation did not clearly explain the variances in absolute changes in QF, the distance walked in 6 min, peak external load, or health-related quality of life following a 12-week exercise-training program. Hence, they seem not very constructive in the characterization of patients with advanced COPD who do or do not respond to exercise training.

Psychosocial Conditions Do Not Affect Short-Term Outcome of Multidisciplinary Rehabilitation in Chronic Obstructive Pulmonary Disease

OBJECTIVES

To characterize patients referred for pulmonary rehabilitation on a large number of psychologic and sociodemographic variables and to determine the contribution of these variables on the response to rehabilitation.

DESIGN

Cross-sectional, explorative.

SETTING

University hospital and outpatient clinic.

PARTICIPANTS

Eighty-one consecutive patients with chronic obstructive pulmonary disease (forced expiratory volume in 1 second, 40%+/-16% of predicted) were included in outpatient pulmonary rehabilitation.

INTERVENTION

Multidisciplinary rehabilitation program.

MAIN OUTCOME MEASURES

Pulmonary function, exercise capacity (Wmax, 6-minute walk test [6MWT]), Chronic Respiratory Disease Questionnaire (CRDQ), Modified Pulmonary Functional Status and Dyspnea Questionnaire (PFSDQ-M), anxiety and depression (Hospital Anxiety and Depression Scale [HADS]) were assessed before and after 3 months rehabilitation. In addition, psychosocial adjustment, social support, marital status, mode of transportation, education, employment, and smoking status were assessed at the start of the rehabilitation.

RESULTS

Rehabilitation improved exercise performance (Wmax, 6+/-12W; P<.01; 6MWT, 41+/-72 m; P<.001), quality of life (CRDQ score, 12+/-13 points; P<.001), functional status (PFSDQ-M activity score, -8+/-11 points; PFSDQ-M dyspnea score, -6+/-12 points; PFSDQ-M fatigue score, -4+/-8 points; all P<.01), HADS anxiety score (-2+/-3 points, P<.01), and HADS depression score (-3+/-3 points, P<.001). In single regression analysis, only baseline depression was weakly negatively correlated with the change in maximal workload. No other relations of initial psychologic or sociodemographic variables with outcome were observed.

CONCLUSIONS

The effects of rehabilitation are not affected by baseline psychosocial factors. Patients with less favorable psychologic or sociodemographic conditions can also benefit from pulmonary rehabilitation. The multidisciplinary approach of the rehabilitation program might have contributed to this improvement.

Hypogonadism, quadriceps weakness, and exercise intolerance in chronic obstructive pulmonary disease

RATIONALE

Circulating levels of testosterone and gonadotrophins of patients with chronic obstructive pulmonary disease (COPD) have never been compared with those of elderly men with normal pulmonary function. Moreover, the relationship of hypogonadism with quadriceps muscle weakness and exercise intolerance has been studied scarcely in men with COPD.

OBJECTIVES

To compare circulating levels of hormones of the pituitary-gonadotrophic axis of men with COPD with those of age-matched control subjects. Moreover, to study the relationship of hypogonadism with quadriceps muscle force, 6-min walking distance, and systemic markers of inflammation in the patients.

METHODS AND MEASUREMENTS

Circulating levels of follicle-stimulating hormone, luteinizing hormone, testosterone, and sex hormone-binding globulin were determined, and free testosterone was calculated in 78 patients (FEV1: 44 +/- 17% of the predicted values) and 21 control subjects. Moreover, quadriceps muscle force, 6-min walking distance, number of pack-yr, and systemic inflammation were determined.

MAIN RESULTS

Follicle-stimulating hormone and luteinizing hormone were higher in the patients, whereas testosterone was lower (p < or = 0.05). The latter finding was also present in 48 non-steroid-using patients with normal blood gases. Low androgen status was significantly related to quadriceps muscle weakness (r = 0.48) and C-reactive protein (r = -0.39) in the patients, but not to exercise intolerance, the number of pack-yr, or increased circulating levels of interleukin 8 or soluble receptors of tumor necrosis factor alpha.

CONCLUSIONS

In contrast to exercise intolerance, quadriceps muscle weakness is related to low circulating levels of testosterone in men with COPD.

High-dose lidocaine reduces airway mucus transport velocity in intubated anesthetized dogs

BACKGROUND

Assessment of mucociliary clearance with displacement of charcoal markers in the central airways needs a bronchoscopic procedure and thus local anesthesia of the upper airways. However, the effects of lidocaine administration on mucus transport in airways are inconclusive. Therefore, detailed information is needed to establish the effects of high- and low-dose lidocaine administration.

OBJECTIVES

To study the dose-dependent effect of instillation of lidocaine on mucus transport velocity (MTV) in intubated, anaesthetized dogs.

METHODS

Displacement of a charcoal spot in time was studied with a bronchoscope in 10 anaesthetized dogs before and after administration of respectively 5 and 10 ml of either 2% lidocaine (n=5) or NaCl 0.9% (n=5). In addition, mucus viscoelastic properties were determined.

RESULTS

No significant differences in MTV were observed after administration of 5 ml of NaCl (8.2+/-3.2 mm/min) or 2% lidocaine (6.7+/-3.8 mm/min) compared to baseline values. By contrast, MTV was reduced after administration of 10 ml of 2% lidocaine (1.9+/-1.0 mm/min; P<0.05 vs. baseline and 5 ml of 2% lidocaine vs. controls, P=0.0035), but not after 10 ml of NaCl (6.2+/-2.1 mm/min). A trend towards an increased mucociliary clearability index was observed for the lidocaine-treated group as compared to the control group (P=0.07). The cough clearability index was not different between groups (P=0.89).

CONCLUSIONS

High-dose lidocaine reduces MTV. Therefore, only low-dose lidocaine administration should be applied in the bronchoscopic procedure for assessment of MTV.

Reloading the Diaphragm Following Mechanical Ventilation Does Not Promote Injury

STUDY OBJECTIVE

Mechanical ventilation (MV) is used clinically to treat patients who are incapable of maintaining adequate alveolar ventilation. Prolonged MV is associated with diaphragmatic atrophy and a decrement in maximal specific force production (P(O)). Collectively, these alterations may predispose the diaphragm to injury on the return to spontaneous breathing (ie, reloading). Therefore, these experiments tested the hypothesis that reloading the diaphragm following MV exacerbates MV-induced diaphragmatic contractile dysfunction, while causing muscle fiber membrane damage and inflammation.

METHODS

To test this postulate, Sprague-Dawley rats were randomly assigned to the following groups: (1) control; (2) 24 h of controlled MV; and (3) 24 h of controlled MV followed by 2 h of anesthetized spontaneous breathing. Controls were anesthetized in the short term but were not exposed to MV, whereas MV animals were anesthetized, tracheostomized, and ventilated. Reloaded animals remained under anesthesia, but were removed from MV and returned to spontaneous breathing for 2 h.

RESULTS

Compared to the situation with control animals, MV resulted in a 26% decrement in diaphragmatic specific P(O) without muscle fiber membrane damage, as measured by an increase in membrane permeability (using the procion orange technique). Further, there were no increases in neutrophil or macrophage influx. Two hours of reloading did not exacerbate MV-induced diaphragmatic contractile dysfunction or cause fiber membrane damage, but increased neutrophil infiltration, myeloperoxidase activity, and muscle edema.

CONCLUSION

We conclude that the return to spontaneous breathing following 24 h of controlled MV does not exacerbate MV-induced diaphragm contractile dysfunction or result in fiber membrane damage, but increases neutrophil infiltration.

Characteristics of Physical Activities in Daily Life in Chronic Obstructive Pulmonary Disease

Quantification of physical activities in daily life in patients with chronic obstructive pulmonary disease has increasing clinical interest. However, detailed comparison with healthy subjects is not available. Furthermore, it is unknown whether time spent actively during daily life is related to lung function, muscle force, or maximal and functional exercise capacity. We assessed physical activities and movement intensity with the DynaPort activity monitor in 50 patients (age 64 +/- 7 years; FEV1 43 +/- 18% predicted) and 25 healthy elderly individuals (age 66 +/- 5 years). Patients showed lower walking time (44 +/- 26 vs. 81 +/- 26 minutes/day), standing time (191 +/- 99 vs. 295 +/- 109 minutes/day), and movement intensity during walking (1.8 +/- 0.3 vs. 2.4 +/- 0.5 m/second2; p < 0.0001 for all), as well as higher sitting time (374 +/- 139 vs. 306 +/- 108 minutes/day; p = 0.04) and lying time (87 +/- 97 vs. 29 +/- 33 minutes/day; p = 0.004). Walking time was highly correlated with the 6-minute walking test (r = 0.76, p < 0.0001) and more modestly to maximal exercise capacity, lung function, and muscle force (0.28 < r < 0.64, p < 0.05). Patients with chronic obstructive pulmonary disease are markedly inactive in daily life. Functional exercise capacity is the strongest correlate of physical activities in daily life.

Effects of N-acetylcysteine on outcomes in chronic obstructive pulmonary disease (Bronchitis Randomized on NAC Cost-Utility Study, BRONCUS): a randomised placebo-controlled trial

BACKGROUND

Increased oxidative stress is important in the pathogenesis of chronic obstructive pulmonary disease (COPD). We postulated that treatment with the antioxidant N-acetylcysteine would reduce the rate of lung-function decline, reduce yearly exacerbation rate, and improve outcomes.

METHODS

In a randomised placebo-controlled study in 50 centres, 523 patients with COPD were randomly assigned to 600 mg daily N-acetylcysteine or placebo. Patients were followed for 3 years. Primary outcomes were yearly reduction in forced expiratory volume in 1 s (FEV1) and the number of exacerbations per year. Analysis was by intention to treat.

FINDINGS

The yearly rate of decline in FEV1 did not differ between patients assigned N-acetylcysteine and those assigned placebo (54 mL [SE 6] vs 47 mL [6]; difference in slope between groups 8 mL [9]; 95% CI -25 to 10). The number of exacerbations per year did not differ between groups (1.25 [SD 1.35] vs 1.29 [SD 1.46]; hazard ratio 0.99 [95% CI 0.89-1.10, p=0.85]). Subgroup analysis suggested that the exacerbation rate might be reduced with N acetylcysteine in patients not treated with inhaled corticosteroids and secondary analysis was suggestive of an effect on hyperinflation.

INTERPRETATION

N-acetylcysteine is ineffective at prevention of deterioration in lung function and prevention of exacerbations in patients with COPD.

Assessment of progression of COPD: report of a workshop held in Leuven, 11-12 March 2004

Recently performed long term trials have enhanced the insight into the assessment of progression of COPD. The present review focuses on the initial assessment of COPD in general practice and the assessment of disease progression. Several variables may be used to assess this progression, all of which are associated with significant methodological problems. Finding the appropriate mix of outcome measures to capture all aspects of disease progression is a significant challenge.

Effect of treatments on the progression of COPD: report of a workshop held in Leuven, 11-12 March 2004

During the last decade several long term studies of interventions in patients with COPD have been published. This review analyses the potential of these interventions to alter the progression of the condition. The only treatment that has unequivocally been shown to reduce the rate of decline in FEV(1) is smoking cessation. Active psychological intervention in combination with pharmacotherapy is required. Other treatments may have an effect on the rate of decline in FEV(1) but this appears to be very small, at most. Several treatments affect the exacerbation rate and therefore might affect the progression of the disease. Further studies are warranted to examine this effect.

Asthma and COPD: differences and similarities. With special reference to the usefulness of budesonide/formoterol in a single inhaler (Symbicort) in both diseases

Asthma and chronic obstructive pulmonary disease (COPD) both have a high prevalence worldwide and yet each condition remains underdiagnosed. Despite a number of common features, these inflammatory respiratory syndromes have distinct clinical outcomes. COPD represents a greater economic burden than asthma because it has a less favourable prognosis and is associated with greater morbidity and mortality. Therefore, it is important to distinguish between these two diseases at an early stage, so that appropriate therapy can be prescribed to prevent deterioration. However, effective treatments that may be used in both conditions can minimise the effects of misdiagnosis and maximise the impact of treatment without the associated complexity when both conditions occur together. The current review summarises the differences and similarities of asthma and COPD, in terms of risk factors, pathophysiology, symptoms and diagnosis, to provide greater understanding of the role of budesonide/formoterol in a single inhaler in both diseases.

Interleukin-6 Causes Myocardial Failure and Skeletal Muscle Atrophy in Rats

Background— The impact of interleukin (IL)-6 on skeletal muscle function remains the subject of controversy.

Methods and Results— The effects of 7-day subcutaneous administration of recombinant human IL-6 were examined at 3 doses, 50, 100, or 250 μg · kg −1 · d −1 , in rats. Skeletal muscle mass decreased dose-dependently (with increasing dose: in the diaphragm, −10%, P =NS; −15%, P =0.0561; and −15% P <0.05; and in the gastrocnemius, −9%, P =NS; −9%, P =NS; and −18%, P <0.005) because of decreases in cross-sectional area of all fiber types without alterations in diaphragm contractile properties. Cardiovascular variables showed a dose-dependent heart dilatation (for end-diastolic volume: control, 78 μL; moderate dose, 123 μL; and high dose, 137 μL, P <0.001), reduced end-systolic pressure (control, 113 mm Hg; moderate dose, 87 mm Hg; and high dose, 90 mm Hg; P =0.037), and decreased myocardial contractility (for preload recruitable stroke work: control, 79 mm Hg; moderate dose, 67 mm Hg; and high dose, 48 mm Hg; P <0.001). Lung edema was confirmed by an increased wet-to-dry ratio (control, 4.2; moderate dose, 4.6; and high dose, 4.5; P <0.001) and microscopy findings. These cardiovascular alterations led to decreases in organ blood flow, particularly in the diaphragm (control, 0.56 mL · min −1 · g −1 ; moderate dose, 0.21 mL · min −1 · g −1 ; and high dose, 0.23 mL · min −1 · g −1 ; P =0.037). In vitro recombinant human IL-6 administration did not cause any alterations in diaphragm force or endurance capacity.

Conclusions— IL-6 clearly caused ventilatory and peripheral skeletal muscle atrophy, even after short-term administration. Blood flow redistribution, resulting from the myocardial failure induced by IL-6, was likely responsible for this muscle atrophy, because IL-6 did not exert any direct effect on the diaphragm.