Effect of compliance to continuous positive airway pressure on exacerbations,lung function and symptoms in patients with chronic obstructive pulmonary disease and obstructive sleep apnea (overlap syndrome)

Introduction

Patients with overlap syndrome (OS), that is obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD), are at increased risk of acute exacerbations related to COPD (AECOPD). We assessed the effect of CPAP compliance on AECOPD, symptoms and pulmonary function in OS patients.

Methods

Consecutive OS patients underwent assessment at baseline and at 12 months under treatment with CPAP of: AECOPD and hospitalizations, COPD Assessment Test (CAT) and modified British Medical Research Council (mMRC) questionnaires, pulmonary function testing and 6-min walking test (6MWT).

Results

In total, 59 patients (54 males) with OS were followed for 12 months and divided post hoc according to CPAP compliance into: group A with good (≥4 h CPAP use/night, n = 29) and group B with poor (<4 h CPAP use/night, n = 30) CPAP compliance. At 12 months, group A showed improvements in FEV₁ (p = 0.024), total lung capacity (p = 0.024), RV/TLC (p = 0.003), 6MWT (p < 0.001) and CAT (p < 0.001). COPD exacerbations decreased in patients with good CPAP compliance from baseline to 12 months (17 before vs. 5 after, p = 0.001), but not in those with poor compliance (15 before vs. 15 after, p = 1). At multivariate regression analysis, COPD exacerbations were associated with poor CPAP compliance (β = 0.362, 95% CI: 0.075–0.649, p = 0.015).

Conclusions

When compared to poorly compliant patients, OS patients with good CPAP compliance had a lower number of AECOPD and showed improved lung function and COPD related symptoms.     

Six-minute Stepper Test to Set Pulmonary Rehabilitation Intensity in Patients with COPD – A Retrospective Study

Pulmonary rehabilitation (PR) improves outcomes in patients with chronic obstructive pulmonary disease (COPD). Optimal assessment includes cardiopulmonary exercise testing (CPET), but consultations are limited. Field tests could be used to individualize PR instead of CPET. The six-minute stepper test (6MST) is easy to set up and its sensitivity and reproducibility have previously been reported in patients with COPD. The aim of this study was to develop a prediction equation to set intensity in patients attending PR, based on the 6MST. The following relationships were analyzed: mean heart rate (HR) during the first (HR_1–3) and last (HR_4–6) 3 minutes of the 6MST and HR at the ventilatory threshold (HRvt) from CPET; step count at the end of the 6MST and workload at the Ventilatory threshold (VT) (Wvt); and forced expiratory volume in 1 second and step count during the 6MST. This retrospective study included patients with COPD referred for PR who underwent CPET, pulmonary function evaluations and the 6MST. Twenty-four patients were included. Prediction equations were HRvt = 0.7887 × HR_1–3 + 20.83 and HRvt = 0.6180 × HR_4–6 + 30.77. There was a strong correlation between HR_1–3 and HR_4–6 and HRvt (r = 0.69, p < 0.001 and r = 0.57, p < 0.01 respectively). A significant correlation was also found between step count and LogWvt (r = 0.63, p < 0.01). The prediction equation was LogWvt = 0.001722 × step count + 1.248. The 6MST could be used to individualize aerobic training in patients with COPD. Further prospective studies are needed to confirm these results.     

A pilot study of short-term hemodynamic effects of negative pressure ventilation in chronic obstructive pulmonary disease assessed using electrical cardiometry

Background

Pulmonary rehabilitation combined with negative pressure ventilation (NPV) demonstrated benefits in patients with chronic obstructive pulmonary disease (COPD). The effect of NPV remains unknown. This study aims to clarify the short-term response of the hemodynamic outcome of NPV in patients with COPD undergoing pulmonary rehabilitation program by electrical cardiometry.

Methods

This is an observational retrospective study of COPD patients who had been treated in a pulmonary rehabilitation unit with NPV between January 2018 and December 2019 that were enrolled to analyze the hemodynamic outcomes.

Results

Thirty patients with COPD that were undergoing a pulmonary rehabilitation program and were regularly receiving NPV were enrolled. Cardiac output (p < .001) and heart rate (p < .001) showed a significant decrease after NPV. Stroke volume did not demonstrate significant change (p = .15). There was a significant decrease in thoracic fluid content (p = .016) and a significant increase in stroke volume variation (p = .038) systemic vascular resistance (p < .001) and left ventricular ejection time (p < .001). Other hemodynamic parameters were all comparable before and after NPV.

Conclusions

Negative pressure ventilation demonstrated an impact on hemodynamics in patients with chronic obstructive pulmonary disease undergoing pulmonary rehabilitation. Electrical cardiometry is a feasible method of determining the hemodynamic effects of negative pressure ventilation. Thoracic fluid content significantly decreased immediately after the NPV.

     

Role of CA-125 in identification of right ventricular failure in chronic obstructive pulmonary disease

Background:

Chronic obstructive pulmonary disease (COPD) is a progressive and debilitating disease. Cor pulmonale, characterized by right ventricular (RV) failure, can severely influence prognosis in these patients. Hence, early recognition might be important for tailoring therapy. An old biomarker, CA‐125, seems to be associated with the right heart. We aimed to show the relationship between CA‐125 levels and RV failure in patients with COPD.

Hypothesis:

CA‐125 might be a useful biomarker in identification of RV failure in patients with COPD.

Methods:

Forty patients with recent exacerbation of COPD were enrolled into the study. Another 40 age‐ and sex‐matched individuals were enrolled for comparison. Levels of CA‐125 were measured in the patients during the hospital stay. The COPD patients underwent echocardiographic study on the same day. Right‐ventricular parameters were evaluated, and RV failure was identified via transthoracic echocardiography.

Results:

Patients with COPD had significantly higher CA‐125 levels compared with controls (median 33.94 U/mL vs 9.76 U/mL, respectively; P < 0.001). Levels of CA‐125 were correlated with systolic pulmonary artery pressure (r = 0.550, P < 0.001), tricuspid annular plane systolic excursion (r = ? 0.496, P = 0.001), and tricuspid lateral annulus S velocity (r = ? 0.549, P = 0.002). High CA‐125 levels, obtained in hospitalized patients with COPD before echocardiography, enabled identification of RV failure with a sensitivity of 89.5% and specificity of 85.7%.

Conclusions:

The CA‐125 biomarker can be used to identify COPD patients with RV failure. © 2011 Wiley Periodicals, Inc. The authors have no funding, financial relationships, or conflicts of interest to disclose.

     

Identification of Phenotypes in People with COPD: Influence of Physical Activity,Sedentary Behaviour,Body Composition and Skeletal Muscle Strength

Introduction

People with chronic obstructive pulmonary disease (COPD) present high prevalence of physical inactivity that leads to a negative effect on health-related quality of life (HRQoL). The present study investigated COPD phenotypes according to their levels of physical activity and sedentary behaviour, as well as body composition and skeletal muscle strength.

Methods

This is an observational and cross-sectional study. Anthropometric data and COPD clinical control were collected and all participants underwent assessments of lung function, HRQoL, dyspnoea, levels of physical activity and sedentary behaviour, body composition and skeletal muscle strength. Participants were classified using hierarchical cluster analysis. Age, dyspnoea and obstruction (ADO) index was used to determine prognosis and calculated for each cluster.

Results

One hundred and fifty-two participants were included. Three distinct phenotypes were identified. Participants in phenotype 1 were more physically active, less sedentary and had better body composition and lower ADO index (p < 0.0001 for all variables). Overall, participants in phenotypes 2 and 3 were less physically active, more sedentary having a higher ADO index. However, participants in phenotype 2 were older, whereas participants in phenotype 3 had worse HRQoL, clinical control and body composition. Lung function did not differ across the three phenotypes.

Conclusions

Our results show that physical activity, sedentary behaviour and body composition should be considered to determine phenotypes in people with COPD and are involved in the prognosis of the disease. Less sedentary patients have better prognosis while age, body composition and clinical control seems to differentiate physically inactive patients.

     

Comparison of Canadian versus United States emergency department visits for chronic obstructive pulmonary disease exacerbation

INTRODUCTION:

Despite the frequency of emergency department (ED) visits for chronic obstructive pulmonary disease (COPD) exacerbation, little is known about practice variation in EDs.

OBJECTIVES:

To examine the differences between Canadian and United States (US) COPD patients, and the ED management they receive.

METHODS:

A prospective multicentre cohort study was conducted involving 29 EDs in the US and Canada. Using a standard protocol, consecutive ED patients with COPD exacerbations were interviewed, their charts reviewed and a two-week telephone follow-up completed. Comparisons between Canadian and US patients, as well as their treatment and outcomes, were made. Predictors of antibiotic use were determined by multivariate logistic regression.

RESULTS:

Of 584 patients who had physician-diagnosed COPD, 397 (68%) were enrolled. Of these, 63 patients (16%) were from Canada. Canadians were older (73 years versus 69 years; P=0.002), more often white (97% versus 65%; P<0.001), less educated (P=0.003) and more commonly insured (P<0.001) than the US patients. US patients more commonly used the ED for their usual COPD medications (17% versus 3%; P=0.005). Although Canadian patients had fewer pack-years of smoking (45 pack-years versus 53 pack-years; P=0.001), current COPD medications and comorbidities were similar. At ED presentation, Canadian patients were more often hypoxic and symptomatic. ED treatment with inhaled beta-agonists (approximately 90%) and systemic corticosteroids (approximately 65%) were similar; Canadians received more antibiotics (46% versus 25%; P<0.001) and other treatments (29% versus 11%; P=0.002). Admission rates were similar in both countries (approximately 65%), although Canadian patients remained in the ED longer than the US patients (10 h versus 5 h, respectively; P<0.001).

CONCLUSIONS:

Overall, patients with acute COPD in Canada and the US appear to have similar history, ED treatment and outcomes; however, Canadian patients are older and receive more aggressive treatment in the ED. In both countries, the prolonged length of stay and high admission rate contribute to the ED overcrowding crisis facing EDs.     

Mechanisms of improvement of respiratory failure in patients with COPD treated with NIV

Background

Noninvasive ventilation (NIV) improves gas-exchange and symptoms in selected chronic obstructive pulmonary disease (COPD) patients with hypercapnic respiratory failure. We hypothesized NIV reverses respiratory failure by one or all of increased ventilatory response to carbon-dioxide, reduced respiratory muscle fatigue, or improved pulmonary mechanics.

Methods

Nineteen stable COPD patients (forced expiratory volume in one second 35% predicted) were studied at baseline (D0), 5–8 days (D5) and 3 months (3M) after starting NIV.

Results

Ventilator use was 6.2 (3.7) hours per night at D5 and 3.4 (1.6) at 3M (p = 0.12). Mean (SD) daytime arterial carbon-dioxide tension (PaCO₂) was reduced from 7.4 (1.2) kPa to 7.0 (1.1) kPa at D5 and 6.5 (1.1) kPa at 3M (p = 0.001). Total lung capacity decreased from 107 (28) % predicted to 103 (28) at D5 and 103 (27) % predicted at 3M (p = 0.035). At D5 there was an increase in the hypercapnic ventilatory response and some volitional measures of inspiratory and expiratory muscle strength, but not isolated diaphragmatic strength whether assessed by volitional or nonvolitional methods.

Conclusion

These findings suggest decreased gas trapping and increased ventilatory sensitivity to CO₂ are the principal mechanism underlying improvements in gas-exchange in patients with COPD following NIV. Changes in some volitional but not nonvolitional muscle strength measures may reflect improved patient effort.     

慢性阻塞性肺疾病患者骨骼肌功能障碍与氧化应激

近年来慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)的全身表现引起关注,尤其是营养不良、体质量减轻、骨骼肌功能障碍等与COPD患者预后密切相关.氧化应激不但是COPD的发病机制之一,也是导致其骨骼肌功能障碍的重要原因,而运动本身可以诱发和加重COPD患者局部和全身的氧化应激,使病情复杂化.抗氧化治疗是COPD治疗的新靶点,为COPD的运动康复治疗带来了新课题.     

Nutritional Status of Patients with Chronic Obstructive Pulmonary Disease in Relation to their Physical Performance

Nutritional abnormalities and physical inactivity are highly prevalent in patients with chronic obstructive pulmonary disease (COPD). The aim of this study was to determine the association between nutritional status/body composition and physical performance in patients with COPD.

A cross-sectional observational study was conducted in outpatients with clinically stable, moderate to very severe COPD. In the assessment of nutritional status, we used dual energy X-ray absorptiometry, anthropometry, serum biomarkers, and the Mini-Nutritional Assessment (MNA) questionnaire. Physical performance was measured by the 6-minute walk distance (6MWD), 4-metre gait speed (4MGS), and physical activity. Univariate and multivariate analyses were performed.

In 111 patients (mean age 68 years, 69% men), the mean 6MWD was 376 ± 119 m, 4MGS 0.9 ± 0.2 m/s, and the average daily step count 8,059 ± 4,757. Patients with low exercise capacity (6MWD ≤ 350 m) had a significantly lower lean mass index (LMI) (p < 0.01), fat-free mass index (FFMI) (p < 0.01), bone mineral content (p < 0.01), bone mineral density (p < 0.01), T-score (p < 0.05), MNA score (p < 0.01), and serum albumin and prealbumin levels (p < 0.05). Patients with low physical activity (daily step count ≤ median) had lower LMI, FFMI, MNA score, serum prealbumin (for all comparisons p < 0.05) and vitamin D levels (p < 0.01). However, none of the nutritional variables showed an independent association with low physical performance in the multivariate models. In conclusion, patients with low physical performance have deficient nutritional status, but we could not demonstrate an independent relationship between nutritional parameters and physical performance.     

Systemic effects of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) affects various structural and functional domains in the lungs. It also has significant extrapulmonary effects, the so-called systemic effects of COPD. Weight loss, nutritional abnormalities, and skeletal muscle dysfunction are well-recognized systemic effects of COPD. Other less well-known but potentially important systemic effects include an increased risk of cardiovascular disease and several neurologic and skeletal defects. The mechanisms underlying these systemic effects are unclear, but they are probably interrelated and multifactorial, including inactivity, systemic inflammation, tissue hypoxia and oxidative stress among others. These systemic effects add to the respiratory morbidity produced by the underlying pulmonary disease and should be considered in the clinical assessment as well as the treatment of affected patients.     

Comparison of oxygenation in peripheral muscle during submaximal aerobic exercise, in persons with COPD and healthy, matched-control persons

Objective

The purpose of this study was to compare peripheral muscle oxygenation in persons with chronic obstructive pulmonary disease (COPD) to healthy control persons, during submaximal exercise.

Methods

Eight persons with COPD (forced expiratory volume in one second [FEV₁] = 1.00 ± 0.27 L) and eight healthy control persons (FEV₁ = 1.88 ± 0.55L) performed a submaximal graded exercise test (GXT), and completed 4 min of constant load exercise (CON) at 50% of peak GXT. Measurements included oxygen uptake, heart rate, arterial oxygen saturation and peripheral muscle oxygenation (%StO₂) at rest, during exercise, and recovery.

Results

Significantly greater workloads were attained for controls compared with COPD for peak GXT and CON. No significant differences in %StO₂ were observed between groups at: rest (GXT: 29.5 ± 22.8 vs 30.4 ± 17.3%; CON: 33.3 ± 15.4 vs 35.1 ± 17.2%); peak GXT (29.4 ± 19.4 vs 26.5 ± 15.9%); 4 min of CON (25.9 ± 13.5 vs 34.5 ± 21.8%); and recovery (GXT: 46.6 ± 29.1 vs 44.3 ± 21.7%; CON: 40.9 ± 21.5 vs 44.5 ± 23.2%).

Conclusion

These results suggest that peripheral skeletal muscle oxygenation is not compromised in COPD during submaximal exercise, and limitations in exercise capacity are most likely a result of muscle disuse and poor lung function.     

How many steps are enough to avoid severe physical inactivity in patients with chronic obstructive pulmonary disease?

While prognostically valuable, physical activity monitoring is not routinely performed for patients with COPD. We aimed to determine the number of daily steps associated with severe physical inactivity (physical activity level <1.40) in this population. We found that a daily step value <4580 is associated with severe physical inactivity. Our results are of significant value for clinicians counselling patients with COPD to help avoid the morbidity of severe physical inactivity.     

Levels of physical activity and predictors of mortality in COPD

OBJECTIVE:

To compare the Body mass index, airway Obstruction, Dyspnea, and Exercise capacity (BODE) index scores and its individual components between COPD patients with and without severe physical inactivity, as well as to correlate the number of steps/day with scores of physical activity questionnaires, age, and the BODE index (including its components).

METHODS:

We included 30 patients, who were evaluated for body composition, pulmonary function (FEV₁), perception of dyspnea (modified Medical Research Council scale), and exercise capacity (six-minute walk distance [6MWD]). The patients also completed the International Physical Activity Questionnaire (IPAQ), short version, and the modified Baecke questionnaire (mBQ). The level of physical activity was assessed by the number of steps/day (as determined by pedometer), using the cut-off of 4,580 steps/day to form two groups: no severe physical inactivity (SPI−) and severe physical inactivity (SPI+). We used the Mann-Whitney test or t-test, as well as Pearson''s or Spearman''s correlation tests, in the statistical analysis.

RESULTS:

In comparison with the SPI− group, the SPI+ group showed more advanced age, higher mBQ scores (leisure domain), lower 6MWD (in m and % of predicted), and lower IPAQ scores (metabolic equivalent-walk/week domain and total). The IPAQ scores showed weak correlations with steps/day (r = 0.399), age (r = −0.459), and 6MWD-in m (r = 0.446) and in % of predicted (r = 0.422).

CONCLUSIONS:

In our sample, the cut-off of 4,580 steps/day was not sensitive enough to identify differences between the groups when compared with the predictors of mortality. The IPAQ, short version score correlated with steps/day.     

Gastroesophageal reflux symptoms and nasal symptoms affect the severity of bronchitis symptoms in patients with chronic obstructive pulmonary disease

Background

Cough and sputum production (symptoms of bronchitis) are common in chronic obstructive pulmonary disease (COPD). Extrapulmonary comorbidities, such as gastroesophageal reflux disease (GERD) and post-nasal drip, also cause bronchitis symptoms. The impact of extrapulmonary comorbidities on the severity of bronchitis symptoms in COPD is unknown. The aim of this study was to quantify bronchitis symptoms and assess the impact of GERD and nasal symptoms on the severity of bronchitis symptoms in COPD.

Increase of Th17 cells in peripheral blood of patients with chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) is a progressive disorder characterized by an inflammatory response to cigarette smoke. A disorder in immune regulation contributing to the pathogenesis of COPD has been suggested, however, little is known about the involvement of CD4 ⁺ T cells. To determine the distribution of different CD4⁺ T cell subsets in patients with COPD, current smokers without COPD (CS) and healthy subjects (HS), and its correlation with pulmonary function.

Methods

Th1, Th2, Th17 and Treg, subsets, were quantified by flow cytometry in peripheral blood (PB) of 39 patients with COPD, 14 CS and 15 HS. Correlations were assessed with Spearman’s rank test. The association between Th17 and lung function was evaluated with a multivariate logistic regression analysis.

Results

An increase of Th17 cells (median 9.7% range 0.8–22.5%) was observed in patients with COPD compared with CS (median 2.8% range 0.8–10.6) and HS (median 0.6% range 0.4–1%, p < 0.0001). Th1 and Tregs subsets were also increased in COPD and CS compared to HS. Inverse correlations were found between Th17 with FEV₁%p r = −0.57 and with FEV₁/FVC r = −0.60, (p < 0.0001 for both comparison). In addition, increase of Th17 predicted the presence [OR 1.76 (CI 95% 1.25–2.49, p = 0.001)] and severity of airflow limitation [OR 1.13 (CI95% 1.02–1.25, p = 0.02)].

Conclusions

The increase of Th17 response and the lost of balance between CD4⁺ T cell subsets, suggest a lack of regulation of the systemic inflammatory response that may contribute to pathogenesis in COPD patients.     

Effect of Rehabilitation Program on Endocrinological Parameters in Patients with COPD and in Healthy Subjects

Background: Skeletal muscle wasting commonly occurs in patients with chronic obstructive pulmonary disease (COPD) and has been associated with the presence of systemic inflammation and endocrinological disturbance. The aim of this study is to analyze the effect of rehabilitation program on the balance of anabolic versus catabolic hormone in patients with COPD and in healthy subjects. Methods: Nineteen patients with COPD and 16 age-matched healthy subjects undertooked exercise training 3 days/week for 8 weeks. Before and after the training program the concentration of growth hormone (GH), Insulin-Like Growth Factor-1 (IGF-1), Insulin-like Growth Factor-Binding Protein 3 (IGF-BP3), testosterone and cortisol in serum were determined. The exercise measurements included a 6-Minute Walking Test (6MWT). Results: After 8 weeks, there was no significant change in lung function in patients with COPD and healthy subjects. Growth hormone, Insulin-like Growth Factor-1 and Insulin-like Growth Factor-Binding Protein 3 increased significantly after rehabilitation training (p < 0.01). The rehabilitation program improves the testosterone/cortisol ratio (T/C ratio) in both groups. There is a significant improvement in the 6-Minute Walking distance (6MWD) in both groups (p < 0.01). Dyspnea and heart rate at rest and at the peak of the 6-Minute Walking Test (6MWT) decreased significantly after training program (p < 0.01). Conclusion: Pulmonary rehabilitation induces an improvement of the anabolic process and reduces proteine distruction by the modifications in endocrinological factors regulating skeletal muscle in patients with COPD.     

Changes in body weight and physical performance after receiving dietary advice in patients with chronic obstructive pulmonary disease (COPD): 1-year follow-up

Nutritional studies in patients with chronic obstructive pulmonary disease (COPD) are often based on oral nutritional supplementation and are of short duration. Our aim was to study the changes in body weight and physical performance in COPD patients after receiving the dietary advice for 1 year. Thirty-six patients with COPD as a primary diagnosis (mean age: 68.5 ± 7.8 years), referred to a pulmonary rehabilitation program were studied. Each patient received dietary advice individually. Body weight had increased significantly by 1.3 kg (p = 0.02) and walking distance by 83.2 m (p = 0.007) after 1 year. There was an increase in mean handgrip strength after 1 year (1.6 kg, p = 0.07). The mean intake of energy and protein expressed as percent of energy and protein requirement had increased after 1 year (15%, p < 0.001, and 5.6%, p = 0.09, respectively). Handgrip strength correlated significantly with energy (r = 0.53, p = 0.002), fat (r = 0.50, p = 0.02) and protein intake (r = 0.41, p = 0.002) after 1 year. In conclusion, positive effects on body weight, handgrip strength and walking distance in patients with COPD were seen after receiving dietary advice with a 1-year follow-up.     

Exertional hypoxemia is more severe in fibrotic interstitial lung disease than in COPD

Background and objective

Despite its clinical and prognostic significance, few studies have evaluated the severity of exertional oxygen desaturation in fibrotic interstitial lung disease (ILD). Our objectives were to identify clinical and physiological variables that predict the extent of exertional oxygen desaturation in fibrotic ILD and to quantify the severity of desaturation compared to chronic obstructive pulmonary disease (COPD).

Methods

This retrospective study compared the results of 6‐min walk test (6MWT) performed while breathing room air in fibrotic ILD patients and COPD patients eligible for pulmonary rehabilitation. Outcomes included the oxygen saturation (SpO₂) nadir and the change in SpO₂ from rest during a 6MWT. Predictor variables were identified on unadjusted analysis, followed by multivariate analysis to identify independent predictors of desaturation.

Results

The study included 134 patients with fibrotic ILD and 274 patients with COPD. The ILD and COPD cohorts had similar age, sex, frequency of major comorbidities, walk distance, baseline SpO₂ and baseline Borg dyspnoea scores. DL_CO was the strongest predictor of desaturation in both cohorts. Compared to patients with COPD, ILD patients had significantly lower SpO₂ nadir values (88.1 ± 6.4 vs 91.0 ± 4.6) and greater decrease in SpO₂ from baseline (7.4 ± 5.2 vs 4.5 ± 3.7) after adjusting for demographic features and pulmonary physiology (P < 0.0005), with greater between‐group differences at lower DL_CO values.

Conclusion

Patients with fibrotic ILD have greater oxygen desaturation during 6MWT compared to patients with COPD when adjusting for demographic features and pulmonary physiology. These findings suggest the need for disease‐specific studies to evaluate the potential utility of ambulatory oxygen in fibrotic ILD.

     

慢性阻塞性肺疾病的全身性炎症影响

目前研究显示慢性阻塞性肺疾病（COPD）并不仅是肺部疾病，而且是一种全身性疾病。它的病理生理改变主要是由于肺部炎症引起全身性炎症，继而引起COPD患者的肺外表现，包括营养不良、体重下降、骨骼肌损耗、骨质疏松以及对心血管、神经系统等全身影响。认识COPD全身性炎症的改变，可能对临床评估患者病情和治疗产生深远的影响。     

Creatine supplementation and physical training in patients with COPD: A double blind, placebo-controlled study

Study objectives

Patients with chronic obstructive pulmonary disease (COPD) have low exercise capacity and low content of high energetic phosphates in their skeletal muscles. The aim of the present study was to investigate whether creatine supplementation together with exercise training may increase physical performance compared with exercise training in patients with COPD.

Design

In a randomized, double-blind, placebo-controlled study, 23 patients with COPD (forced expiratory volume in one second [FEV₁] < 70% of predicted) were randomized to oral creatine (n = 13) or placebo (n = 10) supplementation during an 8-week rehabilitation programme including exercise training. Physical performance was assessed by Endurance Shuttle Walking Test (ESWT), dyspnea and leg fatigue with Borg CR-10, quality of life with St George’s Respiratory Questionnaire (SGRQ). In addition, lung function test, artery blood gases, grip strength test, muscle strength and fatigue in knee extensors were measured.

Results

COPD patients receiving creatine supplementation increased their average walking time by 61% (ESWT) (p < 0.05) after the training period compared with 48% (p = 0.07) in the placebo group. Rated dyspnea directly after the ESWT decreased significantly from 7 to 5 (p < 0.05) in the creatine group. However, the difference between the groups was not statistically significant neither in walking time nor in rated dyspnea. Creatine supplementation did not increase the health related quality of life, lung function, artery blood gases, grip strength and knee extensor strength/fatigue.

Conclusions

Oral creatine supplementation in combination with exercise training showed no significant improvement in physical performance, measured as ESWT, in patients with COPD compared with exercise training alone.